fix(openai-gateway): route APIKey accounts to /v1/chat/completions when upstream lacks Responses API

OpenAI APIKey accounts with base_url pointing to third-party OpenAI-compatible upstreams (DeepSeek, Kimi, GLM, Qwen, etc.) were failing because the gateway unconditionally converted Chat Completions requests to Responses format and forwarded to {base_url}/v1/responses, which only exists on OpenAI's official endpoint. Detection-based routing: - Probe upstream capability on account create/update via a minimal POST to /v1/responses; HTTP 404/405 means 'unsupported', any other response means 'supported'. - Persist result as accounts.extra.openai_responses_supported (bool). - ForwardAsChatCompletions branches at function entry: APIKey accounts with explicit support=false go through new forwardAsRawChatCompletions which passthrough-forwards CC body to /v1/chat/completions without protocol conversion. Default behavior for accounts without the marker preserves the legacy 'always Responses' path — existing OpenAI APIKey accounts that were working before this change continue to work without modification (the 'reality is evidence' principle: an account that has been running implies upstream capability). Probe is fired async after Create / Update / BatchCreate; failures only log, never block the admin flow. BulkUpdate omitted (low signal of base_url changes; can be added if needed). Implementation: - New pkg internal/pkg/openai_compat: marker key + ShouldUseResponsesAPI - New service file openai_apikey_responses_probe.go: probe + persist - New service file openai_gateway_chat_completions_raw.go: CC pass-through - Account test endpoint short-circuits with explicit message for probed-unsupported accounts (full CC test path is a TODO) Zero schema changes, zero migrations, zero frontend changes, zero wire modifications — all wired through existing AccountTestService injection. Closes: DeepSeek-OpenAI account (id=128) production failure
2026-04-30 19:25:45 +08:00
parent 48912014a1
commit 4e4cc80971
7 changed files with 708 additions and 3 deletions
@@ -0,0 +1,368 @@
+package service
+
+import (
+	"bufio"
+	"bytes"
+	"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"
+	"github.com/tidwall/gjson"
+	"go.uber.org/zap"
+)
+
+// forwardAsRawChatCompletions 直转客户端的 Chat Completions 请求到上游
+// `{base_url}/v1/chat/completions`，**不**做 CC↔Responses 协议转换。
+//
+// 适用场景：account.platform=openai && account.type=apikey && 上游已被探测确认
+// 不支持 /v1/responses 端点（如 DeepSeek/Kimi/GLM/Qwen 等第三方 OpenAI 兼容上游）。
+//
+// 与 ForwardAsChatCompletions 的关键差异：
+//
+//   - 不调用 apicompat.ChatCompletionsToResponses，body 仅做模型 ID 改写
+//   - 上游 URL 拼到 /v1/chat/completions 而非 /v1/responses
+//   - 流式响应 SSE 直接透传给客户端（上游 chunk 已是 CC 格式）
+//   - 非流式响应 JSON 直接透传，仅按需提取 usage
+//   - 不应用 codex OAuth transform（APIKey 路径无 OAuth）
+//   - 不注入 prompt_cache_key（OAuth 专属机制）
+//
+// 调用入口：openai_gateway_chat_completions.go::ForwardAsChatCompletions
+// 在函数顶部按 openai_compat.ShouldUseResponsesAPI 分流。
+func (s *OpenAIGatewayService) forwardAsRawChatCompletions(
+	ctx context.Context,
+	c *gin.Context,
+	account *Account,
+	body []byte,
+	defaultMappedModel string,
+) (*OpenAIForwardResult, error) {
+	startTime := time.Now()
+
+	// 1. Parse minimal fields needed for routing/billing
+	originalModel := gjson.GetBytes(body, "model").String()
+	if originalModel == "" {
+		writeChatCompletionsError(c, http.StatusBadRequest, "invalid_request_error", "model is required")
+		return nil, fmt.Errorf("missing model in request")
+	}
+	clientStream := gjson.GetBytes(body, "stream").Bool()
+	includeUsage := gjson.GetBytes(body, "stream_options.include_usage").Bool()
+
+	// 2. Resolve model mapping (same as ForwardAsChatCompletions)
+	billingModel := resolveOpenAIForwardModel(account, originalModel, defaultMappedModel)
+	upstreamModel := normalizeOpenAIModelForUpstream(account, billingModel)
+
+	// 3. Rewrite model in body (no protocol conversion)
+	upstreamBody := body
+	if upstreamModel != originalModel {
+		upstreamBody = ReplaceModelInBody(body, upstreamModel)
+	}
+
+	// 4. Apply OpenAI fast policy on the CC body
+	updatedBody, policyErr := s.applyOpenAIFastPolicyToBody(ctx, account, upstreamModel, upstreamBody)
+	if policyErr != nil {
+		var blocked *OpenAIFastBlockedError
+		if errors.As(policyErr, &blocked) {
+			writeChatCompletionsError(c, http.StatusForbidden, "permission_error", blocked.Message)
+		}
+		return nil, policyErr
+	}
+	upstreamBody = updatedBody
+
