diff --git a/frontend/src/features/providers/components/__tests__/endpoint-default-paths.spec.ts b/frontend/src/features/providers/components/__tests__/endpoint-default-paths.spec.ts
index b95b0894d..e3685af34 100644
--- a/frontend/src/features/providers/components/__tests__/endpoint-default-paths.spec.ts
+++ b/frontend/src/features/providers/components/__tests__/endpoint-default-paths.spec.ts
@@ -69,6 +69,14 @@ describe('endpoint default paths', () => {
       apiFormats,
     })).toBe('/v1internal:{action}')
   })
+  it('uses Anti Gravity v1internal paths for fixed Anti Gravity endpoints', () => {
+    expect(getDefaultEndpointPath({
+      apiFormat: 'gemini:generate_content',
+      providerType: 'antigravity',
+      baseUrl: 'https://daily-cloudcode-pa.googleapis.com',
+      apiFormats,
+    })).toBe('/v1internal:{action}')
+  })
 
   it('keeps Codex Responses root path without duplicating /v1', () => {
     expect(getDefaultEndpointPath({
diff --git a/frontend/src/features/providers/components/endpoint-default-paths.ts b/frontend/src/features/providers/components/endpoint-default-paths.ts
index 44714e0c4..4ca44dbfa 100644
--- a/frontend/src/features/providers/components/endpoint-default-paths.ts
+++ b/frontend/src/features/providers/components/endpoint-default-paths.ts
@@ -182,6 +182,11 @@ export function getDefaultEndpointPath(params: {
       return '/v1internal:{action}'
     }
   }
+  if (providerType === 'antigravity') {
+    if (normalizedApiFormat === 'gemini:generate_content') {
+      return '/v1internal:{action}'
+    }
+  }
   if (providerType === 'vertex_ai') {
     if (normalizedApiFormat === 'gemini:generate_content') {
       return '/v1/projects/{project_id}/locations/{region}/publishers/google/models/{model}:{action}'