diff --git a/apps/desktop/src/main/maker-host/__tests__/codexProxyHost.test.ts b/apps/desktop/src/main/maker-host/__tests__/codexProxyHost.test.ts
index 5547ed9d5d..c51f9ca437 100644
--- a/apps/desktop/src/main/maker-host/__tests__/codexProxyHost.test.ts
+++ b/apps/desktop/src/main/maker-host/__tests__/codexProxyHost.test.ts
@@ -661,9 +661,9 @@ describe('chatBridgeCapabilitiesForRoute', () => {
     ['https://coding.dashscope.aliyuncs.com.evil.example/v1', 'qwen3.7-plus'],
     ['https://example.com/v1', 'qwen3.7-plus'],
     ['https://coding.dashscope.aliyuncs.com/v1', 'qwen3-coder-next'],
-  ])('keeps image input disabled for non-matching route %s / %s', async (upstream, model) => {
+  ])('enables image_url by default for non-matching route %s / %s (fail-open)', async (upstream, model) => {
     const { chatBridgeCapabilitiesForRoute } = await freshCodexProxyHost();
-    expect(chatBridgeCapabilitiesForRoute(upstream, model).imageInput).toBeUndefined();
+    expect(chatBridgeCapabilitiesForRoute(upstream, model).imageInput).toBe('image_url');
   });
 
   it('passes image support into the handler for a preset-derived custom Kimi route', async () => {
diff --git a/apps/desktop/src/main/maker-host/codex-proxy-host.ts b/apps/desktop/src/main/maker-host/codex-proxy-host.ts
index f8a0a5c876..7b41a2d64c 100644
--- a/apps/desktop/src/main/maker-host/codex-proxy-host.ts
+++ b/apps/desktop/src/main/maker-host/codex-proxy-host.ts
@@ -715,6 +715,7 @@ const CHAT_BRIDGE_DEFAULT_CAPABILITIES: ChatBridgeCapabilities = {
   maxTokensField: 'max_tokens',
   reasoningField: 'none',
   streamUsage: true,
+  imageInput: 'image_url',
   // Responses fields with direct Chat equivalents. Provider-specific unsupported fields can
   // be removed later when the model capability catalog becomes more granular.
   passthroughFields: [
@@ -788,14 +789,11 @@ function rewriteChatBridgeModel(model: string, stripPrefix: string | undefined):
 /**
  * 在模型级多模态能力元数据接入路由前,图片桥接先按已验证的上游能力显式开启。
  *
- * 当前覆盖:
- * - Moonshot Kimi K3
- * - Volcengine Doubao Seed 系列
- * - Alibaba Cloud Bailian Coding Plan Qwen 3.7 Plus
+ * 默认已启用 `imageInput: 'image_url'`（fail-open）。此函数仅在已验证路由上
+ * 显式覆盖,确保白名单路由的 `imageInput` 始终为 `'image_url'`。
  *
- * 这里认官方 DNS 边界 + 上游 model,不认 provider id(预设创建后会生成用户自定义
- * id),也不对所有 openai-chat 供应商放开。未命中继续沿用 fail-closed 默认——
- * 无图片能力的上游(如 DeepSeek)保持发送前显式报错,不静默吞图。
+ * 非白名单路由同样走 fail-open：桥接层转换格式，上游不支持时返回错误，
+ * 客户端通过 `isUnsupportedResponsesImageErrorPayload` 检测并提示用户。
  */
 export function chatBridgeCapabilitiesForRoute(
   upstream: string,
diff --git a/packages/responses-chat-bridge/src/__tests__/types.test.ts b/packages/responses-chat-bridge/src/__tests__/types.test.ts
index 6a65269dbb..f33f1c622e 100644
--- a/packages/responses-chat-bridge/src/__tests__/types.test.ts
+++ b/packages/responses-chat-bridge/src/__tests__/types.test.ts
@@ -19,6 +19,10 @@ function codexUnexpectedResponse(messageOrBody: string): string {
   return `unexpected status 400 Bad Request: ${messageOrBody}, url: http://127.0.0.1/v1/responses`;
 }
 
+function codexUnexpectedStatus(status: number, messageOrBody: string): string {
+  return `unexpected status ${status}: ${messageOrBody}, url: http://127.0.0.1/v1/responses`;
+}
+
 describe('isUnsupportedResponsesImageErrorPayload', () => {
   it.each([
     "input content part 'input_image'",
@@ -43,6 +47,144 @@ describe('isUnsupportedResponsesImageErrorPayload', () => {
     expect(isUnsupportedResponsesImageErrorPayload(codexUnexpectedResponse(payload))).toBe(true);
   });
 
