From 45975e5ef6e337e216151bc4243747080c5698da Mon Sep 17 00:00:00 2001
From: Jean Mertz <git@jeanmertz.com>
Date: Mon, 27 Jul 2026 23:32:28 +0200
Subject: [PATCH 1/7] feat(cli): Unify turn selection across
 `print`/`compact`/`fork`
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

`jp c fork` now accepts the same turn selector as `jp c print` and
`jp c compact`: `--from`/`--to`, `--turn`, `--first`/`--last`, and
`--keep-first`/`--keep-last`, replacing its old bespoke
`--from`/`--until`/`--first`/`--last` flags. `--from`/`--to` also
gain duration, absolute date (`2026-01-01`), and RFC 3339 support, and
every bound now resolves to a whole turn instead of splitting one:
`--from <time>` starts at the first turn to begin after the cutoff,
`--to <time>` ends at (and includes) the turn active at the cutoff.

`--first N --last M` given together now compact/fork/print each
window separately and skip the turns between them, rather than the
previous single-range behavior. `--keep-first`/`--keep-last` compose
with every selector (not just `--first`/`--last`) to protect turns at
either end, and an explicit `--keep-first`/`--keep-last` replaces a
configured compaction rule's bound instead of stacking with it.

The conversation-creation range filter on `jp c rm`, `jp c archive`,
and `jp c use` is renamed from `--from`/`--until` to
`--created-since`/`--created-before`, freeing `--from`/`--to` to mean
"which turns" everywhere and `--created-since`/`--created-before` to
mean "which conversations" — the two families accept near-identical
values, so the old shared names were ambiguous. Semantics of the
creation-range filter (half-open, `since` inclusive/`before`
exclusive) are unchanged.

`crates/jp_cli/src/cmd/turn_range.rs` is replaced by
`turn_selection.rs`, which resolves a selection to an ordered,
non-overlapping `TurnSet` of inclusive 0-based windows instead of a
single from/to pair, and `ConversationStream::retain_first_turns`/
`retain_first_and_last_turns` are replaced by a single
`retain_turns(impl Fn(usize) -> bool)`.

Signed-off-by: Jean Mertz <git@jeanmertz.com>
---
 crates/jp_cli/src/cmd.rs                      |   2 +-
 crates/jp_cli/src/cmd/conversation/archive.rs |   3 +-
 .../src/cmd/conversation/archive_tests.rs     |  16 +-
 crates/jp_cli/src/cmd/conversation/compact.rs | 324 +++------
 .../src/cmd/conversation/compact_tests.rs     | 151 ++++-
 crates/jp_cli/src/cmd/conversation/fork.rs    |  86 +--
 .../jp_cli/src/cmd/conversation/fork_tests.rs | 300 +++++----
 crates/jp_cli/src/cmd/conversation/print.rs   |  54 +-
 .../src/cmd/conversation/print_tests.rs       |  86 +--
 crates/jp_cli/src/cmd/conversation/rm.rs      |   3 +-
 .../jp_cli/src/cmd/conversation/rm_tests.rs   |  24 +-
 crates/jp_cli/src/cmd/conversation/use_.rs    |   5 +-
 .../jp_cli/src/cmd/conversation/use_tests.rs  |   8 +-
 crates/jp_cli/src/cmd/query.rs                |   5 +-
 crates/jp_cli/src/cmd/time.rs                 |  71 +-
 crates/jp_cli/src/cmd/time_tests.rs           |  57 +-
 crates/jp_cli/src/cmd/turn_range.rs           | 326 ---------
 crates/jp_cli/src/cmd/turn_range_tests.rs     | 172 -----
 crates/jp_cli/src/cmd/turn_selection.rs       | 616 ++++++++++++++++++
 crates/jp_cli/src/cmd/turn_selection_tests.rs | 549 ++++++++++++++++
 crates/jp_conversation/src/stream.rs          |  78 +--
 .../src/stream/turn_iter_tests.rs             |  51 +-
 crates/jp_conversation/src/stream_tests.rs    |  10 +-
 docs/architecture/indexing-conventions.md     |  59 +-
 docs/rfd/006-turn-scoped-mutations.md         |   3 +
 docs/rfd/023-resumable-conversation-turns.md  |  19 +
 docs/rfd/036-conversation-compaction.md       |   2 +-
 docs/rfd/039-conversation-trees.md            |   5 +-
 ...-ergonomics-for-conversation-management.md |   5 +-
 .../053-auto-refresh-conversation-titles.md   |   2 +-
 ...non-destructive-conversation-compaction.md |   1 +
 docs/rfd/071-conversation-archiving.md        |  45 +-
 ...with-command-declared-data-requirements.md |  12 +-
 ...D33-conversation-store-and-bare-forking.md |   6 +-
 34 files changed, 1850 insertions(+), 1306 deletions(-)
 delete mode 100644 crates/jp_cli/src/cmd/turn_range.rs
 delete mode 100644 crates/jp_cli/src/cmd/turn_range_tests.rs
 create mode 100644 crates/jp_cli/src/cmd/turn_selection.rs
 create mode 100644 crates/jp_cli/src/cmd/turn_selection_tests.rs

diff --git a/crates/jp_cli/src/cmd.rs b/crates/jp_cli/src/cmd.rs
index abdef8487..ba18d701c 100644
--- a/crates/jp_cli/src/cmd.rs
+++ b/crates/jp_cli/src/cmd.rs
@@ -9,7 +9,7 @@ pub(crate) mod plugin;
 mod query;
 pub(crate) mod target;
 pub(crate) mod time;
-pub(crate) mod turn_range;
+pub(crate) mod turn_selection;
 
 use std::{fmt, num::NonZeroU8};
 
diff --git a/crates/jp_cli/src/cmd/conversation/archive.rs b/crates/jp_cli/src/cmd/conversation/archive.rs
index 9c3c14058..9dc8982da 100644
--- a/crates/jp_cli/src/cmd/conversation/archive.rs
+++ b/crates/jp_cli/src/cmd/conversation/archive.rs
@@ -37,7 +37,8 @@ pub(crate) struct Archive {
     #[command(flatten)]
     target: PositionalIds<false, true>,
 
-    /// Archive all conversations created in a `[--from, --until)` range.
+    /// Archive all conversations created in a `[--created-since,
+    /// --created-before)` range.
     #[command(flatten)]
     range: CreationRange,
 
diff --git a/crates/jp_cli/src/cmd/conversation/archive_tests.rs b/crates/jp_cli/src/cmd/conversation/archive_tests.rs
index aa4b8971d..66e4fbb6f 100644
--- a/crates/jp_cli/src/cmd/conversation/archive_tests.rs
+++ b/crates/jp_cli/src/cmd/conversation/archive_tests.rs
@@ -117,8 +117,8 @@ fn inactive_since_returns_no_load_request() {
 fn from_returns_no_load_request() {
     let cmd = Archive {
         range: CreationRange {
-            from: Some("1d".parse().unwrap()),
-            until: None,
+            since: Some("1d".parse().unwrap()),
+            before: None,
         },
         ..empty_archive()
     };
@@ -131,8 +131,8 @@ fn from_returns_no_load_request() {
 fn until_returns_no_load_request() {
     let cmd = Archive {
         range: CreationRange {
-            from: None,
-            until: Some("1d".parse().unwrap()),
+            since: None,
+            before: Some("1d".parse().unwrap()),
         },
         ..empty_archive()
     };
@@ -168,8 +168,8 @@ fn matches_inactive_since_uses_last_activated_at() {
 fn matches_filters_and_compose() {
     let cmd = Archive {
         range: CreationRange {
-            from: Some(ts(1000).into()),
-            until: Some(ts(2000).into()),
+            since: Some(ts(1000).into()),
+            before: Some(ts(2000).into()),
         },
         inactive_since: Some(ts(5000).into()),
         ..empty_archive()
@@ -234,8 +234,8 @@ fn resolve_filtered_composes_range_and_inactive_since() {
 
     let cmd = Archive {
         range: CreationRange {
-            from: Some(ts(1000).into()),
-            until: Some(ts(2000).into()),
+            since: Some(ts(1000).into()),
+            before: Some(ts(2000).into()),
         },
         inactive_since: Some(ts(5000).into()),
         ..empty_archive()
diff --git a/crates/jp_cli/src/cmd/conversation/compact.rs b/crates/jp_cli/src/cmd/conversation/compact.rs
index 160c4dd62..f4cd5fd9c 100644
--- a/crates/jp_cli/src/cmd/conversation/compact.rs
+++ b/crates/jp_cli/src/cmd/conversation/compact.rs
@@ -1,14 +1,12 @@
 use std::{env, fs, path::PathBuf};
 
-use chrono::Utc;
 use jp_config::conversation::compaction::{
     CompactionConfig, CompactionRuleConfig, PartialCompactionRuleConfig, PartialSummaryConfig,
-    ReasoningMode, RuleBound, ToolCallsMode,
+    ReasoningMode, ToolCallsMode,
 };
 use jp_conversation::{
-    Compaction, CompactionRange, ConversationStream, RangeBound, ReasoningPolicy, SummaryPolicy,
-    ToolCallPolicy,
-    compaction::{extend_summary_range, resolve_range},
+    Compaction, CompactionRange, ConversationStream, ReasoningPolicy, SummaryPolicy,
+    ToolCallPolicy, compaction::extend_summary_range,
 };
 use jp_workspace::{ConversationHandle, ConversationMut};
 use tracing::warn;
@@ -18,7 +16,9 @@ use crate::{
         ConversationLoadRequest, Output,
         conversation_id::PositionalIds,
         lock::{LockOutcome, LockRequest, acquire_lock},
-        turn_range::{Bound, TurnRange},
+        turn_selection::{
+            Bound, BoundWindow, TurnSelection, keep_first_bound, keep_last_bound, resolve_window,
+        },
     },
     ctx::Ctx,
     format::compaction_policy_label,
@@ -29,32 +29,16 @@ pub(crate) struct Compact {
     #[command(flatten)]
     target: PositionalIds<true, true>,
 
-    /// Preserve the first N turns (or turns within a duration).
-    ///
-    /// Accepts a turn count (e.g. `2`) or a duration (e.g. `5h`).
-    /// Composes with `--first M`: the pair compacts the first M turns minus the
-    /// preserved prefix, e.g. `--keep-first 1 --first 16` compacts turns 2
-    /// through 16.
-    #[arg(long, conflicts_with_all = ["from", "last", "turn"])]
-    keep_first: Option<RuleBound>,
-
-    /// Preserve the last N turns (or turns within a duration).
-    ///
-    /// Accepts a turn count (e.g. `3`) or a duration (e.g. `2h`).
-    /// Composes with `--last M`: the pair compacts the last M turns minus the
-    /// preserved suffix, e.g. `--keep-last 2 --last 16` compacts the 14 turns
-    /// before the final 2.
-    #[arg(long, conflicts_with_all = ["to", "first", "turn"])]
-    keep_last: Option<RuleBound>,
-
     /// Which turns to compact.
     ///
-    /// `--from`/`--to` bound the compacted range directly (overriding
-    /// `--keep-first`/`--keep-last`); `--first N`/`--last N` compact the first
-    /// or last N turns; `--turn N` compacts a single turn, or `--turn A..B` an
+    /// `--from`/`--to` bound the compacted range; `--first N`/`--last N`
+    /// compact the first or last N turns (both together compact each window and
+    /// skip the middle); `--turn N` compacts a single turn, or `--turn A..B` an
     /// inclusive range (e.g. `1..5` is turns 1-5).
+    /// `--keep-first`/`--keep-last` protect turns at either end from whichever
+    /// range is selected.
     #[command(flatten)]
-    range: TurnRange,
+    range: TurnSelection,
 
     /// Strip reasoning (thinking) blocks from the compacted range.
     #[arg(short, long, conflicts_with = "compact")]
@@ -117,34 +101,6 @@ pub(crate) struct Compact {
 }
 
 impl Compact {
-    /// Reject flag combinations clap cannot express.
-    ///
-    /// `--keep-first N --first M` means "compact the first M turns, minus the
-    /// first N" (and `--keep-last`/`--last` the mirror image at the end): with
-    /// N greater than M the preserved turns swallow the whole selection, so the
-    /// pair is rejected rather than silently selecting nothing.
-    /// Only count-based bounds are comparable up front; durations and the other
-    /// bound forms resolve against the stream and may legitimately come up
-    /// empty.
-    fn validate(&self) -> Result<(), String> {
-        if let (Some(RuleBound::Turns(keep)), Some(first)) = (&self.keep_first, self.range.first())
-            && *keep > first
-        {
-            return Err(format!(
-                "--keep-first {keep} is greater than --first {first}: nothing would remain to \
-                 compact"
-            ));
-        }
-        if let (Some(RuleBound::Turns(keep)), Some(last)) = (&self.keep_last, self.range.last())
-            && *keep > last
-        {
-            return Err(format!(
-                "--keep-last {keep} is greater than --last {last}: nothing would remain to compact"
-            ));
-        }
-        Ok(())
-    }
-
     /// Returns `true` if any dedicated policy flag is set.
     ///
     /// Policy flags (`--reasoning`/`--tools`/`--summarize`) build a single
@@ -212,7 +168,8 @@ fn parse_tool_calls_mode(s: &str) -> Result<ToolCallsMode, String> {
     })
 }
 
-/// Resolve the turn range a single rule would compact.
+/// Resolve the turn range a single rule would compact within one selected
+/// window.
 ///
 /// `range_stream` is the baseline for resolving bounds, including
 /// `AfterLastCompaction` (`--from last-compaction`): it must be the stream as
@@ -231,33 +188,29 @@ fn resolve_rule_range(
     range_stream: &ConversationStream,
     overlap_stream: &ConversationStream,
     rule: &CompactionRuleConfig,
-    from_override: Bound,
-    to_override: Bound,
+    window: &BoundWindow,
+    selection: &TurnSelection,
 ) -> Option<CompactionRange> {
-    // A CLI override (`--from`/`--to`/`--keep-first`/`--keep-last`) takes
-    // precedence; otherwise fall back to the rule's own bound. Either side
-    // resolving to `Empty` means nothing is compacted.
-    let from = match from_override {
-        Bound::Default => keep_first_to_bound(&rule.keep_first, range_stream),
-        other => other,
+    // The rule's own `keep_first`/`keep_last` fills a side the selection left
+    // open, unless the matching CLI keep flag is set: an explicit
+    // `--keep-first` replaces the configured bound rather than stacking on top
+    // of it.
+    let from = match (&window.from, selection.keep_first()) {
+        (Bound::Default, None) => keep_first_bound(&rule.keep_first, range_stream),
+        (side, _) => side.clone(),
     };
-    let to = match to_override {
-        Bound::Default => keep_last_to_bound(&rule.keep_last, range_stream),
-        other => other,
+    let to = match (&window.to, selection.keep_last()) {
+        (Bound::Default, None) => keep_last_bound(&rule.keep_last, range_stream),
+        (side, _) => side.clone(),
     };
 
-    let from = match from {
-        Bound::Empty => return None,
-        Bound::Default => None,
-        Bound::At(b) => Some(b),
-    };
-    let to = match to {
-        Bound::Empty => return None,
-        Bound::Default => None,
-        Bound::At(b) => Some(b),
+    let resolved = resolve_window(&BoundWindow { from, to }, range_stream)?;
+    let trimmed = selection.trim(resolved, range_stream)?;
+    let range = CompactionRange {
+        from_turn: trimmed.from,
+        to_turn: trimmed.to,
     };
 
-    let range = resolve_range(range_stream, from, to)?;
     Some(if rule.summary.is_some() {
         extend_summary_range(overlap_stream, range)
     } else {
@@ -304,14 +257,14 @@ async fn build_compaction_for_range(
 
 /// Build compaction events from the given resolved rules.
 ///
-/// Each rule produces one `Compaction` event.
-/// Runtime range overrides (`--from`/`--to`) apply to every rule.
+/// Each rule produces one `Compaction` event per selected window, so a disjoint
+/// selection (`--first N --last M`) compacts each window separately and leaves
+/// the turns between them untouched.
 pub(crate) async fn build_compaction_events(
     events: &ConversationStream,
     cfg: &jp_config::AppConfig,
     rules: &[CompactionRuleConfig],
-    from_override: Bound,
-    to_override: Bound,
+    selection: &TurnSelection,
     printer: Option<&jp_printer::Printer>,
 ) -> crate::Result<Vec<Compaction>> {
     // Two distinct baselines:
@@ -325,21 +278,18 @@ pub(crate) async fn build_compaction_events(
     // - `overlap` accumulates the compactions generated so far, so a later
     //   summary rule's overlap extension sees earlier summaries in this same
     //   invocation and can't be appended unextended.
+    let windows = selection.windows(events);
     let mut overlap = events.clone();
     let mut compactions = Vec::new();
     for rule in rules {
-        let Some(range) = resolve_rule_range(
-            events,
-            &overlap,
-            rule,
-            from_override.clone(),
-            to_override.clone(),
-        ) else {
-            continue;
-        };
-        let compaction = build_compaction_for_range(events, cfg, rule, range, printer).await?;
-        overlap.add_compaction(compaction.clone());
-        compactions.push(compaction);
+        for window in &windows {
+            let Some(range) = resolve_rule_range(events, &overlap, rule, window, selection) else {
+                continue;
+            };
+            let compaction = build_compaction_for_range(events, cfg, rule, range, printer).await?;
+            overlap.add_compaction(compaction.clone());
+            compactions.push(compaction);
+        }
     }
 
     Ok(compactions)
@@ -501,52 +451,6 @@ fn kept_line(verb: &str, from: usize, to: usize) -> String {
     }
 }
 
-/// Convert a `keep_first` rule bound to a `from` [`Bound`].
-fn keep_first_to_bound(bound: &RuleBound, events: &ConversationStream) -> Bound {
-    match bound {
-        // "Keep first N" means compaction starts at turn N.
-        RuleBound::Turns(n) => Bound::At(RangeBound::Absolute(*n)),
-        // `Absolute` is the 1-based user value; the stream is 0-based.
-        RuleBound::Absolute(n) => Bound::At(RangeBound::Absolute(n.saturating_sub(1))),
-        RuleBound::FromEnd(n) => Bound::At(RangeBound::FromEnd(*n)),
-        RuleBound::Duration(d) => {
-            // Preserve the opening `d` window: start compacting at the first
-            // turn after `conversation_start + d`. A window covering the whole
-            // conversation preserves everything.
-            let Some(first) = events.iter().next() else {
-                return Bound::Empty;
-            };
-            let Ok(d) = chrono::Duration::from_std(*d) else {
-                return Bound::Empty;
-            };
-            match events.turn_at_time(first.event.timestamp + d) {
-                Some(turn) => Bound::At(RangeBound::Absolute(turn.index() + 1)),
-                None => Bound::At(RangeBound::Absolute(0)),
-            }
-        }
-        RuleBound::AfterLastCompaction => Bound::At(RangeBound::AfterLastCompaction),
-    }
-}
-
-/// Convert a `keep_last` rule bound to a `to` [`Bound`].
-fn keep_last_to_bound(bound: &RuleBound, events: &ConversationStream) -> Bound {
-    match bound {
-        // "Keep last N" means compaction stops N turns before the end.
-        RuleBound::Turns(n) | RuleBound::FromEnd(n) => Bound::At(RangeBound::FromEnd(*n)),
-        // `Absolute` is the 1-based user value; the stream is 0-based.
-        RuleBound::Absolute(n) => Bound::At(RangeBound::Absolute(n.saturating_sub(1))),
-        RuleBound::Duration(d) => {
-            // Compact turns older than the last `d` window. A window covering
-            // the whole conversation preserves everything → nothing to compact.
-            match events.turn_at_time(Utc::now() - *d) {
-                Some(turn) => Bound::At(RangeBound::Absolute(turn.index())),
-                None => Bound::Empty,
-            }
-        }
-        RuleBound::AfterLastCompaction => Bound::Default,
-    }
-}
-
 /// Build a `Compaction` event from mechanical policies (no summary).
 fn build_mechanical_compaction(
     from_turn: usize,
@@ -586,7 +490,7 @@ impl Compact {
     }
 
     pub(crate) async fn run(self, ctx: &mut Ctx, handles: Vec<ConversationHandle>) -> Output {
-        self.validate()?;
+        self.range.validate()?;
         for handle in handles {
             self.compact_one(ctx, handle).await?;
         }
@@ -627,18 +531,7 @@ impl Compact {
             return Ok(());
         }
 
-        // `--last 0` explicitly selects no turns.
-        if self.range.is_empty() {
-            ctx.printer.println("Nothing to compact.");
-            return Ok(());
-        }
-
-        // `--turn` names specific turns; an out-of-range endpoint is an error
-        // rather than an empty/clamped range (matching `print`).
-        let count = events_snapshot.turn_count();
-        if let Some(n) = self.range.turn_out_of_range(count) {
-            return Err(format!("turn {n} out of range (conversation has {count} turns)").into());
-        }
+        self.range.check_turn_range(events_snapshot.turn_count())?;
 
         // The effective rules combine the configured rules with any policy
         // flags / inline DSL (replace, or append under bare `--compact`).
@@ -646,14 +539,8 @@ impl Compact {
             .effective_rules(&cfg)
             .map_err(|e| crate::error::Error::Compaction(e.to_string()))?;
 
-        // Range overrides (`--from`/`--to`/`--keep-first`/`--keep-last`) are
-        // resolved at runtime (they need the stream for duration and "last"
-        // resolution) and apply on top of every active rule.
-        let from_override = self.resolve_from(&events_snapshot);
-        let to_override = self.resolve_to(&events_snapshot);
-
         if self.dry_run {
-            Self::preview_compaction(ctx, &events_snapshot, &rules, &from_override, &to_override);
+            Self::preview_compaction(ctx, &events_snapshot, &rules, &self.range);
             return Ok(());
         }
 
@@ -661,8 +548,7 @@ impl Compact {
             &events_snapshot,
             &cfg,
             &rules,
-            from_override,
-            to_override,
+            &self.range,
             Some(&ctx.printer),
         )
         .await?;
@@ -698,45 +584,45 @@ impl Compact {
         ctx: &Ctx,
         events_snapshot: &ConversationStream,
         rules: &[CompactionRuleConfig],
-        from_override: &Bound,
-        to_override: &Bound,
+        selection: &TurnSelection,
     ) {
         // Range resolution uses the original snapshot for every rule, while
         // `overlap` accumulates this run's summaries so later summary rules
         // preview the same (possibly extended) ranges as the real run.
+        let windows = selection.windows(events_snapshot);
         let mut overlap = events_snapshot.clone();
         let mut new_segments = Vec::new();
         for rule in rules {
-            let Some(range) = resolve_rule_range(
-                events_snapshot,
-                &overlap,
-                rule,
-                from_override.clone(),
-                to_override.clone(),
-            ) else {
-                continue;
-            };
-            let label = if rule.summary.is_some() {
-                Some("summary".to_owned())
-            } else {
-                compaction_policy_label(&build_mechanical_compaction(
-                    range.from_turn,
-                    range.to_turn,
-                    rule,
-                ))
-            };
-            new_segments.push(TimelineSegment {
-                from: range.from_turn,
-                to: range.to_turn,
-                label,
-                existing: false,
-            });
-            if rule.summary.is_some() {
-                overlap.add_compaction(
-                    Compaction::new(range.from_turn, range.to_turn).with_summary(SummaryPolicy {
-                        summary: String::new(),
-                    }),
-                );
+            for window in &windows {
+                let Some(range) =
+                    resolve_rule_range(events_snapshot, &overlap, rule, window, selection)
+                else {
+                    continue;
+                };
+                let label = if rule.summary.is_some() {
+                    Some("summary".to_owned())
+                } else {
+                    compaction_policy_label(&build_mechanical_compaction(
+                        range.from_turn,
+                        range.to_turn,
+                        rule,
+                    ))
+                };
+                new_segments.push(TimelineSegment {
+                    from: range.from_turn,
+                    to: range.to_turn,
+                    label,
+                    existing: false,
+                });
+                if rule.summary.is_some() {
+                    overlap.add_compaction(
+                        Compaction::new(range.from_turn, range.to_turn).with_summary(
+                            SummaryPolicy {
+                                summary: String::new(),
+                            },
+                        ),
+                    );
+                }
             }
         }
 
@@ -755,56 +641,6 @@ impl Compact {
             ctx.printer.println(line);
         }
     }
-
-    /// Resolve the `from` range override.
-    ///
-    /// The shared selector (`--from`/`--last`/`--turn`) takes precedence; when
-    /// none is set it falls back to `--keep-first`, and to [`Bound::Default`]
-    /// when that is also unset.
-    /// `--first` is the exception: it composes with `--keep-first`, which then
-    /// supplies the start of the range while `--first` caps its end (via
-    /// [`resolve_to`]).
-    ///
-    /// [`resolve_to`]: Self::resolve_to
-    fn resolve_from(&self, events: &ConversationStream) -> Bound {
-        if let Some(bound) = &self.keep_first
-            && self.range.first().is_some()
-        {
-            return keep_first_to_bound(bound, events);
-        }
-        match self.range.resolve_from(events) {
-            Bound::Default => match &self.keep_first {
-                Some(bound) => keep_first_to_bound(bound, events),
-                None => Bound::Default,
-            },
-            other => other,
-        }
-    }
-
-    /// Resolve the `to` range override.
-    ///
-    /// The shared selector (`--to`/`--turn`) takes precedence; when none is set
-    /// it falls back to `--keep-last`, and to [`Bound::Default`] when that is
-    /// also unset.
-    /// `--last` is the exception: it composes with `--keep-last`, which then
-    /// supplies the end of the range while `--last` sets its start (via
-    /// [`resolve_from`]).
-    ///
-    /// [`resolve_from`]: Self::resolve_from
-    fn resolve_to(&self, events: &ConversationStream) -> Bound {
-        if let Some(bound) = &self.keep_last
-            && self.range.last().is_some()
-        {
-            return keep_last_to_bound(bound, events);
-        }
-        match self.range.resolve_to(events) {
-            Bound::Default => match &self.keep_last {
-                Some(bound) => keep_last_to_bound(bound, events),
-                None => Bound::Default,
-            },
-            other => other,
-        }
-    }
 }
 
 #[cfg(test)]
diff --git a/crates/jp_cli/src/cmd/conversation/compact_tests.rs b/crates/jp_cli/src/cmd/conversation/compact_tests.rs
index f653b8389..577efb4ff 100644
--- a/crates/jp_cli/src/cmd/conversation/compact_tests.rs
+++ b/crates/jp_cli/src/cmd/conversation/compact_tests.rs
@@ -6,14 +6,14 @@ use jp_config::{
     conversation::compaction::{CompactionRuleConfig, ReasoningMode, RuleBound, ToolCallsMode},
 };
 use jp_conversation::{
-    Compaction, ConversationStream, RangeBound, ReasoningPolicy, ToolCallPolicy,
+    Compaction, ConversationStream, ReasoningPolicy, ToolCallPolicy,
     event::{ToolCallRequest, ToolCallResponse},
 };
 use jp_printer::Printer;
 use serde_json::{Map, Value};
 
 use super::{
-    Bound, Compact, TimelineSegment, build_compaction_events, existing_segments,
+    Compact, TimelineSegment, TurnSelection, build_compaction_events, existing_segments,
     segments_for_compactions, timeline_lines,
 };
 
@@ -144,8 +144,7 @@ fn tool_calls_mode_maps_to_policy() {
                 &stream,
                 &cfg,
                 std::slice::from_ref(&rule),
-                Bound::Default,
-                Bound::Default,
+                &TurnSelection::default(),
                 Some(&Printer::sink()),
             ))
             .unwrap();
@@ -176,8 +175,7 @@ fn keep_last_duration_covering_whole_conversation_compacts_nothing() {
             &stream,
             &cfg,
             std::slice::from_ref(&rule),
-            Bound::Default,
-            Bound::Default,
+            &TurnSelection::default(),
             Some(&Printer::sink()),
         ))
         .unwrap();
@@ -188,7 +186,7 @@ fn keep_last_duration_covering_whole_conversation_compacts_nothing() {
 }
 
 #[test]
-fn from_last_resolves_against_original_stream_for_every_rule() {
+fn from_last_compaction_resolves_against_original_stream_for_every_rule() {
     // `--from last-compaction` (AfterLastCompaction) must resolve against the compactions
     // present at invocation start for *every* rule, not against a compaction
     // generated by an earlier rule in the same invocation. With two mechanical
@@ -215,13 +213,13 @@ fn from_last_resolves_against_original_stream_for_every_rule() {
         },
     ];
 
+    let compact = parse_compact(&["--from", "last-compaction"]);
     let compactions = runtime()
         .block_on(build_compaction_events(
             &stream,
             &cfg,
             &rules,
-            Bound::At(RangeBound::AfterLastCompaction),
-            Bound::Default,
+            &compact.range,
             Some(&Printer::sink()),
         ))
         .unwrap();
@@ -279,8 +277,7 @@ fn config_rule_strip_requests_blanks_args_through_projection() {
             &stream,
             &cfg,
             &rules,
-            Bound::Default,
-            Bound::Default,
+            &TurnSelection::default(),
             Some(&Printer::sink()),
         ))
         .unwrap();
@@ -334,16 +331,13 @@ fn keep_first_composes_with_first() {
     let compact = parse_compact(&["--keep-first", "1", "--first", "16", "-r"]);
     let cfg = AppConfig::new_test();
     let rules = compact.effective_rules(&cfg).unwrap();
-    let from = compact.resolve_from(&stream);
-    let to = compact.resolve_to(&stream);
 
     let compactions = runtime()
         .block_on(build_compaction_events(
             &stream,
             &cfg,
             &rules,
-            from,
-            to,
+            &compact.range,
             Some(&Printer::sink()),
         ))
         .unwrap();
@@ -365,16 +359,13 @@ fn keep_last_composes_with_last() {
     let compact = parse_compact(&["--keep-last", "2", "--last", "16", "-r"]);
     let cfg = AppConfig::new_test();
     let rules = compact.effective_rules(&cfg).unwrap();
-    let from = compact.resolve_from(&stream);
-    let to = compact.resolve_to(&stream);
 
     let compactions = runtime()
         .block_on(build_compaction_events(
             &stream,
             &cfg,
             &rules,
-            from,
-            to,
+            &compact.range,
             Some(&Printer::sink()),
         ))
         .unwrap();
@@ -383,21 +374,116 @@ fn keep_last_composes_with_last() {
     assert_eq!((compactions[0].from_turn, compactions[0].to_turn), (4, 17));
 }
 
