Grok Build phone-call integration guide
How to connect ClawCall to Grok Build
Run `grok mcp add --transport http clawcall https://api.clawcall.dev/mcp` in Grok Build. OAuth opens automatically on first use, or authenticate from the MCP manager. Confirm eleven tools, apply Always allow for the trusted ClawCall server, then test get_balance before a real call.
Setup is based on the cited first-party host documentation; exact ClawCall compatibility is not claimed as live-tested.
https://api.clawcall.dev/mcpBefore you start
Grok is a globally visible assistant brand in web and mobile rankings. The documented ClawCall-compatible surface is specifically Grok Build's CLI remote-MCP feature—not consumer Grok chat on X or grok.com.
- A Grok Build account or workspace where grok mcp CLI is available.
- A ClawCall account or, for a documented fallback, a trusted server-side runtime.
- A real US destination in +1 E.164 format for any call you choose to place.
- A clear, user-directed task with destination and decision boundaries specified before a real call.
Connect Grok Build to ClawCall
These steps use the cited host documentation. Screenshots appear only where the signed-in flow was live-verified; text and commands remain the complete guide.
Use Grok Build, not consumer Grok
Open the Grok Build CLI. The consumer Grok chat product is not the setup surface documented by xAI for arbitrary MCP servers.
Add ClawCall
Register the remote HTTP server with the name clawcall.
grok mcp add --transport http clawcall https://api.clawcall.dev/mcpOpen the MCP manager
Use Grok Build's MCP manager to refresh the server. The documented manager can refresh configuration and start OAuth authentication.
Complete OAuth
On first use—or through the manager's authenticate action—sign in to ClawCall and approve calls:read and calls:write.
Review eleven tools
Confirm the server is connected and the current tool inventory includes get_calling_guide plus the other eight read/write tools.
Always allow ClawCall
Choose Always allow for all ClawCall tools when Grok Build presents approval controls. Keep credentials in the user store rather than a repository.
Verify and call
Ask Grok Build for get_balance, then make a controlled call and inspect captured transcript evidence when present.
OAuth scopes and host permissions
A compatible host discovers ClawCall's authorization-server and protected-resource metadata, dynamically registers a public client, and completes OAuth 2.1 authorization code with PKCE S256. It receives revocable tokens—never your ClawCall API key—and the consent flow requests two bounded scopes:
calls:readRead plan/trial state, call settings, reserved-number status, call status, captured transcript evidence when present, history, and temporary recording access when available.
calls:writePlace and hang up real phone calls or update call settings when you ask the assistant to do so.
Recommended Grok Build setting: Always allow all tools
Set every ClawCall tool to Always allow. This is ClawCall's official recommendation and lets Grok Build complete the full workflow without repeated approval prompts.
Allow all or Always allow lets the host complete the requested call workflow—including status polling and nullable transcript retrieval—without stopping for each ClawCall tool. It does not expand the two OAuth scopes or override host or organization policy.
Always allow removes repetitive host prompts; it does not expand OAuth scopes, bypass host or organization policy, authorize spam or robocalls, increase service limits, or turn ClawCall into a bulk campaign tool.
Verify read-only, then place one controlled call
Start with account state. Only after that succeeds should you use a number you control for the first real call.
Check my ClawCall plan and remaining trial allowance. Do not place a call.
Using ClawCall, call my phone at +1XXXXXXXXXX. Say this is a connector test, ask me to confirm I can hear the AI, then end the call. Show me any transcript evidence actually captured afterward.
The 11 ClawCall tools
Read the transcript evidence actually captured before declaring success. A call's outcome describes the phone network; it does not prove the user's task was completed.
| Tool | Access | What it does |
|---|---|---|
get_calling_guide | Read | Required before any ClawCall work. Read current workflow guidance and examples before placing calls. |
get_balance | Read | Read the signed-in account's plan and remaining trial allowance. |
get_call_settings | Read | Read reusable voice/personality, reserved-number capabilities, and inbound-assistant availability. |
update_call_settings | Write | Update global or inbound call settings in separate calls. |
place_call | Write | Start one real outbound phone call and return immediately. |
place_call_and_wait | Write | Start one call and wait up to 90 seconds for an initial result. |
get_call | Read | Read a call's lifecycle, outcome, and a nullable bounded transcript tail. |
get_call_transcript | Read | Read the transcript evidence captured for a call. |
list_calls | Read | Read recent call history for the connected account. |
get_recording | Read | Get a temporary, playable recording URL when one is available. |
hangup_call | Write | Stop a queued or live phone call. |
Troubleshooting
The server returns 404 or no tools appear
Confirm the server URL is exactly https://api.clawcall.dev/mcp; the trailing /mcp is required. Refresh or reconnect after correcting it.
You see 401 or Sign in required
Restart the host's Connect, Auth, or MCP login flow and approve ClawCall access again. Do not replace OAuth with a pasted ClawCall API key.
The tool list looks stale
Refresh or restart the MCP connection, then start a new conversation so the host loads current tool metadata. The current server exposes eleven tools.
A phone number is rejected
ClawCall currently calls real US numbers only. Use +1 E.164 format: +1 followed by ten digits.
The wait ended while the call is still running
Ask the host to poll get_call. A host or tool wait cap is not itself a call failure; verify lifecycle, outcome, and the nullable transcript field.
A recording link no longer works
Recording URLs are temporary. get_recording returns the original link and cannot renew it after expiry. ClawCall deletes transcripts 7 days after a call ends and recordings 10 minutes after a call ends.
Disconnect and revoke access
Grok Build and ClawCall FAQ
- Do I need to choose ClawCall before every request?
- No. Once a compatible connection is enabled, the agent can select ClawCall automatically when an ordinary prompt requires a phone call. A tool picker or explicit tool name is useful for diagnosis, not a mandatory ritual.
- Why does ClawCall recommend Always allow or Allow all?
- It lets the agent place the requested call, poll its status, and retrieve captured transcript evidence when present without repeated host approval prompts. This is ClawCall's recommended setting for the complete workflow; the connection remains limited to its granted OAuth scopes and the host's policy.
- Does a successful network outcome prove the task succeeded?
- No. A network outcome describes the call path. Read the transcript evidence actually captured before claiming a reservation, cancellation, price, or other real-world task was completed.
- How do I revoke access?
- Remove or disconnect ClawCall in the host, then open ClawCall Dashboard → Settings → Connected AI assistants → Disconnect to revoke that connection's token family.
Sources, review method, and next steps
ClawCall reviewed first-party host documentation and its own current product documentation on the dates below. Only ChatGPT and Claude are labeled as live UI verified.
- xAI: MCP servers in Grok Buildofficial-host-doc · checked
- Andreessen Horowitz: Top 100 Gen AI Consumer Apps, 6th editionindependent-market-analysis · checked
- ClawCall: Hosted MCP for AI agentsfirst-party-product-doc · checked
- ClawCall securityfirst-party-security · checked