diff --git a/packages/core/src/core/contentGenerator.ts b/packages/core/src/core/contentGenerator.ts
index f3af06bda2b..ad2326de3f1 100644
--- a/packages/core/src/core/contentGenerator.ts
+++ b/packages/core/src/core/contentGenerator.ts
@@ -70,7 +70,8 @@ export type ContentGeneratorConfig = {
   enableOpenAILogging?: boolean;
   openAILoggingDir?: string;
   timeout?: number; // Timeout configuration in milliseconds
-  maxRetries?: number; // Maximum retries for failed requests
+  maxRetries?: number; // Maximum retries for rate-limit errors
+  retryErrorCodes?: number[]; // Additional error codes that trigger rate-limit retry
   enableCacheControl?: boolean; // Enable cache control for DashScope providers
   samplingParams?: {
     top_p?: number;
diff --git a/packages/core/src/core/geminiChat.ts b/packages/core/src/core/geminiChat.ts
index 0bac7066fea..2e192335515 100644
--- a/packages/core/src/core/geminiChat.ts
+++ b/packages/core/src/core/geminiChat.ts
@@ -286,6 +286,12 @@ export class GeminiChat {
         let lastError: unknown = new Error('Request failed after all retries.');
         let rateLimitRetryCount = 0;
 
+        // Read per-config overrides; fall back to built-in defaults.
+        const cgConfig = self.config.getContentGeneratorConfig();
+        const maxRateLimitRetries =
+          cgConfig?.maxRetries ?? RATE_LIMIT_RETRY_OPTIONS.maxRetries;
+        const extraRetryErrorCodes = cgConfig?.retryErrorCodes;
+
         for (
           let attempt = 0;
           attempt < INVALID_CONTENT_RETRY_OPTIONS.maxAttempts;
@@ -316,18 +322,15 @@ export class GeminiChat {
             // These arrive as StreamContentError with finish_reason="error_finish"
             // from the pipeline, containing the throttling message in the content.
             // Covers TPM throttling, GLM rate limits, and other provider throttling.
-            const isRateLimit = isRateLimitError(error);
-            if (
-              isRateLimit &&
-              rateLimitRetryCount < RATE_LIMIT_RETRY_OPTIONS.maxRetries
-            ) {
+            const isRateLimit = isRateLimitError(error, extraRetryErrorCodes);
+            if (isRateLimit && rateLimitRetryCount < maxRateLimitRetries) {
               rateLimitRetryCount++;
               const delayMs = RATE_LIMIT_RETRY_OPTIONS.delayMs;
               const message = parseAndFormatApiError(
                 error instanceof Error ? error.message : String(error),
               );
               debugLogger.warn(
-                `Rate limit throttling detected (retry ${rateLimitRetryCount}/${RATE_LIMIT_RETRY_OPTIONS.maxRetries}). ` +
+                `Rate limit throttling detected (retry ${rateLimitRetryCount}/${maxRateLimitRetries}). ` +
                   `Waiting ${delayMs / 1000}s before retrying...`,
               );
               yield {
@@ -335,7 +338,7 @@ export class GeminiChat {
                 retryInfo: {
                   message,
                   attempt: rateLimitRetryCount,
-                  maxRetries: RATE_LIMIT_RETRY_OPTIONS.maxRetries,
+                  maxRetries: maxRateLimitRetries,
                   delayMs,
                 },
               };
diff --git a/packages/core/src/models/constants.ts b/packages/core/src/models/constants.ts
index 025e3b9cfd6..00a00ed9485 100644
--- a/packages/core/src/models/constants.ts
+++ b/packages/core/src/models/constants.ts
@@ -22,6 +22,7 @@ export const MODEL_GENERATION_CONFIG_FIELDS = [
   'samplingParams',
   'timeout',
   'maxRetries',
+  'retryErrorCodes',
   'enableCacheControl',
   'schemaCompliance',
   'reasoning',
diff --git a/packages/core/src/models/types.ts b/packages/core/src/models/types.ts
index 69c286729f9..61509c44bd7 100644
--- a/packages/core/src/models/types.ts
+++ b/packages/core/src/models/types.ts
@@ -29,6 +29,7 @@ export type ModelGenerationConfig = Pick<
   | 'samplingParams'
   | 'timeout'
   | 'maxRetries'
+  | 'retryErrorCodes'
   | 'enableCacheControl'
   | 'schemaCompliance'
   | 'reasoning'
diff --git a/packages/core/src/utils/rateLimit.test.ts b/packages/core/src/utils/rateLimit.test.ts
index 48605db20e1..a342a4a0b00 100644
--- a/packages/core/src/utils/rateLimit.test.ts
+++ b/packages/core/src/utils/rateLimit.test.ts
@@ -33,6 +33,13 @@ describe('isRateLimitError — detection paths', () => {
     expect(info).toBe(true);
   });
 
