fix(provider): preserve @cf model identifiers

pkg/providers/factory_provider.go

@@ -46,6 +46,9 @@ func createCodexAuthProvider() (LLMProvider, error) {
 //   - "gpt-4o" -> ("openai", "gpt-4o")  // default protocol
 func ExtractProtocol(model string) (protocol, modelID string) {
 	model = strings.TrimSpace(model)
+	if strings.HasPrefix(model, "@") {
+		return "openai", model
+	}
 	protocol, modelID, found := strings.Cut(model, "/")
 	if !found {
 		return "openai", model

pkg/providers/factory_provider_test.go

@@ -70,6 +70,12 @@ func TestExtractProtocol(t *testing.T) {
 			wantProtocol: "azure",
 			wantModelID:  "my-gpt5-deployment",
 		},
+		{
+			name:         "at-prefixed cloudflare model id",
+			model:        "@cf/qwen/qwen1.5-0.5b-chat",
+			wantProtocol: "openai",
+			wantModelID:  "@cf/qwen/qwen1.5-0.5b-chat",
+		},
 	}
 
 	for _, tt := range tests {
@@ -105,6 +111,26 @@ func TestCreateProviderFromConfig_OpenAI(t *testing.T) {
 	}
 }
 
+func TestCreateProviderFromConfig_OpenAIPreservesAtPrefixedModelID(t *testing.T) {
+	cfg := &config.ModelConfig{
+		ModelName: "test-cf-openai",
+		Model:     "@cf/qwen/qwen1.5-0.5b-chat",
+		APIKey:    "test-key",
+		APIBase:   "https://api.example.com/v1",
+	}
+
+	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 != "@cf/qwen/qwen1.5-0.5b-chat" {
+		t.Fatalf("modelID = %q, want full @cf model id", modelID)
+	}
+}
+
 func TestCreateProviderFromConfig_DefaultAPIBase(t *testing.T) {
 	tests := []struct {
 		name     string

pkg/providers/model_ref.go

@@ -17,6 +17,15 @@ func ParseModelRef(raw string, defaultProvider string) *ModelRef {
 		return nil
 	}
 
+	// Providers like Cloudflare use model IDs such as "@cf/..." where the slash
+	// belongs to the model path, not a provider prefix.
+	if strings.HasPrefix(raw, "@") {
+		return &ModelRef{
+			Provider: NormalizeProvider(defaultProvider),
+			Model:    raw,
+		}
+	}
+
 	if idx := strings.Index(raw, "/"); idx > 0 {
 		provider := NormalizeProvider(raw[:idx])
 		model := strings.TrimSpace(raw[idx+1:])

pkg/providers/model_ref_test.go

@@ -123,3 +123,16 @@ func TestParseModelRef_DefaultProviderNormalization(t *testing.T) {
 		t.Errorf("provider = %q, want openai (normalized from GPT)", ref.Provider)
 	}
 }
+
+func TestParseModelRef_AtPrefixedModelUsesDefaultProvider(t *testing.T) {
+	ref := ParseModelRef("@cf/qwen/qwen1.5-0.5b-chat", "openai")
+	if ref == nil {
+		t.Fatal("expected non-nil ref")
+	}
+	if ref.Provider != "openai" {
+		t.Fatalf("provider = %q, want %q", ref.Provider, "openai")
+	}
+	if ref.Model != "@cf/qwen/qwen1.5-0.5b-chat" {
+		t.Fatalf("model = %q, want full @cf model id", ref.Model)
+	}
+}