fix(provider): auto-fill chat endpoint by chat_api_mode when path is empty

Generated with [codeagent](https://github.com/qbox/codeagent)
Co-authored-by: phantom5099 <245659304+phantom5099@users.noreply.github.com>

Author: xgopilot

internal/provider/openaicompat/generate_sdk.go

@@ -116,13 +116,30 @@ func (p *Provider) newSDKClient() openai.Client {
 }
 
 func resolveChatEndpoint(cfg provider.RuntimeConfig) (string, error) {
-	endpoint, err := provider.ResolveChatEndpointURL(cfg.BaseURL, cfg.ChatEndpointPath)
+	chatEndpointPath := resolveChatEndpointPathByMode(cfg.ChatEndpointPath, cfg.ChatAPIMode)
+	endpoint, err := provider.ResolveChatEndpointURL(cfg.BaseURL, chatEndpointPath)
 	if err != nil {
 		return "", fmt.Errorf("%sinvalid chat endpoint configuration: %w", errorPrefix, err)
 	}
 	return endpoint, nil
 }
 
+// resolveChatEndpointPathByMode 在 chat endpoint 为空时，根据 chat_api_mode 自动回填默认端点路径。
+func resolveChatEndpointPathByMode(rawPath string, chatAPIMode string) string {
+	if strings.TrimSpace(rawPath) != "" {
+		return rawPath
+	}
+
+	mode, err := provider.NormalizeProviderChatAPIMode(chatAPIMode)
+	if err != nil || mode == "" {
+		mode = provider.DefaultProviderChatAPIMode()
+	}
+	if mode == provider.ChatAPIModeResponses {
+		return chatEndpointPathResponses
+	}
+	return chatEndpointPathCompletions
+}
+
 // validateStreamingResponse 校验流式响应协议，避免非 SSE 响应被误交给流解析器。
 func validateStreamingResponse(resp *http.Response) error {
 	if resp == nil || resp.Body == nil {

internal/provider/openaicompat/generate_sdk_test.go

@@ -120,3 +120,41 @@ func TestValidateStreamingResponseAllowsMissingContentTypeForNonHTMLBody(t *test
 		t.Fatalf("expected body stream to remain readable, got %q", string(restoredBody))
 	}
 }
+
+func TestResolveChatEndpointPathByMode(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name string
+		path string
+		mode string
+		want string
+	}{
+		{
+			name: "preserves explicit path",
+			path: "/gateway/chat/completions",
+			mode: "responses",
+			want: "/gateway/chat/completions",
+		},
+		{
+			name: "fills chat completions path by default mode",
+			path: "",
+			mode: "",
+			want: "/chat/completions",
+		},
+		{
+			name: "fills responses path for responses mode",
+			path: "",
+			mode: "responses",
+			want: "/responses",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := resolveChatEndpointPathByMode(tt.path, tt.mode); got != tt.want {
+				t.Fatalf("resolveChatEndpointPathByMode(%q, %q) = %q, want %q", tt.path, tt.mode, got, tt.want)
+			}
+		})
+	}
+}

internal/provider/openaicompat/openaicompat_test.go

@@ -1232,11 +1232,11 @@ data: [DONE]
 	}
 }
 
-func TestGenerate_UsesDirectBaseURLWhenChatEndpointPathEmpty(t *testing.T) {
+func TestGenerate_UsesDefaultCompletionsEndpointWhenChatEndpointPathEmpty(t *testing.T) {
 	t.Setenv(config.OpenAIDefaultAPIKeyEnv, "test-key")
 
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if r.URL.Path != "/v1/text/chatcompletion_v2" {
+		if r.URL.Path != "/v1/text/chatcompletion_v2/chat/completions" {
 			t.Fatalf("unexpected path: %s", r.URL.Path)
 		}
 		w.Header().Set("Content-Type", "text/event-stream")
@@ -1265,11 +1265,11 @@ data: [DONE]
 	}
 }
 
-func TestGenerate_UsesDirectBaseURLWithResponsesModeWhenChatEndpointPathEmpty(t *testing.T) {
+func TestGenerate_UsesDefaultResponsesEndpointWhenChatEndpointPathEmpty(t *testing.T) {
 	t.Setenv(config.OpenAIDefaultAPIKeyEnv, "test-key")
 
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if r.URL.Path != "/v1/text/chatcompletion_v2" {
+		if r.URL.Path != "/v1/text/chatcompletion_v2/responses" {
 			t.Fatalf("unexpected path: %s", r.URL.Path)
 		}
 		w.Header().Set("Content-Type", "text/event-stream")

internal/tui/core/app/update.go

@@ -3219,6 +3219,18 @@ func providerAddDefaultChatEndpointPath(driver string) string {
 	}
 }
 