+#[test]
+fn first_and_last_compact_two_windows_and_skip_the_middle() {
+    // `--first 2 --last 2` over 8 turns compacts turns 1-2 and 7-8, leaving the
+    // four turns between them raw. Each window becomes its own compaction event.
+    let mut stream = ConversationStream::new_test();
+    for t in 0..8 {
+        stream.start_turn(format!("turn {t}"));
+    }
+
+    let compact = parse_compact(&["--first", "2", "--last", "2", "-r"]);
+    let cfg = AppConfig::new_test();
+    let rules = compact.effective_rules(&cfg).unwrap();
+
+    let compactions = runtime()
+        .block_on(build_compaction_events(
+            &stream,
+            &cfg,
+            &rules,
+            &compact.range,
+            Some(&Printer::sink()),
+        ))
+        .unwrap();
+
+    let ranges: Vec<_> = compactions
+        .iter()
+        .map(|c| (c.from_turn, c.to_turn))
+        .collect();
+    assert_eq!(ranges, vec![(0, 1), (6, 7)]);
+}
+
+#[test]
+fn cli_keep_first_replaces_the_configured_keep_first() {
+    // An explicit `--keep-first 1` overrides the rule's `keep_first = 4` rather
+    // than stacking with it: the compacted range starts at turn 2 (index 1).
+    let mut stream = ConversationStream::new_test();
+    for t in 0..8 {
+        stream.start_turn(format!("turn {t}"));
+    }
+
+    let cfg = AppConfig::new_test();
+    let rules = vec![CompactionRuleConfig {
+        keep_first: RuleBound::Turns(4),
+        keep_last: RuleBound::Turns(0),
+        reasoning: Some(ReasoningMode::Strip),
+        tool_calls: None,
+        summary: None,
+    }];
+
+    let compact = parse_compact(&["--keep-first", "1"]);
+    let compactions = runtime()
+        .block_on(build_compaction_events(
+            &stream,
+            &cfg,
+            &rules,
+            &compact.range,
+            Some(&Printer::sink()),
+        ))
+        .unwrap();
+
+    assert_eq!(compactions.len(), 1);
+    assert_eq!((compactions[0].from_turn, compactions[0].to_turn), (1, 7));
+}
+
+#[test]
+fn keep_first_clamps_rather_than_shifts_an_explicit_from() {
+    // Turn 1 is already outside `--from 3`, so `--keep-first 1` has nothing to
+    // protect and the range is unchanged.
+    // `--to -1` pins the end via the CLI; left open, the ad-hoc `-r` rule's
+    // default `keep_last = 1` would supply it and obscure the start behaviour
+    // under test.
+    let mut stream = ConversationStream::new_test();
+    for t in 0..8 {
+        stream.start_turn(format!("turn {t}"));
+    }
+
+    let compact = parse_compact(&["--from", "3", "--to", "-1", "--keep-first", "1", "-r"]);
+    let cfg = AppConfig::new_test();
+    let rules = compact.effective_rules(&cfg).unwrap();
+
+    let compactions = runtime()
+        .block_on(build_compaction_events(
+            &stream,
+            &cfg,
+            &rules,
+            &compact.range,
+            Some(&Printer::sink()),
+        ))
+        .unwrap();
+
+    assert_eq!(compactions.len(), 1);
+    assert_eq!((compactions[0].from_turn, compactions[0].to_turn), (2, 7));
+}
+
 #[test]
 fn keep_first_greater_than_first_is_rejected() {
     // A preserved prefix larger than the selection is nonsensical and must be
     // an error rather than a silent no-op.
     let err = parse_compact(&["--keep-first", "17", "--first", "16"])
+        .range
         .validate()
         .unwrap_err();
     assert_eq!(
         err,
-        "--keep-first 17 is greater than --first 16: nothing would remain to compact"
+        "--keep-first 17 is greater than --first 16: nothing would remain to select"
     );
 
     // Equal values select nothing, which is empty but not nonsensical.
     assert!(
         parse_compact(&["--keep-first", "16", "--first", "16"])
+            .range
             .validate()
             .is_ok()
     );
@@ -408,16 +494,18 @@ fn keep_last_greater_than_last_is_rejected() {
     // A preserved suffix larger than the selection is nonsensical and must be
     // an error rather than a silent no-op.
     let err = parse_compact(&["--keep-last", "17", "--last", "16"])
+        .range
         .validate()
         .unwrap_err();
     assert_eq!(
         err,
-        "--keep-last 17 is greater than --last 16: nothing would remain to compact"
+        "--keep-last 17 is greater than --last 16: nothing would remain to select"
     );
 
     // Equal values select nothing, which is empty but not nonsensical.
     assert!(
         parse_compact(&["--keep-last", "16", "--last", "16"])
+            .range
             .validate()
             .is_ok()
     );
@@ -441,18 +529,23 @@ fn turn_out_of_range_is_rejected() {
     // error rather than an empty (`--turn 100`) or clamped (`--turn ..100`)
     // range. With 5 turns, both forms flag turn 100; an in-range turn does not.
     assert_eq!(
-        parse_compact(&["--turn", "100"]).range.turn_out_of_range(5),
-        Some(100)
+        parse_compact(&["--turn", "100"])
+            .range
+            .check_turn_range(5)
+            .unwrap_err(),
+        "turn 100 out of range (conversation has 5 turns)"
     );
-    assert_eq!(
+    assert!(
         parse_compact(&["--turn", "..100"])
             .range
-            .turn_out_of_range(5),
-        Some(100)
+            .check_turn_range(5)
+            .is_err()
     );
-    assert_eq!(
-        parse_compact(&["--turn", "3"]).range.turn_out_of_range(5),
-        None
+    assert!(
+        parse_compact(&["--turn", "3"])
+            .range
+            .check_turn_range(5)
+            .is_ok()
     );
 }
 
diff --git a/crates/jp_cli/src/cmd/conversation/fork.rs b/crates/jp_cli/src/cmd/conversation/fork.rs
index e242009d8..e3959722c 100644
--- a/crates/jp_cli/src/cmd/conversation/fork.rs
+++ b/crates/jp_cli/src/cmd/conversation/fork.rs
@@ -6,7 +6,10 @@ use jp_workspace::{ConversationHandle, ConversationLock};
 use tracing::debug;
 
 use crate::{
-    cmd::{ConversationLoadRequest, Output, conversation_id::PositionalIds, time::TimeThreshold},
+    cmd::{
+        ConversationLoadRequest, Output, conversation_id::PositionalIds,
+        turn_selection::TurnSelection,
+    },
     ctx::Ctx,
 };
 
@@ -18,37 +21,16 @@ pub(crate) struct Fork {
     #[arg(short, long, default_value = "false")]
     activate: bool,
 
-    /// Ignore all conversation events before the specified timestamp.
+    /// Which turns the fork inherits.
     ///
-    /// Inclusive: an event at exactly this timestamp is kept.
-    /// Timestamp can be relative (5days, 2mins, etc) or absolute.
-    /// Composes with `--until` to form a half-open `[from, until)` range.
-    #[arg(long)]
-    from: Option<TimeThreshold>,
-
-    /// Ignore all conversation events at or after the specified timestamp.
-    ///
-    /// Exclusive: an event at exactly this timestamp is dropped.
-    /// Timestamp can be relative (5days, 2mins, etc) or absolute.
-    /// Composes with `--from` to form a half-open `[from, until)` range.
-    #[arg(long)]
-    until: Option<TimeThreshold>,
-
-    /// Fork the first N turns of the conversation.
-    /// Defaults to 1.
-    ///
-    /// Can be combined with `--last` to keep both the leading and trailing
-    /// windows while dropping the turns in between.
-    #[arg(long, short = 'f')]
-    first: Option<Option<usize>>,
-
-    /// Fork the last N turns of the conversation.
-    /// Defaults to 1.
-    ///
-    /// Can be combined with `--first` to keep both the leading and trailing
-    /// windows while dropping the turns in between.
-    #[arg(long, short = 'l')]
-    last: Option<Option<usize>>,
+    /// Without any selector, the fork inherits every turn.
+    /// `--from`/`--to` bound the inherited range; `--first N`/`--last N`
+    /// inherit the first or last N turns (both together keep each window and
+    /// drop the turns in between); `--turn N` inherits a single turn, or
+    /// `--turn A..B` an inclusive range.
+    /// `--keep-first`/`--keep-last` drop turns at either end of the selection.
+    #[command(flatten)]
+    range: TurnSelection,
 
     /// Fork without inheriting any turns.
     ///
@@ -60,7 +42,9 @@ pub(crate) struct Fork {
     #[arg(
         short = 'N',
         long,
-        conflicts_with_all = ["from", "until", "first", "last", "compact"]
+        conflicts_with_all = [
+            "from", "to", "turn", "first", "last", "keep_first", "keep_last", "compact",
+        ]
     )]
     no_turns: bool,
 
@@ -79,7 +63,12 @@ impl Fork {
     }
 
     pub(crate) async fn run(self, ctx: &mut Ctx, handles: &[ConversationHandle]) -> Output {
+        self.range.validate()?;
+
         for source in handles {
+            self.range
+                .check_turn_range(ctx.workspace.events(source)?.turn_count())?;
+
             // `--no-turns` folds the source's effective config (base + every
             // delta) into a fresh base config; resolving it here lets the
             // fallible `config()` propagate, keeping the closure infallible.
@@ -103,25 +92,17 @@ impl Fork {
                         .with_created_at(events.created_at);
                     return;
                 }
-                // `retain` invalidates compaction overlays from the earliest
-                // removed turn onward (overlays confined to the untouched prefix
-                // survive), so a time filter that strips whole turns *or* events
-                // inside a surviving turn can't leave a stale overlay pointing at
-                // — or summarizing — content no longer in the fork. The
-                // `--first`/`--last` helpers below inherit the same guarantee.
-                events.retain(|event| {
-                    self.from.is_none_or(|t| event.timestamp >= *t)
-                        && self.until.is_none_or(|t| event.timestamp < *t)
-                });
-
-                let first = self.first.map(|v| v.unwrap_or(1));
-                let last = self.last.map(|v| v.unwrap_or(1));
-                match (first, last) {
-                    (None, None) => {}
-                    (Some(f), None) => events.retain_first_turns(f),
-                    (None, Some(l)) => events.retain_last_turns(l),
-                    (Some(f), Some(l)) => events.retain_first_and_last_turns(f, l),
+                if !self.range.is_set() {
+                    return;
                 }
+
+                // `retain_turns` invalidates compaction overlays from the
+                // earliest removed turn onward (overlays confined to the
+                // untouched prefix survive), so a selection that drops turns
+                // can't leave a stale overlay pointing at — or summarizing —
+                // content no longer in the fork.
+                let selected = self.range.resolve(events);
+                events.retain_turns(|index| selected.contains(index));
             })?;
 
             if self.compact.should_compact() {
@@ -131,12 +112,13 @@ impl Fork {
                     .compact
                     .effective_rules(&cfg.conversation.compaction.rules)
                     .map_err(|e| crate::error::Error::Compaction(e.to_string()))?;
+                // The fork's turn selection has already been applied to the
+                // stream, so compaction covers the whole fork.
                 let compactions = super::compact::build_compaction_events(
                     &events_snapshot,
                     &cfg,
                     &rules,
-                    crate::cmd::turn_range::Bound::Default,
-                    crate::cmd::turn_range::Bound::Default,
+                    &TurnSelection::default(),
                     // Compaction during a fork is an implicit adjunct; only an
                     // explicit `jp c compact` reports compaction details.
                     None,
diff --git a/crates/jp_cli/src/cmd/conversation/fork_tests.rs b/crates/jp_cli/src/cmd/conversation/fork_tests.rs
index db943db15..71c1795e0 100644
--- a/crates/jp_cli/src/cmd/conversation/fork_tests.rs
+++ b/crates/jp_cli/src/cmd/conversation/fork_tests.rs
@@ -22,6 +22,55 @@ use crate::{
     cmd::{compact_flag::CompactFlag, conversation_id::PositionalIds},
 };
 
+/// Parse a [`TurnSelection`] from the flags a user would pass to `jp c fork`.
+///
+/// Going through clap keeps these cases pinned to the real flag surface rather
+/// than to the struct's private fields.
+fn selection(args: &[&str]) -> TurnSelection {
+    #[derive(clap::Parser)]
+    struct TestCli {
+        #[command(flatten)]
+        selection: TurnSelection,
+    }
+
+    let mut argv = vec!["fork"];
+    argv.extend_from_slice(args);
+    clap::Parser::try_parse_from(argv)
+        .map(|cli: TestCli| cli.selection)
+        .unwrap()
+}
+
+/// A stream of `count` turns, each holding one request, two minutes apart
+/// starting at 2020-01-01 00:00:00 UTC.
+///
+/// Turn N starts at `00:(2N):00` and its request lands ten seconds later, so a
+/// bound at an odd minute falls strictly inside a turn.
+fn turns(count: u32) -> Vec<ConversationEvent> {
+    (0..count)
+        .flat_map(|turn| {
+            [
+                ConversationEvent::new(
+                    TurnStart,
+                    Utc.with_ymd_and_hms(2020, 1, 1, 0, turn * 2, 0).unwrap(),
+                ),
+                ConversationEvent::new(
+                    ChatRequest::from(format!("Q{}", turn + 1)),
+                    Utc.with_ymd_and_hms(2020, 1, 1, 0, turn * 2, 10).unwrap(),
+                ),
+            ]
+        })
+        .collect()
+}
+
+/// The request contents of a conversation, in stream order.
+fn requests(stream: &ConversationStream) -> Vec<String> {
+    stream
+        .iter()
+        .filter_map(|e| e.event.as_chat_request())
+        .map(|r| r.content.clone())
+        .collect()
+}
+
 #[test]
 #[expect(clippy::too_many_lines)]
 fn test_conversation_fork() {
@@ -36,10 +85,7 @@ fn test_conversation_fork() {
             args: Fork {
                 target: PositionalIds::default(),
                 activate: false,
-                from: None,
-                until: None,
-                last: None,
-                first: None,
+                range: TurnSelection::default(),
                 title: None,
                 compact: CompactFlag::default(),
                 no_turns: false,
@@ -81,10 +127,7 @@ fn test_conversation_fork() {
             args: Fork {
                 target: PositionalIds::default(),
                 activate: false,
-                from: None,
-                until: None,
-                last: None,
-                first: None,
+                range: TurnSelection::default(),
                 title: None,
                 compact: CompactFlag::default(),
                 no_turns: false,
@@ -136,10 +179,7 @@ fn test_conversation_fork() {
             args: Fork {
                 target: PositionalIds::default(),
                 activate: false,
-                from: None,
-                until: None,
-                last: None,
-                first: None,
+                range: TurnSelection::default(),
                 title: None,
                 compact: CompactFlag::default(),
                 no_turns: true,
@@ -194,10 +234,7 @@ fn test_conversation_fork() {
             args: Fork {
                 target: PositionalIds::default(),
                 activate: true,
-                from: None,
-                until: None,
-                last: None,
-                first: None,
+                range: TurnSelection::default(),
                 title: None,
                 compact: CompactFlag::default(),
                 no_turns: false,
@@ -251,10 +288,7 @@ fn test_conversation_fork() {
             args: Fork {
                 target: PositionalIds::default(),
                 activate: false,
-                from: Some(Utc.with_ymd_and_hms(2020, 1, 1, 0, 1, 0).unwrap().into()),
-                until: None,
-                last: None,
-                first: None,
+                range: selection(&["--from", "2020-01-01T00:01:00Z"]),
                 title: None,
                 compact: CompactFlag::default(),
                 no_turns: false,
@@ -269,48 +303,24 @@ fn test_conversation_fork() {
 
                 let h = ctx.workspace.acquire_conversation(&id).unwrap();
                 let lock = ctx.workspace.test_lock(h);
-                lock.as_mut().update_events(|e| {
-                    e.extend(vec![
-                        ConversationEvent::new(
-                            ChatRequest::from("foo"),
-                            Utc.with_ymd_and_hms(2020, 1, 1, 0, 0, 0).unwrap(),
-                        ),
-                        ConversationEvent::new(
-                            ChatResponse::message("bar"),
-                            Utc.with_ymd_and_hms(2020, 1, 1, 0, 1, 0).unwrap(),
-                        ),
-                        ConversationEvent::new(
-                            ChatResponse::message("baz"),
-                            Utc.with_ymd_and_hms(2020, 1, 1, 0, 2, 0).unwrap(),
-                        ),
-                    ]);
-                });
+                lock.as_mut().update_events(|e| e.extend(turns(3)));
                 id
             },
 
             assert: |convs, _| {
                 assert_eq!(convs.len(), 2);
-                assert_eq!(convs[0].2.iter().count(), 3);
-                // +1 for injected TurnStart
-                assert_eq!(convs[1].2.iter().count(), 3);
-                assert_eq!(
-                    convs[0].2.first().unwrap().event.timestamp,
-                    Utc.with_ymd_and_hms(2020, 1, 1, 0, 0, 0).unwrap()
-                );
-                assert_eq!(
-                    convs[1].2.first().unwrap().event.timestamp,
-                    Utc.with_ymd_and_hms(2020, 1, 1, 0, 1, 0).unwrap()
-                );
+                assert_eq!(requests(&convs[0].2), vec!["Q1", "Q2", "Q3"]);
+                // 00:01:00 falls inside turn 1 (00:00:00-00:02:00), so the fork
+                // starts at turn 2 — the first turn to begin after the cutoff.
+                // The bound never splits turn 1.
+                assert_eq!(requests(&convs[1].2), vec!["Q2", "Q3"]);
             },
         }),
-        ("with until", TestCase {
+        ("with to", TestCase {
             args: Fork {
                 target: PositionalIds::default(),
                 activate: false,
-                from: None,
-                until: Some(Utc.with_ymd_and_hms(2020, 1, 1, 0, 1, 0).unwrap().into()),
-                last: None,
-                first: None,
+                range: selection(&["--to", "2020-01-01T00:03:00Z"]),
                 title: None,
                 compact: CompactFlag::default(),
                 no_turns: false,
@@ -325,49 +335,23 @@ fn test_conversation_fork() {
 
                 let h = ctx.workspace.acquire_conversation(&id).unwrap();
                 let lock = ctx.workspace.test_lock(h);
-                lock.as_mut().update_events(|e| {
-                    e.extend(vec![
-                        ConversationEvent::new(
-                            ChatRequest::from("foo"),
-                            Utc.with_ymd_and_hms(2020, 1, 1, 0, 0, 0).unwrap(),
-                        ),
-                        ConversationEvent::new(
-                            ChatResponse::message("bar"),
-                            Utc.with_ymd_and_hms(2020, 1, 1, 0, 1, 0).unwrap(),
-                        ),
-                        ConversationEvent::new(
-                            ChatResponse::message("baz"),
-                            Utc.with_ymd_and_hms(2020, 1, 1, 0, 2, 0).unwrap(),
-                        ),
-                    ]);
-                });
+                lock.as_mut().update_events(|e| e.extend(turns(3)));
                 id
             },
 
             assert: |convs, _| {
                 assert_eq!(convs.len(), 2);
-                assert_eq!(convs[0].2.iter().count(), 3);
-                // --until is exclusive: 00:01:00 event is dropped, only 00:00:00 survives.
-                // +1 for injected TurnStart.
-                assert_eq!(convs[1].2.iter().count(), 2);
-                assert_eq!(
-                    convs[0].2.last().unwrap().event.timestamp,
-                    Utc.with_ymd_and_hms(2020, 1, 1, 0, 2, 0).unwrap()
-                );
-                assert_eq!(
-                    convs[1].2.last().unwrap().event.timestamp,
-                    Utc.with_ymd_and_hms(2020, 1, 1, 0, 0, 0).unwrap()
-                );
+                assert_eq!(requests(&convs[0].2), vec!["Q1", "Q2", "Q3"]);
+                // 00:03:00 falls inside turn 2 (00:02:00-00:04:00). `--to` is
+                // inclusive of the turn it lands in, so turn 2 is kept whole.
+                assert_eq!(requests(&convs[1].2), vec!["Q1", "Q2"]);
             },
         }),
         ("with last (default 1)", TestCase {
             args: Fork {
                 target: PositionalIds::default(),
                 activate: false,
-                from: None,
-                until: None,
-                last: Some(None),
-                first: None,
+                range: selection(&["--last"]),
                 title: None,
                 compact: CompactFlag::default(),
                 no_turns: false,
@@ -444,10 +428,7 @@ fn test_conversation_fork() {
             args: Fork {
                 target: PositionalIds::default(),
                 activate: false,
-                from: None,
-                until: None,
-                last: Some(Some(2)),
-                first: None,
+                range: selection(&["--last", "2"]),
                 title: None,
                 compact: CompactFlag::default(),
                 no_turns: false,
@@ -523,10 +504,7 @@ fn test_conversation_fork() {
             args: Fork {
                 target: PositionalIds::default(),
                 activate: false,
-                from: None,
-                until: None,
-                last: Some(Some(10)),
-                first: None,
+                range: selection(&["--last", "10"]),
                 title: None,
                 compact: CompactFlag::default(),
                 no_turns: false,
@@ -570,10 +548,7 @@ fn test_conversation_fork() {
             args: Fork {
                 target: PositionalIds::default(),
                 activate: false,
-                from: None,
-                until: None,
-                last: Some(Some(1)),
-                first: None,
+                range: selection(&["--last", "1"]),
                 title: None,
                 compact: CompactFlag::default(),
                 no_turns: false,
@@ -614,12 +589,9 @@ fn test_conversation_fork() {
             args: Fork {
                 target: PositionalIds::default(),
                 activate: false,
-                from: None,
-                until: None,
-                last: None,
+                range: selection(&["--first"]),
                 compact: CompactFlag::default(),
                 no_turns: false,
-                first: Some(None),
                 title: None,
             },
             setup: |ctx| {
@@ -693,12 +665,9 @@ fn test_conversation_fork() {
             args: Fork {
                 target: PositionalIds::default(),
                 activate: false,
-                from: None,
-                until: None,
-                last: Some(Some(1)),
+                range: selection(&["--first", "2", "--last", "1"]),
                 compact: CompactFlag::default(),
                 no_turns: false,
-                first: Some(Some(2)),
                 title: None,
             },
             setup: |ctx| {
@@ -765,12 +734,9 @@ fn test_conversation_fork() {
             args: Fork {
                 target: PositionalIds::default(),
                 activate: false,
-                from: None,
-                until: None,
-                last: None,
+                range: selection(&["--first", "10"]),
                 compact: CompactFlag::default(),
                 no_turns: false,
-                first: Some(Some(10)),
                 title: None,
             },
             setup: |ctx| {
@@ -812,12 +778,9 @@ fn test_conversation_fork() {
             args: Fork {
                 target: PositionalIds::default(),
                 activate: false,
-                from: None,
-                until: None,
-                last: None,
+                range: TurnSelection::default(),
                 compact: CompactFlag::default(),
                 no_turns: false,
-                first: None,
                 title: Some("my custom title".to_owned()),
             },
             setup: |ctx| {
@@ -841,14 +804,16 @@ fn test_conversation_fork() {
                 assert_eq!(convs[1].1.title.as_deref(), Some("my custom title"));
             },
         }),
-        ("with from and until", TestCase {
+        ("with from and to", TestCase {
             args: Fork {
                 target: PositionalIds::default(),
                 activate: false,
-                from: Some(Utc.with_ymd_and_hms(2020, 1, 1, 0, 1, 0).unwrap().into()),
-                until: Some(Utc.with_ymd_and_hms(2020, 1, 1, 0, 2, 0).unwrap().into()),
-                last: None,
-                first: None,
+                range: selection(&[
+                    "--from",
+                    "2020-01-01T00:01:00Z",
+                    "--to",
+                    "2020-01-01T00:03:00Z",
+                ]),
                 title: None,
                 compact: CompactFlag::default(),
                 no_turns: false,
@@ -863,47 +828,75 @@ fn test_conversation_fork() {
 
                 let h = ctx.workspace.acquire_conversation(&id).unwrap();
                 let lock = ctx.workspace.test_lock(h);
-                lock.as_mut().update_events(|e| {
-                    e.extend(vec![
-                        ConversationEvent::new(
-                            ChatRequest::from("foo"),
-                            Utc.with_ymd_and_hms(2020, 1, 1, 0, 0, 0).unwrap(),
-                        ),
-                        ConversationEvent::new(
-                            ChatResponse::message("bar"),
-                            Utc.with_ymd_and_hms(2020, 1, 1, 0, 1, 0).unwrap(),
-                        ),
-                        ConversationEvent::new(
-                            ChatResponse::message("baz"),
-                            Utc.with_ymd_and_hms(2020, 1, 1, 0, 2, 0).unwrap(),
-                        ),
-                        ConversationEvent::new(
-                            ChatResponse::message("qux"),
-                            Utc.with_ymd_and_hms(2020, 1, 1, 0, 3, 0).unwrap(),
-                        ),
-                    ]);
-                });
+                lock.as_mut().update_events(|e| e.extend(turns(4)));
                 id
             },
 
             assert: |convs, _| {
                 assert_eq!(convs.len(), 2);
-                assert_eq!(convs[0].2.iter().count(), 4);
-                // `[from, until)` is half-open: 00:01:00 is kept (from is inclusive),
-                // 00:02:00 is dropped (until is exclusive). +1 for injected TurnStart.
-                assert_eq!(convs[1].2.iter().count(), 2);
-                assert_eq!(
-                    convs[0].2.first().unwrap().event.timestamp,
-                    Utc.with_ymd_and_hms(2020, 1, 1, 0, 0, 0).unwrap()
-                );
-                assert_eq!(
-                    convs[1].2.last().unwrap().event.timestamp,
-                    Utc.with_ymd_and_hms(2020, 1, 1, 0, 1, 0).unwrap()
+                assert_eq!(requests(&convs[0].2), vec!["Q1", "Q2", "Q3", "Q4"]);
+                // Both cutoffs fall mid-turn: `--from` starts at turn 2 and
+                // `--to` ends at turn 2, leaving exactly that turn.
+                assert_eq!(requests(&convs[1].2), vec!["Q2"]);
+            },
+        }),
+        ("with turn range", TestCase {
+            args: Fork {
+                target: PositionalIds::default(),
+                activate: false,
+                range: selection(&["--turn", "2..3"]),
+                title: None,
+                compact: CompactFlag::default(),
+                no_turns: false,
+            },
+            setup: |ctx| {
+                let id = ConversationId::try_from(ctx.now()).unwrap();
+                ctx.workspace.create_conversation_with_id(
+                    id,
+                    Conversation::default().with_last_activated_at(ctx.now()),
+                    ctx.config(),
                 );
-                assert_eq!(
-                    convs[0].2.last().unwrap().event.timestamp,
-                    Utc.with_ymd_and_hms(2020, 1, 1, 0, 3, 0).unwrap()
+
+                let h = ctx.workspace.acquire_conversation(&id).unwrap();
+                let lock = ctx.workspace.test_lock(h);
+                lock.as_mut().update_events(|e| e.extend(turns(5)));
+                id
+            },
+
+            assert: |convs, _| {
+                assert_eq!(convs.len(), 2);
+                // `--turn A..B` is inclusive on both ends.
+                assert_eq!(requests(&convs[1].2), vec!["Q2", "Q3"]);
+            },
+        }),
+        ("with keep flags", TestCase {
+            args: Fork {
+                target: PositionalIds::default(),
+                activate: false,
+                range: selection(&["--keep-first", "1", "--keep-last", "1"]),
+                title: None,
+                compact: CompactFlag::default(),
+                no_turns: false,
+            },
+            setup: |ctx| {
+                let id = ConversationId::try_from(ctx.now()).unwrap();
+                ctx.workspace.create_conversation_with_id(
+                    id,
+                    Conversation::default().with_last_activated_at(ctx.now()),
+                    ctx.config(),
                 );
+
+                let h = ctx.workspace.acquire_conversation(&id).unwrap();
+                let lock = ctx.workspace.test_lock(h);
+                lock.as_mut().update_events(|e| e.extend(turns(5)));
+                id
+            },
+
+            assert: |convs, _| {
+                assert_eq!(convs.len(), 2);
+                // The keep flags protect the first and last turns from the
+                // selection, so the fork inherits only the middle three.
+                assert_eq!(requests(&convs[1].2), vec!["Q2", "Q3", "Q4"]);
             },
         }),
     ];
@@ -1055,10 +1048,7 @@ fn fork_targets_correct_source() {
     let fork = Fork {
         target: PositionalIds::default(),
         activate: false,
-        from: None,
-        until: None,
-        last: None,
-        first: None,
+        range: TurnSelection::default(),
         compact: CompactFlag::default(),
         no_turns: false,
         title: Some("forked-from-b".to_owned()),
diff --git a/crates/jp_cli/src/cmd/conversation/print.rs b/crates/jp_cli/src/cmd/conversation/print.rs
index 6f36677ec..c63e48f63 100644
--- a/crates/jp_cli/src/cmd/conversation/print.rs
+++ b/crates/jp_cli/src/cmd/conversation/print.rs
@@ -4,15 +4,14 @@ use jp_config::{
     },
     style::{reasoning::ReasoningDisplayConfig, typewriter::DelayDuration},
 };
-use jp_conversation::{compaction::resolve_range, stream::TurnOrigin};
+use jp_conversation::stream::TurnOrigin;
 use jp_llm::tool::InvocationContext;
 use jp_workspace::ConversationHandle;
 
 use crate::{
     cmd::{
-        ConversationLoadRequest, Output,
-        conversation_id::PositionalIds,
-        turn_range::{Bound, TurnRange},
+        ConversationLoadRequest, Output, conversation_id::PositionalIds,
+        turn_selection::TurnSelection,
     },
     ctx::Ctx,
     render::{ConfigSource, TurnRenderer},
@@ -63,7 +62,7 @@ pub(crate) struct Print {
     ///
     /// Without any selector, prints the whole conversation.
     #[command(flatten)]
-    range: TurnRange,
+    range: TurnSelection,
 
