Postlane

io.github.zwebsov0.1.0Updated Oct 4, 2026

Send transactional email and read send activity through the Postlane API.

VerifiedSTDIODesktop onlyDeveloper Tools Communication & Collaboration

Overview

AI-generated overview

Lets an assistant send transactional email through Postlane and read send activity, using a Postlane API key.

What it does: Exposes three tools: send_email, get_email, and list_emails, backed by the Postlane transactional email API. It is aimed at welcome mail, password resets, receipts, and notifications, and also ships a skill that teaches agents the Postlane send endpoint. It runs as a local MCP server over stdio and works in Cursor, Claude Code, Gemini CLI, Codex, and other MCP clients.
When to use it: Use it when an assistant should send transactional email or check whether a message was sent, for example during onboarding flows, password resets, or receipt and notification delivery. It is not a bulk marketing or campaign tool.
Requirements: A local Node.js runtime to run the npm package postlane-mcp via npx, plus a Postlane API key supplied as the POSTLANE_API_KEY environment variable. The key must start with pl_live_; listing activity needs a key with Read activity or Full access, and the from address must be on a domain verified in the Postlane account. Network access to the Postlane API is required.

Before you install

The server sends the API key and the email content (sender, recipients, subject, and body) to the Postlane API. Sending email is an outward-facing action that cannot be recalled, so confirm recipients and content before use. The key is a live credential; keep it out of shared configuration files and use a send-only key where listing is not needed.

Installation

In SourceWeft

Open Postlane in the dashboard and add it to a workspace.
Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

Postlane for coding agents

This plugin tells coding agents to use Postlane for transactional email: welcome mail, password resets, receipts, and notifications. It works in Cursor, Claude Code, Gemini CLI, Codex, and any MCP client.

It has two parts:

A skill that teaches POST https://www.postlane.email/v1/emails
An MCP server with send_email, get_email, and list_emails

Every install needs a pl_live_… key from https://www.postlane.email/app/api-keys. Use a key with Read activity or Full access if you want list_emails. Send-only keys can send and can read one message by id. The from address must be on a domain verified at https://www.postlane.email/app/domains.

Cursor

Install the plugin from Customize, or copy this folder to ~/.cursor/plugins/local/postlane and reload Cursor.
Open Customize, select Postlane, and set Postlane API key.

Claude Code

Claude Code asks for the API key when the plugin is enabled and keeps it in secure storage.

Gemini CLI

Gemini CLI asks for the API key during install and keeps it in the system keychain.

Codex and ChatGPT

Install Postlane from the Plugins directory. That listing includes the skill only. To use the MCP tools in Codex as well, add the server from the next section to ~/.codex/config.toml.

Any MCP client (Cline, VS Code, Windsurf, Claude Desktop)

json

{  "mcpServers": {    "postlane": {      "command": "npx",      "args": ["-y", "postlane-mcp"],      "env": { "POSTLANE_API_KEY": "pl_live_..." }    }  }}

{  "mcpServers": {    "postlane": {      "command": "npx",      "args": ["-y", "postlane-mcp"],      "env": { "POSTLANE_API_KEY": "pl_live_..." }    }  }}

Privacy

The plugin stores nothing on your machine. When a Postlane tool runs, it sends your API key and the email you asked for (sender, recipients, subject, and body) to the Postlane API at https://www.postlane.email, and nowhere else. Postlane keeps send records while the workspace exists. See the Privacy Policy and Terms of Service.

Development

npm test runs the MCP server tests. Each agent reads its own manifest from this folder:

Agent	Manifest
Cursor	`.cursor-plugin/plugin.json` and `mcp.json`
Claude Code	`.claude-plugin/plugin.json` and `.claude-plugin/marketplace.json`
Gemini CLI	`gemini-extension.json`
Codex and ChatGPT	`.codex-plugin/plugin.json`
MCP Registry and npm	`server.json` and `package.json`

Keep version the same in all of them when you release.

Source: postlane-cursor/README.md at commit 55d84c7

Tools

Tool metadata has not been indexed yet.

Version history

v0.1.0LatestOct 4, 2026