fix(agent-core): recover from unsupported image_url variants

.changeset/quiet-pandas-strip-media.md

@@ -0,0 +1,5 @@
+---
+"@moonshot-ai/kimi-code": patch
+---
+
+Fix context compaction for text-only models by retrying rejected image content without media.

packages/agent-core-v2/src/kosong/contract/errors.ts

@@ -229,6 +229,7 @@ const IMAGE_FORMAT_PROVIDER_MESSAGE_PATTERNS = [
 
 const IMAGE_FORMAT_STATUS_MESSAGE_PATTERNS = [
   /unsupported image (?:url|format|type)/,
+  /unknown variant [`'"]?image_url[`'"]?/,
   /does not represent a valid image/,
   /could not (?:process|decode) (?:the |input )?image/,
   /unable to process (?:the |input )?image/,

packages/agent-core-v2/test/agent/fullCompaction/fullCompaction.test.ts

@@ -649,7 +649,7 @@ describe('FullCompaction', () => {
       );
       if (hasMedia) {
         sawMedia = true;
-        throw new APIStatusError(400, 'unsupported image format: image/avif');
+        throw new APIStatusError(400, 'unknown variant image_url, expected text');
       }
       sawStrippedResend = true;
       return textResult('Recovered compacted summary.');

packages/agent-core-v2/test/kosong/contract/errors.test.ts

@@ -22,6 +22,7 @@ import {
   classifyApiError,
   createAbortError,
   isAbortError,
+  isImageFormatError,
   isRetryableGenerateError,
   normalizeAPIStatusError,
   throwIfAbortError,
@@ -131,6 +132,17 @@ describe('isRetryableGenerateError', () => {
   });
 });
 
+describe('isImageFormatError', () => {
+  it('recognizes providers that reject the image_url content variant', () => {
+    const error = new APIStatusError(
+      400,
+      'messages[124]: unknown variant image_url, expected text at line 1 column 811568',
+    );
+
+    expect(isImageFormatError(error)).toBe(true);
+  });
+});
+
 describe('classifyApiError', () => {
   it('classifies typed errors and carries the status code', () => {
     expect(classifyApiError(new APIContextOverflowError(400, 'context length exceeded'))).toEqual({