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

# Introduction

> REST API reference for Outseta — auth, billing, user accounts, email, and support, all in one platform.

<CardGroup cols={2}>
  <Card title="Auth" icon="lock" href="/api-reference/public/log-a-user-in">
    Login and two-factor authentication flows.
  </Card>

  <Card title="Billing" icon="dollar-sign" href="/api-reference/billing/add-a-new-discount-coupon">
    Subscriptions, plans, invoices, transactions, and usage.
  </Card>

  <Card title="CRM" icon="user-round" href="/api-reference/crm/register-a-new-account">
    Registration, accounts, people, deals, and custom attributes.
  </Card>

  <Card title="Email" icon="at-sign" href="/api-reference/email/retrieve-all-broadcast-campaigns">
    Broadcast and drip campaigns, plus email list subscriptions.
  </Card>

  <Card title="Support" icon="life-buoy" href="/api-reference/support/retrieve-all-knowledge-base-articles">
    Help desk cases, replies, and knowledge base articles.
  </Card>

  <Card title="Activity" icon="zap" href="/api-reference/activity/retrieve-all-activities">
    Account, person, and deal activity, including custom events.
  </Card>
</CardGroup>

The Outseta API is a standard REST service that returns JSON and is documented in
OpenAPI 3. Every endpoint includes its request and response shapes and a
live "Try it" playground.

## Base URL

Outseta is multi-tenant — your API lives at your own subdomain:

```
https://{subdomain}.outseta.com
```

Replace `{subdomain}` with your Outseta account subdomain — the part before
`.outseta.com` in your admin URL. In the "Try it" playground, set the editable
`subdomain` field once and every request targets your account.

## Authentication

Most endpoints require authentication. Server-to-server calls use an API key;
logged-in browser/mobile sessions use a bearer token. See
[Authentication](/essentials/authentication) for details and when to use each.

## Conventions

* All requests are made over HTTPS.
* Timestamps are ISO 8601 UTC.
* Resource identifiers (`Uid`) are short opaque strings, not GUIDs.

<Note>
  Some endpoints that return core CRM entities (accounts, people, subscriptions)
  carry large, deeply nested response schemas, so their pages can take a moment
  to render.
</Note>

## Build with AI tools

Prefer to let an AI agent do the work? Outseta ships a remote MCP server and an agent toolkit.

<CardGroup cols={2}>
  <Card title="MCP server" icon="sparkles" href="/mcp-server">
    Connect your agent to Outseta's remote MCP server to manage your account and analyze your business data directly.
  </Card>

  <Card title="Agent skills" icon="wrench" href="/agent-skills">
    Add the Outseta agent toolkit so your agent can wire Outseta into your app from a prompt.
  </Card>
</CardGroup>