# volai

> Czech telephony for vibe coders. Phone numbers, calls, SMS and an AI voice
> agent through one REST API and one MCP server - billed per second in CZK,
> no contract.

## Docs

- [Quickstart](https://volai.cz/en/docs): first call and first SMS in five minutes, trial call without your own number, MCP server installation.
- [REST API](https://volai.cz/en/docs/api): complete v1 reference - authentication, errors, idempotency, rate limits, pagination, all 37 endpoints with curl examples including agent tools and call recordings.
- [MCP server](https://volai.cz/en/docs/mcp): installation into Claude Code, Cursor, Windsurf, VS Code and Claude Desktop, all 31 tools and their annotations.
- [Webhooks](https://volai.cz/en/docs/webhooks): call.completed, call.failed, call.no_answer, call.missed and message.sent events, Volai-Signature verification, the data field in the call.completed body, retries on failure.
- [Voice agent](https://volai.cz/en/docs/agent): how to write a systemPrompt, languages, voices, connecting to a number, agent tools, transfer to a human, recordings and data collected during a call.
- [Bring your own agent](https://volai.cz/en/docs/bring-your-own-agent): connecting an external platform (ElevenLabs, Asterisk) through relay - without the agent surcharge.
- [SIP](https://volai.cz/en/docs/sip): connecting your own SIP PBX or softphone to a phone number.
- [Pricing](https://volai.cz/en/pricing): current rates for calls, SMS, numbers and the voice agent.
- [Twilio comparison](https://volai.cz/en/twilio-alternative): volai vs Twilio for Czech numbers, calls and SMS - prices, what differs and when Twilio is the better fit.
- [SKILL.md for AI agents](https://volai.cz/SKILL.md): API and MCP summary in a single file to paste into a prompt.
- [Full reference in one file](https://volai.cz/llms-full.txt): everything above flattened into a single llms-full.txt for language models.

## Czech version

The same site in Czech, for readers who prefer it. Every page above has a
Czech counterpart at a Czech address - the docs live at
https://volai.cz/docs, pricing at https://volai.cz/cenik.

## Notes

- Numbers are Czech (+420) and require an emergency-services address in the
  Czech Republic, which is a regulatory requirement, not our rule. Numbers
  from Prague, Brno and the nomadic 910 range are in stock and are bought in
  one step; other regions are ordered with your own address.
- Everything is billed in CZK. Euro amounts shown on the site are
  approximate; your card is always charged in Czech koruna.
- The REST API and the MCP server always answer in English, regardless of
  the account language. The web and the portal follow the language you pick.