diff --git a/server/agent-routes.ts b/server/agent-routes.ts
index e409ec8..2900b61 100644
--- a/server/agent-routes.ts
+++ b/server/agent-routes.ts
@@ -419,7 +419,7 @@ function maybeReplayIdempotentMutation(
     );
     return { handled: true, idempotencyKey, requestHash };
   }
-  sendMutationResponse(res, 200, existing.response, { route: mutationRoute, slug });
+  sendMutationResponse(res, existing.statusCode ?? 200, existing.response, { route: mutationRoute, slug });
   return { handled: true, idempotencyKey, requestHash };
 }
 
@@ -432,7 +432,7 @@ function storeIdempotentMutationResult(
 ): void {
   if (!replay.idempotencyKey) return;
   if (status < 200 || status >= 300) return;
-  storeIdempotencyResult(slug, routeKey, replay.idempotencyKey, body, replay.requestHash);
+  storeIdempotencyResult(slug, routeKey, replay.idempotencyKey, body, replay.requestHash, { statusCode: status });
 }
 
 function routeRequiresMutation(method: string, path: string): boolean {
diff --git a/server/db.ts b/server/db.ts
index e511b23..3c5e831 100644
--- a/server/db.ts
+++ b/server/db.ts
@@ -1973,14 +1973,14 @@ export function getStoredIdempotencyRecord(
   documentSlug: string,
   route: string,
   idempotencyKey: string,
-): { response: Record<string, unknown>; requestHash: string | null } | null {
+): { response: Record<string, unknown>; requestHash: string | null; statusCode: number } | null {
   const d = getDb();
   const coordinatorRow = d.prepare(`
-    SELECT response_json, request_hash
+    SELECT response_json, request_hash, status_code
     FROM ${MUTATION_IDEMPOTENCY_TABLE}
     WHERE idempotency_key = ? AND document_slug = ? AND route = ?
     LIMIT 1
-  `).get(idempotencyKey, documentSlug, route) as { response_json?: string; request_hash?: string | null } | undefined;
+  `).get(idempotencyKey, documentSlug, route) as { response_json?: string; request_hash?: string | null; status_code?: number | null } | undefined;
   const legacyRow = d.prepare(`
     SELECT response_json, request_hash
     FROM idempotency_keys
@@ -2010,6 +2010,7 @@ export function getStoredIdempotencyRecord(
     return {
       response,
       requestHash: typeof row.request_hash === 'string' ? row.request_hash : null,
+      statusCode: typeof (row as { status_code?: number | null }).status_code === 'number' ? (row as { status_code: number }).status_code : 200,
     };
   } catch {
     return null;