chore(test): resolve merge conflict for ws usage window pr

backend/internal/service/gateway_service.go

@@ -5429,6 +5429,11 @@ func extractUpstreamErrorMessage(body []byte) string {
 		return m
 	}
 
+	// ChatGPT 内部 API 风格：{"detail":"..."}
+	if d := gjson.GetBytes(body, "detail").String(); strings.TrimSpace(d) != "" {
+		return d
+	}
+
 	// 兜底：尝试顶层 message
 	return gjson.GetBytes(body, "message").String()
 }

backend/internal/service/openai_codex_transform.go

@@ -77,7 +77,7 @@ type codexTransformResult struct {
 	PromptCacheKey  string
 }
 
-func applyCodexOAuthTransform(reqBody map[string]any, isCodexCLI bool) codexTransformResult {
+func applyCodexOAuthTransform(reqBody map[string]any, isCodexCLI bool, isCompact bool) codexTransformResult {
 	result := codexTransformResult{}
 	// 工具续链需求会影响存储策略与 input 过滤逻辑。
 	needsToolContinuation := NeedsToolContinuation(reqBody)
@@ -95,15 +95,26 @@ func applyCodexOAuthTransform(reqBody map[string]any, isCodexCLI bool) codexTran
 		result.NormalizedModel = normalizedModel
 	}
 
-	// OAuth 走 ChatGPT internal API 时，store 必须为 false；显式 true 也会强制覆盖。
-	// 避免上游返回 "Store must be set to false"。
-	if v, ok := reqBody["store"].(bool); !ok || v {
-		reqBody["store"] = false
-		result.Modified = true
-	}
-	if v, ok := reqBody["stream"].(bool); !ok || !v {
-		reqBody["stream"] = true
-		result.Modified = true
+	if isCompact {
+		if _, ok := reqBody["store"]; ok {
+			delete(reqBody, "store")
+			result.Modified = true
+		}
+		if _, ok := reqBody["stream"]; ok {
+			delete(reqBody, "stream")
+			result.Modified = true
+		}
+	} else {
+		// OAuth 走 ChatGPT internal API 时，store 必须为 false；显式 true 也会强制覆盖。
+		// 避免上游返回 "Store must be set to false"。
+		if v, ok := reqBody["store"].(bool); !ok || v {
+			reqBody["store"] = false
+			result.Modified = true
+		}
+		if v, ok := reqBody["stream"].(bool); !ok || !v {
+			reqBody["stream"] = true
+			result.Modified = true
+		}
 	}
 
 	// Strip parameters unsupported by codex models via the Responses API.

backend/internal/service/openai_codex_transform_test.go

@@ -18,7 +18,7 @@ func TestApplyCodexOAuthTransform_ToolContinuationPreservesInput(t *testing.T) {
 		"tool_choice": "auto",
 	}
 
-	applyCodexOAuthTransform(reqBody, false)
+	applyCodexOAuthTransform(reqBody, false, false)
 
 	// 未显式设置 store=true，默认为 false。
 	store, ok := reqBody["store"].(bool)
@@ -53,7 +53,7 @@ func TestApplyCodexOAuthTransform_ExplicitStoreFalsePreserved(t *testing.T) {
 		"tool_choice": "auto",
 	}
 
-	applyCodexOAuthTransform(reqBody, false)
+	applyCodexOAuthTransform(reqBody, false, false)
 
 	store, ok := reqBody["store"].(bool)
 	require.True(t, ok)
@@ -72,13 +72,29 @@ func TestApplyCodexOAuthTransform_ExplicitStoreTrueForcedFalse(t *testing.T) {
 		"tool_choice": "auto",
 	}
 
-	applyCodexOAuthTransform(reqBody, false)
+	applyCodexOAuthTransform(reqBody, false, false)
 
 	store, ok := reqBody["store"].(bool)
 	require.True(t, ok)
 	require.False(t, store)
 }
 
+func TestApplyCodexOAuthTransform_CompactForcesNonStreaming(t *testing.T) {
+	reqBody := map[string]any{
+		"model":  "gpt-5.1-codex",
+		"store":  true,
+		"stream": true,
+	}
+
+	result := applyCodexOAuthTransform(reqBody, true, true)
+
+	_, hasStore := reqBody["store"]
+	require.False(t, hasStore)
+	_, hasStream := reqBody["stream"]
+	require.False(t, hasStream)
+	require.True(t, result.Modified)
+}
+
 func TestApplyCodexOAuthTransform_NonContinuationDefaultsStoreFalseAndStripsIDs(t *testing.T) {
 	// 非续链场景：未设置 store 时默认 false，并移除 input 中的 id。
 
@@ -89,7 +105,7 @@ func TestApplyCodexOAuthTransform_NonContinuationDefaultsStoreFalseAndStripsIDs(
 		},
 	}
 
-	applyCodexOAuthTransform(reqBody, false)
+	applyCodexOAuthTransform(reqBody, false, false)
 
 	store, ok := reqBody["store"].(bool)
 	require.True(t, ok)
@@ -138,7 +154,7 @@ func TestApplyCodexOAuthTransform_NormalizeCodexTools_PreservesResponsesFunction
 		},
 	}
 
