Move minimax reasoning_split injection to provider factory

Inject reasoning_split at provider creation time to allow user ExtraBody
settings to be preserved

pkg/config/config_test.go

@@ -1194,27 +1194,6 @@ func TestConfigLogLevelEmpty(t *testing.T) {
 	}
 }
 
-func TestDefaultConfig_MinimaxExtraBody(t *testing.T) {
-	cfg := DefaultConfig()
-
-	var minimaxCfg *ModelConfig
-	for i := range cfg.ModelList {
-		if cfg.ModelList[i].Model == "minimax/MiniMax-M2.5" {
-			minimaxCfg = &cfg.ModelList[i]
-			break
-		}
-	}
-	if minimaxCfg == nil {
-		t.Fatal("Minimax model not found in ModelList")
-	}
-	if minimaxCfg.ExtraBody == nil {
-		t.Fatal("Minimax ExtraBody should not be nil")
-	}
-	if got, ok := minimaxCfg.ExtraBody["reasoning_split"]; !ok || got != true {
-		t.Fatalf("Minimax ExtraBody[reasoning_split] = %v, want true", got)
-	}
-}
-
 func TestModelConfig_ExtraBodyRoundTrip(t *testing.T) {
 	dir := t.TempDir()
 	cfgPath := filepath.Join(dir, "config.json")

pkg/providers/factory_provider.go

@@ -117,7 +117,7 @@ func CreateProviderFromConfig(cfg *config.ModelConfig) (LLMProvider, string, err
 	case "litellm", "openrouter", "groq", "zhipu", "gemini", "nvidia",
 		"ollama", "moonshot", "shengsuanyun", "deepseek", "cerebras",
 		"vivgrid", "volcengine", "vllm", "qwen", "qwen-intl", "qwen-international", "dashscope-intl",
-		"qwen-us", "dashscope-us", "mistral", "avian", "minimax", "longcat", "modelscope", "novita",
+		"qwen-us", "dashscope-us", "mistral", "avian", "longcat", "modelscope", "novita",
 		"coding-plan", "alibaba-coding", "qwen-coding":
 		// All other OpenAI-compatible HTTP providers
 		if cfg.APIKey() == "" && cfg.APIBase == "" {
@@ -136,6 +136,31 @@ func CreateProviderFromConfig(cfg *config.ModelConfig) (LLMProvider, string, err
 			cfg.ExtraBody,
 		), modelID, nil
 
+	case "minimax":
+		// Minimax requires reasoning_split: true in the request body
+		if cfg.APIKey == "" && cfg.APIBase == "" {
+			return nil, "", fmt.Errorf("api_key or api_base is required for HTTP-based protocol %q", protocol)
+		}
+		apiBase := cfg.APIBase
+		if apiBase == "" {
+			apiBase = getDefaultAPIBase(protocol)
+		}
+		extraBody := cfg.ExtraBody
+		if extraBody == nil {
+			extraBody = make(map[string]any)
+		}
+		if _, ok := extraBody["reasoning_split"]; !ok {
+			extraBody["reasoning_split"] = true
+		}
+		return NewHTTPProviderWithMaxTokensFieldAndRequestTimeout(
+			cfg.APIKey,
+			apiBase,
+			cfg.Proxy,
+			cfg.MaxTokensField,
+			cfg.RequestTimeout,
+			extraBody,
+		), modelID, nil
+
 	case "anthropic":
 		if cfg.AuthMethod == "oauth" || cfg.AuthMethod == "token" {
 			// Use OAuth credentials from auth store

pkg/providers/factory_provider_test.go

@@ -6,6 +6,7 @@
 package providers
 
 import (
+	"encoding/json"
 	"net/http"
 	"net/http/httptest"
 	"strings"
@@ -604,3 +605,98 @@ func TestGetDefaultAPIBase_QwenUSAliases(t *testing.T) {
 		}
 	}
 }
+
+func TestCreateProviderFromConfig_MinimaxInjectsReasoningSplit(t *testing.T) {
+	var requestBody map[string]any
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if err := json.NewDecoder(r.Body).Decode(&requestBody); err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"choices":[{"message":{"content":"ok"},"finish_reason":"stop"}]}`))
+	}))
+	defer server.Close()
+
+	cfg := &config.ModelConfig{
+		ModelName: "test-minimax",
+		Model:     "minimax/MiniMax-M2.5",
+		APIKey:    "test-key",
+		APIBase:   server.URL,
+	}
+
+	provider, modelID, err := CreateProviderFromConfig(cfg)
+	if err != nil {
+		t.Fatalf("CreateProviderFromConfig() error = %v", err)
+	}
+	if provider == nil {
+		t.Fatal("CreateProviderFromConfig() returned nil provider")
+	}
+	if modelID != "MiniMax-M2.5" {
+		t.Errorf("modelID = %q, want %q", modelID, "MiniMax-M2.5")
+	}
+
+	_, err = provider.Chat(
+		t.Context(),
+		[]Message{{Role: "user", Content: "hi"}},
+		nil,
+		modelID,
+		nil,
+	)
+	if err != nil {
+		t.Fatalf("Chat() error = %v", err)
+	}
+
+	// Verify reasoning_split is automatically injected
+	if got, ok := requestBody["reasoning_split"]; !ok || got != true {
+		t.Fatalf("reasoning_split = %v, want true", got)
+	}
+}
+
+func TestCreateProviderFromConfig_MinimaxPreservesUserExtraBody(t *testing.T) {
+	var requestBody map[string]any
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if err := json.NewDecoder(r.Body).Decode(&requestBody); err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"choices":[{"message":{"content":"ok"},"finish_reason":"stop"}]}`))
+	}))
+	defer server.Close()
+
+	cfg := &config.ModelConfig{
+		ModelName: "test-minimax-custom",
+		Model:     "minimax/MiniMax-M2.5",
+		APIKey:    "test-key",
+		APIBase:   server.URL,
+		ExtraBody: map[string]any{"custom_field": "test"},
+	}
+
+	provider, modelID, err := CreateProviderFromConfig(cfg)
+	if err != nil {
+		t.Fatalf("CreateProviderFromConfig() error = %v", err)
+	}
+
+	_, err = provider.Chat(
+		t.Context(),
+		[]Message{{Role: "user", Content: "hi"}},
+		nil,
+		modelID,
+		nil,
+	)
+	if err != nil {
+		t.Fatalf("Chat() error = %v", err)
+	}
+
+	// Verify reasoning_split is automatically injected
+	if got, ok := requestBody["reasoning_split"]; !ok || got != true {
+		t.Fatalf("reasoning_split = %v, want true", got)
+	}
+	// Verify user's custom field is preserved
+	if got, ok := requestBody["custom_field"]; !ok || got != "test" {
+		t.Fatalf("custom_field = %v, want test", got)
+	}
+}