Antigravity CLI

Antigravity CLI (agy) is Google's successor to Gemini CLI. Configure GitLab MCP in your workspace's .agents/mcp_config.json:

{
  "mcpServers": {
    "gitlab": {
      "command": "npx",
      "args": ["-y", "@structured-world/gitlab-mcp@latest", "stdio"],
      "env": {
        "GITLAB_API_URL": "https://gitlab.com",
        "GITLAB_TOKEN": "<your-token>"
      }
    }
  }
}

Use Node.js 24 or later. Set your GitLab instance URL and token as described in authentication. Keep credentials out of version control. The setup wizard does not currently detect or configure AGY automatically.

For an existing HTTP deployment, use serverUrl instead of command, args and env. See remote deployment for the server configuration.

AGY's global MCP configuration is ~/.gemini/config/mcp_config.json. Its CLI preferences are a separate file, ~/.gemini/antigravity-cli/settings.json. For migration from Gemini CLI, follow Google's migration guide. Copy only the servers you intend to use and avoid configuring the same server in both workspace and global configuration.

JSON lists and structured results

GitLab MCP's entity tools return JSON in a text content block. A list can be [] or an array of entities. The optional MCP structuredContent field has a different contract: it must be an object. Tools that explicitly declare structured output, such as get_profile, retain that object and their output schema. See the MCP tool result specification.

Installed-client qualification on October 30, 2026 used AGY 1.4.10, macOS arm64 and Node.js 26.8.1, with a locally built core package and MCP SDK 1.32.2. The server connected to a synthetic GitLab HTTP fixture. A scripted loopback Gemini endpoint supplied tool calls, so the run used no real credentials or model inference.

Scenario	Server MCP validation	AGY result	Gemini CLI Core 0.66.0 transport
Empty MR list	Valid text []	Preserved	Adds invalid array structuredContent
One MR	Valid text array	Preserved, all fields unchanged	Adds invalid array structuredContent
Project object	Valid text object	Preserved	Valid object structuredContent
Account profile	Valid native structured object	Text preserved	Native envelope preserved
GitLab permission error	Valid isError result	Preserved as a tool error	Valid error envelope

The historical behavior was reproduced using the actual integrity-checked published @google/gemini-cli-core@0.66.0 transport. The current AGY path passed both list cases. Existing Codex and Claude Code text results remain unchanged.

If an old Gemini CLI reports that array structuredContent is invalid, migrate to the current AGY client. AGY's stream-json tool output is a client display result, not a second MCP envelope. The qualification validates the original MCP envelope and the historical transport's modified envelope with the SDK, then independently checks AGY's decoded output and the subsequent provider tool response.

Repeat the qualification

From a repository checkout with dependencies installed:

yarn workspace @structured-world/gitlab-mcp qualify:antigravity --report /tmp/antigravity-results.json

The command builds and packs the core package, installs the archive in a temporary workspace, downloads the current official native AGY release and verifies its SHA-512 checksum. It also verifies the pinned historical Gemini archive's npm integrity. Each scenario gets its own client home, workspace MCP configuration and allow rules for the selected read-only tool. Your existing client settings and authentication are not imported.

The JSON report records versions, archive checksums, selected tools and arguments, server wire messages, SDK validation failures from the historical client, AGY transcripts and provider responses. Temporary binaries, dependencies and client profiles are removed after the report is written. Build output follows the repository's normal build lifecycle.

The native qualification command supports macOS and Linux. This result qualifies stdio and the synthetic scenarios above; it does not qualify every transport or replace testing against your GitLab instance. Downloads require network access; all GitLab and provider traffic in the scenarios stays on loopback. No external model credentials are needed.