     /// Use the current workspace config instead of the per-turn config.
     ///
@@ -133,7 +132,7 @@ impl Print {
     fn print_conversation(
         ctx: &mut Ctx,
         handle: &ConversationHandle,
-        range: &TurnRange,
+        range: &TurnSelection,
         current_config: bool,
         print_style: Option<PrintStyle>,
         compacted: bool,
@@ -193,43 +192,16 @@ impl Print {
         );
         renderer.set_user_only(user_only);
 
-        // `--last 0` / `--first 0` explicitly selects nothing.
-        if range.is_empty() {
-            renderer.flush();
-            return Ok(());
-        }
-
-        // `--turn` names specific turns; an out-of-range endpoint is an error.
-        if let Some(n) = range.turn_out_of_range(raw_count) {
-            return Err(
-                format!("turn {n} out of range (conversation has {raw_count} turns)").into(),
-            );
-        }
-
-        let from = match range.resolve_from(&events) {
-            Bound::Empty => {
-                renderer.flush();
-                return Ok(());
-            }
-            Bound::Default => None,
-            Bound::At(b) => Some(b),
-        };
-        let to = match range.resolve_to(&events) {
-            Bound::Empty => {
-                renderer.flush();
-                return Ok(());
-            }
-            Bound::Default => None,
-            Bound::At(b) => Some(b),
-        };
+        range.validate()?;
+        range.check_turn_range(raw_count)?;
 
-        // The selected raw 0-based turn range. A `from > to` or otherwise empty
-        // range selects nothing. Resolved against the raw stream, before
-        // projection, so it lines up with the header numbers.
-        let Some(selected) = resolve_range(&events, from, to) else {
+        // Resolved against the raw stream, before projection, so the selection
+        // lines up with the header numbers.
+        let selected = range.resolve(&events);
+        if selected.is_empty() {
             renderer.flush();
             return Ok(());
-        };
+        }
 
         // Project for rendering when compacted; `origins` maps each rendered
         // turn back to the raw turn number(s) it represents for the header.
@@ -245,7 +217,7 @@ impl Print {
         );
 
         for (turn, origin) in events.iter_turns().zip(&origins) {
-            if origin.overlaps(selected.from_turn, selected.to_turn) {
+            if selected.overlaps_origin(*origin) {
                 renderer.render_turn(&turn, *origin);
             }
         }
diff --git a/crates/jp_cli/src/cmd/conversation/print_tests.rs b/crates/jp_cli/src/cmd/conversation/print_tests.rs
index c1bcbc5ca..f9250cb41 100644
--- a/crates/jp_cli/src/cmd/conversation/print_tests.rs
+++ b/crates/jp_cli/src/cmd/conversation/print_tests.rs
@@ -85,7 +85,7 @@ fn prints_user_message() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -108,7 +108,7 @@ fn prints_assistant_message() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -137,7 +137,7 @@ fn prints_reasoning_full() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -167,7 +167,7 @@ fn hides_reasoning_when_hidden() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -199,7 +199,7 @@ fn truncates_reasoning() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -240,7 +240,7 @@ fn prints_tool_call_and_result() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -268,7 +268,7 @@ fn prints_structured_data() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -299,7 +299,7 @@ fn structured_fence_is_closed_at_end_of_replay() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -338,7 +338,7 @@ fn structured_response_followed_by_message_closes_fence_first() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -386,7 +386,7 @@ fn structured_to_message_in_same_turn_closes_fence_first() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -424,7 +424,7 @@ fn turn_separators_between_turns() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -452,7 +452,7 @@ fn turn_header_shows_turn_number_and_relative_time() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -507,7 +507,7 @@ fn turn_header_detail_on_assistant_first_turn() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -537,7 +537,7 @@ fn prints_conversation_by_id() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -560,7 +560,7 @@ fn empty_conversation_produces_no_content() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -612,7 +612,7 @@ fn full_conversation_round_trip() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -652,7 +652,7 @@ fn last_prints_only_last_turn() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(Some(1), None),
+        range: TurnSelection::from_last_turn(Some(1), None),
         current_config: false,
         style: None,
         compacted: false,
@@ -693,7 +693,7 @@ fn last_two_with_three_turns() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(Some(2), None),
+        range: TurnSelection::from_last_turn(Some(2), None),
         current_config: false,
         style: None,
         compacted: false,
@@ -722,7 +722,7 @@ fn last_exceeding_turn_count_prints_all() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(Some(5), None),
+        range: TurnSelection::from_last_turn(Some(5), None),
         current_config: false,
         style: None,
         compacted: false,
@@ -767,7 +767,7 @@ fn blank_line_between_tool_calls_and_message() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -820,7 +820,7 @@ fn blank_line_between_message_and_tool_calls() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -889,7 +889,7 @@ fn no_extra_blank_line_between_consecutive_tool_calls() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -926,7 +926,7 @@ fn last_zero_prints_nothing() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(Some(0), None),
+        range: TurnSelection::from_last_turn(Some(0), None),
         current_config: false,
         style: None,
         compacted: false,
@@ -961,7 +961,7 @@ fn turn_prints_specific_turn() {
     // Print only turn 2.
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, Some(2)),
+        range: TurnSelection::from_last_turn(None, Some(2)),
         current_config: false,
         style: None,
         compacted: false,
@@ -999,7 +999,7 @@ fn turn_out_of_range_errors() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, Some(5)),
+        range: TurnSelection::from_last_turn(None, Some(5)),
         current_config: false,
         style: None,
         compacted: false,
@@ -1018,7 +1018,7 @@ fn turn_zero_errors() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, Some(0)),
+        range: TurnSelection::from_last_turn(None, Some(0)),
         current_config: false,
         style: None,
         compacted: false,
@@ -1063,7 +1063,7 @@ fn style_brief_hides_reasoning_and_tool_details() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: Some(PrintStyle::Brief),
         compacted: false,
@@ -1140,7 +1140,7 @@ fn style_chat_hides_reasoning_and_tool_calls() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: Some(PrintStyle::Chat),
         compacted: false,
@@ -1219,7 +1219,7 @@ fn style_user_shows_only_user_messages() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: Some(PrintStyle::User),
         compacted: false,
@@ -1264,7 +1264,7 @@ fn role_header_renders_user_label_from_author() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -1289,7 +1289,7 @@ fn role_header_falls_back_to_user_label_without_author() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -1314,7 +1314,7 @@ fn role_header_renders_assistant_label_with_model_suffix() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -1340,7 +1340,7 @@ fn role_header_assistant_appears_once_per_turn() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -1382,7 +1382,7 @@ fn role_header_assistant_emitted_before_first_tool_call() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -1413,7 +1413,7 @@ fn role_header_does_not_emit_plain_hr_separator() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -1463,7 +1463,7 @@ fn style_chat_separates_messages_across_hidden_reasoning() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: Some(PrintStyle::Chat),
         compacted: false,
@@ -1514,7 +1514,7 @@ fn style_chat_separates_messages_across_hidden_tool_call() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: Some(PrintStyle::Chat),
         compacted: false,
@@ -1575,7 +1575,7 @@ fn style_full_shows_reasoning_and_untruncated_results() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: Some(PrintStyle::Full),
         compacted: false,
@@ -1645,7 +1645,7 @@ fn replay_shades_tool_chrome_after_reasoning() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -1694,7 +1694,7 @@ fn replay_does_not_shade_tool_chrome_when_extension_disabled() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -1744,7 +1744,7 @@ fn replay_suppresses_tool_chrome_when_show_disabled() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -1813,7 +1813,7 @@ fn replay_keeps_the_gap_after_a_result_when_reasoning_renders_nothing() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(None, None),
+        range: TurnSelection::from_last_turn(None, None),
         current_config: false,
         style: None,
         compacted: false,
@@ -1862,7 +1862,7 @@ fn replay_does_not_leak_reasoning_region_across_turns() {
 
     let print = Print {
         target: PositionalIds::from_targets(vec![ConversationTarget::Id(id)]),
-        range: TurnRange::from_last_turn(Some(2), None),
+        range: TurnSelection::from_last_turn(Some(2), None),
         current_config: true,
         style: None,
         compacted: false,
diff --git a/crates/jp_cli/src/cmd/conversation/rm.rs b/crates/jp_cli/src/cmd/conversation/rm.rs
index c64a59cd6..cc1d9dfe5 100644
--- a/crates/jp_cli/src/cmd/conversation/rm.rs
+++ b/crates/jp_cli/src/cmd/conversation/rm.rs
@@ -23,7 +23,8 @@ pub(crate) struct Rm {
     #[command(flatten)]
     target: PositionalIds<true, true>,
 
-    /// Remove all conversations created in a `[--from, --until)` range.
+    /// Remove all conversations created in a `[--created-since,
+    /// --created-before)` range.
     #[command(flatten)]
     range: CreationRange,
 
diff --git a/crates/jp_cli/src/cmd/conversation/rm_tests.rs b/crates/jp_cli/src/cmd/conversation/rm_tests.rs
index 2cf2917d1..6addf87bf 100644
--- a/crates/jp_cli/src/cmd/conversation/rm_tests.rs
+++ b/crates/jp_cli/src/cmd/conversation/rm_tests.rs
@@ -38,8 +38,8 @@ fn workspace_with_conversations(ids: &[ConversationId]) -> Workspace {
 fn load_request_is_none_when_range_set() {
     let cmd = Rm {
         range: CreationRange {
-            from: Some(ts(1000).into()),
-            until: None,
+            since: Some(ts(1000).into()),
+            before: None,
         },
         ..empty_rm()
     };
@@ -47,8 +47,8 @@ fn load_request_is_none_when_range_set() {
 
     let cmd = Rm {
         range: CreationRange {
-            from: None,
-            until: Some(ts(1000).into()),
+            since: None,
+            before: Some(ts(1000).into()),
         },
         ..empty_rm()
     };
@@ -78,8 +78,8 @@ fn resolve_filtered_half_open_range_returns_only_in_range_ids() {
 
     let cmd = Rm {
         range: CreationRange {
-            from: Some(ts(1000).into()),
-            until: Some(ts(2000).into()),
+            since: Some(ts(1000).into()),
+            before: Some(ts(2000).into()),
         },
         ..empty_rm()
     };
@@ -104,8 +104,8 @@ fn resolve_filtered_from_only_includes_from_inclusive() {
 
     let cmd = Rm {
         range: CreationRange {
-            from: Some(ts(1000).into()),
-            until: None,
+            since: Some(ts(1000).into()),
+            before: None,
         },
         ..empty_rm()
     };
@@ -130,8 +130,8 @@ fn resolve_filtered_until_only_excludes_until_exclusive() {
 
     let cmd = Rm {
         range: CreationRange {
-            from: None,
-            until: Some(ts(2000).into()),
+            since: None,
+            before: Some(ts(2000).into()),
         },
         ..empty_rm()
     };
@@ -153,8 +153,8 @@ fn resolve_filtered_empty_when_nothing_matches() {
 
     let cmd = Rm {
         range: CreationRange {
-            from: Some(ts(1000).into()),
-            until: Some(ts(2000).into()),
+            since: Some(ts(1000).into()),
+            before: Some(ts(2000).into()),
         },
         ..empty_rm()
     };
diff --git a/crates/jp_cli/src/cmd/conversation/use_.rs b/crates/jp_cli/src/cmd/conversation/use_.rs
index 07d37e593..3fe87175b 100644
--- a/crates/jp_cli/src/cmd/conversation/use_.rs
+++ b/crates/jp_cli/src/cmd/conversation/use_.rs
@@ -33,7 +33,7 @@ pub(crate) struct Use {
     /// Case-insensitive unless the pattern contains an uppercase character
     /// (smart-case).
     /// Composable with target keywords (`?`, `?p`, `?s`, `?a`) and with
-    /// `--from` / `--until`.
+    /// `--created-since` / `--created-before`.
     #[arg(long)]
     grep: Option<String>,
 
@@ -51,7 +51,8 @@ impl Use {
             .any(ConversationTarget::is_archived)
     }
 
-    /// Whether any candidate-set filter (`--grep`, `--from`, `--until`) is set.
+    /// Whether any candidate-set filter (`--grep`, `--created-since`,
+    /// `--created-before`) is set.
     /// When true, `Use` resolves its handle internally instead of going through
     /// the standard pipeline.
     fn has_filter(&self) -> bool {
diff --git a/crates/jp_cli/src/cmd/conversation/use_tests.rs b/crates/jp_cli/src/cmd/conversation/use_tests.rs
index 76599510c..0c8a6707b 100644
--- a/crates/jp_cli/src/cmd/conversation/use_tests.rs
+++ b/crates/jp_cli/src/cmd/conversation/use_tests.rs
@@ -285,8 +285,8 @@ fn filter_range_narrows_then_grep_matches() {
         target: PositionalIds::from_targets(vec![]),
         grep: Some("shared-marker".into()),
         range: CreationRange {
-            from: Some(cutoff),
-            until: None,
+            since: Some(cutoff),
+            before: None,
         },
     };
     cmd.run(&mut ctx, vec![]).unwrap();
@@ -317,10 +317,10 @@ fn filter_mode_skips_standard_resolution() {
         target: PositionalIds::from_targets(vec![]),
         grep: None,
         range: CreationRange {
-            from: Some(TimeThreshold::from(
+            since: Some(TimeThreshold::from(
                 Utc.with_ymd_and_hms(2020, 1, 1, 0, 0, 0).unwrap(),
             )),
-            until: None,
+            before: None,
         },
     };
     assert!(cmd.conversation_load_request().targets.is_none());
diff --git a/crates/jp_cli/src/cmd/query.rs b/crates/jp_cli/src/cmd/query.rs
index 83e92bd8f..6d8e318e1 100644
--- a/crates/jp_cli/src/cmd/query.rs
+++ b/crates/jp_cli/src/cmd/query.rs
@@ -1049,8 +1049,9 @@ impl Query {
             &events,
             cfg,
             &rules,
-            crate::cmd::turn_range::Bound::Default,
-            crate::cmd::turn_range::Bound::Default,
+            // `--compact` on a query applies the configured rules to the whole
+            // conversation; there are no turn-selection flags to honour.
+            &crate::cmd::turn_selection::TurnSelection::default(),
             // `--compact` on a query is a quick adjunct; apply it silently so
             // compaction details don't clutter the query output.
             None,
diff --git a/crates/jp_cli/src/cmd/time.rs b/crates/jp_cli/src/cmd/time.rs
index 7232e064d..b2d8aafeb 100644
--- a/crates/jp_cli/src/cmd/time.rs
+++ b/crates/jp_cli/src/cmd/time.rs
@@ -73,14 +73,18 @@ impl FromStr for TimeThreshold {
     }
 }
 
-/// A half-open `[from, until)` filter on conversation creation date, shared
+/// A half-open `[since, before)` filter on conversation creation date, shared
 /// between subcommands that want range-based selection (`jp c rm`, `jp c
 /// archive`, `jp c use`, …).
 ///
-/// `--from` is inclusive, `--until` is exclusive.
+/// `--created-since` is inclusive, `--created-before` is exclusive.
 /// Both accept the full [`TimeThreshold`] syntax (conversation ID, relative
 /// duration, or absolute date).
 ///
+/// The flags name what they filter because `--from`/`--to` select *turns*
+/// within a conversation elsewhere in the CLI (see `cmd::turn_selection`), and
+/// the two accept near-identical values.
+///
 /// # Type parameters
 ///
 /// - `EXCLUSIVE`: whether the range is mutually exclusive with the positional
@@ -95,15 +99,15 @@ impl FromStr for TimeThreshold {
 /// manually.
 #[derive(Debug)]
 pub(crate) struct CreationRange<const EXCLUSIVE: bool = true> {
-    pub from: Option<TimeThreshold>,
-    pub until: Option<TimeThreshold>,
+    pub since: Option<TimeThreshold>,
+    pub before: Option<TimeThreshold>,
 }
 
 impl<const EXCLUSIVE: bool> Default for CreationRange<EXCLUSIVE> {
     fn default() -> Self {
         Self {
-            from: None,
-            until: None,
+            since: None,
+            before: None,
         }
     }
 }
@@ -111,13 +115,13 @@ impl<const EXCLUSIVE: bool> Default for CreationRange<EXCLUSIVE> {
 impl<const EXCLUSIVE: bool> CreationRange<EXCLUSIVE> {
     /// Whether either bound is set.
     pub fn is_set(&self) -> bool {
-        self.from.is_some() || self.until.is_some()
+        self.since.is_some() || self.before.is_some()
     }
 
     /// Half-open range test on the conversation's creation timestamp.
     pub fn matches(&self, id: ConversationId) -> bool {
-        self.from.is_none_or(|t| id.timestamp() >= *t)
-            && self.until.is_none_or(|t| id.timestamp() < *t)
+        self.since.is_none_or(|t| id.timestamp() >= *t)
+            && self.before.is_none_or(|t| id.timestamp() < *t)
     }
 }
 
@@ -145,36 +149,37 @@ impl TypedValueParser for TimeThresholdParser {
 
 impl<const EXCLUSIVE: bool> clap::Args for CreationRange<EXCLUSIVE> {
     fn augment_args(cmd: Command) -> Command {
-        let from_help = "Match conversations created at or after the specified time.";
-        let from_long_help = "Match conversations created at or after the specified \
-                              time.\n\nAccepts a conversation ID (uses its creation timestamp), a \
-                              relative duration (e.g. `3w`, `30d`, `6h`), or an absolute date \
-                              (e.g. `2026-01-01`). Composable with `--until`.";
-        let until_help = "Match conversations created before the specified time.";
-        let until_long_help = "Match conversations created before the specified time.\n\nAccepts \
-                               the same formats as `--from`. The range is half-open (`--until` is \
-                               exclusive), so `--from X --until Y` matches everything in `[X, Y)`.";
+        let since_help = "Match conversations created at or after the specified time.";
+        let since_long_help = "Match conversations created at or after the specified \
+                               time.\n\nAccepts a conversation ID (uses its creation timestamp), \
+                               a relative duration (e.g. `3w`, `30d`, `6h`), or an absolute date \
+                               (e.g. `2026-01-01`). Composable with `--created-before`.";
+        let before_help = "Match conversations created before the specified time.";
+        let before_long_help = "Match conversations created before the specified time.\n\nAccepts \
+                                the same formats as `--created-since`. The range is half-open \
+                                (`--created-before` is exclusive), so `--created-since X \
+                                --created-before Y` matches everything in `[X, Y)`.";
 
         let mut group = ArgGroup::new("creation_range")
             .multiple(true)
-            .args(["from", "until"]);
+            .args(["created_since", "created_before"]);
         if EXCLUSIVE {
             group = group.conflicts_with("id");
         }
 
         cmd.arg(
-            Arg::new("from")
-                .long("from")
+            Arg::new("created_since")
+                .long("created-since")
                 .value_parser(TimeThresholdParser)
-                .help(from_help)
-                .long_help(from_long_help),
+                .help(since_help)
+                .long_help(since_long_help),
         )
         .arg(
-            Arg::new("until")
-                .long("until")
+            Arg::new("created_before")
+                .long("created-before")
                 .value_parser(TimeThresholdParser)
-                .help(until_help)
-                .long_help(until_long_help),
+                .help(before_help)
+                .long_help(before_long_help),
         )
         .group(group)
     }
@@ -187,17 +192,17 @@ impl<const EXCLUSIVE: bool> clap::Args for CreationRange<EXCLUSIVE> {
 impl<const EXCLUSIVE: bool> FromArgMatches for CreationRange<EXCLUSIVE> {
     fn from_arg_matches(matches: &ArgMatches) -> Result<Self, clap::Error> {
         Ok(Self {
-            from: matches.get_one::<TimeThreshold>("from").copied(),
-            until: matches.get_one::<TimeThreshold>("until").copied(),
+            since: matches.get_one::<TimeThreshold>("created_since").copied(),
+            before: matches.get_one::<TimeThreshold>("created_before").copied(),
         })
     }
 
     fn update_from_arg_matches(&mut self, matches: &ArgMatches) -> Result<(), clap::Error> {
-        if let Some(v) = matches.get_one::<TimeThreshold>("from").copied() {
-            self.from = Some(v);
+        if let Some(v) = matches.get_one::<TimeThreshold>("created_since").copied() {
+            self.since = Some(v);
         }
-        if let Some(v) = matches.get_one::<TimeThreshold>("until").copied() {
-            self.until = Some(v);
+        if let Some(v) = matches.get_one::<TimeThreshold>("created_before").copied() {
+            self.before = Some(v);
         }
         Ok(())
     }
diff --git a/crates/jp_cli/src/cmd/time_tests.rs b/crates/jp_cli/src/cmd/time_tests.rs
index a560ab604..15aa40717 100644
--- a/crates/jp_cli/src/cmd/time_tests.rs
+++ b/crates/jp_cli/src/cmd/time_tests.rs
@@ -105,23 +105,23 @@ fn creation_range_is_set() {
     assert!(!empty.is_set());
 
     let from_only: CreationRange = CreationRange {
-        from: Some(ts(1000).into()),
-        until: None,
+        since: Some(ts(1000).into()),
+        before: None,
     };
     assert!(from_only.is_set());
 
     let until_only: CreationRange = CreationRange {
-        from: None,
-        until: Some(ts(1000).into()),
+        since: None,
+        before: Some(ts(1000).into()),
     };
     assert!(until_only.is_set());
 }
 
 #[test]
-fn creation_range_from_inclusive() {
+fn creation_range_since_is_inclusive() {
     let range: CreationRange = CreationRange {
-        from: Some(ts(1000).into()),
-        until: None,
+        since: Some(ts(1000).into()),
+        before: None,
     };
 
     // Strictly before: excluded.
@@ -133,10 +133,10 @@ fn creation_range_from_inclusive() {
 }
 
 #[test]
-fn creation_range_until_exclusive() {
+fn creation_range_before_is_exclusive() {
     let range: CreationRange = CreationRange {
-        from: None,
-        until: Some(ts(2000).into()),
+        since: None,
+        before: Some(ts(2000).into()),
     };
 
     assert!(range.matches(make_id(1999)));
@@ -148,8 +148,8 @@ fn creation_range_until_exclusive() {
 #[test]
 fn creation_range_half_open() {
     let range: CreationRange = CreationRange {
-        from: Some(ts(1000).into()),
-        until: Some(ts(2000).into()),
+        since: Some(ts(1000).into()),
+        before: Some(ts(2000).into()),
     };
 
     assert!(!range.matches(make_id(999)));
@@ -184,21 +184,30 @@ struct RangeWithIds {
 }
 
 #[test]
-fn clap_parses_from_and_until() {
-    let cmd =
-        RangeWithIds::try_parse_from(["test-creation-range", "--from", "3w", "--until", "1d"])
-            .unwrap();
-    assert!(cmd.range.from.is_some());
-    assert!(cmd.range.until.is_some());
+fn clap_parses_created_since_and_created_before() {
+    let cmd = RangeWithIds::try_parse_from([
+        "test-creation-range",
+        "--created-since",
+        "3w",
+        "--created-before",
+        "1d",
+    ])
+    .unwrap();
+    assert!(cmd.range.since.is_some());
+    assert!(cmd.range.before.is_some());
     assert!(cmd.range.is_set());
 }
 
