feat: Introduce model alias resolution, enhanced configuration options, and improved OpenAI/Claude adapter handling for responses, embeddings, and tool calls.

2026-05-21 00:17:44 +08:00 · 2026-02-18 23:06:18 +08:00
parent 27ecb4b69b
commit 3a75b75ae0
28 changed files with 1665 additions and 183 deletions
--- a/internal/adapter/claude/error_shape_test.go
+++ b/internal/adapter/claude/error_shape_test.go
@@ -0,0 +1,35 @@
+package claude
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestWriteClaudeErrorIncludesUnifiedFields(t *testing.T) {
+	rec := httptest.NewRecorder()
+	writeClaudeError(rec, http.StatusUnauthorized, "bad token")
+	if rec.Code != http.StatusUnauthorized {
+		t.Fatalf("expected 401, got %d", rec.Code)
+	}
+
+	var body map[string]any
+	if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
+		t.Fatalf("decode body: %v", err)
+	}
+	errObj, _ := body["error"].(map[string]any)
+	if errObj["message"] != "bad token" {
+		t.Fatalf("unexpected message: %v", errObj["message"])
+	}
+	if errObj["type"] != "invalid_request_error" {
+		t.Fatalf("unexpected type: %v", errObj["type"])
+	}
+	if errObj["code"] != "authentication_failed" {
+		t.Fatalf("unexpected code: %v", errObj["code"])
+	}
+	if _, ok := errObj["param"]; !ok {
+		t.Fatal("expected param field")
+	}
+}
+
--- a/internal/adapter/claude/handler.go
+++ b/internal/adapter/claude/handler.go
@@ -43,6 +43,9 @@ func (h *Handler) ListModels(w http.ResponseWriter, _ *http.Request) {
 }

 func (h *Handler) Messages(w http.ResponseWriter, r *http.Request) {
+	if strings.TrimSpace(r.Header.Get("anthropic-version")) == "" {
+		r.Header.Set("anthropic-version", "2023-06-01")
+	}
 	a, err := h.Auth.Determine(r)
 	if err != nil {
 		status := http.StatusUnauthorized
@@ -50,22 +53,25 @@ func (h *Handler) Messages(w http.ResponseWriter, r *http.Request) {
 		if err == auth.ErrNoAccount {
 			status = http.StatusTooManyRequests
 		}
-		writeJSON(w, status, map[string]any{"error": map[string]any{"type": "invalid_request_error", "message": detail}})
+		writeClaudeError(w, status, detail)
 		return
 	}
 	defer h.Auth.Release(a)

 	var req map[string]any
 	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
-		writeJSON(w, http.StatusBadRequest, map[string]any{"error": map[string]any{"type": "invalid_request_error", "message": "invalid json"}})
+		writeClaudeError(w, http.StatusBadRequest, "invalid json")
 		return
 	}
 	model, _ := req["model"].(string)
 	messagesRaw, _ := req["messages"].([]any)
 	if model == "" || len(messagesRaw) == 0 {
-		writeJSON(w, http.StatusBadRequest, map[string]any{"error": map[string]any{"type": "invalid_request_error", "message": "Request must include 'model' and 'messages'."}})
+		writeClaudeError(w, http.StatusBadRequest, "Request must include 'model' and 'messages'.")
 		return
 	}
+	if _, ok := req["max_tokens"]; !ok {
+		req["max_tokens"] = 8192
+	}

 	normalized := normalizeClaudeMessages(messagesRaw)
 	payload := cloneMap(req)
@@ -86,12 +92,12 @@ func (h *Handler) Messages(w http.ResponseWriter, r *http.Request) {

 	sessionID, err := h.DS.CreateSession(r.Context(), a, 3)
 	if err != nil {
-		writeJSON(w, http.StatusUnauthorized, map[string]any{"error": map[string]any{"type": "api_error", "message": "invalid token."}})
+		writeClaudeError(w, http.StatusUnauthorized, "invalid token.")
 		return
 	}
 	pow, err := h.DS.GetPow(r.Context(), a, 3)
 	if err != nil {
-		writeJSON(w, http.StatusUnauthorized, map[string]any{"error": map[string]any{"type": "api_error", "message": "Failed to get PoW"}})
+		writeClaudeError(w, http.StatusUnauthorized, "Failed to get PoW")
 		return
 	}
 	requestPayload := map[string]any{
@@ -104,13 +110,13 @@ func (h *Handler) Messages(w http.ResponseWriter, r *http.Request) {
 	}
 	resp, err := h.DS.CallCompletion(r.Context(), a, requestPayload, pow, 3)
 	if err != nil {
-		writeJSON(w, http.StatusInternalServerError, map[string]any{"error": map[string]any{"type": "api_error", "message": "Failed to get Claude response."}})
+		writeClaudeError(w, http.StatusInternalServerError, "Failed to get Claude response.")
 		return
 	}
 	if resp.StatusCode != http.StatusOK {
 		defer resp.Body.Close()
 		body, _ := io.ReadAll(resp.Body)
-		writeJSON(w, http.StatusInternalServerError, map[string]any{"error": map[string]any{"type": "api_error", "message": string(body)}})
+		writeClaudeError(w, http.StatusInternalServerError, string(body))
 		return
 	}

@@ -162,20 +168,20 @@ func (h *Handler) Messages(w http.ResponseWriter, r *http.Request) {
 func (h *Handler) CountTokens(w http.ResponseWriter, r *http.Request) {
 	a, err := h.Auth.Determine(r)
 	if err != nil {
-		writeJSON(w, http.StatusUnauthorized, map[string]any{"error": err.Error()})
+		writeClaudeError(w, http.StatusUnauthorized, err.Error())
 		return
 	}
 	defer h.Auth.Release(a)

 	var req map[string]any
 	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
-		writeJSON(w, http.StatusBadRequest, map[string]any{"error": "invalid json"})
+		writeClaudeError(w, http.StatusBadRequest, "invalid json")
 		return
 	}
 	model, _ := req["model"].(string)
 	messages, _ := req["messages"].([]any)
 	if model == "" || len(messages) == 0 {
-		writeJSON(w, http.StatusBadRequest, map[string]any{"error": "Request must include 'model' and 'messages'."})
+		writeClaudeError(w, http.StatusBadRequest, "Request must include 'model' and 'messages'.")
 		return
 	}
 	inputTokens := 0
@@ -206,7 +212,7 @@ func (h *Handler) handleClaudeStreamRealtime(w http.ResponseWriter, r *http.Requ
 	defer resp.Body.Close()
 	if resp.StatusCode != http.StatusOK {
 		body, _ := io.ReadAll(resp.Body)
-		writeJSON(w, http.StatusInternalServerError, map[string]any{"error": map[string]any{"type": "api_error", "message": string(body)}})
+		writeClaudeError(w, http.StatusInternalServerError, string(body))
 		return
 	}

