send0 MCP Server

by send0-devio.github.send0-dev/send0v0.2.1

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

0Node.jsstdioremoteofficial registry

context tax

needs auth

security

pending

cold start

pending

freshness

pending

Our reading of send0, from the data

send0 is a email MCP server from send0-dev, listed in the official MCP Registry.

Its endpoint requires sign-in or an API key just to list tools, so we haven't measured its token cost; we never use real credentials.

With 0 GitHub stars it ranks #267 of 932 email servers we index.

It runs either locally over stdio or as a hosted endpoint and needs one secret (SEND0_API_KEY); use a scoped, least-privilege key.

Install send0 MCP server

claude mcp add send0-dev -e SEND0_API_KEY='<send0-api-key>' -- npx -y @send0/mcp

{
  "mcpServers": {
    "send0-dev": {
      "command": "npx",
      "args": [
        "-y",
        "@send0/mcp"
      ],
      "env": {
        "SEND0_API_KEY": "<send0-api-key>"
      }
    }
  }
}

Add to ~/.cursor/mcp.json (global) or .cursor/mcp.json (project).

{
  "mcpServers": {
    "send0-dev": {
      "command": "npx",
      "args": [
        "-y",
        "@send0/mcp"
      ],
      "env": {
        "SEND0_API_KEY": "<send0-api-key>"
      }
    }
  }
}

Settings → Developer → Edit Config (claude_desktop_config.json), then restart.

{
  "servers": {
    "send0-dev": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@send0/mcp"
      ],
      "env": {
        "SEND0_API_KEY": "<send0-api-key>"
      }
    }
  }
}

Add to .vscode/mcp.json in your workspace.

{
  "mcpServers": {
    "send0-dev": {
      "command": "npx",
      "args": [
        "-y",
        "@send0/mcp"
      ],
      "env": {
        "SEND0_API_KEY": "<send0-api-key>"
      }
    }
  }
}

Add to ~/.codeium/windsurf/mcp_config.json.

Configuration

Variable	Required	Secret	Description
SEND0_API_KEY	yes	yes	send0 API key (s0_live_…), from https://app.send0.dev
SEND0_INBOX_ID	—	—	Default inbox (ibx_…) for tools that take an inbox_id
SEND0_BASE_URL	—	—	API base URL, for a self-hosted send0

Remote endpoints

streamable-httphttps://api.send0.dev/mcp

Freshness

Not enough public signals yet to judge maintenance.

Last commit (default branch)
2026-10-13 · 6d ago · GitHub
Latest release
2026-10-07 · 11d ago · GitHub · v0.1.1
Package published
no data · npm/PyPI
Registry entry updated
2026-10-13 · 6d ago · official registry · v0.2.1

How it compares in Email

Against the most-starred email servers we index. Token cost is per model turn, measured from each server's live tool list.

Server	Stars	Tools	Tokens / turn	Freshness	Runs
send0 (this)	0	—	not measured	—	local + hosted
Inbox Zero	12,649	—	not measured	Active	hosted
Useplunk	5,524	—	not measured	—	local
Google Workspace	3,370	—	not measured	Active	—
OpenOSINT	1,776	—	not measured	Active	local
emailmd	1,382	3	954	Active	local + hosted

All email MCP servers

FAQ

›How do I install the send0 MCP server in Claude Code?

Run: claude mcp add send0-dev -e SEND0_API_KEY='<send0-api-key>' -- npx -y @send0/mcp. For Cursor, VS Code, Claude Desktop and Windsurf, use the install tabs above.

›Does send0 require an API key?

Yes. It expects SEND0_API_KEY, of which 1 is a secret.

›Can I use send0 as a remote (hosted) MCP server?

Yes — it offers both a hosted endpoint and a local stdio package.

›Is send0 in the official MCP registry?

Yes, as io.github.send0-dev/send0.

Sources and method

Official MCP Registry entry: updated 2026-10-13
GitHub repository: fetched 2026-10-19
Package registry (npm / PyPI): listed
Last checked against all sources: 2026-10-19

The description, packages and links come from the maintainer's own published metadata. Token cost, security signals, freshness and the reading above are MCPSkillHub's own measurements; see the methodology. Spot an error? Request a correction or claim the listing.