diff --git a/backend/internal/service/openai_gateway_service.go b/backend/internal/service/openai_gateway_service.go
index da3c3a3636..cd84790b98 100644
--- a/backend/internal/service/openai_gateway_service.go
+++ b/backend/internal/service/openai_gateway_service.go
@@ -2795,7 +2795,9 @@ func (s *OpenAIGatewayService) Forward(ctx context.Context, c *gin.Context, acco
 		return nil, errors.New("image generation disabled for group")
 	}
 
-	if imageGenerationAllowed && (codexImageGenerationBridgeEnabled || isOpenAIImageGenerationModel(requestView.Model) || openAIRequestBodyImageGenerationToolNeedsNormalization(body) || isOpenAIImageGenerationModel(upstreamModel)) {
+	// /responses/compact 是会话压缩请求：上游不接受 tool_choice（400 unknown_parameter），
+	// 注入 image_generation 工具也没有意义，整块豁免。
+	if imageGenerationAllowed && !isCompactRequest && (codexImageGenerationBridgeEnabled || isOpenAIImageGenerationModel(requestView.Model) || openAIRequestBodyImageGenerationToolNeedsNormalization(body) || isOpenAIImageGenerationModel(upstreamModel)) {
 		decoded, decodeErr := ensureReqBody()
 		if decodeErr != nil {
 			return nil, decodeErr
diff --git a/backend/internal/service/openai_image_generation_controls_test.go b/backend/internal/service/openai_image_generation_controls_test.go
index e0834fa105..6061a0bf9c 100644
--- a/backend/internal/service/openai_image_generation_controls_test.go
+++ b/backend/internal/service/openai_image_generation_controls_test.go
@@ -208,6 +208,35 @@ func TestOpenAIGatewayServiceForward_CodexBridgePreservesExistingToolChoice(t *t
 	require.Equal(t, "image_generation", gjson.GetBytes(upstream.lastBody, "tool_choice.type").String())
 }
 
+func TestOpenAIGatewayServiceForward_CodexBridgeSkipsCompactRequests(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	upstream := &httpUpstreamRecorder{
+		resp: &http.Response{
+			StatusCode: http.StatusOK,
+			Header:     http.Header{"Content-Type": []string{"application/json"}},
+			Body:       io.NopCloser(strings.NewReader(`{"id":"resp_codex_compact","model":"gpt-5.4","usage":{"input_tokens":1,"output_tokens":1}}`)),
+		},
+	}
+	svc := newOpenAIImageGenerationControlTestService(upstream)
+	svc.cfg.Gateway.CodexImageGenerationBridgeEnabled = true
+	c, _ := newOpenAIImageGenerationControlTestContext(true, "codex_cli_rs/0.98.0")
+	c.Request = httptest.NewRequest(http.MethodPost, "/openai/v1/responses/compact", nil)
+	c.Request.Header.Set("User-Agent", "codex_cli_rs/0.98.0")
+	account := newOpenAIImageGenerationControlTestAccount()
+
+	// /responses/compact 上游不接受 tool_choice，bridge 注入必须整体豁免 compact 请求。
+	result, err := svc.Forward(context.Background(), c, account, []byte(`{"model":"gpt-5.4","input":"summarize the conversation","stream":false}`))
+
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.NotNil(t, upstream.lastReq)
+	require.False(t, gjson.GetBytes(upstream.lastBody, "tool_choice").Exists())
+	require.False(t, gjson.GetBytes(upstream.lastBody, `tools.#(type=="image_generation")`).Exists())
+	instructions := gjson.GetBytes(upstream.lastBody, "instructions").String()
+	require.NotContains(t, instructions, "image_generation")
+}
+
 func TestOpenAIGatewayService_CodexImageGenerationBridgeOverridePrecedence(t *testing.T) {
 	groupID := int64(4242)