Send16 MCP

Name: Send16 MCP
Author: spruikco

by spruikcoversion 0.5.8i★ –iComputer or cloud

Registry nameio.github.spruikco/send16-mcp

Install

Overview

Description from the maker (original English)

Email for AI agents: send mail, manage contacts, automations & webhooks. Zero-DNS first send.

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: Developer tools
You need to fill in: SEND16_API_KEY

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: SEND16_API_KEY

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 …”.

Works in Claude on the web, desktop and mobile:

Open Settings → Connectors
Press Add custom connector
Paste the address below and press Add
If it asks you to sign in, sign in with the maker

https://mcp.send16.com/mcp

Or run it on your computer

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

{
  "mcpServers": {
    "send16": {
      "command": "npx",
      "args": [
        "-y",
        "send16-mcp"
      ],
      "env": {
        "SEND16_API_KEY": "your-value"
      }
    }
  }
}

Run this in your terminal

claude mcp add --transport http send16 https://mcp.send16.com/mcp

Or run it on your computer

claude mcp add send16 --env SEND16_API_KEY=your-value -- npx -y send16-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": {
    "send16": {
      "url": "https://mcp.send16.com/mcp"
    }
  }
}

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": {
    "send16": {
      "command": "npx",
      "args": [
        "-y",
        "send16-mcp"
      ],
      "env": {
        "SEND16_API_KEY": "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": {
    "send16": {
      "type": "http",
      "url": "https://mcp.send16.com/mcp"
    }
  }
}

Or run it on your computer

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "send16": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "send16-mcp"
      ],
      "env": {
        "SEND16_API_KEY": "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.

ChatGPT connects only to servers on the internet:

Open ChatGPT on the web → Settings → Connectors (Apps)
Press Create or Add (some plans need Developer mode under Advanced first)
Paste the address below, give it a name and save
If it asks you to sign in, sign in with the maker

https://mcp.send16.com/mcp

Menu names can differ slightly by plan and over time.

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

Values you fill in

SEND16_API_KEY secret required env
Your Send16 API key (sk_live_...), from https://send16.com/dashboard/developers

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 7, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account spruikco, 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 Developer toolsi

More stars than 0% of the other 4908 servers in this category
Published to the registry more recently than 25% of the other 4908 servers in this category
Basic checks equal to or better than 100% of the other 4908 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 Send16 MCP 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: SEND16_API_KEY

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 (0.5.8) reached the registry 4 months 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: GitHub, Desktop Commander, Cloudflare MCP

Alternatives

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

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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.

send16-mcp

The email API your AI agent can actually use. A Model Context Protocol server for Send16 that gives Claude, Cursor, and any MCP client 79 tools to send transactional & marketing email, manage contacts, audiences, segments, automations, templates, the inbox, suppressions, and webhooks — from natural language.

It ships a zero-DNS sandbox sender, so an agent can send its first real, delivered email in seconds with no domain setup.

npx send16-mcp

Quick start

You need a Send16 API key (sk_live_…) from your dashboard. Then pick your client:

Claude Desktop / Claude Code

claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/, Windows: %APPDATA%\Claude\):

"mcpServers": { "send16": { "command": "npx", "args": ["-y", "send16-mcp"], "env": { "SEND16_API_KEY": "sk_live_..." } } } }

Cursor

.cursor/mcp.json:

"mcpServers": { "send16": { "command": "npx", "args": ["-y", "send16-mcp"], "env": { "SEND16_API_KEY": "sk_live_..." } } } }

Windsurf, VS Code, and any stdio-capable MCP client work the same way — run the send16-mcp binary with SEND16_API_KEY in the environment.

Hosted (no install)

For clients that only speak *remote* MCP (Claude web connectors, ChatGPT custom GPTs), point them at the hosted endpoint and authenticate with your key:

https://mcp.send16.com

One connection, your own sk_live_… key — no install, no config file.

First send in seconds — no DNS

Most email APIs make you verify a domain before you can send *anything*, which blocks an unattended agent on step one. Send16's sandbox sender doesn't:

Ask the agent to call whoami — it returns your workspace and your sandbox_recipient (your account owner's email).
Send from: "onboarding@send16.com" to that address. It delivers with zero DNS setup.
Verify a domain later to send to anyone.

*"Send a test email from onboarding@send16.com to my account email with the subject 'It works'."*

What it can do

79 tools across the platform, including:

Email — send_email (single/batch/scheduled/attachments), transactional templates, delivery status.
Marketing — campaigns, broadcasts, automations, segments, subscription topics.
Contacts — create/search/list/import, audiences, tags, custom fields.
Deliverability — domains, DNS health (SPF/DKIM/DMARC), IP warming & sending capacity.
Inbox — read and manage transactional replies.
Webhooks — create/list/rotate outgoing webhook endpoints (HMAC-SHA256 signed).

Every tool also accepts an optional apiKey parameter that overrides SEND16_API_KEY, so you can switch workspaces in one session.

Environment

Variable	Required	Description
`SEND16_API_KEY`	Yes	Your Send16 key (`sk_live_…`)
`SEND16_API_URL`	No	API base URL (default: `https://api.send16.com`)
`SEND16_MCP_PORT`	No	If set, serves Streamable HTTP (multi-tenant) instead of stdio

Self-hosting the HTTP connector

Presence of SEND16_MCP_PORT flips the server into multi-tenant HTTP mode — each request carries its own Authorization: Bearer sk_live_…, threaded through the whole request, so one process serves many users:

docker build -t send16-mcp . && docker run -p 4242:4242 send16-mcp

Develop

npm install

SEND16_API_KEY=sk_live_... npm run dev # run from source npm run build # bundle to dist/

Send16 MCP

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 Developer toolsi

Common questions

Alternatives

GitHub

Desktop Commander

Cloudflare MCP

README from the maker

send16-mcp

Quick start

Claude Desktop / Claude Code

Cursor

Hosted (no install)

First send in seconds — no DNS

What it can do

Environment

Self-hosting the HTTP connector

Develop

Links

License