---
title: "Developers"
description: "Everything in the app is also a call your own code can make: send mail, scope keys, hear about events, and drive it from a typed client or an agent."
url: "https://nextmail.sh/docs/knowledge/developers"
area: "Knowledge base"
category: "Developers"
---

# Developers

Everything in the app is also a call your own code can make: send mail, scope keys, hear about events, and drive it from a typed client or an agent.

## In this section

- [Email API](https://nextmail.sh/docs/knowledge/developers/email-api.md): Send one message or a hundred per call, now or later, and retry without sending twice.
- [API keys](https://nextmail.sh/docs/knowledge/developers/api-keys.md): A key per job, limited to the scopes and senders it needs, with every call logged.
- [REST API](https://nextmail.sh/docs/knowledge/developers/api.md): A documented HTTP API with issuable, scopable, revocable keys.
- [Webhooks](https://nextmail.sh/docs/knowledge/developers/webhooks.md): Tell your endpoint when mail arrives, instead of making you poll.
- [Typed SDKs](https://nextmail.sh/docs/knowledge/developers/sdk.md): TypeScript, Python, Ruby, PHP, Go, Java and C# clients, one method for every operation.
- [Command line](https://nextmail.sh/docs/knowledge/developers/cli.md): Your mailbox and every API operation, from a terminal or a script.
- [MCP server](https://nextmail.sh/docs/knowledge/developers/mcp.md): Point Claude, or any MCP client, at your mailbox.
- [OAuth for third-party clients](https://nextmail.sh/docs/knowledge/developers/oauth.md): Apps register themselves and sign in with PKCE, and you choose the workspace, addresses and permissions each one gets.
- [Move from Resend](https://nextmail.sh/docs/knowledge/developers/switch-from-resend.md): Bring your suppressions, audiences, contacts, templates and webhooks across with one key, with a checklist for your domains and API keys.
- [Move from SendGrid](https://nextmail.sh/docs/knowledge/developers/switch-from-sendgrid.md): Point the SendGrid SDK at Nextmail and keep your code, then bring lists, suppressions, templates and webhooks across with one key.
- [Move from Postmark](https://nextmail.sh/docs/knowledge/developers/switch-from-postmark.md): Point the Postmark client at Nextmail and keep your code, then bring suppressions, templates and webhooks across with one key.
- [Move from Mailgun](https://nextmail.sh/docs/knowledge/developers/switch-from-mailgun.md): Point the Mailgun SDK at Nextmail and keep your code, then bring mailing lists, suppressions, templates and webhooks across with one key.
- [Move from Mailchimp](https://nextmail.sh/docs/knowledge/developers/switch-from-mailchimp.md): Bring your Mailchimp lists, subscribers and unsubscribes across with one key.
- [Convert your sending code](https://nextmail.sh/docs/knowledge/developers/code-converter.md): Paste code that sends through Resend, SendGrid, Postmark or Mailgun, and get it back written for Nextmail.
- [Try it in the docs](https://nextmail.sh/docs/knowledge/developers/api-playground.md): Send a real request from any page of the API reference, with a temporary key that lasts an hour and is scoped to that call.
- [Address checker](https://nextmail.sh/docs/knowledge/developers/address-check.md): Whether an address is worth sending to, before the first message.
- [Events from your app](https://nextmail.sh/docs/knowledge/developers/contact-events.md): Tell Nextmail what a contact did in your product, to start an automation or end a wait.