+  it('should detect 1305 code from ApiError (issue #1918)', () => {
+    const info = isRateLimitError({
+      error: { code: 1305, message: 'IdealTalk rate limit' },
+    });
+    expect(info).toBe(true);
+  });
+
   it('should detect rate-limit from StructuredError.status', () => {
     const error: StructuredError = { message: 'Rate limited', status: 429 };
     const info = isRateLimitError(error);
@@ -52,6 +59,21 @@ describe('isRateLimitError — detection paths', () => {
     ).toBe(false);
   });
 
+  it('should detect custom error code passed via extraCodes', () => {
+    expect(
+      isRateLimitError(
+        { error: { code: 9999, message: 'Custom rate limit' } },
+        [9999],
+      ),
+    ).toBe(true);
+  });
+
+  it('should not detect custom code when extraCodes is not provided', () => {
+    expect(
+      isRateLimitError({ error: { code: 9999, message: 'Custom rate limit' } }),
+    ).toBe(false);
+  });
+
   it('should return null for invalid inputs', () => {
     expect(isRateLimitError(null)).toBe(false);
     expect(isRateLimitError(undefined)).toBe(false);
diff --git a/packages/core/src/utils/rateLimit.ts b/packages/core/src/utils/rateLimit.ts
index 559cb26fb84..19466e90f6c 100644
--- a/packages/core/src/utils/rateLimit.ts
+++ b/packages/core/src/utils/rateLimit.ts
@@ -10,7 +10,8 @@ import { isApiError, isStructuredError } from './quotaErrorDetection.js';
 // 429  - Standard HTTP "Too Many Requests" (DashScope TPM, OpenAI, etc.)
 // 503  - Provider throttling/overload (treated as rate-limit for retry UI)
 // 1302 - Z.AI GLM rate limit (https://docs.z.ai/api-reference/api-code)
-const RATE_LIMIT_ERROR_CODES = new Set([429, 503, 1302]);
+// 1305 - DashScope/IdealTalk internal rate limit (issue #1918)
+const RATE_LIMIT_ERROR_CODES = new Set([429, 503, 1302, 1305]);
 
 export interface RetryInfo {
   /** Formatted error message for display, produced by parseAndFormatApiError. */
@@ -25,10 +26,20 @@ export interface RetryInfo {
 
 /**
  * Detects rate-limit / throttling errors and returns retry info.
+ *
+ * @param error - The error to check.
+ * @param extraCodes - Additional error codes to treat as rate-limit errors,
+ *   merged with the built-in set at call time (not mutating the default set).
  */
-export function isRateLimitError(error: unknown): boolean {
+export function isRateLimitError(
+  error: unknown,
+  extraCodes?: readonly number[],
+): boolean {
   const code = getErrorCode(error);
-  return code !== null && RATE_LIMIT_ERROR_CODES.has(code);
+  if (code === null) return false;
+  if (RATE_LIMIT_ERROR_CODES.has(code)) return true;
+  if (extraCodes && extraCodes.includes(code)) return true;
+  return false;
 }
 
 /**