-	applyCodexOAuthTransform(reqBody, false)
+	applyCodexOAuthTransform(reqBody, false, false)
 
 	tools, ok := reqBody["tools"].([]any)
 	require.True(t, ok)
@@ -158,7 +174,7 @@ func TestApplyCodexOAuthTransform_EmptyInput(t *testing.T) {
 		"input": []any{},
 	}
 
-	applyCodexOAuthTransform(reqBody, false)
+	applyCodexOAuthTransform(reqBody, false, false)
 
 	input, ok := reqBody["input"].([]any)
 	require.True(t, ok)
@@ -193,7 +209,7 @@ func TestApplyCodexOAuthTransform_CodexCLI_PreservesExistingInstructions(t *test
 		"instructions": "existing instructions",
 	}
 
-	result := applyCodexOAuthTransform(reqBody, true) // isCodexCLI=true
+	result := applyCodexOAuthTransform(reqBody, true, false) // isCodexCLI=true
 
 	instructions, ok := reqBody["instructions"].(string)
 	require.True(t, ok)
@@ -210,7 +226,7 @@ func TestApplyCodexOAuthTransform_CodexCLI_SuppliesDefaultWhenEmpty(t *testing.T
 		// 没有 instructions 字段
 	}
 
-	result := applyCodexOAuthTransform(reqBody, true) // isCodexCLI=true
+	result := applyCodexOAuthTransform(reqBody, true, false) // isCodexCLI=true
 
 	instructions, ok := reqBody["instructions"].(string)
 	require.True(t, ok)
@@ -226,7 +242,7 @@ func TestApplyCodexOAuthTransform_NonCodexCLI_OverridesInstructions(t *testing.T
 		"instructions": "old instructions",
 	}
 
-	result := applyCodexOAuthTransform(reqBody, false) // isCodexCLI=false
+	result := applyCodexOAuthTransform(reqBody, false, false) // isCodexCLI=false
 
 	instructions, ok := reqBody["instructions"].(string)
 	require.True(t, ok)

