diff --git a/agent_assembly/__init__.py b/agent_assembly/__init__.py
index a138365c..f100befd 100644
--- a/agent_assembly/__init__.py
+++ b/agent_assembly/__init__.py
@@ -23,6 +23,7 @@
 _LAZY_EXPORTS: dict[str, str] = {
     "init_assembly": _MODULE_CORE,
     "AssemblyContext": _MODULE_CORE,
+    "ENFORCEMENT_MODES": _MODULE_CORE,
     "GovernanceInterceptor": _MODULE_ADAPTERS,
     "FrameworkAdapter": _MODULE_ADAPTERS,
     "AssemblyError": _MODULE_EXCEPTIONS,
@@ -44,6 +45,7 @@
     "__version__",
     "init_assembly",
     "AssemblyContext",
+    "ENFORCEMENT_MODES",
     "GovernanceInterceptor",
     "FrameworkAdapter",
     "AssemblyError",
@@ -103,6 +105,7 @@ def __dir__() -> list[str]:
 if TYPE_CHECKING:
     from agent_assembly.adapters import FrameworkAdapter as FrameworkAdapter
     from agent_assembly.adapters import GovernanceInterceptor as GovernanceInterceptor
+    from agent_assembly.core import ENFORCEMENT_MODES as ENFORCEMENT_MODES
     from agent_assembly.core import AssemblyContext as AssemblyContext
     from agent_assembly.core import init_assembly as init_assembly
     from agent_assembly.exceptions import (
diff --git a/agent_assembly/core/__init__.py b/agent_assembly/core/__init__.py
index aaff7b6f..82d45c7b 100644
--- a/agent_assembly/core/__init__.py
+++ b/agent_assembly/core/__init__.py
@@ -5,21 +5,27 @@
 from typing import TYPE_CHECKING, Any
 
 if TYPE_CHECKING:
-    from agent_assembly.core.assembly import AssemblyContext, init_assembly
+    from agent_assembly.core.assembly import (
+        ENFORCEMENT_MODES,
+        AssemblyContext,
+        init_assembly,
+    )
     from agent_assembly.core.lineage import LineageRegistry
 
-__all__ = ["init_assembly", "AssemblyContext", "LineageRegistry"]
+__all__ = ["init_assembly", "AssemblyContext", "ENFORCEMENT_MODES", "LineageRegistry"]
 
 
 def __getattr__(name: str) -> Any:
-    if name in ("AssemblyContext", "init_assembly"):
+    if name in ("AssemblyContext", "init_assembly", "ENFORCEMENT_MODES"):
         from agent_assembly.core.assembly import (  # noqa: PLC0415
+            ENFORCEMENT_MODES,
             AssemblyContext,
             init_assembly,
         )
 
         globals()["AssemblyContext"] = AssemblyContext
         globals()["init_assembly"] = init_assembly
+        globals()["ENFORCEMENT_MODES"] = ENFORCEMENT_MODES
         return globals()[name]
     if name == "LineageRegistry":
         from agent_assembly.core.lineage import LineageRegistry  # noqa: PLC0415
diff --git a/agent_assembly/core/assembly.py b/agent_assembly/core/assembly.py
index 6352c1e0..8c483853 100644
--- a/agent_assembly/core/assembly.py
+++ b/agent_assembly/core/assembly.py
@@ -45,13 +45,23 @@
 Mirrors ``aa_core::EnforcementMode`` on the wire; uses the same snake_case
 tokens the gateway expects in the registration body."""
 
