update
May 15, 2026
By Teun
Claude Code users can now leave encrypted messages
A new MCP server called answering-machine lets Claude Code users leave messages for other users to pick up later. The project says messages are encrypted on the sender’s machine, stored unreadable by the postbox, and deleted after pickup or seven days.
A new MCP server for Claude Code lets users leave encrypted messages for each other and have them picked up the next time the recipient opens Claude Code. The project, called answering-machine, was posted on Hacker News and is installed with the Claude Code MCP command.
According to the post, the workflow is simple: a user installs the server, picks a name, and shares an invite code with another person. From there, they can leave a message for that person inside Claude Code, even if the recipient is not online at the time.
The source text shows the command format as claude mcp add answering-machine -- npx answering-machine copied. It also describes the message flow as “copied write” followed by a note such as “reviewed the auth doc, one issue on line 47,” which is then encrypted before it is sent.
The project says the message is sealed on the sender’s machine before it goes anywhere. In the example shown, the message becomes an encrypted payload, then lands in a postbox that can store it but cannot read it.
When the recipient comes online and opens Claude Code, the system pulls the message down on the next open. The message is then read by the intended recipient, according to the project’s description.
The posting also says the postbox deletes messages after pickup or after seven days. That means the system is meant for temporary delivery, not long-term storage.
The project’s main security claim is that only the person the message was sent to can read it. Because the encryption happens before the message leaves the sender’s machine, the postbox itself does not have access to the plaintext content.
The announcement does not mention a separate app or web interface. Instead, it is built as an MCP server, which means it plugs into Claude Code through the Model Context Protocol, the integration layer used by Claude’s tooling ecosystem.
The result is a lightweight way for Claude Code users to pass notes to one another without switching tools. The post says the server is available to install now, and gives the command needed to add it to Claude Code.
Install it, pick a name, and share your invite code with the person you want to message, according to the project’s instructions.