 #[test]
 fn clap_conflicts_range_with_positional_id() {
     let id = ConversationId::try_from(Utc.with_ymd_and_hms(2026, 1, 1, 0, 0, 0).unwrap()).unwrap();
-    let err =
-        RangeWithIds::try_parse_from(["test-creation-range", &id.to_string(), "--from", "3w"])
-            .unwrap_err();
+    let err = RangeWithIds::try_parse_from([
+        "test-creation-range",
+        &id.to_string(),
+        "--created-since",
+        "3w",
+    ])
+    .unwrap_err();
     assert!(
         err.to_string().contains("cannot be used with"),
         "expected clap conflict error, got: {err}"
@@ -219,14 +228,14 @@ struct PermissiveRangeWithIds {
 fn clap_permissive_range_composes_with_positional_id() {
     // `CreationRange<false>` is the candidate-filter variant used by `c use`.
     // It must *not* conflict with the positional id, so combinations like
-    // `jp c use ?p --from 3w` parse successfully.
+    // `jp c use ?p --created-since 3w` parse successfully.
     let id = ConversationId::try_from(Utc.with_ymd_and_hms(2026, 1, 1, 0, 0, 0).unwrap()).unwrap();
     let cmd = PermissiveRangeWithIds::try_parse_from([
         "test-creation-range-permissive",
         &id.to_string(),
-        "--from",
+        "--created-since",
         "3w",
     ])
     .expect("non-exclusive range should compose with positional id");
-    assert!(cmd.range.from.is_some());
+    assert!(cmd.range.since.is_some());
 }
diff --git a/crates/jp_cli/src/cmd/turn_range.rs b/crates/jp_cli/src/cmd/turn_range.rs
deleted file mode 100644
index 9af7bd2d7..000000000
--- a/crates/jp_cli/src/cmd/turn_range.rs
+++ /dev/null
@@ -1,326 +0,0 @@
-//! Shared turn-range selector for `print` and `compact`.
-//!
-//! Both commands need to name a subset of turns.
-//! This module owns that selector — the `--last`/`--turn`/`--from`/`--to`
-//! flags — and the parsing and stream resolution behind them, so a range built
-//! for one command means the same thing in the other.
-//!
-//! Turn positions are 1-based on the CLI and 0-based in the stream; the
-//! translation happens here.
-//! See `docs/architecture/indexing-conventions.md`.
-
-use std::{str::FromStr as _, time::Duration};
-
-use chrono::{DateTime, Utc};
-use jp_conversation::{ConversationStream, RangeBound};
-
-/// A `--from`/`--to` bound before time-based resolution.
-#[derive(Debug, Clone)]
-pub(crate) enum CliRangeBound {
-    /// Already resolved to a `RangeBound` (0-based for the core).
-    Resolved(RangeBound),
-    /// Duration ago — needs the stream to find the turn.
-    Duration(DateTime<Utc>),
-}
-
-/// Whether `s` is the most-recent-compaction marker.
-///
-/// `last-compaction` is canonical; `last` is accepted as a deprecated alias.
-fn is_last_compaction(s: &str) -> bool {
-    s.eq_ignore_ascii_case("last-compaction") || s.eq_ignore_ascii_case("last")
-}
-
-/// Parse a `--from`/`--to` bound.
-///
-/// Accepts a 1-based turn index, `-N` (offset from the end, `-1` is the last
-/// turn), a duration (`5h`), or `last-compaction` (after the most recent
-/// compaction; `last` is accepted as a deprecated alias).
-pub(crate) fn parse_bound(s: &str) -> Result<CliRangeBound, String> {
-    if is_last_compaction(s) {
-        return Ok(CliRangeBound::Resolved(RangeBound::AfterLastCompaction));
-    }
-
-    // From-end offset. `-1` is the last turn, so `-N` maps to `FromEnd(N - 1)`.
-    if let Some(rest) = s.strip_prefix('-')
-        && let Ok(n) = rest.parse::<usize>()
-    {
-        if n == 0 {
-            return Err("from-end offsets are 1-based; use `-1` for the last turn".to_owned());
-        }
-        return Ok(CliRangeBound::Resolved(RangeBound::FromEnd(n - 1)));
-    }
-
-    // 1-based user index → 0-based core index.
-    if let Ok(n) = s.parse::<usize>() {
-        if n == 0 {
-            return Err("turn numbers are 1-based; `0` is not a valid turn".to_owned());
-        }
-        return Ok(CliRangeBound::Resolved(RangeBound::Absolute(n - 1)));
-    }
-
-    humantime::Duration::from_str(s)
-        .map(|d| CliRangeBound::Duration(Utc::now() - Duration::from(d)))
-        .map_err(|e| format!("invalid range bound `{s}`: {e}"))
-}
-
-/// Like [`parse_bound`], but rejects the `last-compaction` marker.
-///
-/// `last-compaction` (the most recent compaction) is only meaningful as a start
-/// bound (`--from last-compaction`), so it is not accepted for `--to`.
-fn parse_to_bound(s: &str) -> Result<CliRangeBound, String> {
-    if is_last_compaction(s) {
-        return Err(
-            "`last-compaction` is only valid for `--from` (it marks the most recent compaction)"
-                .to_owned(),
-        );
-    }
-    parse_bound(s)
-}
-
-/// Parse a 1-based turn number for `--turn`, rejecting `0`.
-fn parse_one_based(s: &str) -> Result<usize, String> {
-    match s.parse::<usize>() {
-        Ok(0) => Err("turn numbers are 1-based; `0` is not a valid turn".to_owned()),
-        Ok(n) => Ok(n),
-        Err(_) => Err(format!("invalid turn number `{s}`")),
-    }
-}
-
-/// A `--turn` value: a single 1-based turn, or an inclusive 1-based range.
-///
-/// Either end of a range may be open: `10..` is turn 10 through the end, `..10`
-/// is the first 10 turns, and `..` is the whole conversation.
-#[derive(Debug, Clone)]
-pub(crate) enum TurnSpec {
-    /// A single turn.
-    Single(usize),
-    /// An inclusive range `from..to`.
-    /// `None` on either side is open (the start or end of the conversation).
-    Range(Option<usize>, Option<usize>),
-}
-
-/// Parse a `--turn` value: `N` (a single turn) or a range `A..B`.
-///
-/// The separator is `..` and both ends are inclusive, matching the compaction
-/// DSL (`1..5` is turns 1 through 5).
-/// Either end may be omitted: `10..`, `..10`, or `..` (all turns).
-fn parse_turn(s: &str) -> Result<TurnSpec, String> {
-    if let Some((a, b)) = s.split_once("..") {
-        let from = if a.is_empty() {
-            None
-        } else {
-            Some(parse_one_based(a)?)
-        };
-        let to = if b.is_empty() {
-            None
-        } else {
-            Some(parse_one_based(b)?)
-        };
-        return Ok(TurnSpec::Range(from, to));
-    }
-    Ok(TurnSpec::Single(parse_one_based(s)?))
-}
-
-/// The resolution of one range bound (`from` or `to`) against a stream.
-///
-/// Separates "no bound configured for this side" (use the side's default) from
-/// "this bound selects no turns" (so the whole selection is empty), which a
-/// plain `Option<RangeBound>` conflates.
-#[derive(Debug, Clone)]
-pub(crate) enum Bound {
-    /// No bound configured; the range defaults to the start (`from`) or end
-    /// (`to`) of the conversation.
-    Default,
-    /// The bound resolves to a concrete `RangeBound`.
-    At(RangeBound),
-    /// The bound falls outside the conversation such that nothing is selected.
-    Empty,
-}
-
-/// Resolve a `--from <bound>` cutoff: the range starts at the first turn after
-/// the cutoff.
-///
-/// No turn after the cutoff (an old conversation) means an empty selection; a
-/// cutoff before the conversation starts selects from the beginning.
-pub(crate) fn resolve_cli_from(bound: &CliRangeBound, events: &ConversationStream) -> Bound {
-    match bound {
-        CliRangeBound::Resolved(b) => Bound::At(b.clone()),
-        CliRangeBound::Duration(dt) => match events.turn_at_time(*dt) {
-            Some(turn) => {
-                let from = turn.index() + 1;
-                if from >= events.turn_count() {
-                    Bound::Empty
-                } else {
-                    Bound::At(RangeBound::Absolute(from))
-                }
-            }
-            None => Bound::At(RangeBound::Absolute(0)),
-        },
-    }
-}
-
-/// Resolve a `--to <bound>` cutoff: the range stops at (and includes) the turn
-/// active at the cutoff.
-///
-/// A cutoff preceding the conversation means an empty selection.
-pub(crate) fn resolve_cli_to(bound: &CliRangeBound, events: &ConversationStream) -> Bound {
-    match bound {
-        CliRangeBound::Resolved(b) => Bound::At(b.clone()),
-        CliRangeBound::Duration(dt) => match events.turn_at_time(*dt) {
-            Some(turn) => Bound::At(RangeBound::Absolute(turn.index())),
-            None => Bound::Empty,
-        },
-    }
-}
-
-/// A positive turn-range selector shared by `print` and `compact`.
-///
-/// Names the turns a command acts on.
-/// The selectors are mutually constrained so only one way of expressing the
-/// range is given at a time.
-#[derive(Debug, Clone, Default, clap::Args)]
-pub(crate) struct TurnRange {
-    /// Select the first N turns.
-    /// Without a value, selects the first turn.
-    #[arg(long, num_args = 0..=1, default_missing_value = "1", conflicts_with_all = ["last", "turn", "from", "to"])]
-    first: Option<usize>,
-
-    /// Select the last N turns.
-    /// Without a value, selects the last turn.
-    #[arg(long, num_args = 0..=1, default_missing_value = "1", conflicts_with_all = ["first", "turn", "from", "to"])]
-    last: Option<usize>,
-
-    /// Select turns by number (1-based): a single turn (`3`), an inclusive
-    /// range (`1..5`), or an open range like `10..` (turn 10 onward), `..10`
-    /// (the first 10), or `..` (all).
-    /// Stable across new turns.
-    #[arg(long, value_parser = parse_turn, conflicts_with_all = ["first", "last", "from", "to"])]
-    turn: Option<TurnSpec>,
-
-    /// Start of the range: a 1-based turn index, `-N` from the end, a duration
-    /// (e.g. `5h`), or `last-compaction` (after the most recent compaction).
-    #[arg(long, value_parser = parse_bound)]
-    from: Option<CliRangeBound>,
-
-    /// End of the range: a 1-based turn index, `-N` from the end, or a duration
-    /// (e.g. `2h`).
-    #[arg(long, value_parser = parse_to_bound)]
-    to: Option<CliRangeBound>,
-}
-
-impl TurnRange {
-    /// Build a selector from explicit `--last`/`--turn` values.
-    #[cfg(test)]
-    pub(crate) fn from_last_turn(last: Option<usize>, turn: Option<usize>) -> Self {
-        Self {
-            first: None,
-            last,
-            turn: turn.map(TurnSpec::Single),
-            from: None,
-            to: None,
-        }
-    }
-
-    /// The `--first N` count, if set.
-    pub(crate) fn first(&self) -> Option<usize> {
-        self.first
-    }
-
-    /// The `--last N` count, if set.
-    pub(crate) fn last(&self) -> Option<usize> {
-        self.last
-    }
-
-    /// The first `--turn` endpoint outside `1..=count`, if any.
-    ///
-    /// `--turn` names specific turns, so an endpoint past the conversation is
-    /// an error rather than a clamped selection (unlike `--first`/`--last`).
-    pub(crate) fn turn_out_of_range(&self, count: usize) -> Option<usize> {
-        let oob = |n: usize| n == 0 || n > count;
-        let ends = match self.turn.as_ref()? {
-            TurnSpec::Single(n) => [Some(*n), None],
-            TurnSpec::Range(a, b) => [*a, *b],
-        };
-        ends.into_iter().flatten().find(|&n| oob(n))
-    }
-
-    /// Whether the selector explicitly names an empty range (`--last 0` or
-    /// `--first 0`).
-    pub(crate) fn is_empty(&self) -> bool {
-        self.last == Some(0) || self.first == Some(0)
-    }
-
-    /// The `from` bound as a CLI bound, folding the positive selectors.
-    ///
-    /// `--first`/`--last`/`--turn` are complete selectors that set both bounds;
-    /// `--from` is the explicit start of a range.
-    fn cli_from_bound(&self) -> Option<CliRangeBound> {
-        if let Some(spec) = &self.turn {
-            let bound = match spec {
-                TurnSpec::Single(n) => RangeBound::Absolute(n.saturating_sub(1)),
-                // Open start (`--turn ..B`) begins at the first turn.
-                TurnSpec::Range(Some(a), _) => RangeBound::Absolute(a.saturating_sub(1)),
-                TurnSpec::Range(None, _) => RangeBound::Absolute(0),
-            };
-            return Some(CliRangeBound::Resolved(bound));
-        }
-        if let Some(n) = self.last {
-            return Some(CliRangeBound::Resolved(RangeBound::FromEnd(
-                n.saturating_sub(1),
-            )));
-        }
-        if self.first.is_some() {
-            // `--first N` starts at the first turn.
-            return Some(CliRangeBound::Resolved(RangeBound::Absolute(0)));
-        }
-        self.from.clone()
-    }
-
-    /// The `to` bound as a CLI bound, folding the positive selectors.
-    ///
-    /// `--first`/`--last`/`--turn` are complete selectors that set both bounds;
-    /// `--to` is the explicit end of a range.
-    fn cli_to_bound(&self) -> Option<CliRangeBound> {
-        if let Some(spec) = &self.turn {
-            let bound = match spec {
-                TurnSpec::Single(n) => RangeBound::Absolute(n.saturating_sub(1)),
-                // Open end (`--turn A..`) runs through the last turn.
-                TurnSpec::Range(_, Some(b)) => RangeBound::Absolute(b.saturating_sub(1)),
-                TurnSpec::Range(_, None) => RangeBound::FromEnd(0),
-            };
-            return Some(CliRangeBound::Resolved(bound));
-        }
-        if self.last.is_some() {
-            // `--last N` ends at the last turn.
-            return Some(CliRangeBound::Resolved(RangeBound::FromEnd(0)));
-        }
-        if let Some(n) = self.first {
-            return Some(CliRangeBound::Resolved(RangeBound::Absolute(
-                n.saturating_sub(1),
-            )));
-        }
-        self.to.clone()
-    }
-
-    /// Resolve the `from` override against the stream.
-    /// Returns [`Bound::Default`] when no `from`-affecting flag is set.
-    pub(crate) fn resolve_from(&self, events: &ConversationStream) -> Bound {
-        match self.cli_from_bound() {
-            Some(bound) => resolve_cli_from(&bound, events),
-            None => Bound::Default,
-        }
-    }
-
-    /// Resolve the `to` override against the stream.
-    /// Returns [`Bound::Default`] when no `to`-affecting flag is set.
-    pub(crate) fn resolve_to(&self, events: &ConversationStream) -> Bound {
-        match self.cli_to_bound() {
-            Some(bound) => resolve_cli_to(&bound, events),
-            None => Bound::Default,
-        }
-    }
-}
-
-#[cfg(test)]
-#[path = "turn_range_tests.rs"]
-mod tests;
diff --git a/crates/jp_cli/src/cmd/turn_range_tests.rs b/crates/jp_cli/src/cmd/turn_range_tests.rs
deleted file mode 100644
index dcdaab1e3..000000000
--- a/crates/jp_cli/src/cmd/turn_range_tests.rs
+++ /dev/null
@@ -1,172 +0,0 @@
-use jp_conversation::RangeBound;
-
-use super::*;
-
-#[test]
-fn parse_bound_absolute_is_one_based() {
-    // `1` is the first turn (0-based `Absolute(0)` internally).
-    assert!(matches!(
-        parse_bound("1").unwrap(),
-        CliRangeBound::Resolved(RangeBound::Absolute(0))
-    ));
-    assert!(matches!(
-        parse_bound("5").unwrap(),
-        CliRangeBound::Resolved(RangeBound::Absolute(4))
-    ));
-}
-
-#[test]
-fn parse_bound_from_end_is_one_based() {
-    // `-1` is the last turn (0-based `FromEnd(0)` internally).
-    assert!(matches!(
-        parse_bound("-1").unwrap(),
-        CliRangeBound::Resolved(RangeBound::FromEnd(0))
-    ));
-    assert!(matches!(
-        parse_bound("-3").unwrap(),
-        CliRangeBound::Resolved(RangeBound::FromEnd(2))
-    ));
-}
-
-#[test]
-fn parse_bound_rejects_zero() {
-    // `0` is not a valid 1-based turn, on either end.
-    assert!(parse_bound("0").is_err());
-    assert!(parse_bound("-0").is_err());
-}
-
-#[test]
-fn parse_bound_accepts_last_compaction_and_alias() {
-    // `last-compaction` is canonical; `last` is a deprecated alias.
-    for s in ["last-compaction", "last"] {
-        assert!(
-            matches!(
-                parse_bound(s).unwrap(),
-                CliRangeBound::Resolved(RangeBound::AfterLastCompaction)
-            ),
-            "`{s}` should parse as the last-compaction marker"
-        );
-    }
-}
-
-#[test]
-fn parse_to_bound_rejects_last_compaction_but_accepts_indices() {
-    // The most-recent-compaction marker is start-only, so `--to` rejects it
-    // (canonical name and alias).
-    assert!(parse_to_bound("last-compaction").is_err());
-    assert!(parse_to_bound("last").is_err());
-    assert!(parse_to_bound("3").is_ok());
-    assert!(parse_to_bound("-1").is_ok());
-}
-
-#[test]
-fn first_and_last_are_complete_selectors() {
-    // `--first N` is the first N turns: start of conversation through turn N.
-    let first = TurnRange {
-        first: Some(3),
-        ..Default::default()
-    };
-    assert!(matches!(
-        first.cli_from_bound(),
-        Some(CliRangeBound::Resolved(RangeBound::Absolute(0)))
-    ));
-    assert!(matches!(
-        first.cli_to_bound(),
-        Some(CliRangeBound::Resolved(RangeBound::Absolute(2)))
-    ));
-
-    // `--last N` is the last N turns: N-from-the-end through the last turn.
-    let last = TurnRange {
-        last: Some(3),
-        ..Default::default()
-    };
-    assert!(matches!(
-        last.cli_from_bound(),
-        Some(CliRangeBound::Resolved(RangeBound::FromEnd(2)))
-    ));
-    assert!(matches!(
-        last.cli_to_bound(),
-        Some(CliRangeBound::Resolved(RangeBound::FromEnd(0)))
-    ));
-}
-
-#[test]
-fn first_zero_is_an_empty_selection() {
-    assert!(
-        TurnRange {
-            first: Some(0),
-            ..Default::default()
-        }
-        .is_empty()
-    );
-}
-
-#[test]
-fn parse_turn_single_and_range() {
-    assert!(matches!(parse_turn("3").unwrap(), TurnSpec::Single(3)));
-    assert!(matches!(
-        parse_turn("1..5").unwrap(),
-        TurnSpec::Range(Some(1), Some(5))
-    ));
-
-    // Open-ended ranges.
-    assert!(matches!(
-        parse_turn("10..").unwrap(),
-        TurnSpec::Range(Some(10), None)
-    ));
-    assert!(matches!(
-        parse_turn("..10").unwrap(),
-        TurnSpec::Range(None, Some(10))
-    ));
-    assert!(matches!(
-        parse_turn("..").unwrap(),
-        TurnSpec::Range(None, None)
-    ));
-
-    // 1-based: `0` is rejected wherever a number appears.
-    assert!(parse_turn("0").is_err());
-    assert!(parse_turn("0..5").is_err());
-    assert!(parse_turn("1..0").is_err());
-
-    // The separator is `..`, not `..=`.
-    assert!(parse_turn("1..=5").is_err());
-}
-
-#[test]
-fn turn_open_ended_ranges_set_both_bounds() {
-    // `--turn 10..` is turn 10 through the last turn.
-    let onward = TurnRange {
-        turn: Some(TurnSpec::Range(Some(10), None)),
-        ..Default::default()
-    };
-    assert!(matches!(
-        onward.cli_from_bound(),
-        Some(CliRangeBound::Resolved(RangeBound::Absolute(9)))
-    ));
-    assert!(matches!(
-        onward.cli_to_bound(),
-        Some(CliRangeBound::Resolved(RangeBound::FromEnd(0)))
-    ));
-
-    // `--turn ..` is the whole conversation.
-    let all = TurnRange {
-        turn: Some(TurnSpec::Range(None, None)),
-        ..Default::default()
-    };
-    assert!(matches!(
-        all.cli_from_bound(),
-        Some(CliRangeBound::Resolved(RangeBound::Absolute(0)))
-    ));
-    assert!(matches!(
-        all.cli_to_bound(),
-        Some(CliRangeBound::Resolved(RangeBound::FromEnd(0)))
-    ));
-}
-
-#[test]
-fn parse_one_based_rejects_zero() {
-    assert_eq!(parse_one_based("1").unwrap(), 1);
-    assert_eq!(parse_one_based("7").unwrap(), 7);
-    assert!(parse_one_based("0").is_err());
-    assert!(parse_one_based("x").is_err());
-}
diff --git a/crates/jp_cli/src/cmd/turn_selection.rs b/crates/jp_cli/src/cmd/turn_selection.rs
new file mode 100644
index 000000000..3c2c85da6
--- /dev/null
+++ b/crates/jp_cli/src/cmd/turn_selection.rs
@@ -0,0 +1,616 @@
+//! Shared turn selection for commands that act on a subset of a conversation's
+//! turns.
+//!
+//! [`TurnSelection`] owns the `--from`/`--to`/`--turn`/`--first`/`--last`/
+//! `--keep-first`/`--keep-last` flags and the resolution behind them, so a
+//! selection built for one command means the same thing in another.
+//!
+//! Resolution produces a [`TurnSet`]: an ordered, non-overlapping list of
+//! inclusive 0-based turn windows.
+//! Most selections are a single window; `--first N --last M` produces two,
+//! skipping the turns in between.
+//!
+//! Every bound resolves to a whole turn — a time-based bound names the turn it
+//! falls in and never splits one.
+//!
+//! Turn positions are 1-based on the CLI and 0-based in the stream; the
+//! translation happens here.
+//! See `docs/architecture/indexing-conventions.md`.
+
+use std::{str::FromStr as _, time::Duration};
+
+use chrono::{DateTime, NaiveDate, Utc};
+use jp_config::conversation::compaction::RuleBound;
+use jp_conversation::{
+    ConversationStream, RangeBound, compaction::resolve_range, stream::TurnOrigin,
+};
+
+/// A `--from`/`--to` bound before stream resolution.
+#[derive(Debug, Clone)]
+pub(crate) enum CliRangeBound {
+    /// A position, already expressed as a `RangeBound` (0-based for the core).
+    Resolved(RangeBound),
+    /// An instant — needs the stream to find the turn it falls in.
+    At(DateTime<Utc>),
+}
+
+/// Whether `s` is the most-recent-compaction marker.
+///
+/// `last-compaction` is canonical; `last` is accepted as a deprecated alias.
+fn is_last_compaction(s: &str) -> bool {
+    s.eq_ignore_ascii_case("last-compaction") || s.eq_ignore_ascii_case("last")
+}
+
+/// Parse a `--from`/`--to` bound.
+///
+/// Accepts a 1-based turn number, `-N` (offset from the end, `-1` is the last
+/// turn), a relative duration (`5h`), an RFC 3339 timestamp, a `YYYY-MM-DD`
+/// date, or `last-compaction` (the turn after the most recent compaction;
+/// `last` is accepted as a deprecated alias).
+///
+/// Integer forms are tried before the time forms, so a bare number is always a
+/// turn number: `2026` is turn 2026, never the year.
+fn parse_bound(s: &str) -> Result<CliRangeBound, String> {
+    if is_last_compaction(s) {
+        return Ok(CliRangeBound::Resolved(RangeBound::AfterLastCompaction));
+    }
+
+    // From-end offset. `-1` is the last turn, so `-N` maps to `FromEnd(N - 1)`.
+    if let Some(rest) = s.strip_prefix('-')
+        && let Ok(n) = rest.parse::<usize>()
+    {
+        if n == 0 {
+            return Err("from-end offsets are 1-based; use `-1` for the last turn".to_owned());
+        }
+        return Ok(CliRangeBound::Resolved(RangeBound::FromEnd(n - 1)));
+    }
+
+    // 1-based user index → 0-based core index.
+    if let Ok(n) = s.parse::<usize>() {
+        if n == 0 {
+            return Err("turn numbers are 1-based; `0` is not a valid turn".to_owned());
+        }
+        return Ok(CliRangeBound::Resolved(RangeBound::Absolute(n - 1)));
+    }
+
+    if let Ok(d) = humantime::Duration::from_str(s) {
+        return Ok(CliRangeBound::At(Utc::now() - Duration::from(d)));
+    }
+
+    if let Ok(dt) = DateTime::parse_from_rfc3339(s) {
+        return Ok(CliRangeBound::At(dt.with_timezone(&Utc)));
+    }
+
+    // Date-only, interpreted as midnight UTC.
+    if let Ok(date) = NaiveDate::parse_from_str(s, "%Y-%m-%d") {
+        let dt = date
+            .and_hms_opt(0, 0, 0)
+            .expect("midnight is valid")
+            .and_utc();
+        return Ok(CliRangeBound::At(dt));
+    }
+
+    Err(format!(
+        "invalid turn bound `{s}`: expected a turn number (`3`), a from-end offset (`-1`), a \
+         duration (`5h`), a date (`2026-01-01`), an RFC 3339 timestamp, or `last-compaction`"
+    ))
+}
+
+/// Like [`parse_bound`], but rejects the `last-compaction` marker.
+///
+/// `last-compaction` (the turn after the most recent compaction) is only
+/// meaningful as a start bound (`--from last-compaction`), so it is not
+/// accepted for `--to`.
+fn parse_to_bound(s: &str) -> Result<CliRangeBound, String> {
+    if is_last_compaction(s) {
+        return Err(
+            "`last-compaction` is only valid for `--from` (it marks the most recent compaction)"
+                .to_owned(),
+        );
+    }
+    parse_bound(s)
+}
+
+/// Parse a 1-based turn number for `--turn`, rejecting `0`.
+fn parse_one_based(s: &str) -> Result<usize, String> {
+    match s.parse::<usize>() {
+        Ok(0) => Err("turn numbers are 1-based; `0` is not a valid turn".to_owned()),
+        Ok(n) => Ok(n),
+        Err(_) => Err(format!("invalid turn number `{s}`")),
+    }
+}
+
+/// A `--turn` value: a single 1-based turn, or an inclusive 1-based range.
+///
+/// Either end of a range may be open: `10..` is turn 10 through the end, `..10`
+/// is the first 10 turns, and `..` is the whole conversation.
+#[derive(Debug, Clone)]
+pub(crate) enum TurnSpec {
+    /// A single turn.
+    Single(usize),
+    /// An inclusive range `from..to`.
+    /// `None` on either side is open (the start or end of the conversation).
+    Range(Option<usize>, Option<usize>),
+}
+
+/// Parse a `--turn` value: `N` (a single turn) or a range `A..B`.
+///
+/// The separator is `..` and both ends are inclusive, matching the compaction
+/// DSL (`1..5` is turns 1 through 5).
+/// Either end may be omitted: `10..`, `..10`, or `..` (all turns).
+fn parse_turn(s: &str) -> Result<TurnSpec, String> {
+    if let Some((a, b)) = s.split_once("..") {
+        let from = if a.is_empty() {
+            None
+        } else {
+            Some(parse_one_based(a)?)
+        };
+        let to = if b.is_empty() {
+            None
+        } else {
+            Some(parse_one_based(b)?)
+        };
+        return Ok(TurnSpec::Range(from, to));
+    }
+    Ok(TurnSpec::Single(parse_one_based(s)?))
+}
+
+/// The resolution of one window bound (`from` or `to`) against a stream.
+///
+/// Separates "this side is unconstrained" (so a caller with its own default for
+/// that side may fill it in) from "this bound selects no turns" (so the window
+/// is empty), which a plain `Option<RangeBound>` conflates.
+#[derive(Debug, Clone)]
+pub(crate) enum Bound {
+    /// Unconstrained; the window extends to the start (`from`) or end (`to`) of
+    /// the conversation unless a caller supplies its own default.
+    Default,
+    /// The bound resolves to a concrete `RangeBound`.
+    At(RangeBound),
+    /// The bound falls outside the conversation such that nothing is selected.
+    Empty,
+}
+
+/// One selected window, before keep-trimming, with unresolved bounds.
+#[derive(Debug, Clone)]
+pub(crate) struct BoundWindow {
+    pub from: Bound,
+    pub to: Bound,
+}
+
+/// An inclusive, 0-based range of turns.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub(crate) struct TurnWindow {
+    pub from: usize,
+    pub to: usize,
+}
+
+/// The turns a command acts on: ordered, non-overlapping, inclusive, 0-based.
+///
+/// Empty when the selection names no turn — an out-of-range bound, `--first
+/// 0`, keep flags that protect everything selected, or a conversation with no
+/// turns.
+#[derive(Debug, Clone, Default, PartialEq, Eq)]
+pub(crate) struct TurnSet(Vec<TurnWindow>);
+
+impl TurnSet {
+    /// Sort and coalesce windows so no turn is selected twice.
+    ///
+    /// Adjacent windows merge as well as overlapping ones, so `--first 2 --last
+    /// 2` on a 4-turn conversation is a single window rather than two abutting
+    /// ones.
+    fn new(mut windows: Vec<TurnWindow>) -> Self {
+        windows.sort_by_key(|w| (w.from, w.to));
+
+        let mut merged: Vec<TurnWindow> = Vec::with_capacity(windows.len());
+        for window in windows {
+            match merged.last_mut() {
+                Some(last) if window.from <= last.to.saturating_add(1) => {
+                    last.to = last.to.max(window.to);
+                }
+                _ => merged.push(window),
+            }
+        }
+        Self(merged)
+    }
+
+    /// Whether the selection names no turn at all.
+    pub(crate) fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+
+    /// The selected windows, in ascending turn order.
+    #[cfg(test)]
+    pub(crate) fn windows(&self) -> &[TurnWindow] {
+        &self.0
+    }
+
+    /// Whether the 0-based turn `index` falls in any window.
+    pub(crate) fn contains(&self, index: usize) -> bool {
+        self.0.iter().any(|w| w.from <= index && index <= w.to)
+    }
+
+    /// Whether any window overlaps the raw turns a projected turn stands for.
+    ///
+    /// A summary turn stands in for a range, so it is selected when the
+    /// selection touches any turn it replaces.
+    pub(crate) fn overlaps_origin(&self, origin: TurnOrigin) -> bool {
+        self.0.iter().any(|w| origin.overlaps(w.from, w.to))
+    }
+}
+
+/// Resolve a `--from <bound>` cutoff to a `Bound`.
+///
+/// A time bound starts the window at the first turn to *begin* after the
+/// cutoff, so `--from 5h` selects the turns started in the last five hours
+/// rather than also pulling in the older turn that was still running at the
+/// cutoff.
+/// A cutoff before the conversation starts selects from the beginning.
+fn resolve_cli_from(bound: &CliRangeBound, events: &ConversationStream) -> Bound {
+    match bound {
+        CliRangeBound::Resolved(b) => Bound::At(b.clone()),
+        CliRangeBound::At(dt) => match events.turn_at_time(*dt) {
+            Some(turn) => Bound::At(RangeBound::Absolute(turn.index() + 1)),
+            None => Bound::At(RangeBound::Absolute(0)),
+        },
+    }
+}
+
+/// Resolve a `--to <bound>` cutoff to a `Bound`.
+///
+/// A time bound ends the window at (and includes) the turn it falls in; a
+/// cutoff preceding the conversation selects nothing.
+fn resolve_cli_to(bound: &CliRangeBound, events: &ConversationStream) -> Bound {
+    match bound {
+        CliRangeBound::Resolved(b) => Bound::At(b.clone()),
+        CliRangeBound::At(dt) => match events.turn_at_time(*dt) {
+            Some(turn) => Bound::At(RangeBound::Absolute(turn.index())),
+            None => Bound::Empty,
+        },
+    }
+}
+
+/// Resolve a window's bounds to concrete turn indices.
+///
+/// `None` when either side is empty, or when the two bounds cross so the window
+/// names no turn.
+pub(crate) fn resolve_window(
+    window: &BoundWindow,
+    events: &ConversationStream,
+) -> Option<TurnWindow> {
+    let from = match &window.from {
+        Bound::Empty => return None,
+        Bound::Default => None,
+        Bound::At(b) => Some(b.clone()),
+    };
+    let to = match &window.to {
+        Bound::Empty => return None,
+        Bound::Default => None,
+        Bound::At(b) => Some(b.clone()),
+    };
+
+    resolve_range(events, from, to).map(|r| TurnWindow {
+        from: r.from_turn,
+        to: r.to_turn,
+    })
+}
+
+/// Resolve a start bound to a concrete 0-based turn index.
+///
+/// Routed through `resolve_range` so the asymmetric clamping rules for the two
+/// ends (a start past the last turn selects nothing; an end is clamped onto the
+/// last turn) are defined in exactly one place.
+fn from_index(bound: RangeBound, events: &ConversationStream) -> Option<usize> {
+    resolve_range(events, Some(bound), None).map(|r| r.from_turn)
+}
+
+/// Resolve an end bound to a concrete 0-based turn index.
+fn to_index(bound: RangeBound, events: &ConversationStream) -> Option<usize> {
+    resolve_range(events, None, Some(bound)).map(|r| r.to_turn)
+}
+
+/// Convert a `keep_first` bound to the first turn it leaves unprotected.
+pub(crate) fn keep_first_bound(bound: &RuleBound, events: &ConversationStream) -> Bound {
+    match bound {
+        // "Keep first N" means the first unprotected turn is N.
+        RuleBound::Turns(n) => Bound::At(RangeBound::Absolute(*n)),
+        // `Absolute` is the 1-based user value; the stream is 0-based.
+        RuleBound::Absolute(n) => Bound::At(RangeBound::Absolute(n.saturating_sub(1))),
+        RuleBound::FromEnd(n) => Bound::At(RangeBound::FromEnd(*n)),
+        RuleBound::Duration(d) => {
+            // Protect the opening `d` window: the first unprotected turn is the
+            // one after `conversation_start + d`. A window covering the whole
+            // conversation protects everything.
+            let Some(first) = events.iter().next() else {
+                return Bound::Empty;
+            };
+            let Ok(d) = chrono::Duration::from_std(*d) else {
+                return Bound::Empty;
+            };
+            match events.turn_at_time(first.event.timestamp + d) {
+                Some(turn) => Bound::At(RangeBound::Absolute(turn.index() + 1)),
+                None => Bound::At(RangeBound::Absolute(0)),
+            }
+        }
+        RuleBound::AfterLastCompaction => Bound::At(RangeBound::AfterLastCompaction),
+    }
+}
+
+/// Convert a `keep_last` bound to the last turn it leaves unprotected.
+pub(crate) fn keep_last_bound(bound: &RuleBound, events: &ConversationStream) -> Bound {
+    match bound {
+        // "Keep last N" means the last unprotected turn is N turns before the
+        // end.
+        RuleBound::Turns(n) | RuleBound::FromEnd(n) => Bound::At(RangeBound::FromEnd(*n)),
+        // `Absolute` is the 1-based user value; the stream is 0-based.
+        RuleBound::Absolute(n) => Bound::At(RangeBound::Absolute(n.saturating_sub(1))),
+        RuleBound::Duration(d) => {
+            // Protect the trailing `d` window. A window covering the whole
+            // conversation protects everything.
+            match events.turn_at_time(Utc::now() - *d) {
+                Some(turn) => Bound::At(RangeBound::Absolute(turn.index())),
+                None => Bound::Empty,
+            }
+        }
+        RuleBound::AfterLastCompaction => Bound::Default,
+    }
+}
+
+/// The turns a command acts on.
+///
+/// One of `--from`/`--to`, `--turn`, or `--first`/`--last` names the base
+/// selection (the whole conversation when none is given); `--keep-first` and
+/// `--keep-last` then protect turns at either end from it.
+#[derive(Debug, Clone, Default, clap::Args)]
+pub(crate) struct TurnSelection {
+    /// Select the first N turns.
+    /// Without a value, selects the first turn.
+    ///
+    /// Composes with `--last`: the pair selects the leading and trailing
+    /// windows and skips the turns in between.
+    #[arg(long, short = 'f', num_args = 0..=1, default_missing_value = "1", conflicts_with_all = ["turn", "from", "to"])]
+    first: Option<usize>,
+
+    /// Select the last N turns.
+    /// Without a value, selects the last turn.
+    ///
+    /// Composes with `--first`: the pair selects the leading and trailing
+    /// windows and skips the turns in between.
+    #[arg(long, short = 'l', num_args = 0..=1, default_missing_value = "1", conflicts_with_all = ["turn", "from", "to"])]
+    last: Option<usize>,
+
+    /// Select turns by number (1-based): a single turn (`3`), an inclusive
+    /// range (`1..5`), or an open range like `10..` (turn 10 onward), `..10`
+    /// (the first 10), or `..` (all).
+    /// Stable across new turns.
+    #[arg(long, value_parser = parse_turn, conflicts_with_all = ["first", "last", "from", "to"])]
+    turn: Option<TurnSpec>,
+
+    /// Start of the range, inclusive.
+    ///
+    /// Accepts a 1-based turn number (`3`), a from-end offset (`-1` is the last
+    /// turn), a relative duration (`5h`), a date (`2026-01-01`), an RFC 3339
+    /// timestamp, or `last-compaction` (the turn after the most recent
+    /// compaction).
+    /// A time-based value names the turn it falls in; a bound never splits a
+    /// turn.
+    // `allow_negative_numbers` keeps the from-end form usable as a
+    // space-separated value (`--from -3`), which clap would otherwise read as an
+    // unknown short flag.
+    #[arg(long, value_parser = parse_bound, allow_negative_numbers = true)]
+    from: Option<CliRangeBound>,
+
+    /// End of the range, inclusive.
+    ///
+    /// Accepts the same forms as `--from`, except `last-compaction`, which only
+    /// makes sense as a start bound.
+    #[arg(long, value_parser = parse_to_bound, allow_negative_numbers = true)]
+    to: Option<CliRangeBound>,
+
+    /// Protect the first N turns from the selection.
+    ///
+    /// Accepts a turn count (`2`), an absolute 1-based turn (`@3`), a from-end
+    /// offset (`-3`), or a duration (`5h`).
+    /// Composes with every other selector: the selection starts no earlier than
+    /// the first unprotected turn.
+    #[arg(long, allow_negative_numbers = true)]
+    keep_first: Option<RuleBound>,
+
+    /// Protect the last N turns from the selection.
+    ///
+    /// Accepts the same forms as `--keep-first`.
+    /// Composes with every other selector: the selection ends no later than the
+    /// last unprotected turn.
+    #[arg(long, allow_negative_numbers = true)]
+    keep_last: Option<RuleBound>,
+}
+
+impl TurnSelection {
+    /// Build a selection from explicit `--last`/`--turn` values.
+    #[cfg(test)]
+    pub(crate) fn from_last_turn(last: Option<usize>, turn: Option<usize>) -> Self {
+        Self {
+            last,
+            turn: turn.map(TurnSpec::Single),
+            ..Self::default()
+        }
+    }
+
+    /// Whether any selector flag is set.
+    ///
+    /// Callers use this to tell "act on the whole conversation" apart from "the
+    /// user asked for a subset", which matters where the two differ (leaving a
+    /// stream untouched instead of filtering it to the same content).
+    pub(crate) fn is_set(&self) -> bool {
+        self.first.is_some()
+            || self.last.is_some()
+            || self.turn.is_some()
+            || self.from.is_some()
+            || self.to.is_some()
+            || self.keep_first.is_some()
+            || self.keep_last.is_some()
+    }
+
+    /// The `--keep-first` bound, if set.
+    pub(crate) fn keep_first(&self) -> Option<&RuleBound> {
+        self.keep_first.as_ref()
+    }
+
+    /// The `--keep-last` bound, if set.
+    pub(crate) fn keep_last(&self) -> Option<&RuleBound> {
+        self.keep_last.as_ref()
+    }
+
+    /// Reject flag combinations clap cannot express.
+    ///
+    /// `--keep-first N --first M` selects the first M turns minus the first N,
+    /// e.g. `--keep-first 1 --first 16` selects turns 2 through 16: with N
+    /// greater than M the protected turns swallow the whole selection, so the
+    /// pair is rejected rather than silently selecting nothing.
+    /// Only count-based bounds are comparable up front; durations and the other
+    /// bound forms resolve against the stream and may legitimately come up
+    /// empty.
+    pub(crate) fn validate(&self) -> Result<(), String> {
+        if let (Some(RuleBound::Turns(keep)), Some(first)) = (&self.keep_first, self.first)
+            && *keep > first
+        {
+            return Err(format!(
+                "--keep-first {keep} is greater than --first {first}: nothing would remain to \
+                 select"
+            ));
+        }
+        if let (Some(RuleBound::Turns(keep)), Some(last)) = (&self.keep_last, self.last)
+            && *keep > last
+        {
+            return Err(format!(
+                "--keep-last {keep} is greater than --last {last}: nothing would remain to select"
+            ));
+        }
+        Ok(())
+    }
+
+    /// Reject a `--turn` endpoint outside `1..=count`.
+    ///
+    /// `--turn` names specific turns, so an endpoint past the conversation is
+    /// an error rather than a clamped selection (unlike `--first`/`--last`).
+    pub(crate) fn check_turn_range(&self, count: usize) -> Result<(), String> {
+        let oob = |n: usize| n == 0 || n > count;
+        let ends = match self.turn.as_ref() {
+            Some(TurnSpec::Single(n)) => [Some(*n), None],
+            Some(TurnSpec::Range(a, b)) => [*a, *b],
+            None => return Ok(()),
+        };
+
+        match ends.into_iter().flatten().find(|&n| oob(n)) {
+            Some(n) => Err(format!(
+                "turn {n} out of range (conversation has {count} turns)"
+            )),
+            None => Ok(()),
+        }
+    }
+
+    /// The base windows named by the positive selectors, with unresolved
+    /// bounds.
+    ///
+    /// One window for `--turn`, for `--from`/`--to`, and for no selector at all
+    /// (the whole conversation); two when `--first` and `--last` are combined.
+    /// `--first 0` and `--last 0` contribute no window.
+    ///
+    /// Keep flags are not applied here — see [`Self::trim`].
+    pub(crate) fn windows(&self, events: &ConversationStream) -> Vec<BoundWindow> {
+        if let Some(spec) = &self.turn {
+            let (from, to) = match spec {
+                TurnSpec::Single(n) => {
+                    let at = RangeBound::Absolute(n.saturating_sub(1));
+                    (at.clone(), at)
+                }
+                TurnSpec::Range(a, b) => (
+                    // Open start (`--turn ..B`) begins at the first turn.
+                    RangeBound::Absolute(a.map_or(0, |a| a.saturating_sub(1))),
+                    // Open end (`--turn A..`) runs through the last turn.
+                    b.map_or(RangeBound::FromEnd(0), |b| {
+                        RangeBound::Absolute(b.saturating_sub(1))
+                    }),
+                ),
+            };
+            return vec![BoundWindow {
+                from: Bound::At(from),
+                to: Bound::At(to),
+            }];
+        }
+
+        if self.first.is_some() || self.last.is_some() {
+            let mut windows = Vec::with_capacity(2);
+            if let Some(n) = self.first.filter(|n| *n > 0) {
+                windows.push(BoundWindow {
+                    from: Bound::At(RangeBound::Absolute(0)),
+                    to: Bound::At(RangeBound::Absolute(n - 1)),
+                });
+            }
+            if let Some(n) = self.last.filter(|n| *n > 0) {
+                windows.push(BoundWindow {
+                    from: Bound::At(RangeBound::FromEnd(n - 1)),
+                    to: Bound::At(RangeBound::FromEnd(0)),
+                });
+            }
+            return windows;
+        }
+
+        let from = match &self.from {
+            Some(bound) => resolve_cli_from(bound, events),
+            None => Bound::Default,
+        };
+        let to = match &self.to {
+            Some(bound) => resolve_cli_to(bound, events),
+            None => Bound::Default,
+        };
+        vec![BoundWindow { from, to }]
+    }
+
+    /// Narrow a resolved window to the turns the keep flags leave unprotected.
+    ///
+    /// Returns `None` when the protected turns cover the whole window.
+    /// The keep flags clamp rather than shift: turns already outside the window
+    /// need no protecting, so `--keep-first 1 --from 3` still starts at turn 3.
+    pub(crate) fn trim(
+        &self,
+        window: TurnWindow,
+        events: &ConversationStream,
+    ) -> Option<TurnWindow> {
+        let mut from = window.from;
+        let mut to = window.to;
+
+        if let Some(bound) = &self.keep_first {
+            match keep_first_bound(bound, events) {
+                Bound::Empty => return None,
+                Bound::Default => {}
+                Bound::At(b) => from = from.max(from_index(b, events)?),
+            }
+        }
+        if let Some(bound) = &self.keep_last {
+            match keep_last_bound(bound, events) {
+                Bound::Empty => return None,
+                Bound::Default => {}
+                Bound::At(b) => to = to.min(to_index(b, events)?),
+            }
+        }
+
+        (from <= to).then_some(TurnWindow { from, to })
+    }
+
+    /// Resolve the selection against `events`.
+    pub(crate) fn resolve(&self, events: &ConversationStream) -> TurnSet {
+        let windows = self
+            .windows(events)
+            .into_iter()
+            .filter_map(|window| resolve_window(&window, events))
+            .filter_map(|window| self.trim(window, events))
+            .collect();
+
+        TurnSet::new(windows)
+    }
+}
+
+#[cfg(test)]
+#[path = "turn_selection_tests.rs"]
+mod tests;
diff --git a/crates/jp_cli/src/cmd/turn_selection_tests.rs b/crates/jp_cli/src/cmd/turn_selection_tests.rs
new file mode 100644
index 000000000..88ae2ce15
--- /dev/null
+++ b/crates/jp_cli/src/cmd/turn_selection_tests.rs
@@ -0,0 +1,549 @@
+use chrono::{TimeZone as _, Utc};
+use jp_conversation::{ConversationEvent, ConversationStream, RangeBound, event::ChatRequest};
+
+use super::*;
+
+/// A stream with `count` turns, one minute apart, starting at 2020-01-01
+/// 00:00:00 UTC.
+fn stream(count: usize) -> ConversationStream {
+    let mut stream = ConversationStream::new_test();
+    let mut events = Vec::new();
+    for turn in 0..count {
+        let ts = Utc
+            .with_ymd_and_hms(2020, 1, 1, 0, u32::try_from(turn).unwrap(), 0)
+            .unwrap();
+        events.push(ConversationEvent::new(
+            jp_conversation::event::TurnStart,
+            ts,
+        ));
+        events.push(ConversationEvent::new(
+            ChatRequest::from(format!("Q{turn}")),
+            ts,
+        ));
+    }
+    stream.extend(events);
+    stream
+}
+
+fn windows(selection: &TurnSelection, count: usize) -> Vec<(usize, usize)> {
+    selection
+        .resolve(&stream(count))
+        .windows()
+        .iter()
+        .map(|w| (w.from, w.to))
+        .collect()
+}
+
+#[test]
+fn parse_bound_absolute_is_one_based() {
+    // `1` is the first turn (0-based `Absolute(0)` internally).
+    assert!(matches!(
+        parse_bound("1").unwrap(),
+        CliRangeBound::Resolved(RangeBound::Absolute(0))
+    ));
+    assert!(matches!(
+        parse_bound("5").unwrap(),
+        CliRangeBound::Resolved(RangeBound::Absolute(4))
+    ));
+}
+
+#[test]
+fn parse_bound_from_end_is_one_based() {
+    // `-1` is the last turn (0-based `FromEnd(0)` internally).
+    assert!(matches!(
+        parse_bound("-1").unwrap(),
+        CliRangeBound::Resolved(RangeBound::FromEnd(0))
+    ));
+    assert!(matches!(
+        parse_bound("-3").unwrap(),
+        CliRangeBound::Resolved(RangeBound::FromEnd(2))
+    ));
+}
+
+#[test]
+fn parse_bound_rejects_zero() {
+    // `0` is not a valid 1-based turn, on either end.
+    assert!(parse_bound("0").is_err());
+    assert!(parse_bound("-0").is_err());
+}
+
+#[test]
+fn parse_bound_accepts_last_compaction_and_alias() {
+    // `last-compaction` is canonical; `last` is a deprecated alias.
+    for s in ["last-compaction", "last"] {
+        assert!(
+            matches!(
+                parse_bound(s).unwrap(),
+                CliRangeBound::Resolved(RangeBound::AfterLastCompaction)
+            ),
+            "`{s}` should parse as the last-compaction marker"
+        );
+    }
+}
+
+#[test]
+fn parse_bound_accepts_relative_and_absolute_times() {
+    assert!(matches!(parse_bound("5h").unwrap(), CliRangeBound::At(_)));
+    assert!(matches!(
+        parse_bound("2days").unwrap(),
+        CliRangeBound::At(_)
+    ));
+
+    let date = parse_bound("2026-01-01").unwrap();
+    let CliRangeBound::At(dt) = date else {
+        panic!("a date must parse as an instant");
+    };
+    assert_eq!(dt, Utc.with_ymd_and_hms(2026, 1, 1, 0, 0, 0).unwrap());
+
+    let rfc3339 = parse_bound("2026-01-01T12:30:00Z").unwrap();
+    let CliRangeBound::At(dt) = rfc3339 else {
+        panic!("an RFC 3339 timestamp must parse as an instant");
+    };
+    assert_eq!(dt, Utc.with_ymd_and_hms(2026, 1, 1, 12, 30, 0).unwrap());
+}
+
+#[test]
+fn parse_bound_reads_a_bare_integer_as_a_turn_not_a_year() {
+    // A four-digit number is ambiguous to a human but never a date here: the
+    // accepted date formats all require separators, so integers stay turns.
+    assert!(matches!(
+        parse_bound("2026").unwrap(),
+        CliRangeBound::Resolved(RangeBound::Absolute(2025))
+    ));
+}
+
+#[test]
+fn parse_bound_rejects_unparseable_values() {
+    assert!(parse_bound("nonsense").is_err());
+    assert!(parse_bound("2026-13-01").is_err());
+}
+
+#[test]
+fn parse_to_bound_rejects_last_compaction_but_accepts_other_forms() {
+    // The most-recent-compaction marker is start-only, so `--to` rejects it
+    // (canonical name and alias).
+    assert!(parse_to_bound("last-compaction").is_err());
+    assert!(parse_to_bound("last").is_err());
+    assert!(parse_to_bound("3").is_ok());
+    assert!(parse_to_bound("-1").is_ok());
+    assert!(parse_to_bound("2026-01-01").is_ok());
+}
+
+#[test]
+fn parse_turn_single_and_range() {
+    assert!(matches!(parse_turn("3").unwrap(), TurnSpec::Single(3)));
+    assert!(matches!(
+        parse_turn("1..5").unwrap(),
+        TurnSpec::Range(Some(1), Some(5))
+    ));
+
+    // Open-ended ranges.
+    assert!(matches!(
+        parse_turn("10..").unwrap(),
+        TurnSpec::Range(Some(10), None)
+    ));
+    assert!(matches!(
+        parse_turn("..10").unwrap(),
+        TurnSpec::Range(None, Some(10))
+    ));
+    assert!(matches!(
+        parse_turn("..").unwrap(),
+        TurnSpec::Range(None, None)
+    ));
+
+    // 1-based: `0` is rejected wherever a number appears.
+    assert!(parse_turn("0").is_err());
+    assert!(parse_turn("0..5").is_err());
+    assert!(parse_turn("1..0").is_err());
+
+    // The separator is `..`, not `..=`.
+    assert!(parse_turn("1..=5").is_err());
+}
+
+#[test]
+fn parse_one_based_rejects_zero() {
+    assert_eq!(parse_one_based("1").unwrap(), 1);
+    assert_eq!(parse_one_based("7").unwrap(), 7);
+    assert!(parse_one_based("0").is_err());
+    assert!(parse_one_based("x").is_err());
+}
+
+/// Parse a selection from CLI arguments.
+fn parse(args: &[&str]) -> Result<TurnSelection, clap::Error> {
+    #[derive(clap::Parser)]
+    struct TestCli {
+        #[command(flatten)]
+        selection: TurnSelection,
+    }
+
+    let mut argv = vec!["test"];
+    argv.extend_from_slice(args);
+    clap::Parser::try_parse_from(argv).map(|cli: TestCli| cli.selection)
+}
+
+#[test]
+fn clap_accepts_from_end_offsets_as_separate_values() {
+    // Without `allow_negative_numbers`, clap reads `-1` as an unknown short flag
+    // rather than as the value of the preceding option.
+    for args in [
+        &["--to", "-1"][..],
+        &["--to=-1"][..],
+        &["--from", "-3"][..],
+        &["--keep-last", "-2"][..],
+    ] {
+        assert!(parse(args).is_ok(), "{args:?} should parse");
+    }
+}
+
+#[test]
+fn clap_conflicts_the_three_ways_of_naming_a_base_range() {
+    for args in [
+        &["--turn", "3", "--first", "2"][..],
+        &["--turn", "3", "--from", "2"][..],
+        &["--first", "2", "--from", "2"][..],
+        &["--last", "2", "--to", "2"][..],
+    ] {
+        assert!(parse(args).is_err(), "{args:?} should conflict");
+    }
+}
+
+#[test]
+fn clap_composes_first_with_last_and_keep_with_everything() {
+    for args in [
+        &["--first", "2", "--last", "2"][..],
+        &["--first", "2", "--keep-first", "1"][..],
+        &["--turn", "1..5", "--keep-last", "1"][..],
+        &["--from", "2", "--keep-first", "1", "--keep-last", "1"][..],
+    ] {
+        assert!(parse(args).is_ok(), "{args:?} should compose");
+    }
+}
+
+#[test]
+fn clap_accepts_short_first_and_last() {
+    assert!(parse(&["-f", "2", "-l", "3"]).is_ok());
+    // Bare `-f` / `-l` default to one turn.
+    let selection = parse(&["-f"]).unwrap();
+    assert_eq!(windows(&selection, 5), vec![(0, 0)]);
+}
+
+#[test]
+fn no_selector_selects_every_turn() {
+    assert_eq!(windows(&TurnSelection::default(), 5), vec![(0, 4)]);
+}
+
+#[test]
+fn no_selector_on_an_empty_conversation_selects_nothing() {
+    assert!(TurnSelection::default().resolve(&stream(0)).is_empty());
+}
+
+#[test]
+fn first_and_last_are_separate_windows() {
+    let selection = TurnSelection {
+        first: Some(1),
+        last: Some(2),
+        ..Default::default()
+    };
+
+    // 6 turns: keep turn 1 and turns 5-6, skipping 2-4.
+    assert_eq!(windows(&selection, 6), vec![(0, 0), (4, 5)]);
+}
+
+#[test]
+fn abutting_first_and_last_windows_merge() {
+    let selection = TurnSelection {
+        first: Some(2),
+        last: Some(2),
+        ..Default::default()
+    };
+
+    // 4 turns: the two windows meet, so the whole conversation is one window.
+    assert_eq!(windows(&selection, 4), vec![(0, 3)]);
+    // 3 turns: they overlap on the middle turn; still one window, no duplicate.
+    assert_eq!(windows(&selection, 3), vec![(0, 2)]);
+}
+
+#[test]
+fn first_alone_selects_a_leading_window() {
+    assert_eq!(
+        windows(
+            &TurnSelection {
+                first: Some(3),
+                ..Default::default()
+            },
+            6
+        ),
+        vec![(0, 2)]
+    );
+}
+
+#[test]
+fn last_alone_selects_a_trailing_window() {
+    assert_eq!(
+        windows(
+            &TurnSelection {
+                last: Some(3),
+                ..Default::default()
+            },
+            6
+        ),
+        vec![(3, 5)]
+    );
+}
+
+#[test]
+fn zero_count_selects_nothing() {
+    for selection in [
+        TurnSelection {
+            first: Some(0),
+            ..Default::default()
+        },
+        TurnSelection {
+            last: Some(0),
+            ..Default::default()
+        },
+    ] {
+        assert!(selection.resolve(&stream(5)).is_empty());
+    }
+}
+
+#[test]
+fn zero_count_on_one_side_leaves_the_other_window() {
+    // `--first 0 --last 2` is the union of an empty window and the last two
+    // turns, so only the trailing window survives.
+    let selection = TurnSelection {
+        first: Some(0),
+        last: Some(2),
+        ..Default::default()
+    };
+    assert_eq!(windows(&selection, 5), vec![(3, 4)]);
+}
+
+#[test]
+fn turn_open_ended_ranges_cover_both_ends() {
+    // `--turn 3..` is turn 3 through the last turn.
+    let onward = TurnSelection {
+        turn: Some(TurnSpec::Range(Some(3), None)),
+        ..Default::default()
+    };
+    assert_eq!(windows(&onward, 5), vec![(2, 4)]);
+
+    // `--turn ..3` is the first three turns.
+    let up_to = TurnSelection {
+        turn: Some(TurnSpec::Range(None, Some(3))),
+        ..Default::default()
+    };
+    assert_eq!(windows(&up_to, 5), vec![(0, 2)]);
+
+    // `--turn ..` is the whole conversation.
+    let all = TurnSelection {
+        turn: Some(TurnSpec::Range(None, None)),
+        ..Default::default()
+    };
+    assert_eq!(windows(&all, 5), vec![(0, 4)]);
+}
+
+#[test]
+fn from_and_to_are_inclusive_on_both_ends() {
+    let selection = TurnSelection {
+        from: Some(parse_bound("2").unwrap()),
+        to: Some(parse_bound("4").unwrap()),
+        ..Default::default()
+    };
+
+    // `--from 2 --to 4` is three turns, matching `--turn 2..4`.
+    assert_eq!(windows(&selection, 6), vec![(1, 3)]);
+}
+
+#[test]
+fn to_minus_one_is_the_last_turn() {
+    let selection = TurnSelection {
+        from: Some(parse_bound("3").unwrap()),
+        to: Some(parse_bound("-1").unwrap()),
+        ..Default::default()
+    };
+    assert_eq!(windows(&selection, 5), vec![(2, 4)]);
+}
+
+#[test]
+fn an_absolute_date_bound_names_a_whole_turn() {
+    // Turns run 00:00, 00:01, ... 00:04. A `--to` cutoff mid-conversation ends
+    // the selection at the turn active then, never inside it.
+    let selection = TurnSelection {
+        to: Some(parse_to_bound("2020-01-01T00:02:30Z").unwrap()),
+        ..Default::default()
+    };
+    assert_eq!(windows(&selection, 5), vec![(0, 2)]);
+}
+
+#[test]
+fn a_from_time_bound_starts_at_the_next_turn_to_begin() {
+    // The turn active at 00:02:30 started before the cutoff, so `--from` starts
+    // at turn 4 (index 3) — the first turn to begin after it.
+    let selection = TurnSelection {
+        from: Some(parse_bound("2020-01-01T00:02:30Z").unwrap()),
+        ..Default::default()
+    };
+    assert_eq!(windows(&selection, 5), vec![(3, 4)]);
+}
+
+#[test]
+fn a_to_cutoff_before_the_conversation_selects_nothing() {
+    let selection = TurnSelection {
+        to: Some(parse_to_bound("2019-01-01").unwrap()),
+        ..Default::default()
+    };
+    assert!(selection.resolve(&stream(5)).is_empty());
+}
+
+#[test]
+fn keep_first_protects_the_leading_turns() {
+    let selection = TurnSelection {
+        keep_first: Some(RuleBound::Turns(2)),
+        ..Default::default()
+    };
+    assert_eq!(windows(&selection, 5), vec![(2, 4)]);
+}
+
+#[test]
+fn keep_last_protects_the_trailing_turns() {
+    let selection = TurnSelection {
+        keep_last: Some(RuleBound::Turns(2)),
+        ..Default::default()
+    };
+    assert_eq!(windows(&selection, 5), vec![(0, 2)]);
+}
+
+#[test]
+fn keep_flags_narrow_a_first_window() {
+    // `--keep-first 1 --first 4` selects turns 2 through 4.
+    let selection = TurnSelection {
+        first: Some(4),
+        keep_first: Some(RuleBound::Turns(1)),
+        ..Default::default()
+    };
+    assert_eq!(windows(&selection, 8), vec![(1, 3)]);
+}
+
+#[test]
+fn keep_flags_narrow_a_last_window() {
+    // `--keep-last 2 --last 4` selects the two turns before the final two.
+    let selection = TurnSelection {
+        last: Some(4),
+        keep_last: Some(RuleBound::Turns(2)),
+        ..Default::default()
+    };
+    assert_eq!(windows(&selection, 8), vec![(4, 5)]);
+}
+
+#[test]
+fn keep_first_clamps_rather_than_shifts_an_explicit_range() {
+    // Turn 1 is already outside `--from 3`, so nothing needs protecting and the
+    // window is unchanged. A shifting trim would wrongly start at turn 4.
+    let selection = TurnSelection {
+        from: Some(parse_bound("3").unwrap()),
+        keep_first: Some(RuleBound::Turns(1)),
+        ..Default::default()
+    };
+    assert_eq!(windows(&selection, 6), vec![(2, 5)]);
+}
+
+#[test]
+fn keep_flags_apply_to_every_window() {
+    let selection = TurnSelection {
+        first: Some(3),
+        last: Some(3),
+        keep_first: Some(RuleBound::Turns(1)),
+        keep_last: Some(RuleBound::Turns(1)),
+        ..Default::default()
+    };
+
+    // 10 turns: leading window 1-3 loses turn 1, trailing window 8-10 loses
+    // turn 10.
+    assert_eq!(windows(&selection, 10), vec![(1, 2), (7, 8)]);
+}
+
+#[test]
+fn keep_flags_covering_the_selection_select_nothing() {
+    let selection = TurnSelection {
+        keep_first: Some(RuleBound::Turns(3)),
+        keep_last: Some(RuleBound::Turns(3)),
+        ..Default::default()
+    };
+    assert!(selection.resolve(&stream(4)).is_empty());
+}
+
+#[test]
+fn validate_rejects_a_keep_that_swallows_the_selection() {
+    let selection = TurnSelection {
+        first: Some(1),
+        keep_first: Some(RuleBound::Turns(2)),
+        ..Default::default()
+    };
+    assert!(selection.validate().is_err());
+
+    let selection = TurnSelection {
+        last: Some(1),
+        keep_last: Some(RuleBound::Turns(2)),
+        ..Default::default()
+    };
+    assert!(selection.validate().is_err());
+
+    // Equal counts are allowed: the selection is empty but not contradictory.
+    let selection = TurnSelection {
+        first: Some(2),
+        keep_first: Some(RuleBound::Turns(2)),
+        ..Default::default()
+    };
+    assert!(selection.validate().is_ok());
+}
+
+#[test]
+fn check_turn_range_rejects_endpoints_past_the_conversation() {
+    let selection = TurnSelection {
+        turn: Some(TurnSpec::Single(7)),
+        ..Default::default()
+    };
+    assert!(selection.check_turn_range(5).is_err());
+    assert!(selection.check_turn_range(7).is_ok());
+
+    let selection = TurnSelection {
+        turn: Some(TurnSpec::Range(Some(2), Some(9))),
+        ..Default::default()
+    };
+    assert!(selection.check_turn_range(5).is_err());
+
+    // Counts clamp instead of erroring, so `--first` is never out of range.
+    let selection = TurnSelection {
+        first: Some(99),
+        ..Default::default()
+    };
+    assert!(selection.check_turn_range(5).is_ok());
+}
+
+#[test]
+fn is_set_reports_whether_the_user_named_a_subset() {
+    assert!(!TurnSelection::default().is_set());
+    assert!(
+        TurnSelection {
+            keep_last: Some(RuleBound::Turns(1)),
+            ..Default::default()
+        }
+        .is_set()
+    );
+}
+
+#[test]
+fn turn_set_contains_only_selected_turns() {
+    let selection = TurnSelection {
+        first: Some(1),
+        last: Some(1),
+        ..Default::default()
+    };
+    let set = selection.resolve(&stream(4));
+
+    assert!(set.contains(0));
+    assert!(!set.contains(1));
+    assert!(!set.contains(2));
+    assert!(set.contains(3));
+}
diff --git a/crates/jp_conversation/src/stream.rs b/crates/jp_conversation/src/stream.rs
index 471c07bf6..c512e8d0f 100644
--- a/crates/jp_conversation/src/stream.rs
+++ b/crates/jp_conversation/src/stream.rs
@@ -1075,76 +1075,28 @@ impl ConversationStream {
         });
     }
 