@@ -241,6 +247,8 @@ func (h *Handler) handleClaudeStreamRealtime(w http.ResponseWriter, r *http.Requ
 			"error": map[string]any{
 				"type":    "api_error",
 				"message": msg,
+				"code":    "internal_error",
+				"param":   nil,
 			},
 		})
 	}
@@ -492,6 +500,28 @@ func (h *Handler) handleClaudeStreamRealtime(w http.ResponseWriter, r *http.Requ
 	}
 }

+func writeClaudeError(w http.ResponseWriter, status int, message string) {
+	code := "invalid_request"
+	switch status {
+	case http.StatusUnauthorized:
+		code = "authentication_failed"
+	case http.StatusTooManyRequests:
+		code = "rate_limit_exceeded"
+	case http.StatusNotFound:
+		code = "not_found"
+	case http.StatusInternalServerError:
+		code = "internal_error"
+	}
+	writeJSON(w, status, map[string]any{
+		"error": map[string]any{
+			"type":    "invalid_request_error",
+			"message": message,
+			"code":    code,
+			"param":   nil,
+		},
+	})
+}
+
 func normalizeClaudeMessages(messages []any) []any {
 	out := make([]any, 0, len(messages))
 	for _, m := range messages {
--- a/internal/adapter/openai/embeddings_handler.go
+++ b/internal/adapter/openai/embeddings_handler.go
@@ -0,0 +1,138 @@
+package openai
+
+import (
+	"crypto/sha256"
+	"encoding/binary"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strings"
+
+	"ds2api/internal/auth"
+	"ds2api/internal/config"
+	"ds2api/internal/util"
+)
+
+func (h *Handler) Embeddings(w http.ResponseWriter, r *http.Request) {
+	a, err := h.Auth.Determine(r)
+	if err != nil {
+		status := http.StatusUnauthorized
+		detail := err.Error()
+		if err == auth.ErrNoAccount {
+			status = http.StatusTooManyRequests
+		}
+		writeOpenAIError(w, status, detail)
+		return
+	}
+	defer h.Auth.Release(a)
+
+	var req map[string]any
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeOpenAIError(w, http.StatusBadRequest, "invalid json")
+		return
+	}
+	model, _ := req["model"].(string)
+	model = strings.TrimSpace(model)
+	if model == "" {
+		writeOpenAIError(w, http.StatusBadRequest, "Request must include 'model'.")
+		return
+	}
+	if _, ok := config.ResolveModel(h.Store, model); !ok {
+		writeOpenAIError(w, http.StatusBadRequest, fmt.Sprintf("Model '%s' is not available.", model))
+		return
+	}
+
+	inputs := extractEmbeddingInputs(req["input"])
+	if len(inputs) == 0 {
+		writeOpenAIError(w, http.StatusBadRequest, "Request must include non-empty 'input'.")
+		return
+	}
+
+	provider := ""
+	if h.Store != nil {
+		provider = strings.ToLower(strings.TrimSpace(h.Store.EmbeddingsProvider()))
+	}
+	if provider == "" {
+		writeOpenAIError(w, http.StatusNotImplemented, "Embeddings provider is not configured. Set embeddings.provider in config.")
+		return
+	}
+	switch provider {
+	case "mock", "deterministic", "builtin":
+		// supported local deterministic provider
+	default:
+		writeOpenAIError(w, http.StatusNotImplemented, fmt.Sprintf("Embeddings provider '%s' is not supported.", provider))
+		return
+	}
+
+	data := make([]map[string]any, 0, len(inputs))
+	totalTokens := 0
+	for i, input := range inputs {
+		totalTokens += util.EstimateTokens(input)
+		data = append(data, map[string]any{
+			"object":    "embedding",
+			"index":     i,
+			"embedding": deterministicEmbedding(input),
+		})
+	}
+	writeJSON(w, http.StatusOK, map[string]any{
+		"object": "list",
+		"data":   data,
+		"model":  model,
+		"usage": map[string]any{
+			"prompt_tokens": totalTokens,
+			"total_tokens":  totalTokens,
+		},
+	})
+}
+
+func extractEmbeddingInputs(raw any) []string {
+	switch v := raw.(type) {
+	case string:
+		s := strings.TrimSpace(v)
+		if s == "" {
+			return nil
+		}
+		return []string{s}
+	case []any:
+		out := make([]string, 0, len(v))
+		for _, item := range v {
+			switch iv := item.(type) {
+			case string:
+				s := strings.TrimSpace(iv)
+				if s != "" {
+					out = append(out, s)
+				}
+			case []any:
+				// Token array input support: convert to stable string form.
+				out = append(out, fmt.Sprintf("%v", iv))
+			default:
+				s := strings.TrimSpace(fmt.Sprintf("%v", iv))
+				if s != "" {
+					out = append(out, s)
+				}
+			}
+		}
+		return out
+	default:
+		return nil
+	}
+}
+
+func deterministicEmbedding(input string) []float64 {
+	// Keep response shape stable without external dependencies.
+	const dims = 64
+	out := make([]float64, dims)
+	seed := sha256.Sum256([]byte(input))
+	buf := seed[:]
+	for i := 0; i < dims; i++ {
+		if len(buf) < 4 {
+			next := sha256.Sum256(buf)
+			buf = next[:]
+		}
+		v := binary.BigEndian.Uint32(buf[:4])
+		buf = buf[4:]
+		// map [0, 2^32) -> [-1, 1]
+		out[i] = (float64(v)/2147483647.5 - 1.0)
+	}
+	return out
+}
--- a/internal/adapter/openai/error_shape_test.go
+++ b/internal/adapter/openai/error_shape_test.go
@@ -0,0 +1,35 @@
+package openai
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestWriteOpenAIErrorIncludesUnifiedFields(t *testing.T) {
+	rec := httptest.NewRecorder()
+	writeOpenAIError(rec, http.StatusBadRequest, "invalid input")
+	if rec.Code != http.StatusBadRequest {
+		t.Fatalf("expected 400, got %d", rec.Code)
+	}
+
+	var body map[string]any
+	if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
+		t.Fatalf("decode body: %v", err)
+	}
+	errObj, _ := body["error"].(map[string]any)
+	if errObj["message"] != "invalid input" {
+		t.Fatalf("unexpected message: %v", errObj["message"])
+	}
+	if errObj["type"] != "invalid_request_error" {
+		t.Fatalf("unexpected type: %v", errObj["type"])
+	}
+	if errObj["code"] != "invalid_request" {
+		t.Fatalf("unexpected code: %v", errObj["code"])
+	}
+	if _, ok := errObj["param"]; !ok {
+		t.Fatal("expected param field")
+	}
+}
+
--- a/internal/adapter/openai/handler.go
+++ b/internal/adapter/openai/handler.go
@@ -31,6 +31,8 @@ type Handler struct {