backend/internal/service/openai_gateway_messages.go

@@ -0,0 +1,378 @@
+package service
+
+import (
+	"bufio"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/Wei-Shaw/sub2api/internal/pkg/apicompat"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/logger"
+	"github.com/Wei-Shaw/sub2api/internal/util/responseheaders"
+	"github.com/gin-gonic/gin"
+	"go.uber.org/zap"
+)
+
+// ForwardAsAnthropic accepts an Anthropic Messages request body, converts it
+// to OpenAI Responses API format, forwards to the OpenAI upstream, and converts
+// the response back to Anthropic Messages format. This enables Claude Code
+// clients to access OpenAI models through the standard /v1/messages endpoint.
+func (s *OpenAIGatewayService) ForwardAsAnthropic(
+	ctx context.Context,
+	c *gin.Context,
+	account *Account,
+	body []byte,
+	promptCacheKey string,
+) (*OpenAIForwardResult, error) {
+	startTime := time.Now()
+
+	// 1. Parse Anthropic request
+	var anthropicReq apicompat.AnthropicRequest
+	if err := json.Unmarshal(body, &anthropicReq); err != nil {
+		return nil, fmt.Errorf("parse anthropic request: %w", err)
+	}
+	originalModel := anthropicReq.Model
+	isStream := anthropicReq.Stream
+
+	// 2. Convert Anthropic → Responses
+	responsesReq, err := apicompat.AnthropicToResponses(&anthropicReq)
+	if err != nil {
+		return nil, fmt.Errorf("convert anthropic to responses: %w", err)
+	}
+
+	// 3. Model mapping
+	mappedModel := account.GetMappedModel(originalModel)
+	responsesReq.Model = mappedModel
+
+	logger.L().Info("openai messages: model mapping applied",
+		zap.Int64("account_id", account.ID),
+		zap.String("original_model", originalModel),
+		zap.String("mapped_model", mappedModel),
+		zap.Bool("stream", isStream),
+	)
+
+	// 4. Marshal Responses request body, then apply OAuth codex transform
+	responsesBody, err := json.Marshal(responsesReq)
+	if err != nil {
+		return nil, fmt.Errorf("marshal responses request: %w", err)
+	}
+
+	if account.Type == AccountTypeOAuth {
+		var reqBody map[string]any
+		if err := json.Unmarshal(responsesBody, &reqBody); err != nil {
+			return nil, fmt.Errorf("unmarshal for codex transform: %w", err)
+		}
+		applyCodexOAuthTransform(reqBody, false)
+		// OAuth codex transform forces stream=true upstream, so always use
+		// the streaming response handler regardless of what the client asked.
+		isStream = true
+		responsesBody, err = json.Marshal(reqBody)
+		if err != nil {
+			return nil, fmt.Errorf("remarshal after codex transform: %w", err)
+		}
+	}
+
+	// 5. Get access token
+	token, _, err := s.GetAccessToken(ctx, account)
+	if err != nil {
+		return nil, fmt.Errorf("get access token: %w", err)
+	}
+
+	// 6. Build upstream request
+	upstreamReq, err := s.buildUpstreamRequest(ctx, c, account, responsesBody, token, isStream, promptCacheKey, false)
+	if err != nil {
+		return nil, fmt.Errorf("build upstream request: %w", err)
+	}
+
+	// 7. Send request
+	proxyURL := ""
+	if account.Proxy != nil {
+		proxyURL = account.Proxy.URL()
+	}
+	resp, err := s.httpUpstream.Do(upstreamReq, proxyURL, account.ID, account.Concurrency)
+	if err != nil {
+		safeErr := sanitizeUpstreamErrorMessage(err.Error())
+		setOpsUpstreamError(c, 0, safeErr, "")
+		appendOpsUpstreamError(c, OpsUpstreamErrorEvent{
+			Platform:           account.Platform,
+			AccountID:          account.ID,
+			AccountName:        account.Name,
+			UpstreamStatusCode: 0,
+			Kind:               "request_error",
+			Message:            safeErr,
+		})
+		writeAnthropicError(c, http.StatusBadGateway, "api_error", "Upstream request failed")
+		return nil, fmt.Errorf("upstream request failed: %s", safeErr)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	// 8. Handle error response with failover
+	if resp.StatusCode >= 400 {
+		if s.shouldFailoverUpstreamError(resp.StatusCode) {
+			respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
+			_ = resp.Body.Close()
+
+			upstreamMsg := strings.TrimSpace(extractUpstreamErrorMessage(respBody))
+			upstreamMsg = sanitizeUpstreamErrorMessage(upstreamMsg)
+			upstreamDetail := ""
+			if s.cfg != nil && s.cfg.Gateway.LogUpstreamErrorBody {
+				maxBytes := s.cfg.Gateway.LogUpstreamErrorBodyMaxBytes
+				if maxBytes <= 0 {
+					maxBytes = 2048
+				}
+				upstreamDetail = truncateString(string(respBody), maxBytes)
+			}
+			appendOpsUpstreamError(c, OpsUpstreamErrorEvent{
+				Platform:           account.Platform,
+				AccountID:          account.ID,
+				AccountName:        account.Name,
+				UpstreamStatusCode: resp.StatusCode,
+				UpstreamRequestID:  resp.Header.Get("x-request-id"),
+				Kind:               "failover",
+				Message:            upstreamMsg,
+				Detail:             upstreamDetail,
+			})
+			if s.rateLimitService != nil {
+				s.rateLimitService.HandleUpstreamError(ctx, account, resp.StatusCode, resp.Header, respBody)
+			}
+			return nil, &UpstreamFailoverError{StatusCode: resp.StatusCode, ResponseBody: respBody}
+		}
+		// Non-failover error: return Anthropic-formatted error to client
+		return s.handleAnthropicErrorResponse(resp, c)
+	}
+
+	// 9. Handle normal response
+	if isStream {
+		return s.handleAnthropicStreamingResponse(resp, c, originalModel, startTime)
+	}
+	return s.handleAnthropicNonStreamingResponse(resp, c, originalModel, startTime)
+}
+
+// handleAnthropicErrorResponse reads an upstream error and returns it in
+// Anthropic error format.
+func (s *OpenAIGatewayService) handleAnthropicErrorResponse(
+	resp *http.Response,
+	c *gin.Context,
+) (*OpenAIForwardResult, error) {
+	body, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
+
+	upstreamMsg := strings.TrimSpace(extractUpstreamErrorMessage(body))
+	if upstreamMsg == "" {
+		upstreamMsg = fmt.Sprintf("Upstream error: %d", resp.StatusCode)
+	}
+	upstreamMsg = sanitizeUpstreamErrorMessage(upstreamMsg)
+
+	// Record upstream error details for ops logging
+	upstreamDetail := ""
+	if s.cfg != nil && s.cfg.Gateway.LogUpstreamErrorBody {
+		maxBytes := s.cfg.Gateway.LogUpstreamErrorBodyMaxBytes
+		if maxBytes <= 0 {
+			maxBytes = 2048
+		}
+		upstreamDetail = truncateString(string(body), maxBytes)
