Sub2API v1.0 - AI API 网关（二开初始版本，基于上游 Wei-Shaw/sub2api）

backend/internal/handler/openai_codex_models_handler.go

@@ -0,0 +1,87 @@
+package handler
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+
+	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
+	middleware2 "github.com/Wei-Shaw/sub2api/internal/server/middleware"
+	"github.com/Wei-Shaw/sub2api/internal/service"
+)
+
+// CodexModels serves the Codex models manifest for Codex clients.
+//
+// Codex CLI and the Codex desktop app refresh their model picker from
+// GET {base_url}/models?client_version=... (custom provider mode) or
+// GET /backend-api/codex/models (chatgpt_base_url mode). Both routes land
+// here. ChatGPT manifests are proxied verbatim; custom API key manifests receive
+// provider-compatibility normalization and use a short-lived, asynchronously
+// revalidated cache to tolerate canceled client requests.
+func (h *OpenAIGatewayHandler) CodexModels(c *gin.Context) {
+	if c.Request.Context().Err() != nil {
+		return
+	}
+	apiKey, ok := middleware2.GetAPIKeyFromContext(c)
+	if !ok || apiKey.Group == nil {
+		h.errorResponse(c, http.StatusUnauthorized, "invalid_request_error", "API key group is required")
+		return
+	}
+	if apiKey.Group.Platform != service.PlatformOpenAI && apiKey.Group.Platform != service.PlatformComposite {
+		h.errorResponse(c, http.StatusNotFound, "not_found_error", "Codex models manifest is only available for OpenAI and Composite groups")
+		return
+	}
+
+	maxAccountSwitches := h.maxAccountSwitches
+	if maxAccountSwitches <= 0 {
+		maxAccountSwitches = 3
+	}
+	failedAccountIDs := make(map[int64]struct{})
+	switchCount := 0
+	var lastUpstreamErr error
+
+	for {
+		account, err := h.gatewayService.SelectAccountForModelWithExclusions(c.Request.Context(), apiKey.GroupID, "", "", failedAccountIDs)
+		if err != nil {
+			if c.Request.Context().Err() != nil {
+				return
+			}
+			if lastUpstreamErr != nil {
+				h.errorResponse(c, infraerrors.Code(lastUpstreamErr), "upstream_error", infraerrors.Message(lastUpstreamErr))
+				return
+			}
+			h.errorResponse(c, http.StatusServiceUnavailable, "upstream_error", "No available OpenAI accounts")
+			return
+		}
+		// 让 ops 错误日志携带实际选中的上游账号，便于定位失效账号（#4544）。
+		setOpsSelectedAccount(c, account.ID, account.Platform)
+
+		manifest, err := h.gatewayService.FetchCodexModelsManifest(c.Request.Context(), account, c.Query("client_version"), c.GetHeader("If-None-Match"))
+		if err != nil {
+			if c.Request.Context().Err() != nil {
+				return
+			}
+			if service.IsRetryableCodexModelsManifestError(err) && switchCount < maxAccountSwitches {
+				failedAccountIDs[account.ID] = struct{}{}
+				switchCount++
+				lastUpstreamErr = err
+				continue
+			}
+			h.errorResponse(c, infraerrors.Code(err), "upstream_error", infraerrors.Message(err))
+			return
+		}
+		if c.Request.Context().Err() != nil {
+			return
+		}
+
+		if manifest.ETag != "" {
+			c.Header("ETag", manifest.ETag)
+		}
+		if manifest.NotModified {
+			c.Status(http.StatusNotModified)
+			return
+		}
+		c.Data(http.StatusOK, "application/json", manifest.Body)
+		return
+	}
+}