No tech team
You do not have to choose models, voices and phone providers. We build the agent and show you test calls before launch.
Kallina vs Vapi and Retell
Kallina vs Vapi and Retell: AI voice agents built for you, versus platforms you build on yourself.
Kallina is an AI voice agent platform. Our team builds the agent: its role, knowledge, tools and handover to a person. Vapi and Retell AI are developer platforms billed per minute. Kallina's price comes in a fixed-scope offer.
In short
The same core technology. A different way of working.
All three do the same basic thing: an agent that talks on the phone or in the browser, understands what the person says, answers by voice and can be interrupted.
The difference is who builds. Vapi and Retell give you the parts: API, models, voices, telephony. Your team puts them together. With Kallina, we put them together and hand you a working agent.
Comparison
Kallina, Vapi and Retell, point by point.
| What you compare | Kallina | Vapi | Retell AI |
|---|---|---|---|
| Who it is for | Businesses that want the agent done for them. | Developers and technical teams. | Developers and technical teams; it also has certified partners who build for you. |
| Price | No public price. The price comes in a fixed-scope offer. | $0.05/min Vapi hosting, plus models, voice and telephony at provider cost. Optional packages: Core $29/mo; Pro 10% of the hosting fee, $999/mo minimum. | $0.07–$0.31/min for voice agents, pay as you go; Enterprise on request. |
| Who builds it | Our team writes the role, the knowledge base, the tools and the handover rules. | You, through the dashboard and API. | You, through the dashboard and API, with ready-made templates. |
| Tools during the call | Yes: the agent calls server functions while it talks. | Yes. | Yes. |
| Transfer to a person | Yes, through the phone system: blind or warm transfer. | Yes. | Yes. |
| After the call | Recording, transcript, analysis and summary. | Monitoring; raw data is kept 14–180 days, depending on package. | Post-call analysis and transcripts. |
| HIPAA | We do not offer a HIPAA BAA today. | HIPAA add-on with BAA: $2,000/mo. | HIPAA and BAA appear in their plan table. |
Other companies' prices are copied from their official pages, checked on 2026-09-25. They can change, so check their page before you decide.
Where it is stronger
Where Vapi and Retell are stronger.
- Public per-minute prices. You can work out the cost before talking to anyone.
- Developer APIs. You control every part: the model, the voice, the telephony.
- High volume: concurrent calls included and room to grow. For example, Retell includes 20 concurrent calls on pay as you go.
- You can start alone, today: Vapi gives $5 in starter credits, and Retell $10.
If you have developers and want to build your own voice product, Vapi or Retell are good choices. Kallina is not a developer API.
Where Kallina fits
Where Kallina fits better.
The agent can be interrupted
The caller can talk over the agent, and the agent stops and listens. We tune this for each agent.
It does things during the call
The agent can check availability, write a booking or send an SMS, through server tools.
It hands over in time
The agent has written limits. Anything beyond its role goes to a colleague, by transfer.
Romanian and Russian
Kallina is strong in Romanian and Russian, as well as English.
Said plainly
Outbound calls in the US: consent is required.
In February 2024, the FCC ruled (FCC 24-17) that AI-generated voices are “artificial” voices under the TCPA. A call made with such a voice needs the prior express consent of the person called, unless it is an emergency or another exemption applies.
That is why Kallina is for inbound calls and for calls to people who agreed to be called. We do not do AI cold calling.
Some states require everyone on the call to agree to recording. The agent can announce the recording at the start of every call.
This is not legal advice. Check the rules for your campaign with a lawyer.
Said plainly
Who should not choose Kallina.
- Developer teams that want to build their voice product on an API.
- Anyone who wants to pay strictly per minute, without an offer.
- US clinics that need a signed HIPAA BAA.
- Anyone who wants cold-calling campaigns.
Price
What Kallina costs
Kallina has no public price. The price depends on call volume, minutes and phone numbers. You get it in a fixed-scope offer after a short call.
Questions
Frequently asked questions
What is the difference between Kallina, Vapi and Retell?
Vapi and Retell are developer platforms billed per minute. Kallina is a voice agent platform where our team builds the agent for you.
How much does Kallina cost?
It has no public price. You get the price in a fixed-scope offer, based on call volume, minutes and phone numbers.
How much do Vapi and Retell cost?
On 2026-09-25, Vapi charged $0.05 per minute for hosting, plus models, voice and telephony at provider cost. Retell charged $0.07–$0.31 per minute for voice agents, pay as you go.
Can Kallina call customers?
Yes. The platform has batch calling, with contact import and retries. In the US, a call with an AI voice needs the prior express consent of the person called (FCC 24-17), so Kallina only calls people who agreed.
Can the agent transfer the call to a person?
Yes. The phone system makes the transfer, blind or warm, to an extension or an outside number.
Which languages does Kallina speak?
Romanian, Russian and English. We check other languages per project, because not every voice covers them equally well.
Sources
Where the figures and rules come from.
Want a voice agent built for your calls?
Tell us which calls you get and what the agent must do. You get a fixed-scope offer.