# Google Antigravity

# Google Antigravity + Nitrosend {#google-antigravity--nitrosend}


[Google Antigravity](https://antigravity.google) runs agents in its App, CLI (`agy`) and IDE extensions. The Nitrosend plugin adds the remote MCP server, seven Nitrosend skills and an email marketing agent in one install. Sign-in uses OAuth, so there is no API key to paste.


## Option 1: Install the plugin (recommended) {#option-1-install-the-plugin-recommended}



### Step 1: Install {#step-1-install}


From your shell:

```bash
agy plugin install https://github.com/nitrosend/claude
```

The CLI installs plugins to `~/.gemini/config/plugins/`, which the Antigravity App and IDE also read. Check it with `agy plugin list`; you should see `nitrosend` with 7 skills, 1 agent and 1 MCP server.


### Step 2: Sign in {#step-2-sign-in}


1. Open Agent settings with **Cmd + ,** (macOS) or **Ctrl + ,** (Windows and Linux).
2. Go to **Customizations** and click **Authenticate** next to `nitrosend`.
3. Sign in to Nitrosend in your browser, or create a free account. Choose the account and access, then click **Connect**.
4. Copy the authorization code Antigravity shows, paste it into the settings panel and click **Submit**.

Antigravity stores the token and refreshes it for you.


### Step 3: Verify {#step-3-verify}


Ask the agent:

```
What's my Nitrosend account status?
```

It calls `nitro_get_status` and shows your account, current brand and sending readiness.


### What the plugin adds {#what-the-plugin-adds}


| Component | Name |
|---|---|
| MCP server | `nitrosend` at `https://api.nitrosend.com/mcp` |
| Skills | `nitrosend-setup`, `compose-email`, `send-campaign`, `send-transactional`, `build-flow`, `import-contacts`, `nitrosend-analytics` |
| Agent | `email-marketer` |

Composing never sends. Campaigns and flows go live only after a separate approve step, and the skills tell the agent to stop and ask you first.


## Option 2: MCP server only {#option-2-mcp-server-only}


Add Nitrosend to `~/.gemini/config/mcp_config.json` for every workspace, or to `.agents/mcp_config.json` for one workspace:

```json
{
  "mcpServers": {
    "nitrosend": {
      "serverUrl": "https://api.nitrosend.com/mcp"
    }
  }
}
```

Or from your shell:

```bash
agy mcp add nitrosend https://api.nitrosend.com/mcp
```

Then sign in as in Step 2 above.



> [!WARNING]
> Antigravity needs `serverUrl` (or `url`). The `httpUrl` key from the [Gemini CLI](https://docs.nitrosend.com/integrations/gemini.md) config is not supported and the server will not load.



To add the skills without the plugin, run `npx skills add nitrosend/claude`.


## Example prompts {#example-prompts}


```
Set up my Brand Kit from https://mysite.com and draft a product launch email.
```

```
Build a welcome flow: send a welcome email when a contact subscribes, wait 3 days, then send a follow-up.
```

```
Show me open and click rates for my last campaign compared to benchmarks.
```


## Troubleshooting {#troubleshooting}








**The plugin installs but Nitrosend tools are missing**

Run `agy plugin list` and check `nitrosend` is enabled with 1 MCP server. Then authenticate `nitrosend` under Agent settings, Customizations. Tools appear once sign-in completes.






**The MCP server does not load**

Check the config is valid JSON and uses `serverUrl`, not `httpUrl`. Antigravity supports Streamable HTTP, which is what `https://api.nitrosend.com/mcp` serves.






**Sign-in lands on the wrong Nitrosend account**

Antigravity keeps MCP tokens in `~/.gemini/antigravity/mcp_oauth_tokens.json`. Remove the `nitrosend` entry, authenticate again and pick the right account and access on the Nitrosend sign-in page. See [choose connection access](https://docs.nitrosend.com/integrations/overview.md#choose-connection-access).