send0

Name: send0
Author: send0-dev

by send0-devversion 0.2.1i★ –iComputer or cloud

Registry nameio.github.send0-dev/send0

Install

Overview

Description from the maker (original English)

Email inboxes for AI agents: create an address, wait for codes and links, send and reply in threads.

PopNx MCP’s three pillars

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

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

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: Computer or cloud
Transport: stdio, Streamable HTTP
Category: Chat & email
You need to fill in: SEND0_API_KEY, Authorization

Install

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

Before you install

Basic checks: 1 of 1 passed
Runs on the maker’s server: what you ask it goes through their server.
You fill in yourself: SEND0_API_KEY, SEND0_INBOX_ID, SEND0_BASE_URL, Authorization, x-send0-inbox

Values marked secret are keys to your account. Never share them or paste them into a chat.

You need

Runs in the cloudNothing to install; it connects over the internet
npmNode.js installed (for the npx command)

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

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

This address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

Or run it on your computer

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "send0": {
      "command": "npx",
      "args": [
        "-y",
        "@send0/mcp"
      ],
      "env": {
        "SEND0_API_KEY": "your-value",
        "SEND0_INBOX_ID": "your-value",
        "SEND0_BASE_URL": "your-value"
      }
    }
  }
}

Run this in your terminal

claude mcp add --transport http send0 https://api.send0.dev/mcp --header 'Authorization: Bearer {api_key}' --header 'x-send0-inbox: your-value'

Or run it on your computer

claude mcp add send0 --env SEND0_API_KEY=your-value --env SEND0_INBOX_ID=your-value --env SEND0_BASE_URL=your-value -- npx -y @send0/mcp

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "send0": {
      "url": "https://api.send0.dev/mcp",
      "headers": {
        "Authorization": "Bearer {api_key}",
        "x-send0-inbox": "your-value"
      }
    }
  }
}

Or run it on your computer

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "send0": {
      "command": "npx",
      "args": [
        "-y",
        "@send0/mcp"
      ],
      "env": {
        "SEND0_API_KEY": "your-value",
        "SEND0_INBOX_ID": "your-value",
        "SEND0_BASE_URL": "your-value"
      }
    }
  }
}

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.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "send0": {
      "type": "http",
      "url": "https://api.send0.dev/mcp",
      "headers": {
        "Authorization": "Bearer {api_key}",
        "x-send0-inbox": "your-value"
      }
    }
  }
}

Or run it on your computer

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "send0": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@send0/mcp"
      ],
      "env": {
        "SEND0_API_KEY": "your-value",
        "SEND0_INBOX_ID": "your-value",
        "SEND0_BASE_URL": "your-value"
      }
    }
  }
}

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 address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

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

Values you fill in

SEND0_API_KEY secret required env
send0 API key (s0_live_…), from https://app.send0.dev
SEND0_INBOX_ID env
Default inbox (ibx_…) for tools that take an inbox_id
SEND0_BASE_URL env
API base URL, for a self-hosted send0
Authorization secret required HTTP header
Your send0 API key as a Bearer token
x-send0-inbox HTTP header
Default inbox (ibx_…) for tools that take an inbox_id

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

What it can do

We have not read this server’s tool list yet; we check endpoints in rotation.

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 with the GitHub account send0-dev, which owns the repo
… 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 checked yet
Endpoint responds
Not checked yet; we check endpoints in rotation
… Not checked yet
Sign-in with OAuth
Not checked yet; we check endpoints in rotation
… Not checked yet
No hidden instructions in tool descriptions
Not checked yet; we read the tool list when we check the endpoint

Compared with others in Chat & emaili

More stars than 0% of the other 1762 servers in this category
Published to the registry more recently than 52% of the other 1762 servers in this category
Basic checks equal to or better than 100% of the other 1762 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 send0 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?

You need to fill in: SEND0_API_KEY, Authorization

Does it run on my computer or in the cloud?

Either way works: install it on your computer or connect to the cloud version.

Is it still maintained?

The GitHub repo last changed –, and the latest version (0.2.1) reached the registry 24 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.

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 WhatsApp Cloud

by codespar

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.

@send0/mcp

MCP server for send0. Give Claude, Cursor or any MCP client its own email inbox: sign up for things, read verification codes, and hold real email conversations.

Tools

Tool	What it does
`create_inbox`	Make a new address, e.g. `signup-agent@send0.email`
`list_inboxes`	Inboxes this key can use
`wait_for_email`	Block until a matching email arrives; returns the one-time code and verify link already extracted
`search_messages`	Full-text search, filter by sender (`*@github.com`) or direction
`get_message`	Read one message (new text only by default, to save tokens)
`list_threads` / `get_thread`	Read whole conversations, oldest first
`send_email`	Start a new thread
`reply`	Answer in the same thread

Email bodies are returned inside tags with a note to treat them as data, and messages flagged for prompt injection carry a visible warning. Read-only tools are annotated readOnlyHint, and sending tools openWorldHint, so clients can ask before sending.

Setup

Get an API key at https://send0.dev. A key limited to one inbox is the safest choice for an agent.

Claude Code

claude mcp add send0 --env SEND0_API_KEY=s0_live_… -- npx -y @send0/mcp

Claude Desktop / Cursor

"mcpServers": { "send0": { "command": "npx", "args": ["-y", "@send0/mcp"], "env": { "SEND0_API_KEY": "s0_live_…" } } } }

Options

Variable
`SEND0_API_KEY`	Required
`SEND0_INBOX_ID`	Default inbox, so tools don't need `inbox_id`
`SEND0_BASE_URL`	For self-hosted send0

Use it from code

import { createSend0Server } from "@send0/mcp";

import { Send0 } from "@send0/sdk";

const server = createSend0Server({ client: new Send0(process.env.SEND0_API_KEY) }); // connect any MCP transport

License

MIT

send0

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

Or run it on your computer

Or run it on your computer

Or run it on your computer

Or run it on your computer

Values you fill in

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Chat & emaili

Common questions

Alternatives

Vexa

emailmd

MCP WhatsApp Cloud

README from the maker

@send0/mcp

Tools

Setup

Claude Code

Claude Desktop / Cursor

Options

Use it from code

License