fix(openai): retry streamed capacity errors in pool mode

backend/internal/service/openai_gateway_passthrough.go

@@ -892,6 +892,15 @@ func openAIStreamFailedEventShouldFailover(payload []byte, message string) bool
 	return true
 }
 
+func openAIStreamFailedEventRetryableOnSameAccount(account *Account, payload []byte, message string) bool {
+	if account == nil || !account.IsPoolMode() {
+		return false
+	}
+	semanticStatus := openAIStreamFailedEventSemanticStatus(payload, message)
+	return account.IsPoolModeRetryableStatus(semanticStatus) ||
+		isOpenAITransientProcessingError(http.StatusBadRequest, message, payload)
+}
+
 func (s *OpenAIGatewayService) recordOpenAIStreamUpstreamError(
 	c *gin.Context,
 	account *Account,
@@ -954,8 +963,9 @@ func (s *OpenAIGatewayService) newOpenAIStreamFailoverError(
 		},
 	})
 	return &UpstreamFailoverError{
-		StatusCode:   http.StatusBadGateway,
+		StatusCode:             http.StatusBadGateway,
-		ResponseBody: body,
+		ResponseBody:           body,
+		RetryableOnSameAccount: openAIStreamFailedEventRetryableOnSameAccount(account, payload, message),
 	}
 }
 

backend/internal/service/openai_gateway_service_test.go

@@ -1474,6 +1474,7 @@ func TestOpenAIStreamingResponseFailedBeforeOutputReturnsFailover(t *testing.T)
 	var failoverErr *UpstreamFailoverError
 	require.ErrorAs(t, err, &failoverErr)
 	require.Equal(t, http.StatusBadGateway, failoverErr.StatusCode)
+	require.False(t, failoverErr.RetryableOnSameAccount)
 	require.Contains(t, string(failoverErr.ResponseBody), "An error occurred while processing your request")
 	require.False(t, c.Writer.Written())
 	require.Empty(t, rec.Body.String())
@@ -1510,11 +1511,21 @@ func TestOpenAIStreamingResponseFailedBeforeOutputCapacityErrorReturnsFailover(t
 		Header: http.Header{"X-Request-Id": []string{"rid-capacity-failed"}},
 	}
 
-	_, err := svc.handleStreamingResponse(c.Request.Context(), resp, c, &Account{ID: 1, Platform: PlatformOpenAI, Name: "acc"}, time.Now(), "model", "model")
+	account := &Account{
+		ID:       1,
+		Platform: PlatformOpenAI,
+		Type:     AccountTypeAPIKey,
+		Name:     "pool-account",
+		Credentials: map[string]any{
+			"pool_mode": true,
+		},
+	}
+	_, err := svc.handleStreamingResponse(c.Request.Context(), resp, c, account, time.Now(), "model", "model")
 	require.Error(t, err)
 	var failoverErr *UpstreamFailoverError
 	require.ErrorAs(t, err, &failoverErr)
 	require.Equal(t, http.StatusBadGateway, failoverErr.StatusCode)
+	require.True(t, failoverErr.RetryableOnSameAccount)
 	require.Contains(t, string(failoverErr.ResponseBody), "Selected model is at capacity")
 	require.False(t, c.Writer.Written())
 	require.Empty(t, rec.Body.String())