 	leaseMu      sync.Mutex
 	streamLeases map[string]streamLease
+	responsesMu  sync.Mutex
+	responses    *responseStore
 }

 type streamLease struct {
@@ -40,13 +42,27 @@ type streamLease struct {

 func RegisterRoutes(r chi.Router, h *Handler) {
 	r.Get("/v1/models", h.ListModels)
+	r.Get("/v1/models/{model_id}", h.GetModel)
 	r.Post("/v1/chat/completions", h.ChatCompletions)
+	r.Post("/v1/responses", h.Responses)
+	r.Get("/v1/responses/{response_id}", h.GetResponseByID)
+	r.Post("/v1/embeddings", h.Embeddings)
 }

 func (h *Handler) ListModels(w http.ResponseWriter, _ *http.Request) {
 	writeJSON(w, http.StatusOK, config.OpenAIModelsResponse())
 }

+func (h *Handler) GetModel(w http.ResponseWriter, r *http.Request) {
+	modelID := strings.TrimSpace(chi.URLParam(r, "model_id"))
+	model, ok := config.OpenAIModelByID(h.Store, modelID)
+	if !ok {
+		writeOpenAIError(w, http.StatusNotFound, "Model not found.")
+		return
+	}
+	writeJSON(w, http.StatusOK, model)
+}
+
 func (h *Handler) ChatCompletions(w http.ResponseWriter, r *http.Request) {
 	if isVercelStreamReleaseRequest(r) {
 		h.handleVercelStreamRelease(w, r)
@@ -81,11 +97,16 @@ func (h *Handler) ChatCompletions(w http.ResponseWriter, r *http.Request) {
 		writeOpenAIError(w, http.StatusBadRequest, "Request must include 'model' and 'messages'.")
 		return
 	}
-	thinkingEnabled, searchEnabled, ok := config.GetModelConfig(model)
+	resolvedModel, ok := config.ResolveModel(h.Store, model)
 	if !ok {
-		writeOpenAIError(w, http.StatusServiceUnavailable, fmt.Sprintf("Model '%s' is not available.", model))
+		writeOpenAIError(w, http.StatusBadRequest, fmt.Sprintf("Model '%s' is not available.", model))
 		return
 	}
+	thinkingEnabled, searchEnabled, _ := config.GetModelConfig(resolvedModel)
+	responseModel := strings.TrimSpace(model)
+	if responseModel == "" {
+		responseModel = resolvedModel
+	}

 	finalPrompt, toolNames := buildOpenAIFinalPrompt(messagesRaw, req["tools"])

@@ -111,16 +132,17 @@ func (h *Handler) ChatCompletions(w http.ResponseWriter, r *http.Request) {
 		"thinking_enabled":  thinkingEnabled,
 		"search_enabled":    searchEnabled,
 	}
+	applyOpenAIChatPassThrough(req, payload)
 	resp, err := h.DS.CallCompletion(r.Context(), a, payload, pow, 3)
 	if err != nil {
 		writeOpenAIError(w, http.StatusInternalServerError, "Failed to get completion.")
 		return
 	}
 	if util.ToBool(req["stream"]) {
-		h.handleStream(w, r, resp, sessionID, model, finalPrompt, thinkingEnabled, searchEnabled, toolNames)
+		h.handleStream(w, r, resp, sessionID, responseModel, finalPrompt, thinkingEnabled, searchEnabled, toolNames)
 		return
 	}
-	h.handleNonStream(w, r.Context(), resp, sessionID, model, finalPrompt, thinkingEnabled, toolNames)
+	h.handleNonStream(w, r.Context(), resp, sessionID, responseModel, finalPrompt, thinkingEnabled, toolNames)
 }

 func (h *Handler) handleNonStream(w http.ResponseWriter, ctx context.Context, resp *http.Response, completionID, model, finalPrompt string, thinkingEnabled bool, toolNames []string) {
@@ -135,7 +157,7 @@ func (h *Handler) handleNonStream(w http.ResponseWriter, ctx context.Context, re

 	finalThinking := result.Thinking
 	finalText := result.Text
-	detected := util.ParseStandaloneToolCalls(finalText, toolNames)
+	detected := util.ParseToolCalls(finalText, toolNames)
 	finishReason := "stop"
 	messageObj := map[string]any{"role": "assistant", "content": finalText}
 	if thinkingEnabled && finalThinking != "" {
@@ -222,7 +244,7 @@ func (h *Handler) handleStream(w http.ResponseWriter, r *http.Request, resp *htt
 	finalize := func(finishReason string) {
 		finalThinking := thinking.String()
 		finalText := text.String()
-		detected := util.ParseStandaloneToolCalls(finalText, toolNames)
+		detected := util.ParseToolCalls(finalText, toolNames)
 		if len(detected) > 0 && !toolCallsEmitted {
 			finishReason = "tool_calls"
 			delta := map[string]any{
@@ -497,6 +519,8 @@ func writeOpenAIError(w http.ResponseWriter, status int, message string) {
 		"error": map[string]any{
 			"message": message,
 			"type":    openAIErrorType(status),
+			"code":    openAIErrorCode(status),
+			"param":   nil,
 		},
 	})
 }
@@ -520,3 +544,41 @@ func openAIErrorType(status int) string {
 		return "invalid_request_error"
 	}
 }
+
+func openAIErrorCode(status int) string {
+	switch status {
+	case http.StatusBadRequest:
+		return "invalid_request"
+	case http.StatusUnauthorized:
+		return "authentication_failed"
+	case http.StatusForbidden:
+		return "forbidden"
+	case http.StatusTooManyRequests:
+		return "rate_limit_exceeded"
+	case http.StatusNotFound:
+		return "not_found"
+	case http.StatusServiceUnavailable:
+		return "service_unavailable"
+	default:
+		if status >= 500 {
+			return "internal_error"
+		}
+		return "invalid_request"
+	}
+}
+
+func applyOpenAIChatPassThrough(req map[string]any, payload map[string]any) {
+	for _, k := range []string{
+		"temperature",
+		"top_p",
+		"max_tokens",
+		"max_completion_tokens",
+		"presence_penalty",
+		"frequency_penalty",
+		"stop",
+	} {
+		if v, ok := req[k]; ok {
+			payload[k] = v
+		}
+	}
+}
--- a/internal/adapter/openai/handler_toolcall_test.go
+++ b/internal/adapter/openai/handler_toolcall_test.go
@@ -210,7 +210,7 @@ func TestHandleNonStreamUnknownToolStillIntercepted(t *testing.T) {
 	}
 }

