> ## Documentation Index
> Fetch the complete documentation index at: https://docs.subscriber.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> Lifecycle email you run from your terminal or your AI agent.

Subscriber.dev sends the emails your product sends automatically, like a welcome email when someone signs up, a reminder before their trial ends, or an announcement to everyone. They go out through your own email provider. There's no dashboard: you set it up and run it through your AI agent over MCP, the CLI, or the REST API.

> [card] [Quickstart](https://docs.subscriber.dev/quickstart.md)
>
> Sign in, connect a provider and send your first workflow email.

> [card] [Connect your AI agent](https://docs.subscriber.dev/mcp.md)
>
> Add the MCP server to Claude, Cursor or any MCP client.

> [card] [Workflows](https://docs.subscriber.dev/workflows.md)
>
> Email and webhook steps, delays, templates and Stripe triggers.

> [card] [API reference](https://docs.subscriber.dev/api-reference/introduction.md)
>
> Every endpoint, with request and response examples.

## How it fits together

There are four things to know about:

* **Workspaces** hold your team's billing and environments. Every workspace starts with a **Production** environment, and you can add more, such as staging.
* **[Subscribers](https://docs.subscriber.dev/subscribers.md)** are the people you email. They belong to an environment and are matched by `email`, `externalId` (your own ID) or their `publicId`.
* **Integrations** connect an environment to an email provider (any SMTP server, or Cloudflare Email) and to event sources such as Stripe. See [Integrations](https://docs.subscriber.dev/integrations/overview.md).
* **Workflows** are a list of email or webhook steps with delays. Your app, your agent or a Stripe event triggers them for one subscriber, or you send them to everyone as a broadcast.


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