# Antigravity MCP: add a remote MCP server to Google Antigravity

> Add a remote MCP server to Google Antigravity: mcp_config.json, serverUrl, Authenticate in Customizations, and common errors.

Source: https://datatomcp.com/guides/antigravity-mcp · By Killian · Updated 2026-10-27

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:

| File | Applies to |
|---|---|
| `~/.gemini/config/mcp_config.json` | Every project |
| `<workspace>/.agents/mcp_config.json` | One workspace |

## 2. Add the server

```json
{
  "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

```json
{
  "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](/guides/add-remote-mcp-server#gemini-cli).

## 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](https://app.datatomcp.com/login), add a CSV or Google Sheet under **Add data**, and add the config above. The [Google Sheets MCP server guide](/guides/google-sheets-mcp-server) 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](/guides/add-remote-mcp-server) · [Cursor](/guides/cursor-mcp) · [VS Code](/guides/vscode-mcp)