feat: add Kimi Coding compatibility and model preset

pkg/config/defaults.go

@@ -177,6 +177,13 @@ func DefaultConfig() *Config {
 				APIBase:   "https://api.moonshot.cn/v1",
 				APIKey:    "",
 			},
+			// Kimi Plan/Coding - https://www.kimi.com/code/docs
+			{
+				ModelName: "kimi-plan-coding",
+				Model:     "moonshot/kimi-k2-thinking",
+				APIBase:   "https://api.kimi.com/coding/v1",
+				APIKey:    "",
+			},
 
 			// Groq - https://console.groq.com/keys
 			{

pkg/providers/openai_compat/provider.go

@@ -125,6 +125,9 @@ func (p *Provider) Chat(
 	if p.apiKey != "" {
 		req.Header.Set("Authorization", "Bearer "+p.apiKey)
 	}
+	if ua := selectUserAgent(p.apiBase); ua != "" {
+		req.Header.Set("User-Agent", ua)
+	}
 
 	resp, err := p.httpClient.Do(req)
 	if err != nil {
@@ -247,6 +250,15 @@ func normalizeModel(model, apiBase string) string {
 	}
 }
 
+func selectUserAgent(apiBase string) string {
+	base := strings.ToLower(apiBase)
+	if strings.Contains(base, "api.kimi.com/coding") {
+		// Kimi For Coding currently restricts access to recognized coding-agent clients.
+		return "KimiCLI/1.3"
+	}
+	return ""
+}
+
 func asInt(v any) (int, bool) {
 	switch val := v.(type) {
 	case int:

pkg/providers/openai_compat/provider_test.go

@@ -232,6 +232,92 @@ func TestProvider_ProxyConfigured(t *testing.T) {
 	}
 }
 
+func TestProviderChat_UsesKimiUserAgentOnCodingEndpoint(t *testing.T) {
+	var gotUA string
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotUA = r.Header.Get("User-Agent")
+		resp := map[string]any{
+			"choices": []map[string]any{
+				{
+					"message":       map[string]any{"content": "ok"},
+					"finish_reason": "stop",
+				},
+			},
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_ = json.NewEncoder(w).Encode(resp)
+	}))
+	defer server.Close()
+
+	kimiBase := server.URL + "/api.kimi.com/coding/v1"
+	p := NewProvider("key", kimiBase, "")
+	_, err := p.Chat(t.Context(), []Message{{Role: "user", Content: "hi"}}, nil, "kimi-for-coding", nil)
+	if err != nil {
+		t.Fatalf("Chat() error = %v", err)
+	}
+
+	if gotUA != "KimiCLI/1.3" {
+		t.Fatalf("User-Agent = %q, want %q", gotUA, "KimiCLI/1.3")
+	}
+}
+
+func TestProviderChat_KimiCodingModelAliases(t *testing.T) {
+	tests := []struct {
+		name  string
+		model string
+	}{
+		{name: "k2.5", model: "kimi-k2.5"},
+		{name: "k2-thinking", model: "kimi-k2-thinking"},
+		{name: "for-coding", model: "kimi-for-coding"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var gotUA string
+			var gotModel string
+
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				gotUA = r.Header.Get("User-Agent")
+				var body map[string]any
+				if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+					http.Error(w, err.Error(), http.StatusBadRequest)
+					return
+				}
+				if m, ok := body["model"].(string); ok {
+					gotModel = m
+				}
+
+				resp := map[string]any{
+					"choices": []map[string]any{
+						{
+							"message":       map[string]any{"content": "ok"},
+							"finish_reason": "stop",
+						},
+					},
+				}
+				w.Header().Set("Content-Type", "application/json")
+				_ = json.NewEncoder(w).Encode(resp)
+			}))
+			defer server.Close()
+
+			kimiBase := server.URL + "/api.kimi.com/coding/v1"
+			p := NewProvider("key", kimiBase, "")
+			_, err := p.Chat(t.Context(), []Message{{Role: "user", Content: "hi"}}, nil, tt.model, nil)
+			if err != nil {
+				t.Fatalf("Chat() error = %v", err)
+			}
+
+			if gotUA != "KimiCLI/1.3" {
+				t.Fatalf("User-Agent = %q, want %q", gotUA, "KimiCLI/1.3")
+			}
+			if gotModel != tt.model {
+				t.Fatalf("model = %q, want %q", gotModel, tt.model)
+			}
+		})
+	}
+}
+
 func TestProviderChat_AcceptsNumericOptionTypes(t *testing.T) {
 	var requestBody map[string]any