+	logger.L().Debug("openai chat_completions raw: forwarding without protocol conversion",
+		zap.Int64("account_id", account.ID),
+		zap.String("original_model", originalModel),
+		zap.String("billing_model", billingModel),
+		zap.String("upstream_model", upstreamModel),
+		zap.Bool("stream", clientStream),
+	)
+
+	// 5. Build upstream request
+	apiKey := account.GetOpenAIApiKey()
+	if apiKey == "" {
+		return nil, fmt.Errorf("account %d missing api_key", account.ID)
+	}
+	baseURL := account.GetOpenAIBaseURL()
+	if baseURL == "" {
+		baseURL = "https://api.openai.com"
+	}
+	validatedURL, err := s.validateUpstreamBaseURL(baseURL)
+	if err != nil {
+		return nil, fmt.Errorf("invalid base_url: %w", err)
+	}
+	targetURL := buildOpenAIChatCompletionsURL(validatedURL)
+
+	upstreamReq, err := http.NewRequestWithContext(ctx, http.MethodPost, targetURL, bytes.NewReader(upstreamBody))
+	if err != nil {
+		return nil, fmt.Errorf("build upstream request: %w", err)
+	}
+	upstreamReq.Header.Set("Content-Type", "application/json")
+	upstreamReq.Header.Set("Authorization", "Bearer "+apiKey)
+	if clientStream {
+		upstreamReq.Header.Set("Accept", "text/event-stream")
+	} else {
+		upstreamReq.Header.Set("Accept", "application/json")
+	}
+
+	// Whitelist passthrough headers (subset of openaiAllowedHeaders relevant to CC).
+	for key, values := range c.Request.Header {
+		lowerKey := strings.ToLower(key)
+		if openaiAllowedHeaders[lowerKey] {
+			for _, v := range values {
+				upstreamReq.Header.Add(key, v)
+			}
+		}
+	}
+	customUA := account.GetOpenAIUserAgent()
+	if customUA != "" {
+		upstreamReq.Header.Set("user-agent", customUA)
+	}
+
+	// 6. 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,
+		})
+		writeChatCompletionsError(c, http.StatusBadGateway, "upstream_error", "Upstream request failed")
+		return nil, fmt.Errorf("upstream request failed: %s", safeErr)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	// 7. Handle error response with failover
+	if resp.StatusCode >= 400 {
+		respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
+		_ = resp.Body.Close()
+		resp.Body = io.NopCloser(bytes.NewReader(respBody))
+
+		upstreamMsg := strings.TrimSpace(extractUpstreamErrorMessage(respBody))
+		upstreamMsg = sanitizeUpstreamErrorMessage(upstreamMsg)
+		if s.shouldFailoverOpenAIUpstreamResponse(resp.StatusCode, upstreamMsg, respBody) {
+			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,
+				RetryableOnSameAccount: account.IsPoolMode() && (isPoolModeRetryableStatus(resp.StatusCode) || isOpenAITransientProcessingError(resp.StatusCode, upstreamMsg, respBody)),
+			}
+		}
+		return s.handleChatCompletionsErrorResponse(resp, c, account)
+	}
+
+	// 8. Forward response
+	if clientStream {
+		return s.streamRawChatCompletions(c, resp, originalModel, billingModel, upstreamModel, includeUsage, startTime)
+	}
+	return s.bufferRawChatCompletions(c, resp, originalModel, billingModel, upstreamModel, startTime)
+}
+
+// streamRawChatCompletions 透传上游 CC SSE 流到客户端，并提取 usage（包括
+// 末尾 [DONE] 之前的 chunk 中的 usage 字段，按 OpenAI CC 协议）。
+func (s *OpenAIGatewayService) streamRawChatCompletions(
+	c *gin.Context,
+	resp *http.Response,
+	originalModel string,
+	billingModel string,
+	upstreamModel string,
+	includeUsage bool,
+	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.Header().Set("X-Accel-Buffering", "no")
+	c.Writer.WriteHeader(http.StatusOK)
+
+	scanner := bufio.NewScanner(resp.Body)
+	maxLineSize := defaultMaxLineSize
+	if s.cfg != nil && s.cfg.Gateway.MaxLineSize > 0 {
+		maxLineSize = s.cfg.Gateway.MaxLineSize
+	}
+	scanner.Buffer(make([]byte, 0, 64*1024), maxLineSize)
+
+	var usage OpenAIUsage
+	var firstTokenMs *int
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		// Direct passthrough: write each line + blank line separator
+		if _, werr := c.Writer.WriteString(line + "\n"); werr != nil {
+			logger.L().Debug("openai chat_completions raw: client write failed",
+				zap.Error(werr),
+				zap.String("request_id", requestID),
+			)
+			break
+		}
+		if line == "" {
+			c.Writer.Flush()
+			continue
+		}
+		c.Writer.Flush()
+
+		// Track first token timing on first non-empty data line
+		if firstTokenMs == nil && strings.HasPrefix(line, "data: ") && line != "data: [DONE]" {
+			elapsed := int(time.Since(startTime).Milliseconds())
+			firstTokenMs = &elapsed
+		}
+
+		// Extract usage from any chunk that carries it (CC streams typically put
+		// usage in the final chunk before [DONE], but may also appear elsewhere).