+	}
+	setOpsUpstreamError(c, resp.StatusCode, upstreamMsg, upstreamDetail)
+
+	errType := "api_error"
+	switch {
+	case resp.StatusCode == 400:
+		errType = "invalid_request_error"
+	case resp.StatusCode == 404:
+		errType = "not_found_error"
+	case resp.StatusCode == 429:
+		errType = "rate_limit_error"
+	case resp.StatusCode >= 500:
+		errType = "api_error"
+	}
+
+	writeAnthropicError(c, resp.StatusCode, errType, upstreamMsg)
+	return nil, fmt.Errorf("upstream error: %d %s", resp.StatusCode, upstreamMsg)
+}
+
+// handleAnthropicNonStreamingResponse reads a Responses API JSON response,
+// converts it to Anthropic Messages format, and writes it to the client.
+func (s *OpenAIGatewayService) handleAnthropicNonStreamingResponse(
+	resp *http.Response,
+	c *gin.Context,
+	originalModel string,
+	startTime time.Time,
+) (*OpenAIForwardResult, error) {
+	requestID := resp.Header.Get("x-request-id")
+
+	respBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("read upstream response: %w", err)
+	}
+
+	var responsesResp apicompat.ResponsesResponse
+	if err := json.Unmarshal(respBody, &responsesResp); err != nil {
+		return nil, fmt.Errorf("parse responses response: %w", err)
+	}
+
+	anthropicResp := apicompat.ResponsesToAnthropic(&responsesResp, originalModel)
+
+	var usage OpenAIUsage
+	if responsesResp.Usage != nil {
+		usage = OpenAIUsage{
+			InputTokens:  responsesResp.Usage.InputTokens,
+			OutputTokens: responsesResp.Usage.OutputTokens,
+		}
+		if responsesResp.Usage.InputTokensDetails != nil {
+			usage.CacheReadInputTokens = responsesResp.Usage.InputTokensDetails.CachedTokens
+		}
+	}
+
+	if s.responseHeaderFilter != nil {
+		responseheaders.WriteFilteredHeaders(c.Writer.Header(), resp.Header, s.responseHeaderFilter)
+	}
+	c.JSON(http.StatusOK, anthropicResp)
+
+	return &OpenAIForwardResult{
+		RequestID: requestID,
+		Usage:     usage,
+		Model:     originalModel,
+		Stream:    false,
+		Duration:  time.Since(startTime),
+	}, nil
+}
+
+// handleAnthropicStreamingResponse reads Responses SSE events from upstream,
+// converts each to Anthropic SSE events, and writes them to the client.
+func (s *OpenAIGatewayService) handleAnthropicStreamingResponse(
+	resp *http.Response,
+	c *gin.Context,
+	originalModel string,
+	startTime time.Time,
+) (*OpenAIForwardResult, error) {
+	requestID := resp.Header.Get("x-request-id")
+
+	if s.responseHeaderFilter != nil {
+		responseheaders.WriteFilteredHeaders(c.Writer.Header(), resp.Header, s.responseHeaderFilter)
+	}
+	c.Writer.Header().Set("Content-Type", "text/event-stream")
+	c.Writer.Header().Set("Cache-Control", "no-cache")
+	c.Writer.Header().Set("Connection", "keep-alive")
+	c.Writer.WriteHeader(http.StatusOK)
+
+	state := apicompat.NewResponsesEventToAnthropicState()
+	state.Model = originalModel
+	var usage OpenAIUsage
+	var firstTokenMs *int
+	firstChunk := true
+
+	scanner := bufio.NewScanner(resp.Body)
+	scanner.Buffer(make([]byte, 0, 64*1024), 1024*1024)
+
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		if !strings.HasPrefix(line, "data: ") || line == "data: [DONE]" {
+			continue
+		}
+		payload := line[6:]
+
+		if firstChunk {
+			firstChunk = false
+			ms := int(time.Since(startTime).Milliseconds())
+			firstTokenMs = &ms
+		}
+
+		// Parse the Responses SSE event
+		var event apicompat.ResponsesStreamEvent
+		if err := json.Unmarshal([]byte(payload), &event); err != nil {
+			logger.L().Warn("openai messages stream: failed to parse event",
+				zap.Error(err),
+				zap.String("request_id", requestID),
+			)
+			continue
+		}
+
+		// Extract usage from completion events
+		if (event.Type == "response.completed" || event.Type == "response.incomplete") &&
+			event.Response != nil && event.Response.Usage != nil {
+			usage = OpenAIUsage{
+				InputTokens:  event.Response.Usage.InputTokens,
+				OutputTokens: event.Response.Usage.OutputTokens,
+			}
+			if event.Response.Usage.InputTokensDetails != nil {
+				usage.CacheReadInputTokens = event.Response.Usage.InputTokensDetails.CachedTokens
+			}
+		}
+
+		// Convert to Anthropic events
+		events := apicompat.ResponsesEventToAnthropicEvents(&event, state)
+		for _, evt := range events {
+			sse, err := apicompat.ResponsesAnthropicEventToSSE(evt)
+			if err != nil {
+				logger.L().Warn("openai messages stream: failed to marshal event",
+					zap.Error(err),
+					zap.String("request_id", requestID),
+				)
+				continue
+			}
+			if _, err := fmt.Fprint(c.Writer, sse); err != nil {
+				// Client disconnected — return collected usage
+				logger.L().Info("openai messages stream: client disconnected",
+					zap.String("request_id", requestID),
+				)
+				return &OpenAIForwardResult{
+					RequestID:    requestID,
+					Usage:        usage,
+					Model:        originalModel,
+					Stream:       true,
+					Duration:     time.Since(startTime),
+					FirstTokenMs: firstTokenMs,
+				}, nil
+			}
+		}
+		if len(events) > 0 {
+			c.Writer.Flush()
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		if !errors.Is(err, context.Canceled) && !errors.Is(err, context.DeadlineExceeded) {
+			logger.L().Warn("openai messages stream: read error",
+				zap.Error(err),
+				zap.String("request_id", requestID),
+			)
+		}
+	}
+
+	// Ensure the Anthropic stream is properly terminated
+	if finalEvents := apicompat.FinalizeResponsesAnthropicStream(state); len(finalEvents) > 0 {
+		for _, evt := range finalEvents {
+			sse, err := apicompat.ResponsesAnthropicEventToSSE(evt)
+			if err != nil {
+				continue
+			}
+			fmt.Fprint(c.Writer, sse) //nolint:errcheck
+		}
+		c.Writer.Flush()
+	}
+
+	return &OpenAIForwardResult{
+		RequestID:    requestID,
+		Usage:        usage,
+		Model:        originalModel,
+		Stream:       true,
+		Duration:     time.Since(startTime),
+		FirstTokenMs: firstTokenMs,
+	}, nil
+}
+
+// writeAnthropicError writes an error response in Anthropic Messages API format.
+func writeAnthropicError(c *gin.Context, statusCode int, errType, message string) {
+	c.JSON(statusCode, gin.H{
+		"type": "error",
+		"error": gin.H{
+			"type":    errType,
+			"message": message,
+		},
+	})
+}

