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Email SDKs

An email SDK for the language you already write.

Create email addresses, receive and read mail, send replies, verify webhooks and stream events, from Python, TypeScript, Go, Rust, Java, C#, PHP, Ruby or Swift. Every SDK does the encryption on your machine, so mail is opened in your code and never on our servers.

Create a free accountSDKs in the docs

Nine languages · One encryption format · Apache 2.0 · Free tier, no card

Pick a language

Install, sign in, receive mail.

Each page has a quickstart, a webhook handler for that language's web frameworks, and how to test email verification with its test runner.

Python email SDK

mailcycle on PyPI · Python 3.10 or later

pip install mailcycleSend and receive email in Python

JavaScript and TypeScript email SDK

mailcycle-sdk on npm · Node.js 20 or later

npm install mailcycle-sdkSend and receive email in TypeScript

Go email SDK

mailcycle.email/go on the Go module proxy · Go 1.26 or later

go get mailcycle.email/goSend and receive email in Go

Rust email SDK

mailcycle on crates.io · Rust 1.75 or later

cargo add mailcycle --features eventsSend and receive email in Rust

Java email SDK

email.mailcycle:mailcycle on Maven Central · Java 17 or later

implementation("email.mailcycle:mailcycle:0.3.0")Send and receive email in Java

C# and .NET email SDK

Mailcycle on NuGet · .NET 8 or later

dotnet add package MailcycleSend and receive email in .NET

PHP email SDK

mailcycle/mailcycle on Mailcycle's Composer repository · PHP 8.1 or later

composer config repositories.mailcycle composer https://mailcycle.email/php composer require mailcycle/mailcycleSend and receive email in PHP

Ruby email SDK

mailcycle on RubyGems · Ruby 3.1 or later

gem install mailcycleSend and receive email in Ruby

Swift email SDK

Mailcycle on Swift Package Manager · Swift 5.9 or later

.package(url: "https://mailcycle.email/swift/mailcycle.git", from: "0.1.0")Send and receive email in Swift
One API, nine languages

The same calls, in each language's own idiom.

Every SDK covers the whole API: email addresses, inbound mail, sending with attachments, webhooks and their signatures, the live event stream, API keys, sessions and device pairing. Method names follow the language, so it is wait_for in Python and WaitForAsync in C#.

The loop every SDK runs
sign in            the recovery phrase, or an API key
create an address  receives mail at once, sealed to your key
wait for mail      the event stream, or a webhook
read it            text, HTML, attachments, decrypted locally
reply              threaded under the original
AI agents

Not writing code? Use the MCP server.

An AI agent in Claude, Cursor, Codex or VS Code gets an inbox of its own through MCP, with tools to wait for, read and reply to mail.

The email MCP server
Questions

About the SDKs.

A library that wraps an email API in your own language, so you call functions rather than writing HTTP requests. Mailcycle's SDKs create email addresses, receive and read the mail that arrives, send and reply, verify webhooks and listen for events, and do the decryption on your machine.

Nine: Python, JavaScript and TypeScript, Go, Rust, Java, C# and .NET, PHP, Ruby and Swift. Each is published to its language's usual registry and documented with a guide.

Yes. One call to the Mailcycle API, or one SDK method such as mc.addresses.create(), creates a new email address on a shared domain or on your own domain, and it receives mail at once. Each address has its own key, mail to it is stored encrypted, and deleting it frees its place on your plan.

Yes. They share one published encryption format, so an address created from Python can be read from Go, a message sent from Ruby shows up in the app, and a team can mix languages on one account.

Not yet. The API is JSON over HTTPS, so any language can call it, and the encryption format and its test vectors are published, so a client can be written against them. For an AI agent, the MCP server needs no SDK at all.

Yes. Every SDK is open source under the Apache 2.0 licence. The Free plan needs no card and receives mail on 3 addresses; sending, API keys, webhooks and sending from an API key unlock on the paid plans.
Every SDK

Jump to a language.

Give your code an address of its own.

Create an account, create an address, and read what arrives. The free tier needs no card.

Get startedThe email API