fix(agents): classify embedded provider business denials for fallback

src/agents/embedded-agent-runner/result-fallback-classifier.test.ts

@@ -89,4 +89,24 @@ describe("classifyEmbeddedAgentRunResultForModelFallback", () => {
 
     expect(result).toBeNull();
   });
+
+  it("does not retry non-business transport error payloads", () => {
+    const result = classifyEmbeddedAgentRunResultForModelFallback({
+      provider: "custom",
+      model: "llama-3.1",
+      result: {
+        payloads: [
+          {
+            isError: true,
+            text: "HTTP 500: internal server error",
+          },
+        ],
+        meta: {
+          durationMs: 42,
+        },
+      },
+    });
+
+    expect(result).toBeNull();
+  });
 });

src/agents/embedded-agent-runner/result-fallback-classifier.ts

@@ -1,5 +1,10 @@
 import { isSilentReplyPayloadText } from "../../auto-reply/tokens.js";
-import { classifyFailoverReason } from "../embedded-agent-helpers.js";
+import {
+  isAuthErrorMessage,
+  isAuthPermanentErrorMessage,
+  isBillingErrorMessage,
+} from "../embedded-agent-helpers/failover-matches.js";
+import type { FailoverReason } from "../embedded-agent-helpers/types.js";
 import { isGpt5ModelId } from "../gpt5-prompt-overlay.js";
 import type { ModelFallbackResultClassification } from "../model-fallback.js";
 import { hasOutboundDeliveryEvidence, hasVisibleAgentPayload } from "./delivery-evidence.js";
@@ -56,6 +61,24 @@ function classifyHarnessResult(params: {
   }
 }
 
+function classifyBusinessDenialErrorPayloadReason(
+  errorText: string,
+): Extract<FailoverReason, "auth" | "auth_permanent" | "billing"> | null {
+  if (!errorText.trim()) {
+    return null;
+  }
+  if (isBillingErrorMessage(errorText)) {
+    return "billing";
+  }
+  if (isAuthPermanentErrorMessage(errorText)) {
+    return "auth_permanent";
+  }
+  if (isAuthErrorMessage(errorText)) {
+    return "auth";
+  }
+  return null;
+}
+
 export function classifyEmbeddedAgentRunResultForModelFallback(params: {
   provider: string;
   model: string;
@@ -105,7 +128,7 @@ export function classifyEmbeddedAgentRunResultForModelFallback(params: {
       code: "incomplete_result",
     };
   }
-  const failoverReason = classifyFailoverReason(errorText, { provider: params.provider });
+  const failoverReason = classifyBusinessDenialErrorPayloadReason(errorText);
   if (failoverReason) {
     return {
       message: `${params.provider}/${params.model} ended with a provider error: ${errorText}`,