-    /// Retain only the first `n` turns, dropping later ones.
-    ///
-    /// Mirrors [`Self::retain_last_turns`] for the leading end of the stream.
-    /// A turn is delimited by a [`TurnStart`] event.
-    /// If there are `n` or fewer turns, the stream is left unchanged.
-    ///
-    /// The kept turns keep their indices.
-    /// A [`Compaction`] overlay confined to them survives; [`Self::retain`]
-    /// drops overlays that reach into the dropped trailing turns.
-    ///
-    /// [`TurnStart`]: crate::event::TurnStart
-    pub fn retain_first_turns(&mut self, n: usize) {
-        if n == 0 {
-            self.retain(|_| false);
-            return;
-        }
-
-        let turn_count = self
-            .events
-            .iter()
-            .filter(|e| matches!(e, InternalEvent::Event(ev) if ev.is_turn_start()))
-            .count();
-
-        if turn_count <= n {
-            return;
-        }
-
-        let mut turns_seen = 0;
-        let mut keeping = false;
-
-        self.retain(|event| {
-            if event.is_turn_start() {
-                turns_seen += 1;
-                keeping = turns_seen <= n;
-            }
-            keeping
-        });
-    }
-
-    /// Retain only the first `first` turns and the last `last` turns, dropping
-    /// the turns in between.
-    ///
-    /// A turn is delimited by a [`TurnStart`] event.
-    /// If `first + last` is greater than or equal to the total number of turns,
-    /// the stream is left unchanged.
-    ///
-    /// Dropping the middle turns renumbers the trailing block; [`Self::retain`]
-    /// drops [`Compaction`] overlays from the first dropped turn onward, while
-    /// overlays confined to the kept leading block survive.
-    ///
-    /// [`TurnStart`]: crate::event::TurnStart
-    pub fn retain_first_and_last_turns(&mut self, first: usize, last: usize) {
-        let turn_count = self
-            .events
-            .iter()
-            .filter(|e| matches!(e, InternalEvent::Event(ev) if ev.is_turn_start()))
-            .count();
-
-        if first.saturating_add(last) >= turn_count && turn_count > 0 {
+    /// Retain only the turns whose 0-based index satisfies `keep`, dropping the
+    /// rest.
+    ///
+    /// Indices are the stream's numbering *before* any removal, so a predicate
+    /// built from resolved turn positions selects the turns the caller meant.
+    /// A predicate that keeps every turn leaves the stream untouched.
+    ///
+    /// Dropping turns renumbers the survivors; [`Self::retain`] drops any
+    /// [`Compaction`] overlay reaching into a removed turn, while an overlay
+    /// confined to an untouched leading block survives.
+    pub fn retain_turns(&mut self, keep: impl Fn(usize) -> bool) {
+        if (0..self.turn_count()).all(&keep) {
             return;
         }
 