+		if strings.HasPrefix(line, "data: ") && line != "data: [DONE]" {
+			payload := line[6:]
+			if u := extractCCStreamUsage(payload); u != nil {
+				usage = *u
+			}
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		if !errors.Is(err, context.Canceled) && !errors.Is(err, context.DeadlineExceeded) {
+			logger.L().Warn("openai chat_completions raw: stream read error",
+				zap.Error(err),
+				zap.String("request_id", requestID),
+			)
+		}
+	}
+
+	_ = includeUsage // CC 协议下 usage 是否包含由客户端的 stream_options 决定，上游会自行处理；我们仅做提取。
+
+	return &OpenAIForwardResult{
+		RequestID:     requestID,
+		Usage:         usage,
+		Model:         originalModel,
+		BillingModel:  billingModel,
+		UpstreamModel: upstreamModel,
+		Stream:        true,
+		Duration:      time.Since(startTime),
+		FirstTokenMs:  firstTokenMs,
+	}, nil
+}
+
+// bufferRawChatCompletions 透传上游 CC 非流式 JSON 响应。
+func (s *OpenAIGatewayService) bufferRawChatCompletions(
+	c *gin.Context,
+	resp *http.Response,
+	originalModel string,
+	billingModel string,
+	upstreamModel string,
+	startTime time.Time,
+) (*OpenAIForwardResult, error) {
+	requestID := resp.Header.Get("x-request-id")
+
+	respBody, err := io.ReadAll(io.LimitReader(resp.Body, 32<<20))
+	if err != nil {
+		writeChatCompletionsError(c, http.StatusBadGateway, "api_error", "Failed to read upstream response")
+		return nil, fmt.Errorf("read upstream body: %w", err)
+	}
+
+	var ccResp apicompat.ChatCompletionsResponse
+	var usage OpenAIUsage
+	if err := json.Unmarshal(respBody, &ccResp); err == nil && ccResp.Usage != nil {
+		usage = OpenAIUsage{
+			InputTokens:  ccResp.Usage.PromptTokens,
+			OutputTokens: ccResp.Usage.CompletionTokens,
+		}
+		if ccResp.Usage.PromptTokensDetails != nil {
+			usage.CacheReadInputTokens = ccResp.Usage.PromptTokensDetails.CachedTokens
+		}
+	}
+
+	if s.responseHeaderFilter != nil {
+		responseheaders.WriteFilteredHeaders(c.Writer.Header(), resp.Header, s.responseHeaderFilter)
+	}
+	if ct := resp.Header.Get("Content-Type"); ct != "" {
+		c.Writer.Header().Set("Content-Type", ct)
+	} else {
+		c.Writer.Header().Set("Content-Type", "application/json")
+	}
+	c.Writer.WriteHeader(http.StatusOK)
+	_, _ = c.Writer.Write(respBody)
+
+	return &OpenAIForwardResult{
+		RequestID:     requestID,
+		Usage:         usage,
+		Model:         originalModel,
+		BillingModel:  billingModel,
+		UpstreamModel: upstreamModel,
+		Stream:        false,
+		Duration:      time.Since(startTime),
+	}, nil
+}
+
+// extractCCStreamUsage 从单个 CC 流式 chunk 的 payload 中提取 usage 字段。
+// CC 协议中 usage 仅出现在末尾 chunk（且仅当客户端请求 stream_options.include_usage
+// 时），但上游可能在多个 chunk 中重复——总是用最新值。
+func extractCCStreamUsage(payload string) *OpenAIUsage {
+	usageResult := gjson.Get(payload, "usage")
+	if !usageResult.Exists() || !usageResult.IsObject() {
+		return nil
+	}
+	u := OpenAIUsage{
+		InputTokens:  int(gjson.Get(payload, "usage.prompt_tokens").Int()),
+		OutputTokens: int(gjson.Get(payload, "usage.completion_tokens").Int()),
+	}
+	if cached := gjson.Get(payload, "usage.prompt_tokens_details.cached_tokens"); cached.Exists() {
+		u.CacheReadInputTokens = int(cached.Int())
+	}
+	return &u
+}
+
+// buildOpenAIChatCompletionsURL 拼接上游 Chat Completions 端点 URL。
+//
+//   - base 已是 /chat/completions：原样返回
+//   - base 以 /v1 结尾：追加 /chat/completions
+//   - 其他情况：追加 /v1/chat/completions
+//
+// 与 buildOpenAIResponsesURL 是姐妹函数。
+func buildOpenAIChatCompletionsURL(base string) string {
+	normalized := strings.TrimRight(strings.TrimSpace(base), "/")
+	if strings.HasSuffix(normalized, "/chat/completions") {
+		return normalized
+	}
+	if strings.HasSuffix(normalized, "/v1") {
+		return normalized + "/chat/completions"
+	}
+	return normalized + "/v1/chat/completions"
+}