Relay MCP server

Remote Model Context Protocol server for Relay, a business phone and SMS app for teams, built in Montreal.

It lets Claude, or any MCP client, work with your team's phone: list calls and texts, read call transcripts, search and update contacts, send an SMS from the team number, and draft call-routing flows.

Endpoint	https://api.yesrelay.com/api/mcp
Transport	Streamable HTTP (spec 2025-06-18), stateless
Authentication	Authorization: Bearer <Relay API key>
Tools	16
Plans	Every plan, free included
Documentation	https://yesrelay.com/en/api-docs

This repository holds no server code: the server is hosted by Relay. Nothing to install on the server side.

Get an API key

1. Create a free account at https://app.yesrelay.com.
2. In the app, open Administration, then Integrations & API, and create a key.
3. The key starts with rk_live_ and is shown once. Keep it in a secrets manager.

Revoking the key in the app cuts MCP and REST access at the same instant.

Connect a client

Claude Code

claude mcp add --transport http relay https://api.yesrelay.com/api/mcp \
  --header "Authorization: Bearer rk_live_..."

Claude Desktop

claude_desktop_config.json, through mcp-remote:

{
  "mcpServers": {
    "relay": {
      "command": "npx",
      "args": ["mcp-remote", "https://api.yesrelay.com/api/mcp",
               "--header", "Authorization:${AUTH}"],
      "env": { "AUTH": "Bearer rk_live_..." }
    }
  }
}

Any other client

Point it at https://api.yesrelay.com/api/mcp with the Authorization header above.

Tools

Calls and messages

Tool	What it does
relay_list_numbers	Lists the organization's teams and their phone numbers
relay_list_calls	Recent calls of a team, newest first
relay_get_transcript	Transcript of a call, with the AI summary and action items
relay_list_messages	Recent texts of a team, newest first, filterable by contact
relay_send_sms	Sends a text from the team number. Real, billed and irreversible

Contacts and team

Tool	What it does
relay_search_contacts	Searches a team's address book by first name, last name or company
relay_create_contact	Adds a contact to the team's address book
relay_update_contact	Replaces the fields of an existing contact
relay_list_members	People in the organization and their identifiers

Flow (call routing, Business and Scale plans)

Tool	What it does
relay_list_flows	Lists the organization's call flows
relay_get_flow	Reads the live graph and the draft of a flow
relay_flow_schema	Block types, expected fields and routing-engine rules
relay_create_flow	Creates a number's flow from a template
relay_save_flow_draft	Replaces the draft. Changes nothing callers hear
relay_check_flow	Tests a graph without writing anything
relay_discard_flow_draft	Throws away the draft and returns to what is live

No tool publishes a flow. An agent can draft and check a call path; a person puts it live from the app.

Safeguards

A text sent through MCP goes through the same checks as a text sent from the app:

Refusal code	When
recipient_opted_out	The recipient replied STOP (or ARRET, UNSUBSCRIBE) to this team
daily_limit_reached	The team's daily cap is reached (the customer's own limit, or the automatic one)
workspace_budget_reached	The team's spending cap is reached
sending_suspended	Outbound sending is paused by the circuit breaker; receiving continues

What you can do also follows your plan: sending texts needs a paid plan, and the Flow tools need Business or Scale.

Limits

Plan	Requests per minute per key	Keys
Free	30	2
Paid	120	5

Each message in a JSON-RPC batch counts as one request.

Troubleshooting

The client shows a read error, or curl fails with error 56 ("chunk hex-length"). Some antivirus software that inspects HTTPS traffic corrupts MCP responses; we have seen it with Avast. The server answered correctly. Exclude api.yesrelay.com from your antivirus HTTPS scanning, then try again.

401 Invalid API key. The key is missing, revoked or expired. Create a new one in the app.

Also available

• REST API: https://api.yesrelay.com/api/v1, reference at https://api.yesrelay.com/docs
• Signed webhooks (HMAC SHA-256) for call and SMS events

Support

hello@yesrelay.com