fix(agents): normalize abort-wrapped RESOURCE_EXHAUSTED into failover errors (#11972)

src/agents/failover-error.ts

@@ -72,9 +72,16 @@ function getStatusCode(err: unknown): number | undefined {
   if (!err || typeof err !== "object") {
     return undefined;
   }
+  // Dig into nested `err.error` shapes (e.g. Google Vertex abort wrappers)
+  const nestedError =
+    "error" in err && err.error && typeof err.error === "object"
+      ? (err.error as { status?: unknown; code?: unknown })
+      : undefined;
   const candidate =
     (err as { status?: unknown; statusCode?: unknown }).status ??
-    (err as { statusCode?: unknown }).statusCode;
+    (err as { statusCode?: unknown }).statusCode ??
+    nestedError?.code ??
+    nestedError?.status;
   if (typeof candidate === "number") {
     return candidate;
   }
@@ -88,7 +95,11 @@ function getErrorCode(err: unknown): string | undefined {
   if (!err || typeof err !== "object") {
     return undefined;
   }
-  const candidate = (err as { code?: unknown }).code;
+  const nestedError =
+    "error" in err && err.error && typeof err.error === "object"
+      ? (err.error as { code?: unknown; status?: unknown })
+      : undefined;
+  const candidate = (err as { code?: unknown }).code ?? nestedError?.status ?? nestedError?.code;
   if (typeof candidate !== "string") {
     return undefined;
   }
@@ -114,10 +125,53 @@ function getErrorMessage(err: unknown): string {
     if (typeof message === "string") {
       return message;
     }
+    // Extract message from nested `err.error.message` (e.g. Google Vertex wrappers)
+    const nestedMessage =
+      "error" in err &&
+      err.error &&
+      typeof err.error === "object" &&
+      typeof (err.error as { message?: unknown }).message === "string"
+        ? ((err.error as { message: string }).message ?? "")
+        : "";
+    if (nestedMessage) {
+      return nestedMessage;
+    }
   }
   return "";
 }
 
+function getErrorCause(err: unknown): unknown {
+  if (!err || typeof err !== "object" || !("cause" in err)) {
+    return undefined;
+  }
+  return (err as { cause?: unknown }).cause;
+}
+
+/** Classify rate-limit / overloaded from symbolic error codes like RESOURCE_EXHAUSTED. */
+function classifyFailoverReasonFromSymbolicCode(raw: string | undefined): FailoverReason | null {
+  const normalized = raw?.trim().toUpperCase();
+  if (!normalized) {
+    return null;
+  }
+  switch (normalized) {
+    case "RESOURCE_EXHAUSTED":
+    case "RATE_LIMIT":
+    case "RATE_LIMITED":
+    case "RATE_LIMIT_EXCEEDED":
+    case "TOO_MANY_REQUESTS":
+    case "THROTTLED":
+    case "THROTTLING":
+    case "THROTTLINGEXCEPTION":
+    case "THROTTLING_EXCEPTION":
+      return "rate_limit";
+    case "OVERLOADED":
+    case "OVERLOADED_ERROR":
+      return "overloaded";
+    default:
+      return null;
+  }
+}
+
 function hasTimeoutHint(err: unknown): boolean {
   if (!err) {
     return false;
@@ -160,6 +214,12 @@ export function resolveFailoverReasonFromError(err: unknown): FailoverReason | n
     return statusReason;
   }
 
+  // Check symbolic error codes (e.g. RESOURCE_EXHAUSTED from Google APIs)
+  const symbolicCodeReason = classifyFailoverReasonFromSymbolicCode(getErrorCode(err));
+  if (symbolicCodeReason) {
+    return symbolicCodeReason;
+  }
+
   const code = (getErrorCode(err) ?? "").toUpperCase();
   if (
     [
@@ -181,6 +241,14 @@ export function resolveFailoverReasonFromError(err: unknown): FailoverReason | n
   if (isTimeoutError(err)) {
     return "timeout";
   }
+  // Walk into error cause chain (e.g. AbortError wrapping a rate-limit cause)
+  const cause = getErrorCause(err);
+  if (cause && cause !== err) {
+    const causeReason = resolveFailoverReasonFromError(cause);
+    if (causeReason) {
+      return causeReason;
+    }
+  }
   if (!message) {
     return null;
   }