Everything Lettr connects to
Lettr is the email platform for SaaS: transactional email and campaigns in one account. It connects through SDKs, a hosted MCP server, SMTP, webhooks and connectors built by partners.
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Start here
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Hosted MCP server
Send email, manage templates and check delivery from Claude, ChatGPT or Cursor. AI agents and MCP Built by Lettr -
Node.js
Type-safe SDK for Node.js and TypeScript, with Next.js and Nuxt guides. SDK Built by Lettr -
Laravel
Mail facade, Mailables and notifications, plus type-safe templates. Framework Built by Lettr -
Supabase
Auth emails over SMTP, everything else from Edge Functions. Platform guide Built by Lettr
AI agents and MCP
Let an AI assistant send email, manage templates and check delivery.
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Hosted MCP server
Send email, manage templates and check delivery from Claude, ChatGPT or Cursor. AI agents and MCP Built by Lettr -
Agent skills
Teach Claude Code, Cursor or Codex to install Lettr and send email correctly. AI agents and MCP Built by Lettr -
One
71 Lettr actions for AI agents, from sending email to campaigns. AI agents and MCP Built by One -
Composio
A 60-tool Lettr toolkit for agents built on Composio. AI agents and MCP Built by Composio
SDKs and frameworks
Official libraries for sending from your own code.
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Node.js
Type-safe SDK for Node.js and TypeScript, with Next.js and Nuxt guides. SDK Built by Lettr -
PHP
Type-safe PHP SDK with a fluent email builder. SDK Built by Lettr -
Laravel
Mail facade, Mailables and notifications, plus type-safe templates. Framework Built by Lettr -
Go
Go SDK for sending email and managing your Lettr account. SDK Built by Lettr -
Rust
Rust SDK for sending email and managing your Lettr account. SDK Built by Lettr
Platforms and plugins
Send from the tools your app already runs on.
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Supabase
Auth emails over SMTP, everything else from Edge Functions. Platform guide Built by Lettr -
WordPress
One plugin for every wp_mail() email, WooCommerce included. Plugin Built by Lettr -
Stripe
Send emails and templates to customers without leaving Stripe. Marketplace app Built by Lettr -
n8n
A verified n8n node for email, templates, audience and campaigns. Automation platform Built by Lettr
Connector platforms
Lettr in integration catalogs, built and maintained by each platform.
Works with everything else
If a tool sends over SMTP or makes HTTP requests, it works with Lettr.
Built a Lettr connector? Get listed.
Connectors built by partners get their own page here, labelled with who built them.
- 01 Send us the link to your live public listing.
- 02 We check it describes Lettr correctly.
- 03 Your connector gets a card and a page here.
Email info@lettr.com
Found an error? Tell us.
Questions
- Does Lettr have an MCP server?
- Yes. Lettr hosts an MCP server at https://app.lettr.com/mcp. You connect by signing in to Lettr or with an API key, and it works with Claude, Claude Code, ChatGPT, Cursor and GitHub Copilot.
- Which languages have an official Lettr SDK?
- Lettr builds SDKs for Node.js, PHP, Go and Rust, and a Laravel package on top of the PHP SDK.
- Can I use Lettr with a tool that is not listed?
- Yes. Any tool that sends over SMTP can use smtp.lettr.com with the username lettr and your API key as the password. Anything that can make an HTTP request can use the REST API.
- Who builds and maintains the connectors on partner platforms?
- The platform that lists them. Every card says who built it. Lettr builds the SDKs, the MCP server, the WordPress plugin, the Stripe app and the n8n node.
- Is there a Ruby or .NET SDK?
- No. Ruby and .NET apps can send through Lettr over SMTP or the REST API.
- How do I get my connector listed or corrected?
- Email info@lettr.com with a link to your live public listing. We check it and add it, or fix what is wrong.