npubmail
com.npubmailv0.2.0Updated Oct 4, 2026
Email inbox for AI agents, owned by a Nostr key. No signup or API key. Receive codes, read, send.
Overview
Gives an AI agent its own email inbox owned by a Nostr key, so it can receive codes and messages, read them, and send mail.
- What it does
- Provides an email mailbox for an agent, keyed to a Nostr keypair rather than a signup or API key. The client library exposes operations such as ensuring a mailbox, creating disposable sender-locked aliases, waiting for incoming mail, extracting codes and links, and sending messages. Mail is sealed to the owner's key, and the clients sign requests locally.
- When to use it
- Useful when an agent needs an address to receive verification codes, links, or replies, or to send mail to people who wrote to it. Suited to agents that should not depend on a human-owned mailbox or a signup flow.
- Requirements
- Runs as a local process over stdio, installed from the MCPB bundle or built from source with Go. It talks to the hosted service at npubmail.com, so network access is needed. The only credential is the Nostr key file at ~/.config/npubmail/nsec. The optional environment variable NPUBMAIL_NAME sets a preferred mailbox name.
Installation
In SourceWeft
- Open npubmail in the dashboard and add it to a workspace.
- Enable the server for the chats that should use its tools.
Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.
Other MCP clients
Follow the launch instructions in the repository.
README
npubmail clients
Email for AI agents, owned by a Nostr key. No signup, no password, no API key: the agent's keypair is the account.
This repository holds the open clients for the hosted service at npubmail.com:
cmd/npubmail: command-line clientcmd/npubmail-mcp: MCP server (Claude Code, Hermes, OpenClaw, any MCP client)client/: Go library (EnsureMailbox,CreateAlias,WaitFor,Send, ...)skills/npubmail/SKILL.md: agent skilldocs/: HTTP API, the sealed-mail format (SEAL.md) with test vectors, and Python/JS examples
Install
One click (Claude Desktop and other MCPB clients): download npubmail-mcp-0.2.0.mcpb and open it.
Listed in the official MCP Registry as com.npubmail/npubmail.
MCP config:
Use it
Agents: start at https://npubmail.com/llms.txt.
What the service does
- Receive: free. Disposable aliases per signup, codes and links extracted.
- Encrypted at rest: each message is sealed to the owner's Nostr key (see
docs/SEAL.md); the server cannot read stored mail. - Send: replies to people who wrote to you are free, and so is mail to other npubmail mailboxes. Mailing a new recipient costs a few sats over Lightning, per message, with no account balance.
- Inbound TLS (STARTTLS), DKIM/SPF/DMARC on outbound.
Your key is your account
~/.config/npubmail/nsec is the only credential. Back it up; there is no reset. The clients sign every request locally (NIP-98) and never send the key anywhere.
Licence
MIT (LICENSE): clients, library, protocol packages, skill and examples. The server is not in this repository.
Source: README.md at commit 9f2b146
Tools
0Version history
1- v0.2.0LatestOct 4, 2026
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