+  it('accepts upstream provider image rejection (DeepSeek-style 400)', () => {
+    const payload = JSON.stringify({
+      error: {
+        code: 'invalid_request_error',
+        message: 'image_url content part is not supported by this model',
+      },
+    });
+    expect(isUnsupportedResponsesImageErrorPayload(payload)).toBe(true);
+  });
+
+  it('accepts upstream provider multimodal rejection', () => {
+    const payload = JSON.stringify({
+      error: {
+        code: 'invalid_request',
+        message: 'This model does not support multimodal input',
+      },
+    });
+    expect(isUnsupportedResponsesImageErrorPayload(payload)).toBe(true);
+  });
+
+  it('accepts handler-wrapped upstream image rejection (DeepSeek via bridge)', () => {
+    // handler.ts wraps: responsesError(status, 'upstream_error', rawUpstreamBody)
+    const innerError = JSON.stringify({
+      error: { code: 'invalid_request_error', message: 'image_url content part is not supported' },
+    });
+    const payload = JSON.stringify({
+      error: { code: 'upstream_error', message: innerError },
+    });
+    expect(isUnsupportedResponsesImageErrorPayload(payload)).toBe(true);
+  });
+
+  it('accepts upstream rejection using error.type without a code field', () => {
+    const payload = JSON.stringify({
+      error: {
+        type: 'invalid_request_error',
+        message: 'This model does not support image_url content parts',
+      },
+    });
+    expect(isUnsupportedResponsesImageErrorPayload(payload)).toBe(true);
+  });
+
+  it('accepts a plain-text (non-JSON) upstream 400 body wrapped by the handler', () => {
+    const payload = JSON.stringify({
+      error: {
+        code: 'upstream_error',
+        message: 'image_url content part is not supported by this model',
+      },
+    });
+    expect(isUnsupportedResponsesImageErrorPayload(payload)).toBe(true);
+  });
+
+  it('accepts a Codex-extracted plain-text capability rejection', () => {
+    // Codex extracts error.message from the wrapped upstream_error envelope, so
+    // the coordinator sees the plain-text message after the unexpected-status
+    // prefix instead of the JSON envelope.
+    expect(
+      isUnsupportedResponsesImageErrorPayload(
+        codexUnexpectedResponse('image_url content part is not supported by this model'),
+      ),
+    ).toBe(true);
+  });
+
+  it('rejects Codex-extracted invalid-image-content errors (not capability rejection)', () => {
+    expect(
+      isUnsupportedResponsesImageErrorPayload(
+        codexUnexpectedResponse('Invalid image_url: image exceeds maximum size'),
+      ),
+    ).toBe(false);
+  });
+
+  it('accepts Codex-rendered 415/422 capability rejections (non-400 client errors)', () => {
+    // Some OpenAI-compatible upstreams use 415 (unsupported_media_type) or
+    // 422 (unprocessable_entity) to signal the model does not accept image
+    // content parts. The plain-text classifier must not be gated on 400.
+    expect(
+      isUnsupportedResponsesImageErrorPayload(
+        codexUnexpectedStatus(415, 'image_url content part is not supported by this model'),
+      ),
+    ).toBe(true);
+    expect(
+      isUnsupportedResponsesImageErrorPayload(
+        codexUnexpectedStatus(422, 'image input is not supported by this model'),
+      ),
+    ).toBe(true);
+  });
+
+  it('accepts Codex-rendered 422 with HTTP reason phrase', () => {
+    // Codex includes the HTTP reason phrase, e.g.
+    // 'unexpected status 422 Unprocessable Entity: ...'.
+    expect(
+      isUnsupportedResponsesImageErrorPayload(
