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

# API Overview

> External API surface and capability-first model.

## Capability-first architecture

Receiptor capabilities are defined once in backend and exposed through:

* External REST API (`/v1/capabilities/*`)
* MCP tools
* CLI commands

This keeps validation and behavior aligned across interfaces.

## Core external endpoints

* `GET /v1/capabilities` (public discovery)
* `POST /v1/capabilities/:slug` (execute)
* `GET /v1/workspaces` (workspace listing for API key context)

## API reference generation

The **API Reference** tab is generated from live OpenAPI:

* `https://developer.api.receiptor.ai/openapi.json`

Capability paths in OpenAPI are generated from the backend capability registry.

Continue with:

* [API Key Auth](/api/authentication/api-keys)
* [Workspace Context](/api/workspaces/context)
* [Capabilities Overview](/api/capabilities/overview)
* [MCP Introduction](/api/mcp/introduction)
* [CLI Overview](/api/cli/introduction)