# Handset

> A complete business phone system for vertical SaaS — compliant two-way SMS/MMS, voice with live transcription and AI summaries, real numbers, media streaming, and realtime events — through one REST API (https://api.handset.dev/v1, bearer auth, mode-scoped keys; test mode simulates the whole carrier for free).

## Docs
- [Documentation](https://docs.handset.dev/index.html): A complete business phone system for your platform, through one REST API.
- [Quickstart](https://docs.handset.dev/quickstart.html): Send your first compliant business text in ten minutes.
- [Your first five minutes](https://docs.handset.dev/five-minutes.html): Key in hand to message on screen, in five steps.
- [Test mode](https://docs.handset.dev/test-mode.html): A simulated carrier on every account: free numbers, instant compliance, magic numbers.
- [Webhooks](https://docs.handset.dev/webhooks.html): Signed events for everything that happens on the line.
- [Realtime events](https://docs.handset.dev/realtime.html): The webhook event catalog, pushed over a WebSocket the moment events commit.
- [AI & MCP](https://docs.handset.dev/ai.html): An MCP server, an agent skill, and machine-readable docs — Handset for AI agents.
- [TypeScript SDK](https://docs.handset.dev/sdk.html): The @handset/sdk guide: install, configure, send, paginate, handle errors.
- [Python SDK](https://docs.handset.dev/python.html): The handset package guide: install, send, errors, pagination, asyncio.
- [Errors](https://docs.handset.dev/errors.html): Every error code the API returns: what happened and what to do.
- [API reference](https://docs.handset.dev/api.html): every endpoint, parameter, and schema (OpenAPI)

## Optional
- [Handset UI](https://ui.handset.dev): open-source React components, shadcn-style
- [Live demo](https://demo.handset.dev): a working app on the real API, no signup
- [OpenAPI spec download](https://docs.handset.dev/api.html): use the download button for the raw spec