adcontextprotocol · aleksUIX · Jul 6, 2026
diff --git a/.changeset/fix-creative-governance-phantom-error-codes.md b/.changeset/fix-creative-governance-phantom-error-codes.md
@@ -0,0 +1,5 @@
+---
+"adcontextprotocol": patch
+---
+
+Replace phantom error codes in creative and campaign-governance task docs with canonical enum members. `sync_creatives`, `build_creative`, the Creative Protocol specification, `check_governance`, and `sync_plans` documented 13 `errors[].code` values that do not exist in `enums/error-code.json` (`INVALID_FORMAT`, `ASSET_PROCESSING_FAILED`, `BRAND_SAFETY_VIOLATION`, `FORMAT_MISMATCH`, `CREATIVE_IN_ACTIVE_DELIVERY`, `ASSET_MISSING`, `ASSET_INVALID`, `GENERATION_FAILED`, `INVALID_MANIFEST`, `AMBIGUOUS_CHECK_TYPE`, `SELLER_NOT_RECOGNIZED`, `INVALID_PLAN`, `BUDGET_BELOW_COMMITTED`). SDKs that validate `errors[].code` against the published enum reject responses built from the docs literally, the same failure mode as #4852 and #5307. Each phantom is remapped to the existing code with matching semantics (`UNSUPPORTED_FEATURE`, `VALIDATION_ERROR`, `CREATIVE_REJECTED`, `INVALID_STATE`, `INVALID_REQUEST`, `PERMISSION_DENIED`); `GENERATION_FAILED` is replaced with guidance that generation-pipeline failures surface as task-level failure with the most specific applicable canonical code, per the open-vocabulary rule on `error-code.json`. Also fixes the one live `INVALID_FORMAT` emission in the training-agent reference implementation. Docs and reference implementation only; no wire change.
diff --git a/docs/creative/specification.mdx b/docs/creative/specification.mdx
@@ -394,10 +394,9 @@ Creative agents MUST return errors using the [standard AdCP error schema](/docs/
 Common error codes:
 
 - `REFERENCE_NOT_FOUND`: Requested format does not exist or is not accessible (`error.field` identifies the `format_id`)
-- `VALIDATION_ERROR`: Manifest failed format validation
-- `ASSET_MISSING`: Required asset not provided in manifest
-- `ASSET_INVALID`: Asset does not meet format constraints
-- `GENERATION_FAILED`: Creative generation could not be completed
+- `VALIDATION_ERROR`: Manifest failed format validation: a required asset is missing from the manifest, or an asset does not meet the format's constraints (`error.field` identifies the offending asset path)
+
+Generation-pipeline failures (model or rendering errors during `build_creative`) surface as task-level failure (`status: "failed"`) with the most specific applicable code in `errors[]`. The error-code vocabulary is open: sellers MAY return platform-specific codes for failure modes the canonical enum does not cover, and agents MUST handle unknown codes by falling back to the recovery classification.
 
 ## Security considerations
 

diff --git a/docs/creative/task-reference/build_creative.mdx b/docs/creative/task-reference/build_creative.mdx
@@ -1526,6 +1526,6 @@ To refine, pass the previous response's `creative_manifest` back as input with a
 | Code | Description |
 |------|-------------|
 | `FORMAT_NOT_SUPPORTED` | The `target_format_id` (or `target_format_ids[N]` in a multi-format request) is not supported by this creative agent. For canonical creative-agent routing, retry with an advertised `creative.supported_formats[].capability_id`; legacy named-format IDs remain valid when the agent still advertises them. |
-| `INVALID_MANIFEST` | The `creative_manifest` is malformed or missing required assets for the target format |
+| `VALIDATION_ERROR` | The `creative_manifest` is malformed or missing required assets for the target format |
 | `CREATIVE_NOT_FOUND` | The `creative_id` does not exist in the agent's library (or in the specified `concept_id`) |
 | `COMPLIANCE_UNSATISFIED` | A required disclosure from the brief cannot be rendered in the target format (e.g., format does not support the required disclosure position) |
diff --git a/docs/creative/task-reference/sync_creatives.mdx b/docs/creative/task-reference/sync_creatives.mdx
@@ -825,12 +825,11 @@ Poll `tasks/get` or wait for the webhook. The completion artifact carries the `c
 
