diff --git a/src/modules/aix/server/dispatch/chatGenerate/parsers/anthropic.parser.ts b/src/modules/aix/server/dispatch/chatGenerate/parsers/anthropic.parser.ts
index b596fe3bd..e06d3d55e 100644
--- a/src/modules/aix/server/dispatch/chatGenerate/parsers/anthropic.parser.ts
+++ b/src/modules/aix/server/dispatch/chatGenerate/parsers/anthropic.parser.ts
@@ -401,6 +401,10 @@ export function createAnthropicMessageParser(): ChatGenerateParseFunction {
         if (delta.container)
           _emitContainerState(pt, delta.container);
 
+        // -> Refusal details (structured) - surface category/explanation when stop_reason === 'refusal'
+        if (delta.stop_reason === 'refusal' && delta.stop_details)
+          _emitRefusalDetails(pt, delta.stop_details);
+
         // -> Token Stop Reason
         const tokenStopReason = _fromAnthropicStopReason(delta.stop_reason, 'message_delta');
         if (tokenStopReason !== null)
@@ -511,6 +515,7 @@ export function createAnthropicMessageParserNS(): ChatGenerateParseFunction {
       content,
       container,
       stop_reason,
+      stop_details,
       usage,
     } = AnthropicWire_API_Message_Create.Response_schema.parse(JSON.parse(fullData));
 
@@ -650,6 +655,10 @@ export function createAnthropicMessageParserNS(): ChatGenerateParseFunction {
         _createAnthropicPauseTurnContinuation(content, container?.id),
       );
 
+    // -> Refusal details (structured) - surface category/explanation when stop_reason === 'refusal'
+    if (stop_reason === 'refusal' && stop_details)
+      _emitRefusalDetails(pt, stop_details);
+
     // -> Token Stop Reason (pause_turn already thrown above)
     const tokenStopReason = _fromAnthropicStopReason(stop_reason, 'parser_NS');
     if (tokenStopReason !== null)
@@ -681,6 +690,20 @@ function _emitContainerState(pt: IParticleTransmitter, container: { id: string;
   });
 }
 
+/**
+ * Surface structured refusal details (stop_reason === 'refusal') as inline text.
+ * Anthropic's streaming classifiers can intervene mid-generation; appending the category + explanation
+ * as text lets the user see WHY the model refused without touching terminationReason (which message_stop
+ * will set to 'done-dialect') - avoids a spurious override warning.
+ */
+function _emitRefusalDetails(pt: IParticleTransmitter, stopDetails: { type: 'refusal'; category?: 'cyber' | 'bio' | null; explanation?: string | null }): void {
+  const parts: string[] = [];
+  if (stopDetails.category) parts.push(`[${stopDetails.category}]`);
+  if (stopDetails.explanation) parts.push(stopDetails.explanation);
+  if (!parts.length) return;
+  pt.appendText(`\n\n${IssueSymbols.PromptBlocked} **Refusal:** ${parts.join(' ')}`);
+}
+
 
 // --- Shared server tool result handlers (used by both S and NS parsers) ---
 
diff --git a/src/modules/aix/server/dispatch/wiretypes/anthropic.wiretypes.ts b/src/modules/aix/server/dispatch/wiretypes/anthropic.wiretypes.ts
index 8262b0e77..1f363a5aa 100644
--- a/src/modules/aix/server/dispatch/wiretypes/anthropic.wiretypes.ts
+++ b/src/modules/aix/server/dispatch/wiretypes/anthropic.wiretypes.ts
@@ -13,6 +13,10 @@ const hotFixAntShipNoEmptyTextBlocks = true; // Replace empty text blocks with a
  *
  * ## Updates
  *
+ * ### 2026-04-24 - API Sync: stop_details for structured refusals
+ * - Response: added `stop_details` ({ type: 'refusal', category: 'cyber'|'bio'|null, explanation: string|null })
+ * - event_MessageDelta.delta: added `stop_details` (arrives alongside stop_reason in streaming)
+ *
  * ### 2026-03-21 - API Sync: GA tool versions, thinking display, caller updates, cache_control
  * - Tools: Added web_search_20260209 (GA), web_fetch_20260209/20260309 (GA), code_execution_20260120 (GA REPL)
  * - Request: Added top-level `cache_control` for automatic caching (Feb 2026)
@@ -825,6 +829,17 @@ export namespace AnthropicWire_API_Message_Create {
     'model_context_window_exceeded',
   ]);
 
+  /**
+   * Structured stop details, paired with stop_reason. Currently only populated when stop_reason === 'refusal'.
+   * - category: 'cyber' | 'bio' when the refusal maps to a named policy category, null otherwise
+   * - explanation: human-readable explanation (NOT guaranteed stable), null when unavailable
+   */
+  const StopDetails_schema = z.object({
+    type: z.literal('refusal'),
+    category: z.enum(['cyber', 'bio']).nullish(),
+    explanation: z.string().nullish(),
+  });
+
   /// Request
 
   export type Request = z.infer<typeof Request_schema>;
@@ -1030,6 +1045,12 @@ export namespace AnthropicWire_API_Message_Create {
     // Which custom stop sequence was generated, if any.
     stop_sequence: z.string().nullable(),
 
+    /**
+     * Structured stop details. Present when stop_reason === 'refusal' (carries category + explanation).
+     * In streaming, stop_details is null at message_start and appears on message_delta alongside stop_reason.
+     */
+    stop_details: StopDetails_schema.nullish(),
+
     /**
      * Billing and rate-limit usage.
      * Token counts represent the underlying cost to Anthropic's systems.
@@ -1088,6 +1109,10 @@ export namespace AnthropicWire_API_Message_Create {
     delta: z.object({
       stop_reason: StopReason_schema.nullable(),
       stop_sequence: z.string().nullable(),
+      /**
+       * Structured stop details - present alongside stop_reason === 'refusal' (category + explanation).
+       */
+      stop_details: StopDetails_schema.nullish(),
       /**
        * Container state updates - present when Skills/code_execution tools are used.
        * Provides container id/expiry that may differ from message_start if the container was created mid-stream.