backend/internal/service/openai_gateway_service.go

@@ -25,6 +25,7 @@ import (
 	"github.com/Wei-Shaw/sub2api/internal/util/responseheaders"
 	"github.com/Wei-Shaw/sub2api/internal/util/urlvalidator"
 	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
 	"github.com/tidwall/gjson"
 	"github.com/tidwall/sjson"
 	"go.uber.org/zap"
@@ -49,6 +50,8 @@ const (
 	openAIWSRetryBackoffInitialDefault = 120 * time.Millisecond
 	openAIWSRetryBackoffMaxDefault     = 2 * time.Second
 	openAIWSRetryJitterRatioDefault    = 0.2
+	openAICompactSessionSeedKey        = "openai_compact_session_seed"
+	codexCLIVersion                    = "0.104.0"
 )
 
 // OpenAI allowed headers whitelist (for non-passthrough).
@@ -898,6 +901,22 @@ func isOpenAIInstructionsRequiredError(upstreamStatusCode int, upstreamMsg strin
 	return false
 }
 
+// ExtractSessionID extracts the raw session ID from headers or body without hashing.
+// Used by ForwardAsAnthropic to pass as prompt_cache_key for upstream cache.
+func (s *OpenAIGatewayService) ExtractSessionID(c *gin.Context, body []byte) string {
+	if c == nil {
+		return ""
+	}
+	sessionID := strings.TrimSpace(c.GetHeader("session_id"))
+	if sessionID == "" {
+		sessionID = strings.TrimSpace(c.GetHeader("conversation_id"))
+	}
+	if sessionID == "" && len(body) > 0 {
+		sessionID = strings.TrimSpace(gjson.GetBytes(body, "prompt_cache_key").String())
+	}
+	return sessionID
+}
+
 // GenerateSessionHash generates a sticky-session hash for OpenAI requests.
 //
 // Priority:
@@ -1615,7 +1634,7 @@ func (s *OpenAIGatewayService) Forward(ctx context.Context, c *gin.Context, acco
 	}
 
 	if account.Type == AccountTypeOAuth {
-		codexResult := applyCodexOAuthTransform(reqBody, isCodexCLI)
+		codexResult := applyCodexOAuthTransform(reqBody, isCodexCLI, isOpenAIResponsesCompactPath(c))
 		if codexResult.Modified {
 			bodyModified = true
 			disablePatch()
@@ -2047,14 +2066,14 @@ func (s *OpenAIGatewayService) forwardOpenAIPassthrough(
 			return nil, fmt.Errorf("openai passthrough rejected before upstream: %s", rejectReason)
 		}
 
-		normalizedBody, normalized, err := normalizeOpenAIPassthroughOAuthBody(body)
+		normalizedBody, normalized, err := normalizeOpenAIPassthroughOAuthBody(body, isOpenAIResponsesCompactPath(c))
 		if err != nil {
 			return nil, err
 		}
 		if normalized {
 			body = normalizedBody
-			reqStream = true
 		}
+		reqStream = gjson.GetBytes(body, "stream").Bool()
 	}
 
 	logger.LegacyPrintf("service.openai_gateway",
@@ -2219,6 +2238,7 @@ func (s *OpenAIGatewayService) buildUpstreamRequestOpenAIPassthrough(
 			targetURL = buildOpenAIResponsesURL(validatedURL)
 		}
 	}
+	targetURL = appendOpenAIResponsesRequestPathSuffix(targetURL, openAIResponsesRequestPathSuffix(c))
 
 	req, err := http.NewRequestWithContext(ctx, http.MethodPost, targetURL, bytes.NewReader(body))
 	if err != nil {
@@ -2252,7 +2272,15 @@ func (s *OpenAIGatewayService) buildUpstreamRequestOpenAIPassthrough(
 		if chatgptAccountID := account.GetChatGPTAccountID(); chatgptAccountID != "" {
 			req.Header.Set("chatgpt-account-id", chatgptAccountID)
 		}
-		if req.Header.Get("accept") == "" {
+		if isOpenAIResponsesCompactPath(c) {
+			req.Header.Set("accept", "application/json")
+			if req.Header.Get("version") == "" {
+				req.Header.Set("version", codexCLIVersion)
+			}
+			if req.Header.Get("session_id") == "" {
+				req.Header.Set("session_id", resolveOpenAICompactSessionID(c))
+			}
+		} else if req.Header.Get("accept") == "" {
 			req.Header.Set("accept", "text/event-stream")
 		}
 		if req.Header.Get("OpenAI-Beta") == "" {
@@ -2599,6 +2627,7 @@ func (s *OpenAIGatewayService) buildUpstreamRequest(ctx context.Context, c *gin.
 	default:
 		targetURL = openaiPlatformAPIURL
 	}
+	targetURL = appendOpenAIResponsesRequestPathSuffix(targetURL, openAIResponsesRequestPathSuffix(c))
 
