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npubmail

by obvioussummer46version 0.2.1i★ –iRuns on your computer
Registry namecom.npubmail/npubmail

Install

Overview

Description from the maker (original English)

Email inbox for AI agents, owned by a Nostr key. No signup or API key. Receive codes, read, send.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

  • Connection: Runs on your computer
  • Transport: stdio
  • Category: Chat & email

Install

Pick the AI app you use, then copy the settings.

Before you install

  • Basic checks: 1 of 1 passed
  • Runs on your computer with your user’s permissions (files, network, apps).
  • You fill in yourself: NPUBMAIL_NAME

Which app do you use?

Pick your app above. We remember it, so next time the button says “Install in …”.

Download the maker’s .mcpb file

The link goes to the maker’s own file; we do not host or repackage it. Open the file and Claude Desktop installs it.

Run this in your terminal

Fill in the empty values before running it.

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

  • NPUBMAIL_NAME env
    Preferred mailbox name (becomes @npubmail.com if free). Optional.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 6, 2026

  • ✓ Pass

    Maker matches the repo

    The registry name was verified against the domain npubmail.com (the registry checks domain ownership)

  • … Not checked yet

    Still maintained

    We have not read this repo from GitHub yet

  • … Not checked yet

    Has a licence

    We have not read this repo from GitHub yet

  • – Not applicable

    Endpoint responds

    This one runs on your computer; there is no internet endpoint

  • – Not applicable

    Sign-in with OAuth

    Runs on your computer and uses local settings instead

  • … Not checked yet

    No hidden instructions in tool descriptions

    Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Chat & emaili

  • More stars than 0% of the other 1763 servers in this category
  • Published to the registry more recently than 47% of the other 1763 servers in this category
  • Basic checks equal to or better than 100% of the other 1763 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is npubmail safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (0.2.1) reached the registry 29 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need MCPB on your computer.

What can I use instead?

In the same category: Vexa, emailmd, MCP WhatsApp Cloud

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Vexa

by Vexa-ai

Meeting bot and transcripts for Google Meet, Teams and Zoom. Live or after, speakers labelled.

Runs in the cloud★ 2,949Apache-2.0Updated 2 months ago
Install

emailmd

by anypost

Render markdown into email-safe HTML, lint drafts for deliverability problems, and preview emails.

Computer or cloud★ 1,385MITUpdated 30 days ago
Install

MCP server for WhatsApp Cloud API (Meta) — messages, media, and templates via Graph API

Runs on your computer★ 277MITUpdated 5 months ago
Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

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](https://npubmail.com):

  • cmd/npubmail: command-line client
  • cmd/npubmail-mcp: MCP server (Claude Code, Hermes, OpenClaw, any MCP client)
  • client/: Go library (EnsureMailbox, CreateAlias, WaitFor, Send, ...)
  • skills/npubmail/SKILL.md: agent skill
  • docs/: 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-0.2.1.mcpb and open it.

Listed in the official MCP Registry as com.npubmail/npubmail.

curl -fsSL https://npubmail.com/install | sh       # prebuilt, checksummed binaries

or from source:

go install github.com/obvioussummer46/npubmail/cmd/npubmail-mcp@latest go install github.com/obvioussummer46/npubmail/cmd/npubmail@latest

MCP config:

mcp_servers:

npubmail: command: npubmail-mcp # talks to https://npubmail.com timeout: 660 # wait_for_* can block up to 600 s

Use it

npubmail init myagent                      # -> myagent@npubmail.com (key at ~/.config/npubmail/nsec)

npubmail alias --from github.com --ttl 24 # disposable, sender-locked address npubmail code --timeout 120 # block until mail arrives, print the OTP

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.

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