+ENFORCEMENT_MODES: tuple[EnforcementMode, ...] = ("enforce", "observe", "disabled")
+"""Canonical, ordered enforcement-mode tokens — the public parity surface.
+
+Single source of truth for the enforcement-mode set: the private
+``_VALID_ENFORCEMENT_MODES`` membership validator is derived from this tuple
+(``frozenset(ENFORCEMENT_MODES)``) so the two can never drift. Ordering is
+significant — the cross-SDK conformance cross-check (AAASM-4856) asserts the
+Python/Node/Go SDKs each expose this exact sequence, matching the canonical
+``aa_core::EnforcementMode`` order on the wire."""
+
 ENV_GATEWAY_URL = "AA_GATEWAY_URL"
 ENV_CONTROL_PLANE_URL = "AA_CONTROL_PLANE_URL"
 
 _DEFAULT_AGENT_ID = "agent-assembly-default"
 _AGENT_ID_RE = re.compile(r"^[A-Za-z0-9_.-]{1,128}$")
 _VALID_RUNTIME_MODES = {"auto", "ebpf", "proxy", "sdk-only"}
-_VALID_ENFORCEMENT_MODES: frozenset[EnforcementMode] = frozenset({"enforce", "observe", "disabled"})
+_VALID_ENFORCEMENT_MODES: frozenset[EnforcementMode] = frozenset(ENFORCEMENT_MODES)
 _INIT_LOCK = Lock()
 _ACTIVE_CONTEXT: AssemblyContext | None = None
 
diff --git a/test/unit/core/test_core_lazy_exports.py b/test/unit/core/test_core_lazy_exports.py
index ca697cbd..9ab8cf02 100644
--- a/test/unit/core/test_core_lazy_exports.py
+++ b/test/unit/core/test_core_lazy_exports.py
@@ -19,6 +19,12 @@ def test_lazy_getattr_resolves_init_assembly_and_assembly_context() -> None:
     assert core.AssemblyContext is AssemblyContext
 
 
+def test_lazy_getattr_resolves_enforcement_modes() -> None:
+    from agent_assembly.core.assembly import ENFORCEMENT_MODES
+
+    assert core.ENFORCEMENT_MODES is ENFORCEMENT_MODES
+
+
 def test_lazy_getattr_resolves_lineage_registry() -> None:
     from agent_assembly.core.lineage import LineageRegistry
 
@@ -32,4 +38,9 @@ def test_lazy_getattr_raises_attribute_error_for_unknown_symbol() -> None:
 
 
 def test_all_lists_the_public_lazy_exports() -> None:
-    assert set(core.__all__) == {"init_assembly", "AssemblyContext", "LineageRegistry"}
+    assert set(core.__all__) == {
+        "init_assembly",
+        "AssemblyContext",
+        "ENFORCEMENT_MODES",
+        "LineageRegistry",
+    }
diff --git a/test/unit/test_enforcement_modes_export.py b/test/unit/test_enforcement_modes_export.py
new file mode 100644
index 00000000..e8c8fa05
--- /dev/null
+++ b/test/unit/test_enforcement_modes_export.py
@@ -0,0 +1,29 @@
+"""AAASM-4856: `agent_assembly.ENFORCEMENT_MODES` public parity surface.
+
+The cross-SDK enforcement-mode parity conformance cross-check in e2e-public
+reads ``getattr(agent_assembly, "ENFORCEMENT_MODES", None)`` to assert the
+installed Python SDK against the canonical ordered set. These tests pin that
+surface: it must resolve, be publicly discoverable via ``__all__``, carry the
+exact canonical order, and stay in sync with the private membership validator
+it is the single source of truth for.
+"""
+
+from __future__ import annotations
+
+import agent_assembly
+import agent_assembly.core.assembly as assembly
+
+
+def test_enforcement_modes_is_the_canonical_ordered_tuple() -> None:
+    # Order is significant — the cross-SDK cross-check compares sequences.
+    assert agent_assembly.ENFORCEMENT_MODES == ("enforce", "observe", "disabled")
+
+
+def test_enforcement_modes_is_a_public_export() -> None:
+    assert "ENFORCEMENT_MODES" in agent_assembly.__all__
+
+
+def test_enforcement_modes_stays_in_sync_with_private_validator() -> None:
+    # The public constant is the single source of truth; the private validator
+    # is derived from it, so the two can never drift.
+    assert frozenset(agent_assembly.ENFORCEMENT_MODES) == assembly._VALID_ENFORCEMENT_MODES