-        let last_start = turn_count.saturating_sub(last);
-        let mut turns_seen = 0;
+        let mut index = 0;
         let mut keeping = false;
 
         self.retain(|event| {
             if event.is_turn_start() {
-                turns_seen += 1;
-                keeping = turns_seen <= first || turns_seen > last_start;
+                keeping = keep(index);
+                index += 1;
             }
             keeping
         });
diff --git a/crates/jp_conversation/src/stream/turn_iter_tests.rs b/crates/jp_conversation/src/stream/turn_iter_tests.rs
index d0576b4ca..ceeae8b00 100644
--- a/crates/jp_conversation/src/stream/turn_iter_tests.rs
+++ b/crates/jp_conversation/src/stream/turn_iter_tests.rs
@@ -189,7 +189,7 @@ fn retain_last_turns_zero_clears() {
 }
 
 #[test]
-fn retain_first_turns_keeps_first_n() {
+fn retain_turns_keeps_a_leading_window() {
     let mut stream = ConversationStream::new_test();
     stream.extend(vec![
         ConversationEvent::new(TurnStart, ts(0, 0, 0)),
@@ -202,7 +202,7 @@ fn retain_first_turns_keeps_first_n() {
         ConversationEvent::new(ChatRequest::from("Q3"), ts(0, 2, 1)),
     ]);
 
-    stream.retain_first_turns(1);
+    stream.retain_turns(|index| index == 0);
 
     let turns: Vec<_> = stream.iter_turns().collect();
     assert_eq!(turns.len(), 1);
@@ -214,33 +214,7 @@ fn retain_first_turns_keeps_first_n() {
 }
 
 #[test]
-fn retain_first_turns_noop_when_fewer_turns() {
-    let mut stream = ConversationStream::new_test();
-    stream.extend(vec![
-        ConversationEvent::new(TurnStart, ts(0, 0, 0)),
-        ConversationEvent::new(ChatRequest::from("Q1"), ts(0, 0, 1)),
-    ]);
-
-    stream.retain_first_turns(5);
-
-    assert_eq!(stream.iter_turns().len(), 1);
-}
-
-#[test]
-fn retain_first_turns_zero_clears() {
-    let mut stream = ConversationStream::new_test();
-    stream.extend(vec![
-        ConversationEvent::new(TurnStart, ts(0, 0, 0)),
-        ConversationEvent::new(ChatRequest::from("Q1"), ts(0, 0, 1)),
-    ]);
-
-    stream.retain_first_turns(0);
-
-    assert_eq!(stream.iter_turns().len(), 0);
-}
-
-#[test]
-fn retain_first_and_last_turns_keeps_both_windows() {
+fn retain_turns_keeps_two_windows() {
     let mut stream = ConversationStream::new_test();
     stream.extend(vec![
         ConversationEvent::new(TurnStart, ts(0, 0, 0)),
@@ -253,8 +227,8 @@ fn retain_first_and_last_turns_keeps_both_windows() {
         ConversationEvent::new(ChatRequest::from("Q4"), ts(0, 3, 1)),
     ]);
 
-    // 4 turns, keep first 1 + last 2 — drop turn 2.
-    stream.retain_first_and_last_turns(1, 2);
+    // Keep the first turn and the last two, dropping turn 2.
+    stream.retain_turns(|index| index == 0 || index >= 2);
 
     let requests: Vec<_> = stream
         .iter()
@@ -265,25 +239,20 @@ fn retain_first_and_last_turns_keeps_both_windows() {
 }
 
 #[test]
-fn retain_first_and_last_turns_noop_when_fits() {
+fn retain_turns_noop_when_every_turn_is_kept() {
     let mut stream = ConversationStream::new_test();
     stream.extend(vec![
         ConversationEvent::new(TurnStart, ts(0, 0, 0)),
         ConversationEvent::new(ChatRequest::from("Q1"), ts(0, 0, 1)),
-        ConversationEvent::new(TurnStart, ts(0, 1, 0)),
-        ConversationEvent::new(ChatRequest::from("Q2"), ts(0, 1, 1)),
-        ConversationEvent::new(TurnStart, ts(0, 2, 0)),
-        ConversationEvent::new(ChatRequest::from("Q3"), ts(0, 2, 1)),
     ]);
 
-    // 3 turns; first 2 + last 2 = 4 >= 3, no-op.
-    stream.retain_first_and_last_turns(2, 2);
+    stream.retain_turns(|index| index < 5);
 
-    assert_eq!(stream.iter_turns().len(), 3);
+    assert_eq!(stream.iter_turns().len(), 1);
 }
 
 #[test]
-fn retain_first_and_last_turns_zero_zero_clears() {
+fn retain_turns_keeping_nothing_clears() {
     let mut stream = ConversationStream::new_test();
     stream.extend(vec![
         ConversationEvent::new(TurnStart, ts(0, 0, 0)),
@@ -292,7 +261,7 @@ fn retain_first_and_last_turns_zero_zero_clears() {
         ConversationEvent::new(ChatRequest::from("Q2"), ts(0, 1, 1)),
     ]);
 
-    stream.retain_first_and_last_turns(0, 0);
+    stream.retain_turns(|_| false);
 
     assert_eq!(stream.iter_turns().len(), 0);
 }
diff --git a/crates/jp_conversation/src/stream_tests.rs b/crates/jp_conversation/src/stream_tests.rs
index 42b39a447..4d2b6b96e 100644
--- a/crates/jp_conversation/src/stream_tests.rs
+++ b/crates/jp_conversation/src/stream_tests.rs
@@ -1105,7 +1105,7 @@ fn test_retain_removing_within_turn_event_drops_compactions() {
 }
 
 #[test]
-fn test_retain_first_turns_drops_compactions() {
+fn test_retain_turns_drops_compactions() {
     let mut stream = ConversationStream::new_test();
     for t in 0..6 {
         stream.start_turn(format!("turn {t}"));
@@ -1114,7 +1114,7 @@ fn test_retain_first_turns_drops_compactions() {
     // summary text covers turns the fork no longer has.
     stream.add_compaction(make_compaction(0, 5));
 
-    stream.retain_first_turns(2);
+    stream.retain_turns(|index| index < 2);
 
     assert_eq!(stream.turn_count(), 2);
     assert_eq!(
@@ -1135,7 +1135,7 @@ fn test_retain_keeps_compactions_entirely_before_removal() {
 
     // `--first 4` drops turns 4-5; turns 0-1 are untouched and not renumbered,
     // so the overlay over them keeps valid anchors and survives.
-    stream.retain_first_turns(4);
+    stream.retain_turns(|index| index < 4);
 
     assert_eq!(stream.turn_count(), 4);
     let compactions: Vec<_> = stream.compactions().collect();
@@ -1148,7 +1148,7 @@ fn test_retain_keeps_compactions_entirely_before_removal() {
 }
 
 #[test]
-fn test_retain_first_and_last_keeps_leading_block_compaction() {
+fn test_retain_turns_two_windows_keeps_leading_block_compaction() {
     let mut stream = ConversationStream::new_test();
     for t in 0..8 {
         stream.start_turn(format!("turn {t}"));
@@ -1158,7 +1158,7 @@ fn test_retain_first_and_last_keeps_leading_block_compaction() {
     stream.add_compaction(make_compaction(3, 6));
 
     // Keep first 3 and last 2 turns, dropping the middle (turns 3-5).
-    stream.retain_first_and_last_turns(3, 2);
+    stream.retain_turns(|index| !(3..6).contains(&index));
 
     let compactions: Vec<_> = stream.compactions().collect();
     assert_eq!(
diff --git a/docs/architecture/indexing-conventions.md b/docs/architecture/indexing-conventions.md
index 9b750d622..498f2535e 100644
--- a/docs/architecture/indexing-conventions.md
+++ b/docs/architecture/indexing-conventions.md
@@ -39,7 +39,7 @@ A *count* — "how many turns" — is base-independent and is never shifted.
 | Position (absolute) | `--turn N`, `--from N`, `--to N`, DSL `N..M`, config `keep_first = "@N"`                                | yes, `N` (1-based) → `N - 1` (0-based)               |
 | Position (from end) | `--from -N`, `--to -N`                                                                                  | yes, `-1` is the last turn (`-N` → `FromEnd(N - 1)`) |
 | Count               | `--first N`, `--last N`, `--keep-first N`, `--keep-last N`, config `keep_first = N`, DSL `-N` shorthand | no                                                   |
-| Duration            | `5h`, `2days`                                                                                           | n/a (resolved against timestamps)                    |
+| Time                | `5h`, `2days`, `2026-01-01`, RFC 3339                                                                   | resolved against timestamps, then snapped to a turn  |
 
 Two consequences worth calling out:
 
@@ -53,6 +53,10 @@ Two consequences worth calling out:
   meaning.
   Only the DSL's absolute bounds (`5..`) are positions and are 1-based.
 
+- A bare integer in a position slot is always a turn number, never a year.
+  The accepted date formats all require separators, so `--from 2026` is turn
+  2026 and `--from 2026-01-01` is the date.
+
 - Ranges are written `A..B` and are **inclusive on both ends** — `1..5` is
   turns 1 through 5 (five turns).
   This one format is shared by `--turn A..B`, the compaction DSL, and the
@@ -62,24 +66,45 @@ Two consequences worth calling out:
   Note this diverges from Rust's `..` (which is exclusive); there is no `..=`
   form.
 
+## A bound never splits a turn
+
+Every position form resolves to a whole turn, including the time-based ones.
+A time value is an *addressing mode for a turn*, not a cut point inside one:
+`--from <time>` starts at the first turn to begin after the cutoff, and `--to
+<time>` ends at (and includes) the turn that was running at the cutoff.
+
+This is why the range ends are inclusive rather than half-open.
+Half-open reads well for a continuous coordinate, but once a bound names a turn,
+"which turn" is inherently inclusive.
+The conversation-creation filter on `jp c rm` / `jp c archive` / `jp c use` is
+the opposite case — it compares raw timestamps and never snaps to anything —
+so it is half-open and uses distinct flag names (`--created-since` /
+`--created-before`).
+
 ## Where the translation lives
 
-- **CLI `--from`/`--to`/`--first`/`--last`/`--turn`**
-  (`jp_cli::cmd::turn_range`): `parse_bound` maps a 1-based absolute `N` to
-  `RangeBound::Absolute(N - 1)` and a from-end `-N` to `RangeBound::FromEnd(N -
-  1)`.
-  `--first`/`--last`/`--turn` are complete selectors that set both bounds:
-  `--turn N` is `Absolute(N - 1)` on both ends (`--turn A..B` spans \`Absolute(A
-
-  - 1\)`through`Absolute(B - 1)` ),  `--first
-    N`is`Absolute(0)`through`Absolute(N - 1)` , and  `--last N`is`FromEnd(N -
-    1)\` through the last turn.
-
-- **Config `keep_first`/`keep_last` and the inline DSL**
-  (`jp_cli::cmd::conversation::compact`): `keep_first_to_bound` /
-  `keep_last_to_bound` map `RuleBound::Absolute(N)` (the 1-based value parsed
-  from `@N`) to `RangeBound::Absolute(N - 1)`.
-  The `RuleBound::Turns(N)` (count) arm is untouched.
+- **CLI turn selection** (`jp_cli::cmd::turn_selection`): `parse_bound` maps a
+  1-based absolute `N` to `RangeBound::Absolute(N - 1)` and a from-end `-N` to
+  `RangeBound::FromEnd(N - 1)`.
+  `TurnSelection::resolve` then resolves every bound against the stream and
+  produces a `TurnSet` of inclusive 0-based windows.
+
+  `--turn`, `--from`/`--to`, and `--first`/`--last` are three ways of naming the
+  base selection and are mutually exclusive.
+  `--turn N` is `Absolute(N - 1)` on both ends; `--turn A..B` spans \`Absolute(A
+
+  - 1\)`through`Absolute(B - 1)` ;  `--first N`is`Absolute(0)`through`Absolute(N
+    - 1)` ;  `--last N`is`FromEnd(N - 1)`through the last
+    turn.`--first`and`--last\` given together produce two windows and skip the
+    turns between them.
+
+- **Keep flags** (`jp_cli::cmd::turn_selection`): `keep_first_bound` /
+  `keep_last_bound` map `RuleBound::Absolute(N)` (the 1-based value parsed from
+  `@N`) to `RangeBound::Absolute(N - 1)`; the `RuleBound::Turns(N)` (count) arm
+  is untouched.
+  `TurnSelection::trim` then clamps each window to the turns those bounds leave
+  unprotected — it clamps rather than shifts, so a turn already outside the
+  window needs no protecting.
 
 - **Timeline output** (`jp_cli::cmd::conversation::compact::timeline_lines`):
   the stored 0-based `from_turn`/`to_turn` are rendered as 1-based, e.g.
diff --git a/docs/rfd/006-turn-scoped-mutations.md b/docs/rfd/006-turn-scoped-mutations.md
index e77e928a5..bd923a1a3 100644
--- a/docs/rfd/006-turn-scoped-mutations.md
+++ b/docs/rfd/006-turn-scoped-mutations.md
@@ -26,6 +26,9 @@ This has caused real bugs:
 - Fork with `--from`/`--until` can produce streams that start with assistant
   responses, causing provider API errors (Anthropic rejects streams where the
   first message isn't from the user).
+  (Fork's range flags are now `--from`/`--to` and resolve to whole turns, so
+  this particular shape no longer arises from range filtering; the invariant the
+  builder API enforces still matters for every other caller.)
 - Streams without `TurnStart` markers break `--last` (which counts turn
   boundaries).
 - `sanitize()` exists specifically to repair these invariant violations after
diff --git a/docs/rfd/023-resumable-conversation-turns.md b/docs/rfd/023-resumable-conversation-turns.md
index 8dae7492b..30421b4c1 100644
--- a/docs/rfd/023-resumable-conversation-turns.md
+++ b/docs/rfd/023-resumable-conversation-turns.md
@@ -136,6 +136,16 @@ applies: if the slice point falls mid-turn, fork produces `(ConversationStream,
 IncompleteTurn)` where the stream satisfies the structural invariants and the
 incomplete turn is the valid residual.
 
+> [!NOTE]
+> `conversation fork` no longer has a slice point that can fall mid-turn.
+> Its range flags are `--from`/`--to` (the shared turn selector; `--until` is
+> gone), and every bound — including the time-based ones — resolves to a whole
+> turn.
+> A fork therefore never produces a residual partial turn from range filtering,
+> so this section applies only to forking a conversation whose *latest* turn is
+> already incomplete (the case described just above).
+> See [Indexing and Counting Conventions].
+
 ### Incremental Persistence
 
 Today, tool call responses are persisted as a batch.
@@ -551,6 +561,12 @@ events.
 The fork is valid — it just has an incomplete turn that can be resumed or
 discarded.
 
+> [!NOTE]
+> This paragraph is obsolete: fork's range bounds are turn-granular, so no fork
+> range can slice mid-turn.
+> The preceding paragraph — forking a conversation that already carries an
+> incomplete trailing turn — is the live case.
+
 ### ConfigDelta events in incomplete turns
 
 The `IncompleteTurn` may contain `ConfigDelta` events that were applied during
@@ -627,7 +643,10 @@ Depends on Phase 1.
 - `ConversationStream::sanitize()` (`crates/jp_conversation/src/stream.rs`) —
   existing structural repair logic; scope narrowed by this RFD to only cover
   complete turns.
+- [Indexing and Counting Conventions] — why fork's range bounds resolve to
+  whole turns and never slice one.
 
+[Indexing and Counting Conventions]: ../architecture/indexing-conventions.md
 [RFD 005]: 005-first-class-inquiry-events.md
 [RFD 009]: 009-stateful-tool-protocol.md
 [RFD 020]: 020-parallel-conversations.md
diff --git a/docs/rfd/036-conversation-compaction.md b/docs/rfd/036-conversation-compaction.md
index 5147bca3a..6e2498d95 100644
--- a/docs/rfd/036-conversation-compaction.md
+++ b/docs/rfd/036-conversation-compaction.md
@@ -465,7 +465,7 @@ Composability lets users tailor the operation.
 - **Conversation merging.** Combining two conversations into one.
   Related but distinct.
 - **Conversation rollback.** Undoing specific turns.
-  The `fork` command with `--until` already covers this.
+  The `fork` command with `--to` already covers this.
 - **Token counting accuracy.** This RFD uses the existing char-based heuristic
   for token estimation.
   Accurate token counting (per-provider tokenizer) is orthogonal.
diff --git a/docs/rfd/039-conversation-trees.md b/docs/rfd/039-conversation-trees.md
index 6200aab3c..2d1a6197b 100644
--- a/docs/rfd/039-conversation-trees.md
+++ b/docs/rfd/039-conversation-trees.md
@@ -171,7 +171,8 @@ jp conversation fork <id>
 ```
 
 Creates a child conversation with `parent_id` set to `<id>` and copied events
-(filtered by `--from`, `--until`, `--last` as today).
+(filtered by the shared turn selector — `--from`/`--to`, `--turn`,
+`--first`/`--last` — as today).
 
 The `--activate` flag continues to work — it sets the fork as the active
 conversation.
@@ -260,7 +261,7 @@ The existing `--yes` flag (skip confirmation prompt) is orthogonal to the
 strategy flags.
 `--cascade --yes` deletes the tree without prompts.
 
-### `conversation fork` with `--from` / `--until` / `--last`
+### `conversation fork` with `--from` / `--to` / `--last`
 
 The current fork command supports time-based and count-based event filtering.
 These continue to work: the fork creates a child conversation with a filtered
diff --git a/docs/rfd/050-scripting-ergonomics-for-conversation-management.md b/docs/rfd/050-scripting-ergonomics-for-conversation-management.md
index f5f709727..cbd94a966 100644
--- a/docs/rfd/050-scripting-ergonomics-for-conversation-management.md
+++ b/docs/rfd/050-scripting-ergonomics-for-conversation-management.md
@@ -215,8 +215,9 @@ The only output on stdout is the conversation ID.
 
 #### `jp conversation fork` (updated)
 
-`conversation fork` currently accepts `--activate`, `--from`, `--until`, and
-`--last` but does not support config overrides or print the new conversation ID.
+`conversation fork` accepts `--activate` plus the shared turn selector
+(`--from`/`--to`, `--turn`, `--first`/`--last`, `--keep-first`/`--keep-last`),
+but does not support config overrides or print the new conversation ID.
 This RFD adds both:
 
 ```sh
diff --git a/docs/rfd/053-auto-refresh-conversation-titles.md b/docs/rfd/053-auto-refresh-conversation-titles.md
index 33bd024e2..4083c9355 100644
--- a/docs/rfd/053-auto-refresh-conversation-titles.md
+++ b/docs/rfd/053-auto-refresh-conversation-titles.md
@@ -195,7 +195,7 @@ Concretely, this affects forks that retain a tail of the stream:
   The fork inherits the source's metadata via clone, so a source with
   `title_generated_at_turn = Some(k)` and `k > N` produces a fork whose
   watermark exceeds its own turn count.
-- `conversation fork --from/--until` similarly drops events.
+- `conversation fork --from/--to` similarly drops events.
 
 **The rule:** any operation that drops `turn_start` events from a stream clamps
 the resulting watermark to `min(watermark, new_turn_count)`.
diff --git a/docs/rfd/064-non-destructive-conversation-compaction.md b/docs/rfd/064-non-destructive-conversation-compaction.md
index 4b077dec3..ddca6f7a8 100644
--- a/docs/rfd/064-non-destructive-conversation-compaction.md
+++ b/docs/rfd/064-non-destructive-conversation-compaction.md
@@ -965,6 +965,7 @@ Can proceed in parallel with Phases 3 and 4.
 - [Issue #57] — Make conversation management more powerful
 - [Multi-turn degradation paper][paper] — cited in Issue \#57
 
+[Indexing and Counting Conventions]: ../architecture/indexing-conventions.md
 [InternalEvent]: https://github.com/dcdpr/jp/blob/main/crates/jp_conversation/src/stream.rs
 [Issue #57]: https://github.com/dcdpr/jp/issues/57
 [RFD 011]: 011-system-notification-queue.md
diff --git a/docs/rfd/071-conversation-archiving.md b/docs/rfd/071-conversation-archiving.md
index 566320b01..3ecc4d9df 100644
--- a/docs/rfd/071-conversation-archiving.md
+++ b/docs/rfd/071-conversation-archiving.md
@@ -55,17 +55,17 @@ jp c archive +pinned
 # Archive a range of conversations by creation date. Both bounds accept a
 # conversation ID (uses its creation timestamp), a relative duration
 # (3w, 30d, 6h), or an absolute date (2026-01-01). The range is half-open:
-# --from is inclusive, --until is exclusive.
-jp c archive --from 3w --until 1d
-jp c archive --from jp-c123
+# --created-since is inclusive, --created-before is exclusive.
+jp c archive --created-since 3w --created-before 1d
+jp c archive --created-since jp-c123
 
 # Archive every conversation unused since a given time (last_activated_at,
-# not creation date). Accepts the same syntax as --from.
+# not creation date). Accepts the same syntax as --created-since.
 jp c archive --inactive-since 30d
 
 # Filters AND-compose; this archives conversations created in the last
 # month that have been idle for at least a week.
-jp c archive --from 30d --inactive-since 7d
+jp c archive --created-since 30d --inactive-since 7d
 
 # Skip the per-conversation confirmation prompt for pinned/active entries.
 jp c archive --inactive-since 6mo --yes
@@ -211,7 +211,8 @@ is straightforward.
 `jp c archive` participates in the standard conversation resolution pipeline.
 Its `conversation_load_request` behaves in two modes:
 
-- **Filter mode** (any of `--from`/`--until`/`--inactive-since` set): returns
+- **Filter mode** (any of
+  `--created-since`/`--created-before`/`--inactive-since` set): returns
   `ConversationLoadRequest::none()`.
   The subcommand iterates the workspace and selects matching conversations
   internally, mirroring `jp c unarchive`'s internal-resolution pattern.
@@ -221,9 +222,20 @@ Its `conversation_load_request` behaves in two modes:
   Resolution happens in the startup pipeline and the subcommand receives
   pre-resolved handles.
 
-The shared `--from`/`--until` range filter is implemented as a flattened
-`CreationRange` args struct in `crates/jp_cli/src/cmd/time.rs`, reused by `jp c
-rm` so the two commands' creation-range semantics stay in lockstep.
+The shared `--created-since`/`--created-before` range filter is implemented as a
+flattened `CreationRange` args struct in `crates/jp_cli/src/cmd/time.rs`, reused
+by `jp c rm` so the two commands' creation-range semantics stay in lockstep.
+
+> [!NOTE]
+> The creation-range flags shipped as `--from`/`--until` and are now spelled
+> `--created-since`/`--created-before`.
+> They were renamed when `--from`/`--to` became the turn-range selector shared
+> by `jp c print`, `jp c compact`, and `jp c fork`: both families accept nearly
+> the same values (durations, absolute dates), so one flag name could no longer
+> mean both "which conversations" and "which turns".
+> Semantics are unchanged — the range is still half-open on conversation
+> creation time.
+> See [Indexing and Counting Conventions] for the turn-range side.
 
 `jp c unarchive` returns `ConversationLoadRequest::none()` because its targets
 are in the archive partition and cannot be resolved through the active index.
@@ -312,12 +324,12 @@ Add `--archived` flag to `jp c ls`.
 Add `archived`/`+archived`/`?archived` targeting keywords.
 Update `jp c use` to support unarchive-and-activate via the `archived` keyword.
 
-Archive's selection flags ship as `--from`/`--until` (creation-date range) and
-`--inactive-since` (last-activity threshold); all three accept the
-`TimeThreshold` syntax (conversation ID, relative duration, or absolute date)
-and AND-compose.
-`--from`/`--until` are extracted into a shared `CreationRange` args struct
-reused by `jp c rm`.
+Archive's selection flags ship as `--created-since`/`--created-before`
+(creation-date range) and `--inactive-since` (last-activity threshold); all
+three accept the `TimeThreshold` syntax (conversation ID, relative duration, or
+absolute date) and AND-compose.
+The range flags are extracted into a shared `CreationRange` args struct reused
+by `jp c rm`.
 
 Depends on Phase 1.
 
@@ -327,6 +339,9 @@ Depends on Phase 1.
   invalid conversations
 - [RFD 073: Layered Storage Backend for Workspaces][RFD 073] — backend trait
   architecture
+- [Indexing and Counting Conventions] — the turn-range selector the range flags
+  were renamed to make room for
 
+[Indexing and Counting Conventions]: ../architecture/indexing-conventions.md
 [RFD 052]: 052-workspace-data-store-sanitization.md
 [RFD 073]: 073-layered-storage-backend-for-workspaces.md
diff --git a/docs/rfd/074-eager-loading-with-command-declared-data-requirements.md b/docs/rfd/074-eager-loading-with-command-declared-data-requirements.md
index b9d945e05..e62ccb65e 100644
--- a/docs/rfd/074-eager-loading-with-command-declared-data-requirements.md
+++ b/docs/rfd/074-eager-loading-with-command-declared-data-requirements.md
@@ -54,9 +54,9 @@ For built-in commands, the set of conversations whose events need loading is
 determined entirely by the command and its arguments — it is known before
 command execution begins.
 Even bulk commands like `conversation grep` (all conversations) and
-`conversation rm --from/--until` (a filtered subset) can express their scope
-through `filter_needs` — the data requirements are known statically, only the
-exact IDs are resolved at startup.
+`conversation rm --created-since/--created-before` (a filtered subset) can
+express their scope through `filter_needs` — the data requirements are known
+statically, only the exact IDs are resolved at startup.
 
 Two mechanisms serve bulk commands:
 
@@ -270,9 +270,9 @@ The `conversation_load_request()` method will need to branch on whether
 does not yet make this distinction.
 The table shows both modes as separate rows.
 
