Phone number for your app
in one prompt
volai is the Czech Twilio for vibe coders. Buy a number, make a call, send an SMS, or run a voice agent - one API and MCP, billed in Czech koruna, no contract.
Add calls and SMS to my app via volai: https://volai.cz/SKILL.md
MCP: https://volai.cz/mcp · llms.txt: https://volai.cz/llms.txt
Try it now
+420 266 266 641
The volai voice agent picks up. Ask it anything - like how much an SMS costs.
Call the agentPreview of the volai portal
Works with the tools you already build in
Czech numbers
A Prague or mobile number for 25.00 CZK (~EUR 1.04) a month, no contract, no activation fee. Buy it in the portal or with a single API call and it's ringing within a minute.
Calls and SMS
Outbound calls cost 0.92 CZK (~EUR 0.04) and inbound 0.50 CZK (~EUR 0.02) per minute, SMS 1.36 CZK (~EUR 0.06). Billed by the second, never rounded up to the minute.
Voice agent
A Czech-speaking agent that answers calls and can place them too. Every call's transcript lands in a webhook. 2.50 CZK (~EUR 0.10) per minute on top of the call rate.
Product
Call
curl -X POST https://volai.cz/v1/calls \
-H "Authorization: Bearer vk_YOUR_KEY" \
-H "Content-Type: application/json" \
-d '{"to": "+420777123456", "from": "+420601234567"}'{
"id": "call_9d4e2b7f",
"status": "initiated"
}Pricing
Inbound calls cost 0.50 CZK (~EUR 0.02) a minute. Twilio charges 6.54 CZK for the same.
- Outbound call
- 0.92 CZK/min (~EUR 0.04)
- Inbound call
- 0.50 CZK/min (~EUR 0.02)
Twilio charges 6.54 CZK/min for an inbound call on a toll-free line.
Prices exclude VAT, credit never expires. No bundles, no custom plans.
API and MCP
Connect
REST API
A vk_… key and curl. No SDK required - responses are JSON with the price in CZK cents (1/100 CZK).
MCP server
Webhooks with HMAC
Bring your own agent over SIP
Phone platform
- Numbers
- Calls and SMS
- Voice agent
- REST API
- MCP server
- Webhooks
Billing by the second
We never round up to the minute. A 42-second call costs 42 seconds.
Free sandbox
Verify your email and get 50.00 CZK (~EUR 2.08) in credit plus a test number that an agent will answer.
Data in the EU
Servers in Frankfurt, numbers from the Czech network, invoices that satisfy Czech accounting rules.
Voice agent
Talk
Answers you can trust
The agent only knows what you give it: context from your app, opening hours, your calendar. It sends a transcript and summary of every call over a webhook.
Frequently asked questions
Didn't find an answer? Email podpora@volai.cz - we reply fast.
- What do I need?
- Just an email. Signup takes a minute, no card required - your first credit is free.
- Does it work right away?
- Yes, numbers are in stock. Buy one and it's active within seconds.
- Do you support inbound SMS?
- Not yet. Our carrier can only deliver those to a SIM card, not to the API - we're working on it and will announce it once it ships.
- How does billing work?
- With prepaid credit you top up by card. No end-of-month invoices - you only spend what you've topped up.
- Can I cancel?
- Anytime, no commitment and no notice period. We'll refund any remaining credit on request.
- Do you record calls?
- Yes, for the voice agent - you can play the recording in the portal next to the call, and we keep it for 90 days before deleting it. Each agent has a single toggle to turn recording off. Informing the caller that the call is recorded is your responsibility, ideally in the agent's first sentence.
- Is this for businesses?
- Yes. Every credit top-up gets a tax invoice - find it in the portal under Credit and download it as a PDF. Add your company name, business ID (ICO) and VAT ID (DIC) in settings.