-func TestHandleNonStreamEmbeddedToolCallExampleNotIntercepted(t *testing.T) {
+func TestHandleNonStreamEmbeddedToolCallExampleIntercepted(t *testing.T) {
 	h := &Handler{}
 	resp := makeSSEHTTPResponse(
 		`data: {"p":"response/content","v":"下面是示例："}`,
@@ -228,16 +228,16 @@ func TestHandleNonStreamEmbeddedToolCallExampleNotIntercepted(t *testing.T) {
 	out := decodeJSONBody(t, rec.Body.String())
 	choices, _ := out["choices"].([]any)
 	choice, _ := choices[0].(map[string]any)
-	if choice["finish_reason"] != "stop" {
-		t.Fatalf("expected finish_reason=stop, got %#v", choice["finish_reason"])
+	if choice["finish_reason"] != "tool_calls" {
+		t.Fatalf("expected finish_reason=tool_calls, got %#v", choice["finish_reason"])
 	}
 	msg, _ := choice["message"].(map[string]any)
-	if _, ok := msg["tool_calls"]; ok {
-		t.Fatalf("did not expect tool_calls field for embedded example: %#v", msg["tool_calls"])
+	toolCalls, _ := msg["tool_calls"].([]any)
+	if len(toolCalls) == 0 {
+		t.Fatalf("expected tool_calls field for embedded example: %#v", msg["tool_calls"])
 	}
-	content, _ := msg["content"].(string)
-	if !strings.Contains(content, "示例") || !strings.Contains(content, `"tool_calls"`) {
-		t.Fatalf("expected embedded example to pass through as text, got %q", content)
+	if msg["content"] != nil {
+		t.Fatalf("expected content nil when tool_calls detected, got %#v", msg["content"])
 	}
 }

@@ -471,8 +471,8 @@ func TestHandleStreamToolCallMixedWithPlainTextSegments(t *testing.T) {
 	if !done {
 		t.Fatalf("expected [DONE], body=%s", rec.Body.String())
 	}
-	if streamHasToolCallsDelta(frames) {
-		t.Fatalf("did not expect tool_calls delta in mixed prose stream, body=%s", rec.Body.String())
+	if !streamHasToolCallsDelta(frames) {
+		t.Fatalf("expected tool_calls delta in mixed prose stream, body=%s", rec.Body.String())
 	}
 	content := strings.Builder{}
 	for _, frame := range frames {
@@ -489,11 +489,11 @@ func TestHandleStreamToolCallMixedWithPlainTextSegments(t *testing.T) {
 	if !strings.Contains(got, "下面是示例：") || !strings.Contains(got, "请勿执行。") {
 		t.Fatalf("expected pre/post plain text to pass sieve, got=%q", got)
 	}
-	if !strings.Contains(got, `"tool_calls"`) {
-		t.Fatalf("expected mixed stream to preserve embedded tool_calls example text, got=%q", got)
+	if strings.Contains(strings.ToLower(got), `"tool_calls"`) {
+		t.Fatalf("expected no raw tool_calls json leak in content, got=%q", got)
 	}
-	if streamFinishReason(frames) != "stop" {
-		t.Fatalf("expected finish_reason=stop for mixed prose, body=%s", rec.Body.String())
+	if streamFinishReason(frames) != "tool_calls" {
+		t.Fatalf("expected finish_reason=tool_calls for mixed prose, body=%s", rec.Body.String())
 	}
 }