-For `rm --from/--until`, the range filter currently loads all conversations
-inside `run()` and does not actually filter by the `from`/`until` values — this
-is a pre-existing gap in the implementation.
+For `rm --created-since/--created-before`, the range filter currently loads all
+conversations inside `run()` and does not actually filter by the
+`since`/`before` values — this is a pre-existing gap in the implementation.
 With the new model, range mode should declare `filter_needs: METADATA` (so
 metadata is available for date-based filtering) and a target set derived from
 the range.
diff --git a/docs/rfd/drafts/D33-conversation-store-and-bare-forking.md b/docs/rfd/drafts/D33-conversation-store-and-bare-forking.md
index 7079c9e7e..3ac345699 100644
--- a/docs/rfd/drafts/D33-conversation-store-and-bare-forking.md
+++ b/docs/rfd/drafts/D33-conversation-store-and-bare-forking.md
@@ -195,11 +195,11 @@ config show`).
 
 ### Fork with event filtering instead of `--no-turns`
 
-Instead of `--no-turns`, add `--from=start --until=0` or similar to copy config
+Instead of `--no-turns`, add `--from=start --to=0` or similar to copy config
 with an empty event range.
 
-Rejected because the existing `--from`/`--until` flags operate on turn
-boundaries within the event stream.
+Rejected because the existing `--from`/`--to` flags operate on turn boundaries
+within the event stream.
 "Zero events" is a degenerate case that deserves its own flag with clear
 semantics rather than being expressed as an edge case of range filtering.
 

From d27a5250d937878cc553ae4e797cec1b45c96c7f Mon Sep 17 00:00:00 2001
From: Jean Mertz <git@jeanmertz.com>
Date: Tue, 28 Jul 2026 06:57:16 +0200
Subject: [PATCH 2/7] review feedback

Signed-off-by: Jean Mertz <git@jeanmertz.com>
---
 crates/jp_cli/src/cmd/conversation/archive.rs | 10 ++-
 crates/jp_cli/src/cmd/conversation/compact.rs | 11 +++
 crates/jp_cli/src/cmd/conversation/fork.rs    |  6 ++
 .../jp_cli/src/cmd/conversation/fork_tests.rs | 80 +++++++++++++++++++
 crates/jp_cli/src/cmd/conversation/rm.rs      |  6 +-
 crates/jp_cli/src/cmd/conversation/use_.rs    |  6 +-
 .../jp_cli/src/cmd/conversation/use_tests.rs  |  2 +-
 crates/jp_cli/src/cmd/turn_selection.rs       | 44 ++++++++--
 crates/jp_cli/src/cmd/turn_selection_tests.rs | 28 +++++++
 docs/architecture/indexing-conventions.md     | 16 ++--
 10 files changed, 186 insertions(+), 23 deletions(-)

diff --git a/crates/jp_cli/src/cmd/conversation/archive.rs b/crates/jp_cli/src/cmd/conversation/archive.rs
index 9dc8982da..3d76adc14 100644
--- a/crates/jp_cli/src/cmd/conversation/archive.rs
+++ b/crates/jp_cli/src/cmd/conversation/archive.rs
@@ -25,8 +25,9 @@ use crate::{
 /// Pass `--confirm` to prompt for every conversation, or `--no-confirm` /
 /// `--yes` to skip all prompts.
 ///
-/// Use `--from`/`--until` to archive a range of conversations by creation date,
-/// or `--inactive-since` to archive everything unused since a given time.
+/// Use `--created-since`/`--created-before` to archive a range of conversations
+/// by creation date, or `--inactive-since` to archive everything unused since a
+/// given time.
 /// The three filters AND together when combined.
 ///
 /// Archived conversations are hidden from listings and pickers.
@@ -44,9 +45,10 @@ pub(crate) struct Archive {
 
     /// Archive all conversations inactive since a given time.
     ///
-    /// Accepts the same formats as `--from`.
+    /// Accepts the same formats as `--created-since`.
     /// Filters on `last_activated_at` (when the conversation was last used)
-    /// rather than its creation date, which makes this distinct from `--until`.
+    /// rather than its creation date, which makes this distinct from the
+    /// `--created-since`/`--created-before` range.
     #[arg(long, conflicts_with = "id")]
     inactive_since: Option<TimeThreshold>,
 
diff --git a/crates/jp_cli/src/cmd/conversation/compact.rs b/crates/jp_cli/src/cmd/conversation/compact.rs
index 22580e619..a3e9639a2 100644
--- a/crates/jp_cli/src/cmd/conversation/compact.rs
+++ b/crates/jp_cli/src/cmd/conversation/compact.rs
@@ -545,6 +545,17 @@ impl Compact {
 
     pub(crate) async fn run(self, ctx: &mut Ctx, handles: Vec<ConversationHandle>) -> Output {
         self.range.validate()?;
+
+        // Reject an out-of-range `--turn` against every target before compacting
+        // any of them, so a bad endpoint on the last conversation can't leave the
+        // earlier ones already compacted.
+        // `compact_one` re-checks against the locked snapshot, which is the
+        // authoritative count if a concurrent writer appends in between.
+        for handle in &handles {
+            self.range
+                .check_turn_range(ctx.workspace.events(handle)?.turn_count())?;
+        }
+
         for handle in handles {
             self.compact_one(ctx, handle).await?;
         }
diff --git a/crates/jp_cli/src/cmd/conversation/fork.rs b/crates/jp_cli/src/cmd/conversation/fork.rs
index e3959722c..84e2e9d78 100644
--- a/crates/jp_cli/src/cmd/conversation/fork.rs
+++ b/crates/jp_cli/src/cmd/conversation/fork.rs
@@ -65,10 +65,16 @@ impl Fork {
     pub(crate) async fn run(self, ctx: &mut Ctx, handles: &[ConversationHandle]) -> Output {
         self.range.validate()?;
 
+        // Reject an out-of-range `--turn` against every source before forking any
+        // of them: `fork` accepts multiple sources, and checking inside the loop
+        // would leave the earlier forks created when a later source turns out to
+        // be too short.
         for source in handles {
             self.range
                 .check_turn_range(ctx.workspace.events(source)?.turn_count())?;
+        }
 
+        for source in handles {
             // `--no-turns` folds the source's effective config (base + every
             // delta) into a fresh base config; resolving it here lets the
             // fallible `config()` propagate, keeping the closure infallible.
diff --git a/crates/jp_cli/src/cmd/conversation/fork_tests.rs b/crates/jp_cli/src/cmd/conversation/fork_tests.rs
index 71c1795e0..b77e3aec3 100644
--- a/crates/jp_cli/src/cmd/conversation/fork_tests.rs
+++ b/crates/jp_cli/src/cmd/conversation/fork_tests.rs
@@ -1097,6 +1097,86 @@ fn fork_targets_correct_source() {
     assert_eq!(a_requests, vec!["alpha question"]);
 }
 
+/// An out-of-range `--turn` on *any* source must be rejected before *any* fork
+/// is created.
+///
+/// Validating inside the mutation loop would fork the first source, then error
+/// on the second — leaving a conversation behind that the failed command
+/// appears not to have created.
+#[test]
+fn turn_out_of_range_on_a_later_source_forks_nothing() {
+    let tmp = tempdir().unwrap();
+    let (printer, _, _) = Printer::memory(OutputFormat::TextPretty);
+    let config = AppConfig::new_test();
+    let storage = tmp.path().join(".jp");
+    let user = tmp.path().join("user");
+    let fs = Arc::new(
+        FsStorageBackend::new(&storage)
+            .unwrap()
+            .with_user_storage(&user, None, "abc")
+            .unwrap(),
+    );
+    let workspace = Workspace::new(tmp.path()).with_backend(fs);
+    let mut ctx = Ctx::new(
+        workspace,
+        None,
+        Runtime::new().unwrap(),
+        Globals::default(),
+        config,
+        None,
+        printer,
+    );
+
+    // Source A has three turns, source B only one.
+    let id_a = ConversationId::try_from(ctx.now()).unwrap();
+    ctx.workspace.create_conversation_with_id(
+        id_a,
+        Conversation::default().with_last_activated_at(ctx.now()),
+        ctx.config(),
+    );
+    let h_a = ctx.workspace.acquire_conversation(&id_a).unwrap();
+    let lock_a = ctx.workspace.test_lock(h_a);
+    lock_a.as_mut().update_events(|e| e.extend(turns(3)));
+    drop(lock_a);
+
+    ctx.set_now(ctx.now() + Duration::from_secs(1));
+
+    let id_b = ConversationId::try_from(ctx.now()).unwrap();
+    ctx.workspace.create_conversation_with_id(
+        id_b,
+        Conversation::default().with_last_activated_at(ctx.now()),
+        ctx.config(),
+    );
+    let h_b = ctx.workspace.acquire_conversation(&id_b).unwrap();
+    let lock_b = ctx.workspace.test_lock(h_b);
+    lock_b.as_mut().update_events(|e| e.extend(turns(1)));
+    drop(lock_b);
+
+    ctx.set_now(ctx.now() + Duration::from_secs(1));
+
+    // Turn 3 exists in A but not in B.
+    let fork = Fork {
+        target: PositionalIds::default(),
+        activate: false,
+        range: selection(&["--turn", "3"]),
+        compact: CompactFlag::default(),
+        no_turns: false,
+        title: None,
+    };
+    let handle_a = ctx.workspace.acquire_conversation(&id_a).unwrap();
+    let handle_b = ctx.workspace.acquire_conversation(&id_b).unwrap();
+    let result = tokio::runtime::Runtime::new()
+        .unwrap()
+        .block_on(fork.run(&mut ctx, &[handle_a, handle_b]));
+
+    assert!(result.is_err(), "turn 3 is out of range for source B");
+    assert_eq!(
+        ctx.workspace.conversations().count(),
+        2,
+        "a rejected multi-source fork must not leave a partial fork behind"
+    );
+}
+
 /// Regression test: forking a `--local` conversation must keep the fork
 /// local-only instead of projecting it into the workspace.
 #[test]
diff --git a/crates/jp_cli/src/cmd/conversation/rm.rs b/crates/jp_cli/src/cmd/conversation/rm.rs
index cc1d9dfe5..6a0d7f712 100644
--- a/crates/jp_cli/src/cmd/conversation/rm.rs
+++ b/crates/jp_cli/src/cmd/conversation/rm.rs
@@ -77,9 +77,9 @@ impl Rm {
     ///
     /// Extracted from `run` so the filter step can be exercised in tests
     /// without driving the async confirmation/lock path.
-    /// This is the load-bearing line between `--from/--until` and actual
-    /// deletion; regressing it would silently turn a range delete into a full
-    /// wipe.
+    /// This is the dividing line between `--created-since`/`--created-before`
+    /// and actual deletion; regressing it would silently turn a range delete
+    /// into a full wipe.
     fn resolve_filtered(
         &self,
         workspace: &Workspace,
diff --git a/crates/jp_cli/src/cmd/conversation/use_.rs b/crates/jp_cli/src/cmd/conversation/use_.rs
index 3fe87175b..8b22a2d62 100644
--- a/crates/jp_cli/src/cmd/conversation/use_.rs
+++ b/crates/jp_cli/src/cmd/conversation/use_.rs
@@ -18,9 +18,9 @@ use crate::{
 ///
 /// Without flags, `jp c use [ID]` activates the given conversation (or opens a
 /// picker when no target is provided).
-/// `--grep` and `--from`/`--until` restrict the picker's candidate set; when
-/// the combined filter leaves a single conversation, it is activated directly
-/// without prompting.
+/// `--grep` and `--created-since`/`--created-before` restrict the picker's
+/// candidate set; when the combined filter leaves a single conversation, it is
+/// activated directly without prompting.
 #[derive(Debug, clap::Args)]
 pub(crate) struct Use {
     #[command(flatten)]
diff --git a/crates/jp_cli/src/cmd/conversation/use_tests.rs b/crates/jp_cli/src/cmd/conversation/use_tests.rs
index 0c8a6707b..acf858cfa 100644
--- a/crates/jp_cli/src/cmd/conversation/use_tests.rs
+++ b/crates/jp_cli/src/cmd/conversation/use_tests.rs
@@ -145,7 +145,7 @@ fn run_with_contention_skips_metadata_bump() {
     );
 }
 
-// --- Filter mode (`--grep`, `--from`, `--until`) ----------------------------
+// --- Filter mode (`--grep`, `--created-since`, `--created-before`) ----------
 //
 // Filter mode resolves handles internally instead of going through the
 // standard pipeline. These tests exercise the N=1 short-circuit path that
diff --git a/crates/jp_cli/src/cmd/turn_selection.rs b/crates/jp_cli/src/cmd/turn_selection.rs
index 84ecb8e0d..6aedfe3a2 100644
--- a/crates/jp_cli/src/cmd/turn_selection.rs
+++ b/crates/jp_cli/src/cmd/turn_selection.rs
@@ -10,8 +10,10 @@
 //! Most selections are a single window; `--first N --last M` produces two,
 //! skipping the turns in between.
 //!
-//! Every bound resolves to a whole turn — a time-based bound names the turn it
-//! falls in and never splits one.
+//! A bound never splits a turn.
+//! The two ends resolve a time value differently: `--from <time>` starts at the
+//! first turn to *begin* after the cutoff, while `--to <time>` ends at (and
+//! includes) the turn that was running at it.
 //!
 //! Turn positions are 1-based on the CLI and 0-based in the stream; the
 //! translation happens here.
@@ -111,6 +113,27 @@ fn parse_to_bound(s: &str) -> Result<CliRangeBound, String> {
     parse_bound(s)
 }
 
+/// Parse a `--keep-last` bound, rejecting the `last-compaction` marker.
+///
+/// `keep_last_bound` maps `AfterLastCompaction` to [`Bound::Default`], which
+/// leaves the end of the selection untrimmed.
+/// Accepting the marker here would make an explicit `--keep-last
+/// last-compaction` a silent no-op, and in `compact` it would additionally
+/// suppress the rule's own configured `keep_last` — compacting *more* than
+/// omitting the flag.
+/// `--keep-first last-compaction` is meaningful and stays accepted.
+fn parse_keep_last(s: &str) -> Result<RuleBound, String> {
+    let bound = RuleBound::from_str(s).map_err(|e| e.to_string())?;
+    if bound == RuleBound::AfterLastCompaction {
+        return Err(
+            "`last-compaction` is only valid for `--from` and `--keep-first` (it marks the most \
+             recent compaction)"
+                .to_owned(),
+        );
+    }
+    Ok(bound)
+}
+
 /// Parse a 1-based turn number for `--turn`, rejecting `0`.
 fn parse_one_based(s: &str) -> Result<usize, String> {
     match s.parse::<usize>() {
@@ -392,8 +415,11 @@ pub(crate) struct TurnSelection {
     /// turn), a relative duration (`5h`), a date (`2026-01-01`), an RFC 3339
     /// timestamp, or `last-compaction` (the turn after the most recent
     /// compaction).
-    /// A time-based value names the turn it falls in; a bound never splits a
-    /// turn.
+    ///
+    /// A time-based value starts the selection at the first turn to *begin*
+    /// after the given instant, so the turn that was already running at that
+    /// instant is excluded.
+    /// A bound never splits a turn.
     // `allow_negative_numbers` keeps the from-end form usable as a
     // space-separated value (`--from -3`), which clap would otherwise read as an
     // unknown short flag.
@@ -404,6 +430,11 @@ pub(crate) struct TurnSelection {
     ///
     /// Accepts the same forms as `--from`, except `last-compaction`, which only
     /// makes sense as a start bound.
+    ///
+    /// A time-based value ends the selection at (and includes) the turn that
+    /// was running at the given instant — the mirror of `--from`, which
+    /// excludes it.
+    /// A bound never splits a turn.
     #[arg(long, value_parser = parse_to_bound, allow_negative_numbers = true)]
     to: Option<CliRangeBound>,
 
@@ -418,10 +449,11 @@ pub(crate) struct TurnSelection {
 
     /// Protect the last N turns from the selection.
     ///
-    /// Accepts the same forms as `--keep-first`.
+    /// Accepts the same forms as `--keep-first`, except `last-compaction`,
+    /// which only makes sense at the start.
     /// Composes with every other selector: the selection ends no later than the
     /// last unprotected turn.
-    #[arg(long, allow_negative_numbers = true)]
+    #[arg(long, value_parser = parse_keep_last, allow_negative_numbers = true)]
     keep_last: Option<RuleBound>,
 }
 
diff --git a/crates/jp_cli/src/cmd/turn_selection_tests.rs b/crates/jp_cli/src/cmd/turn_selection_tests.rs
index 88ae2ce15..cf51f4c55 100644
--- a/crates/jp_cli/src/cmd/turn_selection_tests.rs
+++ b/crates/jp_cli/src/cmd/turn_selection_tests.rs
@@ -129,6 +129,34 @@ fn parse_to_bound_rejects_last_compaction_but_accepts_other_forms() {
     assert!(parse_to_bound("2026-01-01").is_ok());
 }
 
+#[test]
+fn parse_keep_last_rejects_the_last_compaction_marker() {
+    // `keep_last_bound` maps the marker to `Bound::Default`, so accepting it
+    // would make the flag a silent no-op — and in `compact` it would suppress
+    // the rule's own `keep_last` on top of that.
+    assert!(parse_keep_last("last-compaction").is_err());
+    // The deprecated bare alias reaches the same arm.
+    assert!(parse_keep_last("last").is_err());
+
+    // Every other bound form still parses.
+    assert_eq!(parse_keep_last("2").unwrap(), RuleBound::Turns(2));
+    assert_eq!(parse_keep_last("@3").unwrap(), RuleBound::Absolute(3));
+    assert_eq!(parse_keep_last("-3").unwrap(), RuleBound::FromEnd(3));
+    assert!(matches!(
+        parse_keep_last("5h").unwrap(),
+        RuleBound::Duration(_)
+    ));
+}
+
+#[test]
+fn clap_rejects_last_compaction_only_at_the_end_of_the_selection() {
+    // Start-side bounds accept the marker; end-side bounds reject it.
+    assert!(parse(&["--from", "last-compaction"]).is_ok());
+    assert!(parse(&["--keep-first", "last-compaction"]).is_ok());
+    assert!(parse(&["--to", "last-compaction"]).is_err());
+    assert!(parse(&["--keep-last", "last-compaction"]).is_err());
+}
+
 #[test]
 fn parse_turn_single_and_range() {
     assert!(matches!(parse_turn("3").unwrap(), TurnSpec::Single(3)));
diff --git a/docs/architecture/indexing-conventions.md b/docs/architecture/indexing-conventions.md
index 498f2535e..5386a637e 100644
--- a/docs/architecture/indexing-conventions.md
+++ b/docs/architecture/indexing-conventions.md
@@ -90,13 +90,17 @@ so it is half-open and uses distinct flag names (`--created-since` /
   produces a `TurnSet` of inclusive 0-based windows.
 
   `--turn`, `--from`/`--to`, and `--first`/`--last` are three ways of naming the
-  base selection and are mutually exclusive.
-  `--turn N` is `Absolute(N - 1)` on both ends; `--turn A..B` spans \`Absolute(A
+  base selection and are mutually exclusive:
 
-  - 1\)`through`Absolute(B - 1)` ;  `--first N`is`Absolute(0)`through`Absolute(N
-    - 1)` ;  `--last N`is`FromEnd(N - 1)`through the last
-    turn.`--first`and`--last\` given together produce two windows and skip the
-    turns between them.
+  | Selector     | Start bound      | End bound        |
+  | ------------ | ---------------- | ---------------- |
+  | `--turn N`   | `Absolute(N - 1)` | `Absolute(N - 1)` |
+  | `--turn A..B` | `Absolute(A - 1)` | `Absolute(B - 1)` |
+  | `--first N`  | `Absolute(0)`    | `Absolute(N - 1)` |
+  | `--last N`   | `FromEnd(N - 1)` | `FromEnd(0)`     |
+
+  `--first` and `--last` given together produce two windows and skip the turns
+  between them.
 
 - **Keep flags** (`jp_cli::cmd::turn_selection`): `keep_first_bound` /
   `keep_last_bound` map `RuleBound::Absolute(N)` (the 1-based value parsed from

From 6f421706b1ba569f1697c84e0d20108265b5a75f Mon Sep 17 00:00:00 2001
From: Jean Mertz <git@jeanmertz.com>
Date: Tue, 28 Jul 2026 06:59:34 +0200
Subject: [PATCH 3/7] fixup! review feedback

Signed-off-by: Jean Mertz <git@jeanmertz.com>
---
 docs/architecture/indexing-conventions.md | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/docs/architecture/indexing-conventions.md b/docs/architecture/indexing-conventions.md
index 5386a637e..a409b1e15 100644
--- a/docs/architecture/indexing-conventions.md
+++ b/docs/architecture/indexing-conventions.md
@@ -92,12 +92,12 @@ so it is half-open and uses distinct flag names (`--created-since` /
   `--turn`, `--from`/`--to`, and `--first`/`--last` are three ways of naming the
   base selection and are mutually exclusive:
 
-  | Selector     | Start bound      | End bound        |
-  | ------------ | ---------------- | ---------------- |
-  | `--turn N`   | `Absolute(N - 1)` | `Absolute(N - 1)` |
+  | Selector      | Start bound       | End bound         |
+  | ------------- | ----------------- | ----------------- |
+  | `--turn N`    | `Absolute(N - 1)` | `Absolute(N - 1)` |
   | `--turn A..B` | `Absolute(A - 1)` | `Absolute(B - 1)` |
-  | `--first N`  | `Absolute(0)`    | `Absolute(N - 1)` |
-  | `--last N`   | `FromEnd(N - 1)` | `FromEnd(0)`     |
+  | `--first N`   | `Absolute(0)`     | `Absolute(N - 1)` |
+  | `--last N`    | `FromEnd(N - 1)`  | `FromEnd(0)`      |
 
   `--first` and `--last` given together produce two windows and skip the turns
   between them.

From b3e1bb6ba53286b7f7c63f9e704884756dadf73b Mon Sep 17 00:00:00 2001
From: Jean Mertz <git@jeanmertz.com>
Date: Tue, 28 Jul 2026 08:43:15 +0200
Subject: [PATCH 4/7] review feedback

Signed-off-by: Jean Mertz <git@jeanmertz.com>
---
 crates/jp_cli/src/cmd/conversation/compact.rs | 55 ++++++++++---
 .../src/cmd/conversation/compact_tests.rs     | 77 ++++++++++++++++++-
 crates/jp_cli/src/cmd/turn_selection.rs       | 27 +++++--
 crates/jp_cli/src/cmd/turn_selection_tests.rs | 47 +++++++++++
 crates/jp_conversation/src/stream.rs          | 19 +++--
 .../src/stream/turn_iter_tests.rs             | 42 ++++++++++
 6 files changed, 243 insertions(+), 24 deletions(-)

diff --git a/crates/jp_cli/src/cmd/conversation/compact.rs b/crates/jp_cli/src/cmd/conversation/compact.rs
index a3e9639a2..8aeccdda4 100644
--- a/crates/jp_cli/src/cmd/conversation/compact.rs
+++ b/crates/jp_cli/src/cmd/conversation/compact.rs
@@ -272,6 +272,49 @@ fn resolve_rule_range(
     })
 }
 
+/// Resolve every selected window into the ranges one rule will compact.
+///
+/// A summary rule's range grows to subsume any summary it touches
+/// ([`extend_summary_range`]), so two windows that started out disjoint can
+/// extend onto each other — or onto the same pre-existing summary — and end
+/// up overlapping or identical.
+/// Coalescing here, before any text is generated, keeps one region from being
+/// compacted twice and one summary from being generated only to be immediately
+/// superseded by the next.
+///
+/// Sorting by start turn first makes a single left-to-right sweep enough:
+/// extending the open range as it goes absorbs transitive chains (A touches B,
+/// B touches C) without a second pass.
+fn plan_rule_ranges(
+    range_stream: &ConversationStream,
+    overlap_stream: &ConversationStream,
+    rule: &CompactionRuleConfig,
+    windows: &[BoundWindow],
+    selection: &TurnSelection,
+) -> Vec<CompactionRange> {
+    let mut ranges: Vec<CompactionRange> = windows
+        .iter()
+        .filter_map(|window| {
+            resolve_rule_range(range_stream, overlap_stream, rule, window, selection)
+        })
+        .collect();
+
+    ranges.sort_by_key(|r| (r.from_turn, r.to_turn));
+
+    let mut merged: Vec<CompactionRange> = Vec::with_capacity(ranges.len());
+    for range in ranges {
+        match merged.last_mut() {
+            // Intersection only: two abutting ranges are distinct regions, and
+            // for a summary rule two adjacent summaries are legal.
+            Some(last) if range.from_turn <= last.to_turn => {
+                last.to_turn = last.to_turn.max(range.to_turn);
+            }
+            _ => merged.push(range),
+        }
+    }
+    merged
+}
+
 /// Generate the summary text (if any) and assemble a [`Compaction`] for an
 /// already-resolved range.
 ///
@@ -336,10 +379,7 @@ pub(crate) async fn build_compaction_events(
     let mut overlap = events.clone();
     let mut compactions = Vec::new();
     for rule in rules {
-        for window in &windows {
-            let Some(range) = resolve_rule_range(events, &overlap, rule, window, selection) else {
-                continue;
-            };
+        for range in plan_rule_ranges(events, &overlap, rule, &windows, selection) {
             let compaction = build_compaction_for_range(events, cfg, rule, range, printer).await?;
             overlap.add_compaction(compaction.clone());
             compactions.push(compaction);
@@ -658,12 +698,7 @@ impl Compact {
         let mut overlap = events_snapshot.clone();
         let mut new_segments = Vec::new();
         for rule in rules {
-            for window in &windows {
-                let Some(range) =
-                    resolve_rule_range(events_snapshot, &overlap, rule, window, selection)
-                else {
-                    continue;
-                };
+            for range in plan_rule_ranges(events_snapshot, &overlap, rule, &windows, selection) {
                 let label = if rule.summary.is_some() {
                     Some("summary".to_owned())
                 } else {
diff --git a/crates/jp_cli/src/cmd/conversation/compact_tests.rs b/crates/jp_cli/src/cmd/conversation/compact_tests.rs
index 4d8fe2ccf..fa1733bd9 100644
--- a/crates/jp_cli/src/cmd/conversation/compact_tests.rs
+++ b/crates/jp_cli/src/cmd/conversation/compact_tests.rs
@@ -10,7 +10,7 @@ use jp_config::{
     model::{PartialModelConfig, id::PartialModelIdOrAliasConfig},
 };
 use jp_conversation::{
-    Compaction, ConversationStream, ReasoningPolicy, ToolCallPolicy,
+    Compaction, ConversationStream, ReasoningPolicy, SummaryPolicy, ToolCallPolicy,
     event::{ToolCallRequest, ToolCallResponse},
 };
 use jp_printer::Printer;
@@ -18,7 +18,7 @@ use serde_json::{Map, Value};
 
 use super::{
     Compact, IntoPartialAppConfig as _, TimelineSegment, TurnSelection, build_compaction_events,
-    existing_segments, segments_for_compactions, timeline_lines,
+    existing_segments, plan_rule_ranges, segments_for_compactions, timeline_lines,
 };
 
 /// Parse a `Compact` from `jp conversation compact <args>` for flag tests.
@@ -34,6 +34,19 @@ fn parse_compact(args: &[&str]) -> Compact {
     TestCli::try_parse_from(argv).unwrap().compact
 }
 
+/// A rule that summarizes the whole selection, with both keep bounds open so
+/// the rule's own bounds never narrow the window under test.
+fn summary_rule() -> CompactionRuleConfig {
+    CompactionConfig::finalize_rules(vec![PartialCompactionRuleConfig {
+        keep_first: Some(RuleBound::Turns(0)),
+        keep_last: Some(RuleBound::Turns(0)),
+        summary: Some(PartialSummaryConfig::default()),
+        ..PartialCompactionRuleConfig::default()
+    }])
+    .unwrap()
+    .remove(0)
+}
+
 #[test]
 fn bare_compact_flag_parses_without_a_value() {
     // Bare `--compact` (no value) means "apply config rules".
@@ -539,6 +552,66 @@ fn first_and_last_compact_two_windows_and_skip_the_middle() {
     assert_eq!(ranges, vec![(0, 1), (6, 7)]);
 }
 