+// providerAddDefaultOpenAICompatChatEndpointPath 根据 chat_api_mode 返回 openaicompat 的默认聊天端点路径。
+func providerAddDefaultOpenAICompatChatEndpointPath(chatAPIMode string) string {
+	mode, err := provider.NormalizeProviderChatAPIMode(chatAPIMode)
+	if err != nil || mode == "" {
+		mode = provider.DefaultProviderChatAPIMode()
+	}
+	if mode == provider.ChatAPIModeResponses {
+		return "/responses"
+	}
+	return "/chat/completions"
+}
+
 // providerAddDefaultBaseURL 返回 provider add 表单的驱动默认 base URL。
 func providerAddDefaultBaseURL(driver string) string {
 	switch provider.NormalizeProviderDriver(driver) {
@@ -3309,7 +3321,11 @@ func buildProviderAddRequest(form providerAddFormState) (providerAddRequest, str
 	}
 
 	if strings.TrimSpace(request.ChatEndpointPath) == "" {
-		request.ChatEndpointPath = providerAddDefaultChatEndpointPath(request.Driver)
+		if request.Driver == provider.DriverOpenAICompat {
+			request.ChatEndpointPath = providerAddDefaultOpenAICompatChatEndpointPath(request.ChatAPIMode)
+		} else {
+			request.ChatEndpointPath = providerAddDefaultChatEndpointPath(request.Driver)
+		}
 	}
 
 	switch request.Driver {

internal/tui/core/app/update_test.go

@@ -2568,6 +2568,28 @@ func TestBuildProviderAddRequest(t *testing.T) {
 		}
 	})
 
+	t.Run("openai compat fills chat endpoint by chat api mode when empty", func(t *testing.T) {
+		req, err := buildProviderAddRequest(providerAddFormState{
+			Name:                  "openai-compat-responses-endpoint",
+			Driver:                provider.DriverOpenAICompat,
+			ModelSource:           config.ModelSourceDiscover,
+			ChatAPIMode:           provider.ChatAPIModeResponses,
+			ChatEndpointPath:      "",
+			APIKey:                "k",
+			APIKeyEnv:             "OPENAI_COMPAT_RESPONSES_ENDPOINT_API_KEY",
+			DiscoveryEndpointPath: provider.DiscoveryEndpointPathModels,
+		})
+		if err != "" {
+			t.Fatalf("unexpected error: %s", err)
+		}
+		if req.ChatAPIMode != provider.ChatAPIModeResponses {
+			t.Fatalf("expected chat api mode responses, got %q", req.ChatAPIMode)
+		}
+		if req.ChatEndpointPath != "/responses" {
+			t.Fatalf("expected responses endpoint path, got %q", req.ChatEndpointPath)
+		}
+	})
+
 	t.Run("strips control chars from env key before validation", func(t *testing.T) {
 		req, err := buildProviderAddRequest(providerAddFormState{
 			Name:                  "openai-compat",

internal/tui/core/app/view.go

@@ -324,8 +324,10 @@ func (a App) renderProviderAddForm() string {
 		case providerAddFieldChatEndpointPath:
 			note := ""
 			trimmedPath := strings.TrimSpace(a.providerAddForm.ChatEndpointPath)
-			if trimmedPath == "" || trimmedPath == "/" {
-				note = "留空或\"/\" 使用直连 base_url"
+			if trimmedPath == "" {
+				note = "留空会按 Chat API Mode 自动回填默认端点"
+			} else if trimmedPath == "/" {
+				note = "\"/\" 使用直连 base_url"
 			} else {
 				note = "以 \"/\" 开头的端点路径"
 			}

internal/tui/core/app/view_test.go

@@ -293,8 +293,8 @@ func TestRenderProviderAddFormMasksAPIKeyAndShowsHints(t *testing.T) {
 	if !strings.Contains(form, "留空会自动填充默认地址") {
 		t.Fatalf("expected base url hint, got %q", form)
 	}
-	if !strings.Contains(form, "留空或\"/\" 使用直连 base_url") {
-		t.Fatalf("expected chat endpoint direct-mode hint, got %q", form)
+	if !strings.Contains(form, "留空会按 Chat API Mode 自动回填默认端点") {
+		t.Fatalf("expected chat endpoint autofill hint, got %q", form)
 	}
 	if !strings.Contains(form, "[Error] input invalid") {
 		t.Fatalf("expected hard error label, got %q", form)