[codex] add xAI model constants

README.md

@@ -67,7 +67,7 @@ Or use the xAI Responses API with built-in web search:
 ```go
 import "github.com/katasec/forge/provider/xai"
 
-provider := xai.New(os.Getenv("XAI_API_KEY"), "grok-4-1-fast-non-reasoning", xai.WithWebSearch())
+provider := xai.New(os.Getenv("XAI_API_KEY"), xai.ModelGrok4FastNonReasoning, xai.WithWebSearch())
 
 // After running the agent, access citations:
 citations := provider.LastCitations()

_examples/chat-console/main.go

@@ -45,7 +45,7 @@ func buildProvider(name string) (forge.Provider, func()) {
 		return openai.New("https://api.x.ai/v1", key, "grok-3-mini"), func() {}
 	case "xai-search":
 		key := requireEnv("XAI_API_KEY")
-		provider := xai.New(key, "grok-4-1-fast-non-reasoning", xai.WithWebSearch())
+		provider := xai.New(key, xai.ModelGrok4FastNonReasoning, xai.WithWebSearch())
 		return provider, func() { printCitations(provider.LastCitations()) }
 	default:
 		log.Fatalf("unknown provider %q; use anthropic, xai, or xai-search", name)

_examples/hello-world/main.go

@@ -55,7 +55,7 @@ func main() {
 		if key == "" {
 			log.Fatal("Set XAI_API_KEY environment variable")
 		}
-		xaiProvider = xai.New(key, "grok-4-1-fast-non-reasoning", xai.WithWebSearch())
+		xaiProvider = xai.New(key, xai.ModelGrok4FastNonReasoning, xai.WithWebSearch())
 		provider = xaiProvider
 	default:
 		log.Fatalf("Unknown provider: %s (use 'anthropic', 'xai', or 'xai-search')", *providerFlag)

provider/xai/model.go

@@ -0,0 +1,12 @@
+package xai
+
+// Model is an xAI model identifier.
+type Model string
+
+const (
+	// ModelGrok3Mini is xAI's Grok 3 mini model.
+	ModelGrok3Mini Model = "grok-3-mini"
+
+	// ModelGrok4FastNonReasoning is xAI's fast non-reasoning Grok 4.1 model.
+	ModelGrok4FastNonReasoning Model = "grok-4-1-fast-non-reasoning"
+)

provider/xai/xai.go

@@ -5,7 +5,7 @@
 //
 // Usage:
 //
-//	provider := xai.New(apiKey, "grok-3-mini", xai.WithWebSearch())
+//	provider := xai.New(apiKey, xai.ModelGrok3Mini, xai.WithWebSearch())
 package xai
 
 import (
@@ -62,11 +62,11 @@ type xSearchConfig struct {
 }
 
 // New creates an xAI provider using the Responses API.
-func New(apiKey, model string, opts ...Option) *Provider {
+func New(apiKey string, model Model, opts ...Option) *Provider {
 	p := &Provider{
 		baseURL: "https://api.x.ai/v1",
 		apiKey:  apiKey,
-		model:   model,
+		model:   string(model),
 		client:  &http.Client{},
 	}
 	for _, opt := range opts {

provider/xai/xai_test.go

@@ -14,12 +14,12 @@ import (
 var _ forge.Provider = (*Provider)(nil)
 
 func TestNew(t *testing.T) {
-	p := New("test-key", "grok-3-mini")
+	p := New("test-key", ModelGrok3Mini)
 	if p.apiKey != "test-key" {
 		t.Errorf("apiKey = %q, want %q", p.apiKey, "test-key")
 	}
-	if p.model != "grok-3-mini" {
-		t.Errorf("model = %q, want %q", p.model, "grok-3-mini")
+	if p.model != string(ModelGrok3Mini) {
+		t.Errorf("model = %q, want %q", p.model, ModelGrok3Mini)
 	}
 	if p.baseURL != "https://api.x.ai/v1" {
 		t.Errorf("baseURL = %q, want default", p.baseURL)
@@ -30,7 +30,7 @@ func TestNew(t *testing.T) {
 }
 
 func TestNewWithOptions(t *testing.T) {
-	p := New("key", "model",
+	p := New("key", Model("custom-model"),
 		WithBaseURL("http://localhost"),
 		WithWebSearch(AllowedDomains("wikipedia.org", "github.com")),
 		WithXSearch(ExcludedHandles("@spam")),
@@ -72,7 +72,7 @@ func TestGenerate(t *testing.T) {
 		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
 			t.Fatalf("decode request: %v", err)
 		}
-		if req.Model != "grok-3-mini" {
+		if req.Model != string(ModelGrok3Mini) {
 			t.Errorf("model = %q", req.Model)
 		}
 		// Should have system + user message.
@@ -103,7 +103,7 @@ func TestGenerate(t *testing.T) {
 	}))
 	defer srv.Close()
 
-	p := New("test-key", "grok-3-mini", WithBaseURL(srv.URL))
+	p := New("test-key", ModelGrok3Mini, WithBaseURL(srv.URL))
 	resp, err := p.Generate(context.Background(), forge.ProviderRequest{
 		SystemPrompt: "Be helpful.",
 		Messages: []forge.Message{
@@ -164,7 +164,7 @@ func TestGenerateWithFunctionCalls(t *testing.T) {
 	}))
 	defer srv.Close()
 
-	p := New("key", "grok-3-mini", WithBaseURL(srv.URL))
+	p := New("key", ModelGrok3Mini, WithBaseURL(srv.URL))
 	resp, err := p.Generate(context.Background(), forge.ProviderRequest{
 		Messages: []forge.Message{{Role: forge.RoleUser, Content: "Weather in SF?"}},
 		Tools: []forge.ToolDefinition{{
@@ -235,7 +235,7 @@ func TestGenerateWithToolResults(t *testing.T) {
 	}))
 	defer srv.Close()
 
-	p := New("key", "grok-3-mini", WithBaseURL(srv.URL))
+	p := New("key", ModelGrok3Mini, WithBaseURL(srv.URL))
 	resp, err := p.Generate(context.Background(), forge.ProviderRequest{
 		Messages: []forge.Message{
 			{Role: forge.RoleUser, Content: "Weather in SF?"},
@@ -306,7 +306,7 @@ func TestGenerateWithWebSearch(t *testing.T) {
 	}))
 	defer srv.Close()
 
-	p := New("key", "grok-3-mini",
+	p := New("key", ModelGrok3Mini,
 		WithBaseURL(srv.URL),
 		WithWebSearch(AllowedDomains("reuters.com")),
 	)
@@ -348,7 +348,7 @@ func TestGenerateAPIError(t *testing.T) {
 	}))
 	defer srv.Close()
 
-	p := New("key", "grok-3-mini", WithBaseURL(srv.URL))
+	p := New("key", ModelGrok3Mini, WithBaseURL(srv.URL))
 	_, err := p.Generate(context.Background(), forge.ProviderRequest{
 		Messages: []forge.Message{{Role: forge.RoleUser, Content: "Hi"}},
 	})