+        'unexpected status 422 Unprocessable Entity: image_url content part is not supported by this model, url: http://127.0.0.1/v1/responses',
+      ),
+    ).toBe(true);
+    expect(
+      isUnsupportedResponsesImageErrorPayload(
+        'unexpected status 415 Unsupported Media Type: image input is not supported by this model, url: http://127.0.0.1/v1/responses',
+      ),
+    ).toBe(true);
+  });
+
+  it('accepts a JSON error whose error value is a plain string (Ollama-style)', () => {
+    const payload = JSON.stringify({
+      error: { code: 'upstream_error', message: JSON.stringify({ error: 'this model does not support images' }) },
+    });
+    expect(isUnsupportedResponsesImageErrorPayload(payload)).toBe(true);
+  });
+
+  it('accepts a handler-wrapped rejection whose inner error uses error.type', () => {
+    const innerError = JSON.stringify({
+      error: { type: 'invalid_request_error', message: 'image input is not supported' },
+    });
+    const payload = JSON.stringify({
+      error: { code: 'upstream_error', message: innerError },
+    });
+    expect(isUnsupportedResponsesImageErrorPayload(payload)).toBe(true);
+  });
+
+  it.each([
+    JSON.stringify({
+      error: { code: 'invalid_request_error', message: 'Invalid image_url: image exceeds maximum size' },
+    }),
+    JSON.stringify({
+      error: { code: 'invalid_request_error', message: 'image_url must be a valid URL' },
+    }),
+    JSON.stringify({
+      error: { code: 'invalid_request_error', message: 'image exceeds maximum size' },
+    }),
+    JSON.stringify({
+      error: { code: 'upstream_error', message: 'Invalid image_url: image exceeds maximum size' },
+    }),
+  ])('rejects invalid-image-content errors (not capability rejection): %s', (payload) => {
+    // A message about the image being invalid (size, format, URL) is NOT a
+    // capability rejection — stripping the attachment would resend text without
+    // the image the user asked about.
+    expect(isUnsupportedResponsesImageErrorPayload(payload)).toBe(false);
+  });
+
   it.each([
     unsupportedFeaturePayload("input content part 'input_file'"),
     unsupportedFeaturePayload("input content part 'input_image'", 'invalid_request'),
diff --git a/packages/responses-chat-bridge/src/types.ts b/packages/responses-chat-bridge/src/types.ts
index b474bc5259..c6aed94adc 100644
--- a/packages/responses-chat-bridge/src/types.ts
+++ b/packages/responses-chat-bridge/src/types.ts
@@ -290,8 +290,8 @@ export interface ChatBridgeCapabilities {
    */
   reasoningHistoryField?: ChatReasoningHistoryField;
   /**
-   * Responses `input_image` 的上游等价形态。默认未声明 = fail closed；只由
-   * 已确认支持视觉输入的运行时（当前为 upstream 白名单）开启。
+   * Responses `input_image` 的上游等价形态。默认 `image_url`（fail-open：桥接层
+   * 负责格式转换，上游不支持时由客户端检测并提示用户）。
    */
   imageInput?: ChatImageInput;
   /** Responses `input_file` 的上游等价形态；默认未声明 = fail closed。 */
@@ -368,7 +368,8 @@ export interface ResponsesChatBridgeHandler {
 const UNSUPPORTED_RESPONSES_FEATURE_MESSAGE_PREFIX =
   'Responses feature is not supported by the Chat Completions bridge: ';
 const RESPONSES_IMAGE_CONTENT_PART_TYPES = new Set(['input_image', 'image_url', 'image']);
-const CODEX_UNEXPECTED_BAD_REQUEST_PREFIX = /^unexpected status 400(?: Bad Request)?: /;
+const CODEX_UNEXPECTED_BAD_REQUEST_PREFIX =
+  /^unexpected status (?:400(?: Bad Request)?|415(?: Unsupported Media Type)?|422(?: Unprocessable Entity)?): /;
 const CODEX_ERROR_METADATA_MARKERS = [
   ', url: ',
   ', cf-ray: ',
@@ -396,14 +397,106 @@ function isUnsupportedResponsesImageFeature(feature: string): boolean {
     || contentPartType.startsWith('input_image.');
 }
 