 | Error Code                | Description                                       | Resolution                                                           |
 | ------------------------- | ------------------------------------------------- | -------------------------------------------------------------------- |
-| `INVALID_FORMAT`          | Format not supported by product                   | Check product's supported formats via `list_creative_formats`        |
-| `ASSET_PROCESSING_FAILED` | Asset file corrupt or invalid                     | Verify asset meets format requirements (codec, dimensions, duration) |
+| `UNSUPPORTED_FEATURE`     | Format not supported by this seller or product    | Check product's supported formats via `list_creative_formats`        |
+| `VALIDATION_ERROR`        | Manifest failed format validation: an asset file is corrupt or invalid, or assets don't match the format's requirements (codec, dimensions, duration). `error.field` identifies the offending asset path | Verify asset types and specifications match the format definition |
 | `PACKAGE_NOT_FOUND`       | Package ID doesn't exist in media buy             | Verify `package_id`; for legacy package correlation use `get_media_buys` + package `context.buyer_ref` |
-| `BRAND_SAFETY_VIOLATION`  | Creative failed brand safety scan                 | Review content against publisher's brand safety guidelines           |
-| `FORMAT_MISMATCH`         | Assets don't match format requirements            | Verify asset types and specifications match format definition        |
-| `CREATIVE_IN_ACTIVE_DELIVERY` | Creative is assigned to an active, non-paused package (blocks updates and `delete_missing` deletions) | Pause the package first, or create a new creative version        |
+| `CREATIVE_REJECTED`       | Creative failed content policy or brand safety review | Review content against the seller's advertising policies         |
+| `INVALID_STATE`           | Creative is assigned to an active, non-paused package (blocks updates and `delete_missing` deletions) | Pause the package first, or create a new creative version        |
 
 ## Best practices
 

diff --git a/docs/governance/campaign/tasks/check_governance.mdx b/docs/governance/campaign/tasks/check_governance.mdx
@@ -478,9 +478,9 @@ The seller MUST adjust pacing and re-call `check_governance` immediately. The `n
 | Code | Recovery | Description |
 |------|----------|-------------|
 | `PLAN_NOT_FOUND` | correctable | No plan with this ID. The buyer may not have synced the plan yet. |
-| `AMBIGUOUS_CHECK_TYPE` | correctable | Request contains both intent fields (`tool` + `payload`) and execution fields (`governance_context` + `planned_delivery`). Send one set or the other. |
+| `INVALID_REQUEST` | correctable | Request contains both intent fields (`tool` + `payload`) and execution fields (`governance_context` + `planned_delivery`), so the check type cannot be inferred. Send one set or the other. |
 | `CAMPAIGN_SUSPENDED` | correctable | Campaign governance is suspended pending human review. |
-| `SELLER_NOT_RECOGNIZED` | correctable | The caller URL is not in the plan's `approved_sellers` list. |
+| `PERMISSION_DENIED` | correctable | The caller URL is not in the plan's `approved_sellers` list. |
 
 ## Related tasks
 

diff --git a/docs/governance/campaign/tasks/sync_plans.mdx b/docs/governance/campaign/tasks/sync_plans.mdx
@@ -231,9 +231,9 @@ Policy categories are distinct from `brand.industries`. Industries describe what
 
 | Code | Recovery | Description |
 |------|----------|-------------|
-| `INVALID_PLAN` | correctable | Plan is missing required fields or has invalid values. |
+| `INVALID_REQUEST` | correctable | Plan is missing required fields or has invalid values. `error.field` identifies the offending plan field. |
 | `REFERENCE_NOT_FOUND` | correctable | Brand domain could not be resolved via the Brand Protocol. The governance agent cannot determine applicable compliance policies without a valid brand reference. `error.field` MUST identify the brand field that failed to resolve. |
-| `BUDGET_BELOW_COMMITTED` | correctable | Cannot reduce budget below the amount already committed (on plan update). |
+| `VALIDATION_ERROR` | correctable | Cannot reduce budget below the amount already committed (on plan update). `error.field` identifies the budget field. |
 
 ## Related tasks
 

diff --git a/server/src/training-agent/task-handlers.ts b/server/src/training-agent/task-handlers.ts
@@ -7189,7 +7189,7 @@ export async function handlePreviewCreative(args: ToolArgs, ctx: TrainingContext
   if (!preview) {
     const fmtId = manifest.format_id?.id || 'unknown';
     return {
-      errors: [{ code: 'INVALID_FORMAT', message: `Format "${fmtId}" is not supported. Use list_creative_formats to discover available formats.` }],
+      errors: [{ code: 'UNSUPPORTED_FEATURE', message: `Format "${fmtId}" is not supported. Use list_creative_formats to discover available formats.` }],
     };
   }