 	req, err := http.NewRequestWithContext(ctx, "POST", targetURL, bytes.NewReader(body))
 	if err != nil {
@@ -2635,7 +2664,17 @@ func (s *OpenAIGatewayService) buildUpstreamRequest(ctx context.Context, c *gin.
 		} else {
 			req.Header.Set("originator", "opencode")
 		}
-		req.Header.Set("accept", "text/event-stream")
+		if isOpenAIResponsesCompactPath(c) {
+			req.Header.Set("accept", "application/json")
+			if req.Header.Get("version") == "" {
+				req.Header.Set("version", codexCLIVersion)
+			}
+			if req.Header.Get("session_id") == "" {
+				req.Header.Set("session_id", resolveOpenAICompactSessionID(c))
+			}
+		} else {
+			req.Header.Set("accept", "text/event-stream")
+		}
 		if promptCacheKey != "" {
 			req.Header.Set("conversation_id", promptCacheKey)
 			req.Header.Set("session_id", promptCacheKey)
@@ -3426,6 +3465,95 @@ func buildOpenAIResponsesURL(base string) string {
 	return normalized + "/v1/responses"
 }
 
+func IsOpenAIResponsesCompactPathForTest(c *gin.Context) bool {
+	return isOpenAIResponsesCompactPath(c)
+}
+
+func OpenAICompactSessionSeedKeyForTest() string {
+	return openAICompactSessionSeedKey
+}
+
+func NormalizeOpenAICompactRequestBodyForTest(body []byte) ([]byte, bool, error) {
+	return normalizeOpenAICompactRequestBody(body)
+}
+
+func isOpenAIResponsesCompactPath(c *gin.Context) bool {
+	suffix := strings.TrimSpace(openAIResponsesRequestPathSuffix(c))
+	return suffix == "/compact" || strings.HasPrefix(suffix, "/compact/")
+}
+
+func normalizeOpenAICompactRequestBody(body []byte) ([]byte, bool, error) {
+	if len(body) == 0 {
+		return body, false, nil
+	}
+
+	normalized := []byte(`{}`)
+	for _, field := range []string{"model", "input", "instructions", "previous_response_id"} {
+		value := gjson.GetBytes(body, field)
+		if !value.Exists() {
+			continue
+		}
+		next, err := sjson.SetRawBytes(normalized, field, []byte(value.Raw))
+		if err != nil {
+			return body, false, fmt.Errorf("normalize compact body %s: %w", field, err)
+		}
+		normalized = next
+	}
+
+	if bytes.Equal(bytes.TrimSpace(body), bytes.TrimSpace(normalized)) {
+		return body, false, nil
+	}
+	return normalized, true, nil
+}
+
+func resolveOpenAICompactSessionID(c *gin.Context) string {
+	if c != nil {
+		if sessionID := strings.TrimSpace(c.GetHeader("session_id")); sessionID != "" {
+			return sessionID
+		}
+		if conversationID := strings.TrimSpace(c.GetHeader("conversation_id")); conversationID != "" {
+			return conversationID
+		}
+		if seed, ok := c.Get(openAICompactSessionSeedKey); ok {
+			if seedStr, ok := seed.(string); ok && strings.TrimSpace(seedStr) != "" {
+				return strings.TrimSpace(seedStr)
+			}
+		}
+	}
+	return uuid.NewString()
+}
+
+func openAIResponsesRequestPathSuffix(c *gin.Context) string {
+	if c == nil || c.Request == nil || c.Request.URL == nil {
+		return ""
+	}
+	normalizedPath := strings.TrimRight(strings.TrimSpace(c.Request.URL.Path), "/")
+	if normalizedPath == "" {
+		return ""
+	}
+	idx := strings.LastIndex(normalizedPath, "/responses")
+	if idx < 0 {
+		return ""
+	}
+	suffix := normalizedPath[idx+len("/responses"):]
+	if suffix == "" || suffix == "/" {
+		return ""
+	}
+	if !strings.HasPrefix(suffix, "/") {
+		return ""
+	}
+	return suffix
+}
+
+func appendOpenAIResponsesRequestPathSuffix(baseURL, suffix string) string {
+	trimmedBase := strings.TrimRight(strings.TrimSpace(baseURL), "/")
+	trimmedSuffix := strings.TrimSpace(suffix)
+	if trimmedBase == "" || trimmedSuffix == "" {
+		return trimmedBase
+	}
+	return trimmedBase + trimmedSuffix
+}
+
 func (s *OpenAIGatewayService) replaceModelInResponseBody(body []byte, fromModel, toModel string) []byte {
 	// 使用 gjson/sjson 精确替换 model 字段，避免全量 JSON 反序列化
 	if m := gjson.GetBytes(body, "model"); m.Exists() && m.Str == fromModel {
@@ -3815,8 +3943,8 @@ func extractOpenAIRequestMetaFromBody(body []byte) (model string, stream bool, p
 }
 