+#[test]
+fn an_existing_summary_spanning_both_windows_plans_one_range() {
+    // An existing summary over turns 1-8 sits under both `--first 2` and
+    // `--last 2`. `extend_summary_range` grows each window onto it, so both
+    // become 1-8: without coalescing that is two LLM calls and two identical
+    // compactions, the second immediately superseding the first.
+    //
+    // Asserted at the planning seam, which is where the duplicate would be
+    // introduced; going through `build_compaction_events` would need a live
+    // summarizer.
+    let mut stream = ConversationStream::new_test();
+    for t in 0..8 {
+        stream.start_turn(format!("turn {t}"));
+    }
+    stream.add_compaction(Compaction::new(0, 7).with_summary(SummaryPolicy {
+        summary: "existing".to_owned(),
+    }));
+
+    let rule = summary_rule();
+    let compact = parse_compact(&["--first", "2", "--last", "2"]);
+    let windows = compact.range.windows(&stream);
+    assert_eq!(windows.len(), 2, "the two windows start out disjoint");
+
+    let ranges = plan_rule_ranges(&stream, &stream, &rule, &windows, &compact.range);
+
+    assert_eq!(
+        ranges
+            .iter()
+            .map(|r| (r.from_turn, r.to_turn))
+            .collect::<Vec<_>>(),
+        vec![(0, 7)],
+        "both windows extend onto the same existing summary, so they are one range"
+    );
+}
+
+#[test]
+fn disjoint_windows_without_an_overlapping_summary_stay_separate() {
+    // The coalescing must not collapse windows that genuinely name distinct
+    // regions: with no summary to extend onto, `--first 2 --last 2` over 8 turns
+    // plans two ranges.
+    let mut stream = ConversationStream::new_test();
+    for t in 0..8 {
+        stream.start_turn(format!("turn {t}"));
+    }
+
+    let rule = summary_rule();
+    let compact = parse_compact(&["--first", "2", "--last", "2"]);
+    let windows = compact.range.windows(&stream);
+
+    let ranges = plan_rule_ranges(&stream, &stream, &rule, &windows, &compact.range);
+
+    assert_eq!(
+        ranges
+            .iter()
+            .map(|r| (r.from_turn, r.to_turn))
+            .collect::<Vec<_>>(),
+        vec![(0, 1), (6, 7)]
+    );
+}
+
 #[test]
 fn overlapping_first_and_last_windows_compact_once() {
     // On a 3-turn conversation `--first 2 --last 2` covers every turn twice.
diff --git a/crates/jp_cli/src/cmd/turn_selection.rs b/crates/jp_cli/src/cmd/turn_selection.rs
index 6aedfe3a2..ddef49f3c 100644
--- a/crates/jp_cli/src/cmd/turn_selection.rs
+++ b/crates/jp_cli/src/cmd/turn_selection.rs
@@ -497,22 +497,37 @@ impl TurnSelection {
     ///
     /// `--keep-first N --first M` selects the first M turns minus the first N,
     /// e.g. `--keep-first 1 --first 16` selects turns 2 through 16: with N
-    /// greater than M the protected turns swallow the whole selection, so the
-    /// pair is rejected rather than silently selecting nothing.
+    /// greater than M the protected turns swallow that window.
+    /// Swallowing a window is only an error when it takes the whole selection
+    /// with it — `--first`/`--last` are a union, so `--first 1 --last 2
+    /// --keep-first 2` still legitimately selects the final two turns.
     /// Only count-based bounds are comparable up front; durations and the other
     /// bound forms resolve against the stream and may legitimately come up
     /// empty.
     pub(crate) fn validate(&self) -> Result<(), String> {
-        if let (Some(RuleBound::Turns(keep)), Some(first)) = (&self.keep_first, self.first)
-            && *keep > first
+        // The `(keep, count)` pair for a window whose keep flag provably covers
+        // it, or `None` when it doesn't.
+        let swallowed = |keep: Option<&RuleBound>, count: Option<usize>| match (keep, count) {
+            (Some(RuleBound::Turns(keep)), Some(count)) if *keep > count => Some((*keep, count)),
+            _ => None,
+        };
+        let first_swallowed = swallowed(self.keep_first.as_ref(), self.first);
+        let last_swallowed = swallowed(self.keep_last.as_ref(), self.last);
+
+        // A window survives when it names at least one turn and isn't swallowed.
+        let first_survives = self.first.is_some_and(|n| n > 0) && first_swallowed.is_none();
+        let last_survives = self.last.is_some_and(|n| n > 0) && last_swallowed.is_none();
+
+        if let Some((keep, first)) = first_swallowed
+            && !last_survives
         {
             return Err(format!(
                 "--keep-first {keep} is greater than --first {first}: nothing would remain to \
                  select"
             ));
         }
-        if let (Some(RuleBound::Turns(keep)), Some(last)) = (&self.keep_last, self.last)
-            && *keep > last
+        if let Some((keep, last)) = last_swallowed
+            && !first_survives
         {
             return Err(format!(
                 "--keep-last {keep} is greater than --last {last}: nothing would remain to select"
diff --git a/crates/jp_cli/src/cmd/turn_selection_tests.rs b/crates/jp_cli/src/cmd/turn_selection_tests.rs
index cf51f4c55..3c3c50b23 100644
--- a/crates/jp_cli/src/cmd/turn_selection_tests.rs
+++ b/crates/jp_cli/src/cmd/turn_selection_tests.rs
@@ -526,6 +526,53 @@ fn validate_rejects_a_keep_that_swallows_the_selection() {
     assert!(selection.validate().is_ok());
 }
 
+#[test]
+fn validate_allows_a_swallowed_window_when_the_other_survives() {
+    // `--first`/`--last` are a union, so a keep flag covering one window is not
+    // a contradiction while the other window still names turns.
+    let selection = TurnSelection {
+        first: Some(1),
+        last: Some(2),
+        keep_first: Some(RuleBound::Turns(2)),
+        ..Default::default()
+    };
+    assert!(selection.validate().is_ok());
+    // Only the trailing window survives.
+    assert_eq!(windows(&selection, 8), vec![(6, 7)]);
+
+    // The mirror image: `--keep-last` swallows the trailing window.
+    let selection = TurnSelection {
+        first: Some(2),
+        last: Some(1),
+        keep_last: Some(RuleBound::Turns(2)),
+        ..Default::default()
+    };
+    assert!(selection.validate().is_ok());
+    assert_eq!(windows(&selection, 8), vec![(0, 1)]);
+}
+
+#[test]
+fn validate_rejects_keeps_that_swallow_both_windows() {
+    // Neither window survives, so the pair is contradictory after all.
+    let selection = TurnSelection {
+        first: Some(1),
+        last: Some(1),
+        keep_first: Some(RuleBound::Turns(2)),
+        keep_last: Some(RuleBound::Turns(2)),
+        ..Default::default()
+    };
+    assert!(selection.validate().is_err());
+
+    // An explicit zero on the other side is not a surviving window either.
+    let selection = TurnSelection {
+        first: Some(1),
+        last: Some(0),
+        keep_first: Some(RuleBound::Turns(2)),
+        ..Default::default()
+    };
+    assert!(selection.validate().is_err());
+}
+
 #[test]
 fn check_turn_range_rejects_endpoints_past_the_conversation() {
     let selection = TurnSelection {
diff --git a/crates/jp_conversation/src/stream.rs b/crates/jp_conversation/src/stream.rs
index c512e8d0f..fe8718a62 100644
--- a/crates/jp_conversation/src/stream.rs
+++ b/crates/jp_conversation/src/stream.rs
@@ -1090,15 +1090,22 @@ impl ConversationStream {
             return;
         }
 
-        let mut index = 0;
-        let mut keeping = false;
+        let mut turn: usize = 0;
+        // Whether the current turn already holds a conversation event. A
+        // `TurnStart` opens a new turn only when this is set, which is the
+        // boundary rule [`Self::iter_turns`] and
+        // `projection::assign_turn_indices` use: events before the first
+        // `TurnStart` form an implicit turn 0, and the first explicit
+        // `TurnStart` opens turn 1. Numbering the turns any other way here
+        // would drop the turns the caller's predicate meant to keep.
+        let mut current_has_event = false;
 
         self.retain(|event| {
-            if event.is_turn_start() {
-                keeping = keep(index);
-                index += 1;
+            if event.is_turn_start() && current_has_event {
+                turn += 1;
             }
-            keeping
+            current_has_event = true;
+            keep(turn)
         });
     }
 
diff --git a/crates/jp_conversation/src/stream/turn_iter_tests.rs b/crates/jp_conversation/src/stream/turn_iter_tests.rs
index ceeae8b00..57ed4d6bf 100644
--- a/crates/jp_conversation/src/stream/turn_iter_tests.rs
+++ b/crates/jp_conversation/src/stream/turn_iter_tests.rs
@@ -251,6 +251,48 @@ fn retain_turns_noop_when_every_turn_is_kept() {
     assert_eq!(stream.iter_turns().len(), 1);
 }
 
+#[test]
+fn retain_turns_numbers_an_implicit_leading_turn_like_iter_turns() {
+    // `[A, TurnStart, B]` is turn 0 = `[A]` and turn 1 = `[TurnStart, B]`:
+    // a `TurnStart` opens a turn only when the current one already holds an
+    // event. A predicate built from resolved turn positions must agree, or
+    // `--first 1` on a fork keeps B instead of A.
+    let events = || {
+        vec![
+            ConversationEvent::new(ChatRequest::from("A"), ts(0, 0, 0)),
+            ConversationEvent::new(TurnStart, ts(0, 1, 0)),
+            ConversationEvent::new(ChatRequest::from("B"), ts(0, 1, 1)),
+        ]
+    };
+
+    let mut stream = ConversationStream::new_test();
+    stream.extend(events());
+    assert_eq!(
+        stream.iter_turns().len(),
+        2,
+        "fixture has an implicit turn 0"
+    );
+
+    stream.retain_turns(|index| index == 0);
+    let requests: Vec<_> = stream
+        .iter()
+        .filter_map(|e| e.event.as_chat_request())
+        .map(|r| r.content.clone())
+        .collect();
+    assert_eq!(requests, vec!["A"], "turn 0 is the unmarked prefix");
+
+    let mut stream = ConversationStream::new_test();
+    stream.extend(events());
+
+    stream.retain_turns(|index| index == 1);
+    let requests: Vec<_> = stream
+        .iter()
+        .filter_map(|e| e.event.as_chat_request())
+        .map(|r| r.content.clone())
+        .collect();
+    assert_eq!(requests, vec!["B"], "turn 1 is the marked suffix");
+}
+
 #[test]
 fn retain_turns_keeping_nothing_clears() {
     let mut stream = ConversationStream::new_test();

From aaed3c8961fca8fb27140674ab48673661d9f335 Mon Sep 17 00:00:00 2001
From: Jean Mertz <git@jeanmertz.com>
Date: Tue, 28 Jul 2026 09:44:24 +0200
Subject: [PATCH 5/7] review feedback

Signed-off-by: Jean Mertz <git@jeanmertz.com>
---
 crates/jp_cli/src/cmd/turn_selection.rs       | 26 +++++++++---
 crates/jp_cli/src/cmd/turn_selection_tests.rs | 42 +++++++++++++++++++
 2 files changed, 63 insertions(+), 5 deletions(-)

diff --git a/crates/jp_cli/src/cmd/turn_selection.rs b/crates/jp_cli/src/cmd/turn_selection.rs
index ddef49f3c..627fc97a1 100644
--- a/crates/jp_cli/src/cmd/turn_selection.rs
+++ b/crates/jp_cli/src/cmd/turn_selection.rs
@@ -501,22 +501,38 @@ impl TurnSelection {
     /// Swallowing a window is only an error when it takes the whole selection
     /// with it — `--first`/`--last` are a union, so `--first 1 --last 2
     /// --keep-first 2` still legitimately selects the final two turns.
+    /// A window its own keep flag covers exactly (`--last 1 --keep-last 1`)
+    /// contributes no turns either, so it can't stand in as that survivor.
     /// Only count-based bounds are comparable up front; durations and the other
     /// bound forms resolve against the stream and may legitimately come up
     /// empty.
     pub(crate) fn validate(&self) -> Result<(), String> {
-        // The `(keep, count)` pair for a window whose keep flag provably covers
-        // it, or `None` when it doesn't.
+        // The `(keep, count)` pair for a window the keep flag swallows outright
+        // (`keep > count`), or `None` when it doesn't. This is what the error
+        // reports.
         let swallowed = |keep: Option<&RuleBound>, count: Option<usize>| match (keep, count) {
             (Some(RuleBound::Turns(keep)), Some(count)) if *keep > count => Some((*keep, count)),
             _ => None,
         };
+
+        // Whether the keep flag provably leaves the window empty (`keep >=
+        // count`). Equality on its own is allowed — empty but not
+        // contradictory — so this is deliberately a wider test than
+        // `swallowed`: an exactly-covered window names no turn, and so cannot
+        // excuse a swallowed sibling.
+        let covered = |keep: Option<&RuleBound>, count: Option<usize>| match (keep, count) {
+            (Some(RuleBound::Turns(keep)), Some(count)) => *keep >= count,
+            _ => false,
+        };
+
         let first_swallowed = swallowed(self.keep_first.as_ref(), self.first);
         let last_swallowed = swallowed(self.keep_last.as_ref(), self.last);
 
-        // A window survives when it names at least one turn and isn't swallowed.
-        let first_survives = self.first.is_some_and(|n| n > 0) && first_swallowed.is_none();
-        let last_survives = self.last.is_some_and(|n| n > 0) && last_swallowed.is_none();
+        // A window survives when it names at least one turn and isn't covered.
+        let first_survives =
+            self.first.is_some_and(|n| n > 0) && !covered(self.keep_first.as_ref(), self.first);
+        let last_survives =
+            self.last.is_some_and(|n| n > 0) && !covered(self.keep_last.as_ref(), self.last);
 
         if let Some((keep, first)) = first_swallowed
             && !last_survives
diff --git a/crates/jp_cli/src/cmd/turn_selection_tests.rs b/crates/jp_cli/src/cmd/turn_selection_tests.rs
index 3c3c50b23..331ad6fef 100644
--- a/crates/jp_cli/src/cmd/turn_selection_tests.rs
+++ b/crates/jp_cli/src/cmd/turn_selection_tests.rs
@@ -573,6 +573,48 @@ fn validate_rejects_keeps_that_swallow_both_windows() {
     assert!(selection.validate().is_err());
 }
 
+#[test]
+fn validate_rejects_a_swallowed_window_beside_an_exactly_covered_one() {
+    // `--keep-last 1 --last 1` names no turn on any stream, so it cannot be the
+    // survivor that excuses `--keep-first 2 --first 1`. Recognising only
+    // `keep > count` here would let this through while the `--keep-first 2
+    // --first 1` pair errors on its own.
+    let selection = TurnSelection {
+        first: Some(1),
+        last: Some(1),
+        keep_first: Some(RuleBound::Turns(2)),
+        keep_last: Some(RuleBound::Turns(1)),
+        ..Default::default()
+    };
+    assert!(selection.validate().is_err());
+    assert!(selection.resolve(&stream(8)).is_empty());
+
+    // The mirror image.
+    let selection = TurnSelection {
+        first: Some(1),
+        last: Some(1),
+        keep_first: Some(RuleBound::Turns(1)),
+        keep_last: Some(RuleBound::Turns(2)),
+        ..Default::default()
+    };
+    assert!(selection.validate().is_err());
+    assert!(selection.resolve(&stream(8)).is_empty());
+}
+
+#[test]
+fn validate_allows_equal_keep_and_count_on_both_windows() {
+    // Equality alone stays allowed — empty but not contradictory — and that
+    // policy doesn't change just because both windows hit it.
+    let selection = TurnSelection {
+        first: Some(2),
+        last: Some(2),
+        keep_first: Some(RuleBound::Turns(2)),
+        keep_last: Some(RuleBound::Turns(2)),
+        ..Default::default()
+    };
+    assert!(selection.validate().is_ok());
+}
+
 #[test]
 fn check_turn_range_rejects_endpoints_past_the_conversation() {
     let selection = TurnSelection {

From dcb9e4fca2fd14a7397e5fa4bb551cf470b6b54f Mon Sep 17 00:00:00 2001
From: Jean Mertz <git@jeanmertz.com>
Date: Tue, 28 Jul 2026 11:16:23 +0200
Subject: [PATCH 6/7] review feedback

Signed-off-by: Jean Mertz <git@jeanmertz.com>
---
 crates/jp_cli/src/cmd/time.rs                 |  9 ++++-
 crates/jp_cli/src/cmd/time_tests.rs           | 12 ++++++
 crates/jp_cli/src/cmd/turn_selection.rs       | 29 ++++++++++++---
 crates/jp_cli/src/cmd/turn_selection_tests.rs | 37 +++++++++++++++++++
 4 files changed, 80 insertions(+), 7 deletions(-)

diff --git a/crates/jp_cli/src/cmd/time.rs b/crates/jp_cli/src/cmd/time.rs
index b2d8aafeb..40c2e269a 100644
--- a/crates/jp_cli/src/cmd/time.rs
+++ b/crates/jp_cli/src/cmd/time.rs
@@ -48,7 +48,14 @@ impl FromStr for TimeThreshold {
 
         // Try as relative duration (e.g. "3w", "30d", "6h").
         if let Ok(dur) = humantime::parse_duration(s) {
-            let cutoff = Utc::now() - dur;
+            // `humantime` accepts durations far outside chrono's representable
+            // range, and subtracting one panics rather than saturating, so an
+            // oversized value has to fail as a parse error instead of aborting
+            // the process.
+            let cutoff = chrono::Duration::from_std(dur)
+                .ok()
+                .and_then(|dur| Utc::now().checked_sub_signed(dur))
+                .ok_or_else(|| format!("invalid time threshold '{s}': duration is too large"))?;
             return Ok(Self(cutoff));
         }
 
diff --git a/crates/jp_cli/src/cmd/time_tests.rs b/crates/jp_cli/src/cmd/time_tests.rs
index 15aa40717..30c3c086f 100644
--- a/crates/jp_cli/src/cmd/time_tests.rs
+++ b/crates/jp_cli/src/cmd/time_tests.rs
@@ -27,6 +27,18 @@ fn parse_relative_duration_days() {
     assert!((diff.num_days() - 30).abs() <= 1);
 }
 
+#[test]
+fn parse_rejects_a_duration_chrono_cannot_represent() {
+    // `humantime` parses durations far larger than chrono's date range, and
+    // subtracting one from `now` panics. `--created-since 10000000000000s` must
+    // return a parse error rather than abort the process.
+    let err = "10000000000000s".parse::<TimeThreshold>().unwrap_err();
+    assert!(
+        err.contains("too large"),
+        "expected a too-large error, got: {err}"
+    );
+}
+
 #[test]
 fn parse_relative_duration_hours() {
     let t: TimeThreshold = "6h".parse().unwrap();
diff --git a/crates/jp_cli/src/cmd/turn_selection.rs b/crates/jp_cli/src/cmd/turn_selection.rs
index 627fc97a1..160276df5 100644
--- a/crates/jp_cli/src/cmd/turn_selection.rs
+++ b/crates/jp_cli/src/cmd/turn_selection.rs
@@ -76,7 +76,14 @@ fn parse_bound(s: &str) -> Result<CliRangeBound, String> {
     }
 
     if let Ok(d) = humantime::Duration::from_str(s) {
-        return Ok(CliRangeBound::At(Utc::now() - Duration::from(d)));
+        // `humantime` accepts durations far outside chrono's representable range,
+        // and subtracting one panics rather than saturating, so an oversized
+        // value has to fail as a parse error instead of aborting the process.
+        let cutoff = chrono::Duration::from_std(Duration::from(d))
+            .ok()
+            .and_then(|d| Utc::now().checked_sub_signed(d))
+            .ok_or_else(|| format!("invalid turn bound `{s}`: duration is too large"))?;
+        return Ok(CliRangeBound::At(cutoff));
     }
 
     if let Ok(dt) = DateTime::parse_from_rfc3339(s) {
@@ -347,10 +354,15 @@ pub(crate) fn keep_first_bound(bound: &RuleBound, events: &ConversationStream) -
             let Some(first) = events.iter().next() else {
                 return Bound::Empty;
             };
-            let Ok(d) = chrono::Duration::from_std(*d) else {
+            // An unrepresentable duration, or a cutoff past the end of
+            // representable time, means the window covers every turn.
+            let Some(cutoff) = chrono::Duration::from_std(*d)
+                .ok()
+                .and_then(|d| first.event.timestamp.checked_add_signed(d))
+            else {
                 return Bound::Empty;
             };
-            match events.turn_at_time(first.event.timestamp + d) {
+            match events.turn_at_time(cutoff) {
                 Some(turn) => Bound::At(RangeBound::Absolute(turn.index() + 1)),
                 None => Bound::At(RangeBound::Absolute(0)),
             }
@@ -369,8 +381,12 @@ pub(crate) fn keep_last_bound(bound: &RuleBound, events: &ConversationStream) ->
         RuleBound::Absolute(n) => Bound::At(RangeBound::Absolute(n.saturating_sub(1))),
         RuleBound::Duration(d) => {
             // Protect the trailing `d` window. A window covering the whole
-            // conversation protects everything.
-            match events.turn_at_time(Utc::now() - *d) {
+            // conversation protects everything, which is also what a duration
+            // chrono can't represent amounts to.
+            let cutoff = chrono::Duration::from_std(*d)
+                .ok()
+                .and_then(|d| Utc::now().checked_sub_signed(d));
+            match cutoff.and_then(|cutoff| events.turn_at_time(cutoff)) {
                 Some(turn) => Bound::At(RangeBound::Absolute(turn.index())),
                 None => Bound::Empty,
             }
@@ -441,7 +457,8 @@ pub(crate) struct TurnSelection {
     /// Protect the first N turns from the selection.
     ///
     /// Accepts a turn count (`2`), an absolute 1-based turn (`@3`), a from-end
-    /// offset (`-3`), or a duration (`5h`).
+    /// offset (`-3`), a duration (`5h`), or `last-compaction` (protect every
+    /// turn through the most recent compaction).
     /// Composes with every other selector: the selection starts no earlier than
     /// the first unprotected turn.
     #[arg(long, allow_negative_numbers = true)]
diff --git a/crates/jp_cli/src/cmd/turn_selection_tests.rs b/crates/jp_cli/src/cmd/turn_selection_tests.rs
index 331ad6fef..0b489753b 100644
--- a/crates/jp_cli/src/cmd/turn_selection_tests.rs
+++ b/crates/jp_cli/src/cmd/turn_selection_tests.rs
@@ -118,6 +118,43 @@ fn parse_bound_rejects_unparseable_values() {
     assert!(parse_bound("2026-13-01").is_err());
 }
 
+#[test]
+fn parse_bound_rejects_a_duration_chrono_cannot_represent() {
+    // `humantime` happily parses durations far larger than chrono's date range.
+    // Subtracting one from `now` panics, so an oversized value must come back as
+    // a parse error rather than aborting the process mid-parse.
+    for s in ["10000000000000s", "100000000years"] {
+        let err = parse_bound(s).unwrap_err();
+        assert!(
+            err.contains("too large"),
+            "`{s}` should be rejected as too large, got: {err}"
+        );
+    }
+
+    // The clap-level forms reject it too, on both ends.
+    assert!(parse(&["--from", "10000000000000s"]).is_err());
+    assert!(parse(&["--to", "10000000000000s"]).is_err());
+}
+
+#[test]
+fn keep_bounds_treat_an_unrepresentable_duration_as_covering_everything() {
+    // The duration arms resolve against the stream, so an oversized value can't
+    // fail at parse time. It means "the protected window covers every turn",
+    // which is what `Bound::Empty` already encodes in both arms.
+    let huge = RuleBound::Duration(std::time::Duration::from_secs(10_000_000_000_000));
+    let events = stream(5);
+
+    assert!(matches!(keep_first_bound(&huge, &events), Bound::Empty));
+    assert!(matches!(keep_last_bound(&huge, &events), Bound::Empty));
+
+    // And the whole selection resolves to nothing rather than panicking.
+    let selection = TurnSelection {
+        keep_first: Some(huge),
+        ..Default::default()
+    };
+    assert!(selection.resolve(&events).is_empty());
+}
+
 #[test]
 fn parse_to_bound_rejects_last_compaction_but_accepts_other_forms() {
     // The most-recent-compaction marker is start-only, so `--to` rejects it

From 5b1c36a526c9e2f1c4ac2f440828df0848b11ce3 Mon Sep 17 00:00:00 2001
From: Jean Mertz <git@jeanmertz.com>
Date: Tue, 28 Jul 2026 11:22:52 +0200
Subject: [PATCH 7/7] fixup! review feedback

Signed-off-by: Jean Mertz <git@jeanmertz.com>
---
 docs/.vitepress/rfd-summaries.json | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/docs/.vitepress/rfd-summaries.json b/docs/.vitepress/rfd-summaries.json
index 731e64e9b..8a9cd2094 100644
--- a/docs/.vitepress/rfd-summaries.json
+++ b/docs/.vitepress/rfd-summaries.json
@@ -16,7 +16,7 @@
     "summary": "Record inquiry events in conversation stream with centralized filtering to keep them hidden from LLM providers."
   },
   "006-turn-scoped-mutations.md": {
-    "hash": "6868fb798f157a665458061f41be6833471569f0a335d44eb12c0bc07805e64b",
+    "hash": "a5f4fd2d6efca102688b41d46ac3168a80bc9e52bfc6c32eb173994094008183",
     "summary": "Restrict stream mutations to turn-scoped accessors, preventing invalid event sequences through compile-time guarantees."
   },
   "007-llamacpp-reasoning.md": {
@@ -84,7 +84,7 @@
     "summary": "Detached conversation execution via background processes and attachment—abandoned, split into RFD 023 and 027."
   },
   "023-resumable-conversation-turns.md": {
-    "hash": "51e4f08b8b9594121c6ded7cd7e40229e9394f4e40519829cd4edf2a5c775cdc",
+    "hash": "61271dd23ac8ff587c9030fdd0d0982a1e0367e186ecd4273b6e5bca039eac41",
     "summary": "Persist tool results incrementally, split incomplete turns from stream, resume with interactive prompt or --continue-turn flag."
   },
   "024-detached-query-execution.md": {
@@ -140,7 +140,7 @@
     "summary": "Extend `--cfg` path resolution to search user-global, workspace, and user-workspace config roots, merging matches."
   },
   "036-conversation-compaction.md": {
-    "hash": "a4bc90faba1ea514edb3b0a9414304a55c4b1c92f47ec516a4385c83596fa4c3",
+    "hash": "eed749e23c5a92222b9741d9895df53bc14092cc5d692e162f4b7537b302b94a",
     "summary": "Composable conversation compaction via mechanical strategies, tool-aware deduplication, LLM summarization, and protocol extensions for declarative compaction hints."
   },
   "037-await-tool-for-stateful-handle-synchronization.md": {
@@ -148,7 +148,7 @@
     "summary": "Introduces `await` built-in tool to synchronize on parallel stateful tool handles with `any`/`all` completion modes."
   },
   "039-conversation-trees.md": {
-    "hash": "7b6dad7a980ab18e0ada448b13caa0f89423fc2b33117cee5b2e1372f51dcbb6",
+    "hash": "75366f5877cf5bfc4d48c2f21f8cd6a51ba78bfa8f67ebc78a233539db9c6c45",
     "summary": "Add parent-child conversation relationships via metadata field, enabling fork lineage and hierarchical organization without nested directories."
   },
   "040-hidden-conversations-and-tool-context.md": {
@@ -192,7 +192,7 @@
     "summary": "Introduces configurable detached prompt policy, `--non-interactive` flag, and `exclusive` question property for non-interactive environments."
   },
   "050-scripting-ergonomics-for-conversation-management.md": {
-    "hash": "1a775369266ab20158c1b77693098649e2f1cf0bc3d035becb3c3c88753bbd76",
+    "hash": "a37bf1a1d4aa1fcccd42b7ab1f669acc6195a01b22859ee04586a57ca5b7bfbd",
     "summary": "Adds scripting ergonomics: shared config structs, `conversation new` command, `--no-activate` flag, and `--root-id` ancestry constraint."
   },
   "051-sub-agent-workflows.md": {
@@ -204,8 +204,8 @@
     "summary": "Introduces Workspace::sanitize() method that validates .jp data store, moves corrupt conversations to .trash/ with error explanations, and ensures four invariants before CLI commands run."
   },
   "053-auto-refresh-conversation-titles.md": {
-    "hash": "245eac64105b376afb1148a74c06983f4b26258cc6281300f0ea90292ed8f20b",
-    "summary": "Auto-refresh stale conversation titles periodically by re-running LLM generation when accumulated turns exceed a configured threshold."
+    "hash": "5d1c5c9e3f674780d3b34a01e8c8739e76eb121fa35a62a9ba8040fb7ae08592",
+    "summary": "Periodically auto-refresh stale conversation titles via background LLM calls with configurable thresholds, context windows, and legacy-conversation handling."
   },
   "054-split-conversation-config-and-events.md": {
     "hash": "56fc95c6c22e284ae9d5b2d87cbee0cf4ded0ac4a7ef77ac4b2da32dfa943883",
@@ -248,7 +248,7 @@
     "summary": "Extend config wizard with frecency-based field ordering using CLI usage tracking data."
   },
   "064-non-destructive-conversation-compaction.md": {
-    "hash": "e1407202e2c53a7168b2b92ca4f0528644848cb8ca40062fe9883557be713b9a",
+    "hash": "418d90052040c11bb52c94998ea718c45198f2063fb416747a943dfcdbd0e2ea",
     "summary": "Non-destructive conversation compaction through overlay events that project reduced views without mutating stored data."
   },
   "065-typed-resource-model-for-attachments.md": {
@@ -284,7 +284,7 @@
     "summary": "Introduces `-C` flag to selectively revert previously applied config sources using provenance tracking via claims maps."
   },
   "071-conversation-archiving.md": {
-    "hash": "62504943171f773f43669b93da6a2ec48077ee64e3742b6d63da743777845171",
+    "hash": "610123dc36a3a09bbf3f9b26b9910b7c37bf0e45ae43e0b65e6420b7b94eb69c",
     "summary": "Adds conversation archiving to JP, moving inactive conversations to a hidden partition while preserving them."
   },
   "038-config-reset-keywords.md": {
@@ -296,7 +296,7 @@
     "summary": "JP loads config from four implicit sources plus environment variables, with extends directives and inherit flags controlling precedence."
   },
   "074-eager-loading-with-command-declared-data-requirements.md": {
-    "hash": "02ee9a3d5c2f160e6b4a241c9fba4f23b968cbd09657b0078143efba3d381a37",
+    "hash": "bbf0001f9297d9cc00382c84f310f9fe3a389f3f194b62d1f9d389fbc52bce62",
     "summary": "Commands declare data needs upfront; startup eagerly loads and validates it, enabling infallible access during execution."
   },
   "075-tool-sandbox-and-access-policy.md": {