Antigravity MCP: add a remote MCP server to Google Antigravity

By Killian, founder · Updated 27 October 2026 · Markdown

To add a remote MCP server to Google Antigravity, open the agent side panel’s … menu, choose MCP Servers → Manage MCP Servers → View raw config, and add the server under mcpServers with a serverUrl in mcp_config.json. Then go to the Customizations tab in Agent settings and click Authenticate next to the server to sign in. Servers in the MCP Store install with one click instead. This guide covers the config file, OAuth and header sign-in, how to check the tools loaded, and the common errors.

The example server is datatomcp, which lets Antigravity’s agent query your CSVs and Google Sheets.

1. Open the config

1. In the agent side panel, click … at the top and select MCP Servers.
2. Click Manage MCP Servers.
3. Click View raw config. This opens mcp_config.json.

There are two files:

2. Add the server

{
  "mcpServers": {
    "datatomcp": {
      "serverUrl": "https://app.datatomcp.com/mcp"
    }
  }
}

Antigravity requires Streamable HTTP for remote servers. The legacy HTTP+SSE transport and the httpUrl field aren’t supported. url works as an alias for serverUrl.

Save the file. In the Antigravity App, click the refresh button in the Installed MCP Servers section so it picks up the change.

Servers that use an API key

{
  "mcpServers": {
    "my-api": {
      "serverUrl": "https://api.example.com/mcp/",
      "headers": { "Authorization": "Bearer YOUR_API_TOKEN" }
    }
  }
}

Keep this file out of version control if it holds a literal token.

3. Sign in

For servers that support dynamic client registration, like datatomcp, the serverUrl is all Antigravity needs.

1. Open Agent settings and go to the Customizations tab.
2. Click Authenticate next to the server.
3. Complete the sign-in in your browser. For datatomcp you log in with your datatomcp account and approve read access to your datasets.
4. Copy the code shown at the end, paste it back into Antigravity and click Submit.

Servers that need a pre-registered OAuth app take an oauth object with clientId and clientSecret, and the app must list https://antigravity.google/oauth-callback as a redirect URI.

4. Check it worked

• The server appears under installed MCP servers without an error, and its tools are listed.
• Ask the agent: “Use datatomcp to list my datasets.” It should call list_datasets and show the result.

Troubleshooting

• Server doesn’t appear after editing the file. Click refresh in Installed MCP Servers, and check that the JSON is valid. A trailing comma breaks the whole file.
• No connection to an older server. It may only offer SSE. Antigravity needs Streamable HTTP; ask the provider for an /mcp endpoint.
• Authenticate fails or loops. Check that you pasted the whole code and clicked Submit. If the provider rejects Antigravity’s redirect address, the provider has to allow it on their side.
• Wrong file. A server in a workspace’s .agents/mcp_config.json only shows up in that workspace.

Gemini CLI users

Google moved free-tier and Google One users from Gemini CLI to Antigravity CLI in June 2026. If you still use Gemini CLI, the command is gemini mcp add --transport http -s user datatomcp https://app.datatomcp.com/mcp, then /mcp auth datatomcp inside the CLI. More in the any-client guide.

A data server for Antigravity

Agents building dashboards, scripts or reports often need the numbers behind them. With datatomcp connected, the agent queries your spreadsheet instead of reading it: describe_dataset for the columns, distinct_values for exact category names, aggregate for totals and query_rows for rows, all read-only. Totals come from a database over every row, and each result names the dataset version it came from.

Create a free account, add a CSV or Google Sheet under Add data, and add the config above. The Google Sheets MCP server guide covers the sheet side.

FAQ

Where is Antigravity’s MCP config? ~/.gemini/config/mcp_config.json globally, <workspace>/.agents/mcp_config.json per workspace.

Does Antigravity support SSE MCP servers? No, remote servers must use Streamable HTTP.

serverUrl or url? Either; serverUrl is the documented key.

More clients: Add a remote MCP server to any AI client · Cursor · VS Code