 // normalizeOpenAIPassthroughOAuthBody 将透传 OAuth 请求体收敛为旧链路关键行为：
-// 1) store=false 2) stream=true
-func normalizeOpenAIPassthroughOAuthBody(body []byte) ([]byte, bool, error) {
+// 1) store=false 2) 非 compact 保持 stream=true；compact 强制 stream=false
+func normalizeOpenAIPassthroughOAuthBody(body []byte, compact bool) ([]byte, bool, error) {
 	if len(body) == 0 {
 		return body, false, nil
 	}
@@ -3824,22 +3952,40 @@ func normalizeOpenAIPassthroughOAuthBody(body []byte) ([]byte, bool, error) {
 	normalized := body
 	changed := false
 
-	if store := gjson.GetBytes(normalized, "store"); !store.Exists() || store.Type != gjson.False {
-		next, err := sjson.SetBytes(normalized, "store", false)
-		if err != nil {
-			return body, false, fmt.Errorf("normalize passthrough body store=false: %w", err)
+	if compact {
+		if store := gjson.GetBytes(normalized, "store"); store.Exists() {
+			next, err := sjson.DeleteBytes(normalized, "store")
+			if err != nil {
+				return body, false, fmt.Errorf("normalize passthrough body delete store: %w", err)
+			}
+			normalized = next
+			changed = true
 		}
-		normalized = next
-		changed = true
-	}
-
-	if stream := gjson.GetBytes(normalized, "stream"); !stream.Exists() || stream.Type != gjson.True {
-		next, err := sjson.SetBytes(normalized, "stream", true)
-		if err != nil {
-			return body, false, fmt.Errorf("normalize passthrough body stream=true: %w", err)
+		if stream := gjson.GetBytes(normalized, "stream"); stream.Exists() {
+			next, err := sjson.DeleteBytes(normalized, "stream")
+			if err != nil {
+				return body, false, fmt.Errorf("normalize passthrough body delete stream: %w", err)
+			}
+			normalized = next
+			changed = true
+		}
+	} else {
+		if store := gjson.GetBytes(normalized, "store"); !store.Exists() || store.Type != gjson.False {
+			next, err := sjson.SetBytes(normalized, "store", false)
+			if err != nil {
+				return body, false, fmt.Errorf("normalize passthrough body store=false: %w", err)
+			}
+			normalized = next
+			changed = true
+		}
+		if stream := gjson.GetBytes(normalized, "stream"); !stream.Exists() || stream.Type != gjson.True {
+			next, err := sjson.SetBytes(normalized, "stream", true)
+			if err != nil {
+				return body, false, fmt.Errorf("normalize passthrough body stream=true: %w", err)
+			}
+			normalized = next
+			changed = true
 		}
-		normalized = next
-		changed = true
 	}
 
 	return normalized, changed, nil

backend/internal/service/openai_gateway_service_test.go

@@ -1288,6 +1288,92 @@ func TestOpenAIUpdateCodexUsageSnapshotFromHeaders(t *testing.T) {
 	}
 }
 
+func TestOpenAIResponsesRequestPathSuffix(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	rec := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(rec)
+
+	tests := []struct {
+		name string
+		path string
+		want string
+	}{
+		{name: "exact v1 responses", path: "/v1/responses", want: ""},
+		{name: "compact v1 responses", path: "/v1/responses/compact", want: "/compact"},
+		{name: "compact alias responses", path: "/responses/compact/", want: "/compact"},
+		{name: "nested suffix", path: "/openai/v1/responses/compact/detail", want: "/compact/detail"},
+		{name: "unrelated path", path: "/v1/chat/completions", want: ""},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			c.Request = httptest.NewRequest(http.MethodPost, tt.path, nil)
+			require.Equal(t, tt.want, openAIResponsesRequestPathSuffix(c))
+		})
+	}
+}
+
+func TestOpenAIBuildUpstreamRequestOpenAIPassthroughPreservesCompactPath(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	rec := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(rec)
+	c.Request = httptest.NewRequest(http.MethodPost, "/v1/responses/compact", bytes.NewReader([]byte(`{"model":"gpt-5"}`)))
+
+	svc := &OpenAIGatewayService{}
+	account := &Account{Type: AccountTypeOAuth}
+
+	req, err := svc.buildUpstreamRequestOpenAIPassthrough(c.Request.Context(), c, account, []byte(`{"model":"gpt-5"}`), "token")
+	require.NoError(t, err)
+	require.Equal(t, chatgptCodexURL+"/compact", req.URL.String())
+	require.Equal(t, "application/json", req.Header.Get("Accept"))
+	require.Equal(t, codexCLIVersion, req.Header.Get("Version"))
+	require.NotEmpty(t, req.Header.Get("Session_Id"))
+}
+
+func TestOpenAIBuildUpstreamRequestCompactForcesJSONAcceptForOAuth(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	rec := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(rec)
+	c.Request = httptest.NewRequest(http.MethodPost, "/v1/responses/compact", bytes.NewReader([]byte(`{"model":"gpt-5"}`)))
+
+	svc := &OpenAIGatewayService{}
+	account := &Account{
+		Type:        AccountTypeOAuth,
+		Credentials: map[string]any{"chatgpt_account_id": "chatgpt-acc"},
+	}
+
+	req, err := svc.buildUpstreamRequest(c.Request.Context(), c, account, []byte(`{"model":"gpt-5"}`), "token", false, "", true)
+	require.NoError(t, err)
+	require.Equal(t, chatgptCodexURL+"/compact", req.URL.String())
+	require.Equal(t, "application/json", req.Header.Get("Accept"))
+	require.Equal(t, codexCLIVersion, req.Header.Get("Version"))
+	require.NotEmpty(t, req.Header.Get("Session_Id"))
+}
+
+func TestOpenAIBuildUpstreamRequestPreservesCompactPathForAPIKeyBaseURL(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	rec := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(rec)
+	c.Request = httptest.NewRequest(http.MethodPost, "/responses/compact", bytes.NewReader([]byte(`{"model":"gpt-5"}`)))
+
+	svc := &OpenAIGatewayService{cfg: &config.Config{
+		Security: config.SecurityConfig{
+			URLAllowlist: config.URLAllowlistConfig{Enabled: false},
+		},
+	}}
+	account := &Account{
+		Type:        AccountTypeAPIKey,
+		Platform:    PlatformOpenAI,
+		Credentials: map[string]any{"base_url": "https://example.com/v1"},
+	}
+
+	req, err := svc.buildUpstreamRequest(c.Request.Context(), c, account, []byte(`{"model":"gpt-5"}`), "token", false, "", false)
+	require.NoError(t, err)
+	require.Equal(t, "https://example.com/v1/responses/compact", req.URL.String())
+}
+
+// ==================== P1-08 修复：model 替换性能优化测试 ====================
+
 // ==================== P1-08 修复：model 替换性能优化测试 =============
 func TestReplaceModelInSSELine(t *testing.T) {
 	svc := &OpenAIGatewayService{}

