Phone number for your app
in one prompt
volai is the Czech Twilio for vibe coders. Numbers, calls, SMS and a voice agent over one API and MCP, billed in Czech koruna, no contract. Sign up and you get 50 CZK in credit - no card needed.
Try it now
+420 266 266 641
The volai voice agent picks up. Ask it anything - like how much an SMS costs.
This call is a demo. We process the audio to produce a transcript and the call is recorded. Privacy policy The demo agent speaks Czech.
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
Preview of the volai portal
Works with the tools you already build in
Czech numbers
A number from any Czech region or the 910 range 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.
Calls and SMS number
A Prague landline number that people can call and text, and that your agent places calls and sends SMS from. 49.00 CZK (~EUR 2.04) per 30 days excluding VAT, SMS from the number 2.50 CZK (~EUR 0.10) per segment. We register the number with the operator, usually within 1 business day.
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, topped-up credit never expires.
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, voice 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.
AI receptionist
A ready-made prompt for your industry
Dental clinics, auto repair, ecommerce and more - pick an industry and see exactly how the agent talks and what it costs.
An AI receptionist for dental clinics that books patients while you're chairside
An AI receptionist for auto repair shops that answers while you're under the car
An AI receptionist for restaurants that takes reservations even during the rush
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, voice numbers are in stock. Buy one and it's active within seconds.
- Do you support inbound SMS?
- Yes, on two kinds of numbers. volai voice numbers (landline and VoIP) cannot receive SMS. The SMS number is a Czech mobile number for SMS only, with no calls (per 30 days, the price is on the pricing page). The calls and SMS number is a Prague landline number that people can call and text, and that your agent places calls and sends SMS from; after you order it we register it with the operator, usually within 1 business day (no later than 48 hours), and the fee is charged only after activation. On both, received SMS are included in the fee for the number. You read the messages in the portal, in the API (GET /v1/messages?direction=in), in MCP (list_messages with direction in) or through the message.received webhook, and we keep them for 90 days. You can also send SMS from the number, only to Czech numbers: from an SMS number with a delivery report, from a calls and SMS number without one. A number in another country (the offer includes landline numbers in other countries, you see it when you order) handles calls only, with no SMS, and calls out only to the country of the number and to Czechia. We do not guarantee verification codes from services (banks, Google and similar) - the numbers are meant for texting with people, and receiving has been verified on the O2 network. SMS sent without your own number still go out under the shared sender name SMSinfo, which recipients cannot reply to and which has no delivery reports.
- 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 topped-up 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.
- How much does an AI receptionist cost a small business per month?
- For a typical workload (30 calls a day, 2 minutes each) an AI receptionist runs 5,425 CZK a month excluding VAT - the number, call minutes and the agent surcharge combined. The AI receptionist page has a calculator for your own numbers.
- How does the agent sound in Czech?
- The agent speaks Czech (the default voice is Milena, a calm, natural female voice; you can pick another one, a male voice too, from the voice catalog) and you write its system prompt in Czech too. Besides Czech it also handles English, Slovak, German and Polish.
- What happens when the AI receptionist can't handle a call?
- Without a transfer set up, it ends the call politely and sends you a transcript and summary of what the caller wanted - in the portal or via webhook. With a transfer configured (the transferTo field), it hands the call straight to your phone.
- How fast can I get an AI receptionist running?
- Minutes, not days - buy a number, write a few sentences telling the agent how to behave, then either let it answer the new number right away or forward your existing one to it.
Blog
Latest from the blog
Guides, comparisons and notes on telephony.
AI Receptionist
Five Questions Before You Get an AI Receptionist
Price, a 5-minute setup, forwarding a number from O2/T-Mobile/Vodafone, Slovak numbers and VAT - five answers straight from volai's rate card and settings.
September 19, 2026 · 5 min read
AI Receptionist
How Much Does an AI Receptionist Cost
A line-by-line breakdown of AI receptionist pricing on volai: number, minutes, agent surcharge, three volume scenarios, and what Czech competitors charge.
September 2, 2026 · 6 min read
AI Receptionist
Never Miss a Call With an AI Receptionist
Why calls get lost even with a working phone line, what the call.missed webhook tells you, and how an AI receptionist keeps every call answered.
September 2, 2026 · 6 min read