--- a/internal/adapter/openai/models_route_test.go
+++ b/internal/adapter/openai/models_route_test.go
@@ -0,0 +1,46 @@
+package openai
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/go-chi/chi/v5"
+)
+
+func TestGetModelRouteDirectAndAlias(t *testing.T) {
+	h := &Handler{}
+	r := chi.NewRouter()
+	RegisterRoutes(r, h)
+
+	t.Run("direct", func(t *testing.T) {
+		req := httptest.NewRequest(http.MethodGet, "/v1/models/deepseek-chat", nil)
+		rec := httptest.NewRecorder()
+		r.ServeHTTP(rec, req)
+		if rec.Code != http.StatusOK {
+			t.Fatalf("expected 200, got %d body=%s", rec.Code, rec.Body.String())
+		}
+	})
+
+	t.Run("alias", func(t *testing.T) {
+		req := httptest.NewRequest(http.MethodGet, "/v1/models/gpt-4.1", nil)
+		rec := httptest.NewRecorder()
+		r.ServeHTTP(rec, req)
+		if rec.Code != http.StatusOK {
+			t.Fatalf("expected 200 for alias, got %d body=%s", rec.Code, rec.Body.String())
+		}
+	})
+}
+
+func TestGetModelRouteNotFound(t *testing.T) {
+	h := &Handler{}
+	r := chi.NewRouter()
+	RegisterRoutes(r, h)
+
+	req := httptest.NewRequest(http.MethodGet, "/v1/models/not-exists", nil)
+	rec := httptest.NewRecorder()
+	r.ServeHTTP(rec, req)
+	if rec.Code != http.StatusNotFound {
+		t.Fatalf("expected 404, got %d body=%s", rec.Code, rec.Body.String())
+	}
+}
--- a/internal/adapter/openai/response_store.go
+++ b/internal/adapter/openai/response_store.go
@@ -0,0 +1,91 @@
+package openai
+
+import (
+	"sync"
+	"time"
+)
+
+type storedResponse struct {
+	Value     map[string]any
+	ExpiresAt time.Time
+}
+
+type responseStore struct {
+	mu    sync.Mutex
+	ttl   time.Duration
+	items map[string]storedResponse
+}
+
+func newResponseStore(ttl time.Duration) *responseStore {
+	if ttl <= 0 {
+		ttl = 15 * time.Minute
+	}
+	return &responseStore{
+		ttl:   ttl,
+		items: make(map[string]storedResponse),
+	}
+}
+
+func (s *responseStore) put(id string, value map[string]any) {
+	if s == nil || id == "" || value == nil {
+		return
+	}
+	now := time.Now()
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.sweepLocked(now)
+	s.items[id] = storedResponse{
+		Value:     cloneAnyMap(value),
+		ExpiresAt: now.Add(s.ttl),
+	}
+}
+
+func (s *responseStore) get(id string) (map[string]any, bool) {
+	if s == nil || id == "" {
+		return nil, false
+	}
+	now := time.Now()
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.sweepLocked(now)
+	item, ok := s.items[id]
+	if !ok {
+		return nil, false
+	}
+	return cloneAnyMap(item.Value), true
+}
+
+func (s *responseStore) sweepLocked(now time.Time) {
+	for k, v := range s.items {
+		if now.After(v.ExpiresAt) {
+			delete(s.items, k)
+		}
+	}
+}
+
+func cloneAnyMap(in map[string]any) map[string]any {
+	if in == nil {
+		return nil
+	}
+	out := make(map[string]any, len(in))
+	for k, v := range in {
+		out[k] = v
+	}
+	return out
+}
+
+func (h *Handler) getResponseStore() *responseStore {
+	if h == nil {
+		return nil
+	}
+	h.responsesMu.Lock()
+	defer h.responsesMu.Unlock()
+	if h.responses == nil {
+		ttl := 15 * time.Minute
+		if h.Store != nil {
+			ttl = time.Duration(h.Store.ResponsesStoreTTLSeconds()) * time.Second
+		}
+		h.responses = newResponseStore(ttl)
+	}
+	return h.responses
+}
--- a/internal/adapter/openai/responses_embeddings_test.go
+++ b/internal/adapter/openai/responses_embeddings_test.go
@@ -0,0 +1,65 @@
+package openai
+
+import (
+	"testing"
+	"time"
+)
+
+func TestNormalizeResponsesInputAsMessagesString(t *testing.T) {
+	msgs := normalizeResponsesInputAsMessages("hello")
+	if len(msgs) != 1 {
+		t.Fatalf("expected one message, got %d", len(msgs))
+	}
+	m, _ := msgs[0].(map[string]any)
+	if m["role"] != "user" || m["content"] != "hello" {
+		t.Fatalf("unexpected message: %#v", m)
+	}
+}
+
+func TestResponsesMessagesFromRequestWithInstructions(t *testing.T) {
+	req := map[string]any{
+		"model":        "gpt-4.1",
+		"input":        "ping",
+		"instructions": "system text",
+	}
+	msgs := responsesMessagesFromRequest(req)
+	if len(msgs) != 2 {
+		t.Fatalf("expected two messages, got %d", len(msgs))
+	}
+	sys, _ := msgs[0].(map[string]any)
+	if sys["role"] != "system" {
+		t.Fatalf("unexpected first message: %#v", sys)
+	}
+}
+
+func TestExtractEmbeddingInputs(t *testing.T) {
+	got := extractEmbeddingInputs([]any{"a", "b"})
+	if len(got) != 2 || got[0] != "a" || got[1] != "b" {
+		t.Fatalf("unexpected inputs: %#v", got)
+	}
+}
+
+func TestDeterministicEmbeddingStable(t *testing.T) {
+	a := deterministicEmbedding("hello")
+	b := deterministicEmbedding("hello")
+	if len(a) != 64 || len(b) != 64 {
+		t.Fatalf("expected 64 dims, got %d and %d", len(a), len(b))
+	}
+	for i := range a {
+		if a[i] != b[i] {
+			t.Fatalf("expected stable embedding at %d: %v != %v", i, a[i], b[i])
+		}
+	}
+}
+
+func TestResponseStorePutGet(t *testing.T) {
+	st := newResponseStore(100 * time.Millisecond)
+	st.put("resp_1", map[string]any{"id": "resp_1"})
+	got, ok := st.get("resp_1")
+	if !ok {
+		t.Fatal("expected stored response")
+	}
+	if got["id"] != "resp_1" {
+		t.Fatalf("unexpected response payload: %#v", got)
+	}
+}
--- a/internal/adapter/openai/responses_handler.go
+++ b/internal/adapter/openai/responses_handler.go
@@ -0,0 +1,407 @@
+package openai
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/google/uuid"
+
+	"ds2api/internal/auth"
+	"ds2api/internal/config"
+	"ds2api/internal/sse"
+	"ds2api/internal/util"
+)
+
+func (h *Handler) GetResponseByID(w http.ResponseWriter, r *http.Request) {
+	id := strings.TrimSpace(chi.URLParam(r, "response_id"))
+	if id == "" {
+		writeOpenAIError(w, http.StatusBadRequest, "response_id is required.")
+		return
+	}
+	st := h.getResponseStore()
+	item, ok := st.get(id)
+	if !ok {
+		writeOpenAIError(w, http.StatusNotFound, "Response not found.")
+		return
+	}
+	writeJSON(w, http.StatusOK, item)
+}
+
+func (h *Handler) Responses(w http.ResponseWriter, r *http.Request) {
+	a, err := h.Auth.Determine(r)
+	if err != nil {
+		status := http.StatusUnauthorized
+		detail := err.Error()
+		if err == auth.ErrNoAccount {
+			status = http.StatusTooManyRequests
+		}
+		writeOpenAIError(w, status, detail)
+		return
+	}
+	defer h.Auth.Release(a)
+	r = r.WithContext(auth.WithAuth(r.Context(), a))
+
+	var req map[string]any
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeOpenAIError(w, http.StatusBadRequest, "invalid json")
+		return
+	}
+
+	model, _ := req["model"].(string)
+	model = strings.TrimSpace(model)
+	if model == "" {
+		writeOpenAIError(w, http.StatusBadRequest, "Request must include 'model'.")
+		return
+	}
+	resolvedModel, ok := config.ResolveModel(h.Store, model)
+	if !ok {
+		writeOpenAIError(w, http.StatusBadRequest, fmt.Sprintf("Model '%s' is not available.", model))
+		return
+	}
+	thinkingEnabled, searchEnabled, _ := config.GetModelConfig(resolvedModel)
+
+	messagesRaw := responsesMessagesFromRequest(req)
+	if len(messagesRaw) == 0 {
+		writeOpenAIError(w, http.StatusBadRequest, "Request must include 'input' or 'messages'.")
+		return
+	}
+	finalPrompt, toolNames := buildOpenAIFinalPrompt(messagesRaw, req["tools"])
+
+	sessionID, err := h.DS.CreateSession(r.Context(), a, 3)
+	if err != nil {
+		if a.UseConfigToken {
+			writeOpenAIError(w, http.StatusUnauthorized, "Account token is invalid. Please re-login the account in admin.")
+		} else {
+			writeOpenAIError(w, http.StatusUnauthorized, "Invalid token. If this should be a DS2API key, add it to config.keys first.")
+		}
+		return
+	}
+	pow, err := h.DS.GetPow(r.Context(), a, 3)
+	if err != nil {
+		writeOpenAIError(w, http.StatusUnauthorized, "Failed to get PoW (invalid token or unknown error).")
+		return
+	}
+	payload := map[string]any{
+		"chat_session_id":   sessionID,
+		"parent_message_id": nil,
+		"prompt":            finalPrompt,
+		"ref_file_ids":      []any{},
+		"thinking_enabled":  thinkingEnabled,
+		"search_enabled":    searchEnabled,
+	}
+	applyOpenAIChatPassThrough(req, payload)
+	resp, err := h.DS.CallCompletion(r.Context(), a, payload, pow, 3)
+	if err != nil {
+		writeOpenAIError(w, http.StatusInternalServerError, "Failed to get completion.")
+		return
+	}
+
+	responseID := "resp_" + strings.ReplaceAll(uuid.NewString(), "-", "")
+	if util.ToBool(req["stream"]) {
+		h.handleResponsesStream(w, r, resp, responseID, model, finalPrompt, thinkingEnabled, searchEnabled, toolNames)
+		return
+	}
+	h.handleResponsesNonStream(w, resp, responseID, model, finalPrompt, thinkingEnabled, toolNames)
+}
+
+func (h *Handler) handleResponsesNonStream(w http.ResponseWriter, resp *http.Response, responseID, model, finalPrompt string, thinkingEnabled bool, toolNames []string) {
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		writeOpenAIError(w, resp.StatusCode, strings.TrimSpace(string(body)))
+		return
+	}
+	result := sse.CollectStream(resp, thinkingEnabled, true)
