API key or OAuth

Send email from LangChain

Our tools as LangChain tools, through the MCP adapter.

Remote server, nothing to install

Setup

Load the tools

from langchain_mcp_adapters.client import MultiServerMCPClient

client = MultiServerMCPClient({
    "sending": {
        "transport": "streamable_http",
        "url": "https://sending.dev/api/mcp",
        "headers": {"Authorization": "Bearer sk_your_api_key"},
    }
})

tools = await client.get_tools()

Create the API key under Settings › API Keys. The plaintext token is shown once, at creation.

The thing that catches people

LangChain · gotcha

`get_tools()` is awaitable, and the tools it returns open a new MCP session per call. For a run that sends several emails hold one session open with `client.session("sending")` instead.

Check it works

`len(tools)` matches the tool count listed on this page.

What it can do once connected

85 tools: send transactional email and campaigns, manage contacts and lists, build and activate automations, run an inbox that receives and replies, and read back why a message never went out. All of it inside verified domains, suppression, idempotency, spend caps and an audit log, enforced on our servers rather than in the prompt.

All 85 tools · MCP docs

Other clients

Claude Code

Send email from the terminal, inside the session you are already in.

Claude Desktop

Give Claude an email stack without pasting a secret anywhere.

claude.ai

The same connector, in the browser.

ChatGPT

Custom connectors, and the API path where a key still works.

Cursor

Email tools in the editor where you are writing the app that sends them.

VS Code

GitHub Copilot with a mailer attached, and the key never committed.