+// Capability-rejection keywords: an upstream message that states the *model*
+// does not support image/vision input. Deliberately narrower than a generic
+// "mentions image" test: messages like "Invalid image_url: image exceeds
+// maximum size" or "image_url must be a valid URL" describe invalid *content*,
+// not a missing capability. Treating those as capability rejection would strip
+// the user's attachment and resend text without the image they asked about.
+function imageRejectionKeywords(msg: string): boolean {
+  const m = msg.toLowerCase();
+  // Capability rejection: the model/provider explicitly says it does not support
+  // image/vision input. This is distinct from content errors like "image format
+  // not supported" or "image exceeds maximum size" which describe invalid content.
+  const capabilityPhrases = [
+    'image input is not supported',
+    'vision is not supported',
+    'images are not supported',
+    'image_url content part is not supported',
+    'image content part is not supported',
+    'multimodal input is not supported',
+    'does not support image input',
+    'does not support vision input',
+    'does not support image_url',
+    'does not support images',
+    'does not support multimodal',
+    'does not support image',
+    'does not support vision',
+    'not support image',
+    'not support vision',
+    'not support multimodal',
+  ];
+  for (const phrase of capabilityPhrases) {
+    if (m.includes(phrase)) return true;
+  }
+  return false;
+}
+
 function isUnsupportedResponsesImageErrorObject(value: unknown): boolean {
   if (typeof value !== 'object' || value === null || Array.isArray(value)) return false;
   const error = (value as Record<string, unknown>).error;
   if (typeof error !== 'object' || error === null || Array.isArray(error)) return false;
   const { code, message } = error as Record<string, unknown>;
-  if (code !== 'unsupported_feature' || typeof message !== 'string') return false;
-  const feature = unsupportedResponsesFeatureFromMessage(message);
-  return feature !== null && isUnsupportedResponsesImageFeature(feature);
+  if (typeof message !== 'string') return false;
+  // Bridge-generated unsupported_feature error (fail-closed path)
+  if (code === 'unsupported_feature') {
+    const feature = unsupportedResponsesFeatureFromMessage(message);
+    return feature !== null && isUnsupportedResponsesImageFeature(feature);
+  }
+  // Upstream provider rejection: detect image-related 400 errors from providers
+  // that don't support vision (e.g. DeepSeek, Ollama without vision model).
+  //
+  // The handler (handler.ts) wraps upstream errors as:
+  //   {error: {code: "upstream_error", message: "<raw upstream JSON body>"}}
+  // So we check both the outer code and also parse the wrapped inner error.
+  const { type } = error as Record<string, unknown>;
+  // Accept both `code` (OpenAI-style) and `type` (some providers only emit
+  // `type: 'invalid_request_error'` with no code at all) as the
+  // request-invalid signal.
+  // Accept invalid_request (400), unsupported_media_type (415), and
+  // unprocessable_entity (422) as request-invalid signals. Some providers use
+  // 415/422 to indicate the model does not accept image content parts.
+  const invalidRequest =
+    (typeof code === 'string' && (code.includes('invalid_request')
+      || code.includes('unsupported_media') || code.includes('unprocessable')))
+    || (typeof type === 'string' && (type.toLowerCase().includes('invalid_request')
+      || type.toLowerCase().includes('unsupported_media')
+      || type.toLowerCase().includes('unprocessable')));
+  if (invalidRequest
+      && !message.startsWith(UNSUPPORTED_RESPONSES_FEATURE_MESSAGE_PREFIX)) {
+    if (imageRejectionKeywords(message)) return true;
+  }
+  if (code === 'upstream_error' && typeof message === 'string') {
+    const inner = parseJson(message);
+    if (inner && typeof inner === 'object' && inner !== null) {
+      const innerErr = (inner as Record<string, unknown>).error;
+      if (typeof innerErr === 'string') {
+        // Some providers (e.g. Ollama) return a native JSON error whose
+        // `error` value is a plain string, e.g. {"error":"this model
+        // does not support images"}. Classify it directly.
+        if (imageRejectionKeywords(innerErr)) return true;
+      } else if (innerErr && typeof innerErr === 'object') {
+        const ic = (innerErr as Record<string, unknown>).code;
+        const it = (innerErr as Record<string, unknown>).type;
+        const im = (innerErr as Record<string, unknown>).message;
+        const innerInvalid =
+          (typeof ic === 'string' && (ic.includes('invalid_request')
+            || ic.includes('unsupported_media') || ic.includes('unprocessable')))
+          || (typeof it === 'string' && (it.toLowerCase().includes('invalid_request')
+            || it.toLowerCase().includes('unsupported_media')
+            || it.toLowerCase().includes('unprocessable')));
+        if (innerInvalid && typeof im === 'string' && imageRejectionKeywords(im)) {
+          return true;
+        }
+      }
+    } else {
+      // Upstream returned a plain-text (non-JSON) 400 body, e.g.
+      // "image_url content part is not supported by this model". The handler
+      // wraps it as upstream_error with the raw text as message.
+      if (imageRejectionKeywords(message)) return true;
+    }
+  }
+  return false;
 }
 
 function parseJson(value: string): unknown {
@@ -455,7 +548,12 @@ export function isUnsupportedResponsesImageErrorPayload(payload: string | null):
 
   const message = stripCodexErrorMetadata(renderedBody);
   const feature = unsupportedResponsesFeatureFromMessage(message);
-  return feature !== null && isUnsupportedResponsesImageFeature(feature);
+  if (feature !== null && isUnsupportedResponsesImageFeature(feature)) return true;
+  // Codex extracts error.message from the wrapped upstream_error envelope, so a
+  // plain-text capability rejection (e.g. "image_url content part is not
+  // supported by this model, url: ...") arrives directly after the prefix.
+  // Classify the stripped plain text with the same keyword set as the JSON path.
+  return imageRejectionKeywords(message);
 }
 
 export class UnsupportedResponsesFeatureError extends Error {