+	responseObj := buildResponseObject(responseID, model, finalPrompt, result.Thinking, result.Text, toolNames)
+	h.getResponseStore().put(responseID, responseObj)
+	writeJSON(w, http.StatusOK, responseObj)
+}
+
+func (h *Handler) handleResponsesStream(w http.ResponseWriter, r *http.Request, resp *http.Response, responseID, model, finalPrompt string, thinkingEnabled, searchEnabled bool, toolNames []string) {
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		writeOpenAIError(w, resp.StatusCode, strings.TrimSpace(string(body)))
+		return
+	}
+	w.Header().Set("Content-Type", "text/event-stream")
+	w.Header().Set("Cache-Control", "no-cache, no-transform")
+	w.Header().Set("Connection", "keep-alive")
+	w.Header().Set("X-Accel-Buffering", "no")
+	rc := http.NewResponseController(w)
+	canFlush := rc.Flush() == nil
+
+	sendEvent := func(event string, payload map[string]any) {
+		b, _ := json.Marshal(payload)
+		_, _ = w.Write([]byte("event: " + event + "\n"))
+		_, _ = w.Write([]byte("data: "))
+		_, _ = w.Write(b)
+		_, _ = w.Write([]byte("\n\n"))
+		if canFlush {
+			_ = rc.Flush()
+		}
+	}
+
+	sendEvent("response.created", map[string]any{
+		"type":   "response.created",
+		"id":     responseID,
+		"object": "response",
+		"model":  model,
+		"status": "in_progress",
+	})
+
+	initialType := "text"
+	if thinkingEnabled {
+		initialType = "thinking"
+	}
+	parsedLines, done := sse.StartParsedLinePump(r.Context(), resp.Body, thinkingEnabled, initialType)
+	bufferToolContent := len(toolNames) > 0
+	var sieve toolStreamSieveState
+	thinking := strings.Builder{}
+	text := strings.Builder{}
+	toolCallsEmitted := false
+	streamToolCallIDs := map[int]string{}
+
+	finalize := func() {
+		finalThinking := thinking.String()
+		finalText := text.String()
+		if bufferToolContent {
+			for _, evt := range flushToolSieve(&sieve, toolNames) {
+				if evt.Content != "" {
+					finalText += evt.Content
+					sendEvent("response.output_text.delta", map[string]any{
+						"type":  "response.output_text.delta",
+						"id":    responseID,
+						"delta": evt.Content,
+					})
+				}
+				if len(evt.ToolCalls) > 0 {
+					toolCallsEmitted = true
+					sendEvent("response.output_tool_call.done", map[string]any{
+						"type":       "response.output_tool_call.done",
+						"id":         responseID,
+						"tool_calls": util.FormatOpenAIStreamToolCalls(evt.ToolCalls),
+					})
+				}
+			}
+		}
+		obj := buildResponseObject(responseID, model, finalPrompt, finalThinking, finalText, toolNames)
+		if toolCallsEmitted {
+			obj["status"] = "completed"
+		}
+		h.getResponseStore().put(responseID, obj)
+		sendEvent("response.completed", map[string]any{
+			"type":     "response.completed",
+			"response": obj,
+		})
+		_, _ = w.Write([]byte("data: [DONE]\n\n"))
+		if canFlush {
+			_ = rc.Flush()
+		}
+	}
+
+	for {
+		select {
+		case <-r.Context().Done():
+			return
+		case parsed, ok := <-parsedLines:
+			if !ok {
+				_ = <-done
+				finalize()
+				return
+			}
+			if !parsed.Parsed {
+				continue
+			}
+			if parsed.ContentFilter || parsed.ErrorMessage != "" || parsed.Stop {
+				finalize()
+				return
+			}
+			for _, p := range parsed.Parts {
+				if p.Text == "" {
+					continue
+				}
+				if p.Type != "thinking" && searchEnabled && sse.IsCitation(p.Text) {
+					continue
+				}
+				if p.Type == "thinking" {
+					if !thinkingEnabled {
+						continue
+					}
+					thinking.WriteString(p.Text)
+					sendEvent("response.reasoning.delta", map[string]any{
+						"type":  "response.reasoning.delta",
+						"id":    responseID,
+						"delta": p.Text,
+					})
+					continue
+				}
+				text.WriteString(p.Text)
+				if !bufferToolContent {
+					sendEvent("response.output_text.delta", map[string]any{
+						"type":  "response.output_text.delta",
+						"id":    responseID,
+						"delta": p.Text,
+					})
+					continue
+				}
+				for _, evt := range processToolSieveChunk(&sieve, p.Text, toolNames) {
+					if evt.Content != "" {
+						sendEvent("response.output_text.delta", map[string]any{
+							"type":  "response.output_text.delta",
+							"id":    responseID,
+							"delta": evt.Content,
+						})
+					}
+					if len(evt.ToolCallDeltas) > 0 {
+						toolCallsEmitted = true
+						sendEvent("response.output_tool_call.delta", map[string]any{
+							"type":       "response.output_tool_call.delta",
+							"id":         responseID,
+							"tool_calls": formatIncrementalStreamToolCallDeltas(evt.ToolCallDeltas, streamToolCallIDs),
+						})
+					}
+					if len(evt.ToolCalls) > 0 {
+						toolCallsEmitted = true
+						sendEvent("response.output_tool_call.done", map[string]any{
+							"type":       "response.output_tool_call.done",
+							"id":         responseID,
+							"tool_calls": util.FormatOpenAIStreamToolCalls(evt.ToolCalls),
+						})
+					}
+				}
+			}
+		}
+	}
+}
+
+func buildResponseObject(responseID, model, finalPrompt, finalThinking, finalText string, toolNames []string) map[string]any {
+	detected := util.ParseToolCalls(finalText, toolNames)
+	output := make([]any, 0, 2)
+	if len(detected) > 0 {
+		toolCalls := make([]any, 0, len(detected))
+		for _, tc := range detected {
+			toolCalls = append(toolCalls, map[string]any{
+				"type":      "tool_call",
+				"name":      tc.Name,
+				"arguments": tc.Input,
+			})
+		}
+		output = append(output, map[string]any{
+			"type":       "tool_calls",
+			"tool_calls": toolCalls,
+		})
+	} else {
+		content := []any{
+			map[string]any{
+				"type": "output_text",
+				"text": finalText,
+			},
+		}
+		if finalThinking != "" {
+			content = append([]any{map[string]any{
+				"type": "reasoning",
+				"text": finalThinking,
+			}}, content...)
+		}
+		output = append(output, map[string]any{
+			"type":    "message",
+			"id":      "msg_" + strings.ReplaceAll(uuid.NewString(), "-", ""),
+			"role":    "assistant",
+			"content": content,
+		})
+	}
+	promptTokens := util.EstimateTokens(finalPrompt)
+	reasoningTokens := util.EstimateTokens(finalThinking)
+	completionTokens := util.EstimateTokens(finalText)
+	return map[string]any{
+		"id":          responseID,
+		"type":        "response",
+		"object":      "response",
+		"created_at":  time.Now().Unix(),
+		"status":      "completed",
+		"model":       model,
+		"output":      output,
+		"output_text": finalText,
+		"usage": map[string]any{
+			"input_tokens":  promptTokens,
+			"output_tokens": reasoningTokens + completionTokens,
+			"total_tokens":  promptTokens + reasoningTokens + completionTokens,
+		},
+	}
+}
+
+func responsesMessagesFromRequest(req map[string]any) []any {
+	if msgs, ok := req["messages"].([]any); ok && len(msgs) > 0 {
+		return prependInstructionMessage(msgs, req["instructions"])
+	}
+	if rawInput, ok := req["input"]; ok {
+		if msgs := normalizeResponsesInputAsMessages(rawInput); len(msgs) > 0 {
+			return prependInstructionMessage(msgs, req["instructions"])
+		}
+	}
+	return nil
+}
+
+func prependInstructionMessage(messages []any, instructions any) []any {
+	sys, _ := instructions.(string)
+	sys = strings.TrimSpace(sys)
+	if sys == "" {
+		return messages
+	}
+	out := make([]any, 0, len(messages)+1)
+	out = append(out, map[string]any{"role": "system", "content": sys})
+	out = append(out, messages...)
+	return out
+}
+
+func normalizeResponsesInputAsMessages(input any) []any {
+	switch v := input.(type) {
+	case string:
+		if strings.TrimSpace(v) == "" {
+			return nil
+		}
+		return []any{map[string]any{"role": "user", "content": v}}
+	case []any:
+		if len(v) == 0 {
+			return nil
+		}
+		// If caller already provides role-shaped items, keep as-is.
+		if first, ok := v[0].(map[string]any); ok {
+			if _, hasRole := first["role"]; hasRole {
+				return v
+			}
+		}
+		parts := make([]string, 0, len(v))
+		for _, item := range v {
+			if m, ok := item.(map[string]any); ok {
+				if t, _ := m["type"].(string); strings.EqualFold(strings.TrimSpace(t), "input_text") {
+					if txt, _ := m["text"].(string); strings.TrimSpace(txt) != "" {
+						parts = append(parts, txt)
+						continue
+					}
+				}
+			}
+			if s := strings.TrimSpace(fmt.Sprintf("%v", item)); s != "" {
+				parts = append(parts, s)
+			}
+		}
+		if len(parts) == 0 {
+			return nil
+		}
+		return []any{map[string]any{"role": "user", "content": strings.Join(parts, "\n")}}
+	case map[string]any:
+		if txt, _ := v["text"].(string); strings.TrimSpace(txt) != "" {
+			return []any{map[string]any{"role": "user", "content": txt}}
+		}
+		if content, ok := v["content"].(string); ok && strings.TrimSpace(content) != "" {
+			return []any{map[string]any{"role": "user", "content": content}}
+		}
+	}
+	return nil
+}
--- a/internal/adapter/openai/tool_sieve.go
+++ b/internal/adapter/openai/tool_sieve.go
@@ -7,17 +7,16 @@ import (
 )

