diff --git a/pkg/providers/antigravity_provider.go b/pkg/providers/antigravity_provider.go
index d4ee528b7..0e7608cc3 100644
--- a/pkg/providers/antigravity_provider.go
+++ b/pkg/providers/antigravity_provider.go
@@ -33,13 +33,22 @@ type AntigravityProvider struct {
 }
 
 // NewAntigravityProvider creates a new Antigravity provider using stored auth credentials.
-func NewAntigravityProvider() *AntigravityProvider {
+// Returns an error if credentials are not available or invalid.
+func NewAntigravityProvider() (*AntigravityProvider, error) {
+	// Validate credentials exist before creating the provider
+	cred, err := getCredential("google-antigravity")
+	if err != nil {
+		return nil, fmt.Errorf("loading auth credentials: %w", err)
+	}
+	if cred == nil {
+		return nil, fmt.Errorf("no credentials for google-antigravity. Run: picoclaw auth login --provider google-antigravity")
+	}
 	return &AntigravityProvider{
 		tokenSource: createAntigravityTokenSource(),
 		httpClient: &http.Client{
 			Timeout: 120 * time.Second,
 		},
-	}
+	}, nil
 }
 
 // Chat implements LLMProvider.Chat using the Cloud Code Assist v1internal API.
diff --git a/pkg/providers/factory_provider.go b/pkg/providers/factory_provider.go
index 53f7a08a0..0e710ade5 100644
--- a/pkg/providers/factory_provider.go
+++ b/pkg/providers/factory_provider.go
@@ -137,7 +137,11 @@ func CreateProviderFromConfig(cfg *config.ModelConfig) (LLMProvider, string, err
 		), modelID, nil
 
 	case "antigravity":
-		return NewAntigravityProvider(), modelID, nil
+		provider, err := NewAntigravityProvider()
+		if err != nil {
+			return nil, "", err
+		}
+		return provider, modelID, nil
 
 	case "claude-cli", "claudecli":
 		workspace := cfg.Workspace
diff --git a/pkg/providers/factory_provider_test.go b/pkg/providers/factory_provider_test.go
index e0c0eddef..74bbc2e5a 100644
--- a/pkg/providers/factory_provider_test.go
+++ b/pkg/providers/factory_provider_test.go
@@ -160,15 +160,14 @@ func TestCreateProviderFromConfig_Antigravity(t *testing.T) {
 		Model:     "antigravity/gemini-2.0-flash",
 	}
 
-	provider, modelID, err := CreateProviderFromConfig(cfg)
-	if err != nil {
-		t.Fatalf("CreateProviderFromConfig() error = %v", err)
+	// Antigravity requires OAuth credentials, which should fail in test environment
+	_, _, err := CreateProviderFromConfig(cfg)
+	if err == nil {
+		t.Fatal("CreateProviderFromConfig() expected error for antigravity without credentials")
 	}
-	if provider == nil {
-		t.Fatal("CreateProviderFromConfig() returned nil provider")
-	}
-	if modelID != "gemini-2.0-flash" {
-		t.Errorf("modelID = %q, want %q", modelID, "gemini-2.0-flash")
+	// Verify error message mentions credentials
+	if !strings.Contains(err.Error(), "credentials") && !strings.Contains(err.Error(), "auth") {
+		t.Errorf("Expected credential-related error, got: %v", err)
 	}
 }