Short answer: Grok Build, xAI's terminal coding agent, connects remote MCP servers with automatic sign-in. One command adds OsmO; the first time the agent uses it, a browser opens for your mobile number and code.
grok mcp add --transport http osmo https://api.getosmo.app/mcp.
Sign-in opens in the browser on first use.
/mcps shows the connection.
How it works
- Sign in with your mobile numberYou get 50 free credits. Nothing to pay.
- Add OsmO to Grok BuildChatGPT, Claude, Grok and other apps that take connectors.
- Ask it to callOsmO calls, talks, and tells you what was said.
The full guide
Before you start
- Grok Build (beta for SuperGrok and X Premium Plus).
- A mobile number from the US, Canada, the UK or Australia (India also works) to receive a sign-in code.
- Nothing to pay: you start with 50 free credits.
Connect OsmO to Grok Build
- Run
grok mcp add --transport http osmo https://api.getosmo.app/mcp. - Start Grok Build. On first use a browser opens OsmO's sign-in; enter your mobile number and the texted code.
- Type
/mcpsin the terminal UI to confirm OsmO is connected, then ask for a call.
Where the settings live
Servers are stored in ~/.grok/config.toml under [mcp_servers.osmo]; add --scope project to keep OsmO to one project. Grok Build also reads servers you already added for Claude Code or Cursor.
Grok Build is in beta for SuperGrok and X Premium Plus subscribers, so commands may change. xAI's docs have the current form.
Make a first test call
Make your first call a low-stakes one, such as asking a shop for its opening hours. You will see how your AI app confirms the call, how long a call takes and what the answer looks like, before you send it on anything that matters.
If something goes wrong
| What you see | What it means | What to do |
|---|---|---|
| "You've used your free OsmO credits" | Not enough credits left for this request (each call needs 3) | Ask for fewer calls at once, or keep calling from the OsmO app: getosmo.app/app |
| "OsmO can call listed businesses and toll-free numbers" | The number is not a listed business, a toll-free line or one of your saved contacts | Give the business name instead. To call your contacts from your AI app, use the OsmO app, which syncs them |
| The sign-in page will not take your number | Sign-in accepts US, Canadian, UK, Australian and Indian mobile numbers | Use a mobile number from one of those countries |
| "Scheduling calls for later is available in the OsmO app" | Calls booked for a later time need the app | Ask for the call now, or schedule it in the OsmO app |
| A call is refused for the same number | OsmO places at most 5 calls to one number in any 24 hours | Try again once 24 hours have passed since the earliest of those calls |
Turn it off
To disconnect, remove OsmO from your AI app's connector settings. Some apps do not tell OsmO when you do that. If you use the OsmO app, also open the Sharing card, then Connect AI apps, and tap Disconnect. If you only use OsmO from AI apps, email [email protected] with the mobile number you signed in with and we will end the access.
Questions people ask
Can Grok Build call without asking me?
OsmO asks your AI app to read you who it will call and why, and to wait for your yes before it dials. Some apps also ask permission before using a connector at all.
Sources
Checked November 13, 2026. Vendors change their products often; follow the links for the current version.