 type toolStreamSieveState struct {
-	pending           strings.Builder
-	capture           strings.Builder
-	capturing         bool
-	hasMeaningfulText bool
-	recentTextTail    string
-	toolNameSent      bool
-	toolName          string
-	toolArgsStart     int
-	toolArgsSent      int
-	toolArgsString    bool
-	toolArgsDone      bool
+	pending        strings.Builder
+	capture        strings.Builder
+	capturing      bool
+	recentTextTail string
+	toolNameSent   bool
+	toolName       string
+	toolArgsStart  int
+	toolArgsSent   int
+	toolArgsString bool
+	toolArgsDone   bool
 }

 type toolStreamEvent struct {
@@ -197,14 +196,22 @@ func findToolSegmentStart(s string) int {
 		return -1
 	}
 	lower := strings.ToLower(s)
-	keyIdx := strings.Index(lower, "tool_calls")
-	if keyIdx < 0 {
-		return -1
+	offset := 0
+	for {
+		keyRel := strings.Index(lower[offset:], "tool_calls")
+		if keyRel < 0 {
+			return -1
+		}
+		keyIdx := offset + keyRel
+		start := strings.LastIndex(s[:keyIdx], "{")
+		if start < 0 {
+			start = keyIdx
+		}
+		if !insideCodeFence(s[:start]) {
+			return start
+		}
+		offset = keyIdx + len("tool_calls")
 	}
-	if start := strings.LastIndex(s[:keyIdx], "{"); start >= 0 {
-		return start
-	}
-	return keyIdx
 }

