RelayMCP

What the RelayMCP MCP server does

RelayMCP connects an AI assistant to one person's personal WhatsApp through a hosted, per-user MCP endpoint. It supports chat and contact lookup, message retrieval, conversation summaries, reminders, follow-ups, and replies to individual contacts. The service also exposes operations for voice notes, images, documents, and other media sent in WhatsApp chats.

The RelayMCP MCP server is intended for personal conversations rather than campaigns or broadcast messaging. It does not import old chat history when the WhatsApp account is linked. During the private pilot, access is invite-only through relaymcp.app.

How it works

First, link WhatsApp by scanning a QR code from the phone's Linked devices section. RelayMCP joins the account as a companion device. Next, configure the personal RelayMCP URL as a remote MCP server in an MCP client. After privacy settings are chosen, the assistant can call the available tools through that connection.

Each user receives an endpoint in the form https://<user>-mcp.relaymcp.app/mcp. The connection uses Streamable HTTP. Authentication is available through OAuth 2.1 with Dynamic Client Registration or an API key sent as a bearer token. Clients that support OAuth, including ChatGPT and Claude, only need the endpoint URL.

Setup and configuration

The RelayMCP MCP server requires a pilot-issued endpoint and either an OAuth connection or a bearer API key. An API-key configuration uses the endpoint URL and an Authorization header containing a token beginning with rmcp_live_. Setup instructions are provided at relaymcp.app/guides/.

Privacy settings can block individual chats or groups and control message retention. The default retention period is 72 hours and can be adjusted. Blocking a chat prevents new messages from being stored or shown to the AI, prevents media downloads, and removes previously stored data for that chat. Only the account owner can approve an unblock request using a code shown in the RelayMCP dashboard.

Tools and capabilities

The RelayMCP MCP server exposes 34 tools across these areas:

• Contacts and chats: search contacts, inspect chats, find direct conversations, and view recent interaction data.
• Messages: list messages, retrieve message context, mark messages read, and find messages waiting for the user.
• Sending: send text, reactions, files, and audio; inspect the send queue; and cancel queued messages.
• Media: download or view media and transcribe audio, including Hindi and English voice notes.
• Groups: list groups and group members. Group operations are read-only.
• Reminders and follow-ups: create reminders, schedule or update follow-ups, list them, and cancel them.
• Privacy and account: block chats, review blocked chats, request an unblock, inspect privacy status, and check account status.

Limitations and notes

Messages are encrypted at rest in AWS storage in Mumbai, India, and logs do not contain message text. Unlinking the device deletes the account data. The service states that messages are used only to operate requested features and are not sold or used for advertising.

Sending is deliberately restricted. Messages are delayed randomly by 30 to 120 seconds, cannot be sent in bursts, and are limited to one recipient at a time. The recipient must already be in the user's contacts or an existing chat. Quiet hours prevent sends from 9 PM to 9 AM in the recipient's local time. Daily and repeated-text limits also apply, and suspected spam or bulk messaging can result in an account pause or ban.

RelayMCP is an independent product and is not affiliated with WhatsApp or Meta. It is currently offered free to early users during the private pilot, with planned plans listed on the product website.