From d62684908f99fa02bea804c1f1f43f662b210122 Mon Sep 17 00:00:00 2001
From: "A.K.M. Adib" <adibakm@google.com>
Date: Wed, 18 Mar 2026 14:50:44 -0400
Subject: [PATCH] fix(core): treat RESOURCE_EXHAUSTED 429 errors without
 details as TerminalQuotaError

---
 packages/core/src/utils/googleErrors.ts         |  6 +++++-
 .../core/src/utils/googleQuotaErrors.test.ts    | 17 +++++++++++++++++
 packages/core/src/utils/googleQuotaErrors.ts    | 12 ++++++++++++
 3 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/packages/core/src/utils/googleErrors.ts b/packages/core/src/utils/googleErrors.ts
index 4439d55de5..231ff7993d 100644
--- a/packages/core/src/utils/googleErrors.ts
+++ b/packages/core/src/utils/googleErrors.ts
@@ -128,12 +128,14 @@ export interface GoogleApiError {
   code: number;
   message: string;
   details: GoogleApiErrorDetail[];
+  status?: string;
 }
 
 type ErrorShape = {
   message?: string;
   details?: unknown[];
   code?: number;
+  status?: string;
 };
 
 /**
@@ -213,6 +215,7 @@ export function parseGoogleApiError(error: unknown): GoogleApiError | null {
   const code = currentError.code;
   const message = currentError.message;
   const errorDetails = currentError.details;
+  const status = currentError.status;
 
   if (code && message) {
     const details: GoogleApiErrorDetail[] = [];
@@ -231,7 +234,7 @@ export function parseGoogleApiError(error: unknown): GoogleApiError | null {
             }
             // Basic structural check before casting.
             // Since the proto definitions are loose, we primarily rely on @type presence.
-            // eslint-disable-next-line no-restricted-syntax
+             
             if (typeof detailObj['@type'] === 'string') {
               // We can just cast it; the consumer will have to switch on @type
               // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
@@ -246,6 +249,7 @@ export function parseGoogleApiError(error: unknown): GoogleApiError | null {
       code,
       message,
       details,
+      status,
     };
   }
 
diff --git a/packages/core/src/utils/googleQuotaErrors.test.ts b/packages/core/src/utils/googleQuotaErrors.test.ts
index 90769def35..ec699f4ecc 100644
--- a/packages/core/src/utils/googleQuotaErrors.test.ts
+++ b/packages/core/src/utils/googleQuotaErrors.test.ts
@@ -81,6 +81,23 @@ describe('classifyGoogleError', () => {
     }
   });
 
+  it('should return TerminalQuotaError for 429 when status is RESOURCE_EXHAUSTED and details are empty', () => {
+    const apiError: GoogleApiError = {
+      code: 429,
+      status: 'RESOURCE_EXHAUSTED',
+      message: 'Your prepayment funds are depleted.',
+      details: [],
+    };
+    vi.spyOn(errorParser, 'parseGoogleApiError').mockReturnValue(apiError);
+    const originalError = new Error('Your prepayment funds are depleted.');
+    const result = classifyGoogleError(originalError);
+    expect(result).toBeInstanceOf(TerminalQuotaError);
+    if (result instanceof TerminalQuotaError) {
+      expect(result.cause).toBe(apiError);
+      expect(result.message).toBe('Your prepayment funds are depleted.');
+    }
+  });
+
   it('should return original error if code is not 429, 499 or 503', () => {
     const apiError: GoogleApiError = {
       code: 500,
diff --git a/packages/core/src/utils/googleQuotaErrors.ts b/packages/core/src/utils/googleQuotaErrors.ts
index 5a0bf48092..c523581279 100644
--- a/packages/core/src/utils/googleQuotaErrors.ts
+++ b/packages/core/src/utils/googleQuotaErrors.ts
@@ -268,6 +268,13 @@ export function classifyGoogleError(error: unknown): unknown {
     } else if (status === 429 || status === 499) {
       // Fallback: If it is a 429 or 499 but doesn't have a specific "retry in" message,
       // assume it is a temporary rate limit and retry after 5 sec (same as DEFAULT_RETRY_OPTIONS).
+
+      // However, if the API explicitly returns RESOURCE_EXHAUSTED without details,
+      // it indicates a hard quota exhaustion rather than a transient rate limit.
+      if (googleApiError?.status === 'RESOURCE_EXHAUSTED') {
+        return new TerminalQuotaError(errorMessage, googleApiError);
+      }
+
       return new RetryableQuotaError(
         errorMessage,
         googleApiError ?? {
@@ -405,6 +412,11 @@ export function classifyGoogleError(error: unknown): unknown {
     const errorMessage =
       googleApiError?.message ||
       (error instanceof Error ? error.message : String(error));
+
+    if (googleApiError?.status === 'RESOURCE_EXHAUSTED') {
+      return new TerminalQuotaError(errorMessage, googleApiError);
+    }
+
     return new RetryableQuotaError(
       errorMessage,
       googleApiError ?? {