backend/internal/service/openai_oauth_passthrough_test.go

@@ -236,6 +236,60 @@ func TestOpenAIGatewayService_OAuthPassthrough_StreamKeepsToolNameAndBodyNormali
 	require.NotContains(t, body, "\"name\":\"edit\"")
 }
 
+func TestOpenAIGatewayService_OAuthPassthrough_CompactUsesJSONAndKeepsNonStreaming(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	rec := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(rec)
+	c.Request = httptest.NewRequest(http.MethodPost, "/v1/responses/compact", bytes.NewReader(nil))
+	c.Request.Header.Set("User-Agent", "codex_cli_rs/0.1.0")
+	c.Request.Header.Set("Content-Type", "application/json")
+
+	originalBody := []byte(`{"model":"gpt-5.1-codex","stream":true,"store":true,"instructions":"local-test-instructions","input":[{"type":"text","text":"compact me"}]}`)
+
+	resp := &http.Response{
+		StatusCode: http.StatusOK,
+		Header:     http.Header{"Content-Type": []string{"application/json"}, "x-request-id": []string{"rid-compact"}},
+		Body:       io.NopCloser(strings.NewReader(`{"id":"cmp_123","usage":{"input_tokens":11,"output_tokens":22}}`)),
+	}
+	upstream := &httpUpstreamRecorder{resp: resp}
+
+	svc := &OpenAIGatewayService{
+		cfg:          &config.Config{Gateway: config.GatewayConfig{ForceCodexCLI: false}},
+		httpUpstream: upstream,
+	}
+
+	account := &Account{
+		ID:             123,
+		Name:           "acc",
+		Platform:       PlatformOpenAI,
+		Type:           AccountTypeOAuth,
+		Concurrency:    1,
+		Credentials:    map[string]any{"access_token": "oauth-token", "chatgpt_account_id": "chatgpt-acc"},
+		Extra:          map[string]any{"openai_passthrough": true},
+		Status:         StatusActive,
+		Schedulable:    true,
+		RateMultiplier: f64p(1),
+	}
+
+	result, err := svc.Forward(context.Background(), c, account, originalBody)
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.False(t, result.Stream)
+
+	require.False(t, gjson.GetBytes(upstream.lastBody, "store").Exists())
+	require.False(t, gjson.GetBytes(upstream.lastBody, "stream").Exists())
+	require.Equal(t, "gpt-5.1-codex", gjson.GetBytes(upstream.lastBody, "model").String())
+	require.Equal(t, "compact me", gjson.GetBytes(upstream.lastBody, "input.0.text").String())
+	require.Equal(t, "local-test-instructions", strings.TrimSpace(gjson.GetBytes(upstream.lastBody, "instructions").String()))
+	require.Equal(t, "application/json", upstream.lastReq.Header.Get("Accept"))
+	require.Equal(t, codexCLIVersion, upstream.lastReq.Header.Get("Version"))
+	require.NotEmpty(t, upstream.lastReq.Header.Get("Session_Id"))
+	require.Equal(t, "chatgpt.com", upstream.lastReq.Host)
+	require.Equal(t, "chatgpt-acc", upstream.lastReq.Header.Get("chatgpt-account-id"))
+	require.Contains(t, rec.Body.String(), `"id":"cmp_123"`)
+}
+
 func TestOpenAIGatewayService_OAuthPassthrough_CodexMissingInstructionsRejectedBeforeUpstream(t *testing.T) {
 	gin.SetMode(gin.TestMode)
 	logSink, restore := captureStructuredLog(t)