 func consumeToolCapture(state *toolStreamSieveState, toolNames []string) (prefix string, calls []util.ParsedToolCall, suffix string, ready bool) {
@@ -227,7 +234,7 @@ func consumeToolCapture(state *toolStreamSieveState, toolNames []string) (prefix
 	}
 	prefixPart := captured[:start]
 	suffixPart := captured[end:]
-	if !state.toolNameSent && (strings.TrimSpace(prefixPart) != "" || looksLikeToolExampleContext(state.recentTextTail) || looksLikeToolExampleContext(suffixPart)) {
+	if insideCodeFence(state.recentTextTail + prefixPart) {
 		return captured, nil, "", true
 	}
 	parsed := util.ParseStandaloneToolCalls(obj, toolNames)
@@ -293,16 +300,16 @@ func buildIncrementalToolDeltas(state *toolStreamSieveState) []toolCallDelta {
 	if captured == "" {
 		return nil
 	}
-	if looksLikeToolExampleContext(state.recentTextTail) {
-		return nil
-	}
 	lower := strings.ToLower(captured)
 	keyIdx := strings.Index(lower, "tool_calls")
 	if keyIdx < 0 {
 		return nil
 	}
 	start := strings.LastIndex(captured[:keyIdx], "{")
-	if start < 0 || strings.TrimSpace(captured[:start]) != "" {
+	if start < 0 {
+		return nil
+	}
+	if insideCodeFence(state.recentTextTail + captured[:start]) {
 		return nil
 	}
 	callStart, ok := findFirstToolCallObjectStart(captured, keyIdx)
@@ -612,7 +619,6 @@ func (s *toolStreamSieveState) noteText(content string) {
 	if strings.TrimSpace(content) == "" {
 		return
 	}
-	s.hasMeaningfulText = true
 	s.recentTextTail = appendTail(s.recentTextTail, content, toolSieveContextTailLimit)
 }

@@ -628,25 +634,12 @@ func appendTail(prev, next string, max int) string {
 }

 func looksLikeToolExampleContext(text string) bool {
-	t := strings.ToLower(strings.TrimSpace(text))
-	if t == "" {
+	return insideCodeFence(text)
+}
+
+func insideCodeFence(text string) bool {
+	if text == "" {
 		return false
 	}
-	cues := []string{
-		"示例",
-		"例子",
-		"for example",
-		"example",
-		"demo",
-		"请勿执行",
-		"不要执行",
-		"do not execute",
-		"```",
-	}
-	for _, cue := range cues {
-		if strings.Contains(t, cue) {
-			return true
-		}
-	}
-	return false
+	return strings.Count(text, "```")%2 == 1
 }
--- a/internal/adapter/openai/vercel_stream.go
+++ b/internal/adapter/openai/vercel_stream.go
@@ -62,11 +62,16 @@ func (h *Handler) handleVercelStreamPrepare(w http.ResponseWriter, r *http.Reque
 		writeOpenAIError(w, http.StatusBadRequest, "Request must include 'model' and 'messages'.")
 		return
 	}
-	thinkingEnabled, searchEnabled, ok := config.GetModelConfig(model)
+	resolvedModel, ok := config.ResolveModel(h.Store, model)
 	if !ok {
-		writeOpenAIError(w, http.StatusServiceUnavailable, fmt.Sprintf("Model '%s' is not available.", model))
+		writeOpenAIError(w, http.StatusBadRequest, fmt.Sprintf("Model '%s' is not available.", model))
 		return
 	}
+	thinkingEnabled, searchEnabled, _ := config.GetModelConfig(resolvedModel)
+	responseModel := strings.TrimSpace(model)
+	if responseModel == "" {
+		responseModel = resolvedModel
+	}

 	finalPrompt, _ := buildOpenAIFinalPrompt(messagesRaw, req["tools"])

@@ -97,6 +102,7 @@ func (h *Handler) handleVercelStreamPrepare(w http.ResponseWriter, r *http.Reque
 		"thinking_enabled":  thinkingEnabled,
 		"search_enabled":    searchEnabled,
 	}
+	applyOpenAIChatPassThrough(req, payload)
 	leaseID := h.holdStreamLease(a)
 	if leaseID == "" {
 		writeOpenAIError(w, http.StatusInternalServerError, "failed to create stream lease")
@@ -106,7 +112,7 @@ func (h *Handler) handleVercelStreamPrepare(w http.ResponseWriter, r *http.Reque
 	writeJSON(w, http.StatusOK, map[string]any{
 		"session_id":       sessionID,
 		"lease_id":         leaseID,
-		"model":            model,
+		"model":            responseModel,
 		"final_prompt":     finalPrompt,
 		"thinking_enabled": thinkingEnabled,
 		"search_enabled":   searchEnabled,