Vapi vs Retell AI (2026): Pricing, Free Tier and MCP
I compare Vapi and Retell AI for AI phone agents: per-minute pricing, free credits, concurrency, MCP servers and which one fits a solo founder.
By agentools
Short answer
Pick Retell AI if you want one all-in price of $0.07 to $0.31 per minute, $10 in free credits and 20 free concurrent calls. Pick Vapi if you want to choose your own model, voice and transcriber at cost plus a $0.05 per minute hosting fee. Both platforms are closed source and both ship an official MCP server.
- Retell AI: An all-in per-minute price and generous free concurrency
- Vapi: Developers who want to pick every provider
Vapi and Retell AI are the two platforms I see most often when a solo founder wants an AI agent that answers or makes phone calls. Both give you a phone number, a voice agent, call logs and an API. The real difference is how you pay and how much of the stack you want to pick yourself.
Vapi bills a hosting fee per minute and passes your transcriber, model and voice costs through at cost, so you assemble the stack. Retell AI quotes one per-minute price that already bundles its voice infrastructure, a voice, a model and telephony, with no platform fee. Every number below comes from the vendors' own pricing pages and docs, checked on October 30, 2026.
At a glance
| Tool | Pricing | Free tier | MCP support | Open source |
|---|---|---|---|---|
 Retell AI | $0.07 to $0.31/min all in, no platform fee. Numbers $2/mo | $10 free credits, 20 concurrent calls and 10 knowledge bases included | Yes. Hosted server at mcp.retellai.com plus @retell-ai/mcp-server | No. The MCP package is Apache-2.0 |
 Vapi | $0.05/min hosting plus provider costs at cost. Core $29/mo, Pro from $999/mo | $5 free credits, 4 concurrent calls, 1 Vapi number | Yes. Remote server at mcp.vapi.ai/mcp or npx -y @vapi-ai/mcp-server | No. The MCP server repo is MIT |
The 2 picks
1. Retell AI
AI phone agents for inbound and outbound calls
Retell AI sells pay-as-you-go voice agents with no platform fee and no monthly minimum. A minute costs $0.07 to $0.31 depending on the parts you pick: Retell voice infrastructure is $0.055 per minute, voices start at $0.015 per minute, the model is billed per minute (GPT 5.4 mini is $0.024), and Twilio or Telnyx telephony is $0.015 per minute. Custom SIP telephony has no Retell charge. Billing is per second.
The free allowance is the strongest part for a small team. You start with $10 in free credits, the first 20 concurrent calls are included, and the first 10 knowledge bases are free. After that, extra concurrency is $8 per call line per month and a Retell phone number is $2 per month. Enterprise pricing is custom. Retell states HIPAA and GDPR compliance and SOC 2 Type I and Type II.
Retell runs a hosted MCP server at https://mcp.retellai.com that takes your API key as a Bearer token, and a local npm package, @retell-ai/mcp-server, licensed Apache-2.0. In Claude Code:
claude mcp add --transport http retell https://mcp.retellai.com --header "Authorization: Bearer YOUR_RETELL_API_KEY"
Retell agents can also call external MCP tools during a live call.
Caveat: the platform itself is closed source, and the per-minute price moves with the model and voice you choose, so check the calculator on the pricing page before you quote a client.
Pricing: Pay as you goAPI platform
2. Vapi
Developer platform for phone voice agents
Vapi is a developer platform for phone voice agents. Usage is a $0.05 per minute Vapi hosting fee, prepaid, plus the transcriber, model and voice you choose, passed through at cost. You start with $5 in free credits, one included Vapi phone number and 4 concurrent calls.
Optional success packages add capacity and support. Core is $29 per month with 10 concurrent calls, 5 included numbers, 30 days of raw data retention, zero data retention and email support. Pro is 10% of your Vapi hosting fee with a $999 per month minimum and 30 concurrent calls. Premier is custom. Extra concurrency is $10 per line per month on any package, and HIPAA eligible data handling is a $2,000 per month add-on per organization.
Vapi runs an official remote MCP server at https://mcp.vapi.ai/mcp, with your API key as a Bearer token. It can list and create assistants, list phone numbers and create or schedule calls. In Claude Code:
claude mcp add --transport http vapi https://mcp.vapi.ai/mcp --header "Authorization: Bearer YOUR_VAPI_API_KEY"
To run it locally instead, use npx -y @vapi-ai/mcp-server. The server's GitHub repo is MIT licensed. Vapi assistants can also use external MCP servers as tools during calls.
Caveat: the platform is closed source, and because model and voice costs are separate, your real per-minute cost is the hosting fee plus whatever your providers charge.
Pricing: Pay as you goAPI platform
More to consider
Which one should you choose?
I would start with Retell AI if the goal is to ship a receptionist, booking line or lead qualification agent quickly and keep the bill easy to predict. One per-minute number, $10 of credits and 20 free concurrent calls cover most first deployments.
I would pick Vapi if I already know which transcriber, model and voice I want, or I want to swap them freely, and I am fine paying each provider separately on top of the $0.05 hosting fee. The Core package at $29 per month is the step up once you need more concurrency, more numbers or zero data retention.
For regulated calls, compare the add-ons: Retell lists HIPAA compliance on its pricing page, while Vapi sells HIPAA eligible data handling as a $2,000 per month add-on.
How I checked these numbers
I read the Vapi pricing page, the Retell AI pricing page and both MCP docs on October 30, 2026. Voice platform prices change often, so treat the per-minute ranges as a starting point and confirm on vapi.ai/pricing and retellai.com/pricing before you commit.
Questions
Is Vapi or Retell AI cheaper?
It depends on your stack. Retell AI quotes $0.07 to $0.31 per minute all in. Vapi charges $0.05 per minute for hosting plus your transcriber, model and voice at cost, so a cheap stack on Vapi can cost less and a premium stack can cost more.
Do Vapi and Retell AI have a free tier?
Both let you start for $0. Vapi gives $5 in free credits with 4 concurrent calls and one Vapi number. Retell AI gives $10 in free credits, 20 free concurrent calls and 10 free knowledge bases.
Do Vapi and Retell AI support MCP?
Yes. Vapi has an official MCP server at mcp.vapi.ai/mcp and Retell AI has a hosted one at mcp.retellai.com. Both authenticate with your API key, and agents on both platforms can call external MCP tools during calls.
Are Vapi or Retell AI open source?
No. Both platforms are closed source. Their MCP servers are open on GitHub and npm: Vapi's MCP server is MIT and Retell's @retell-ai/mcp-server package is Apache-2.0.
Which is better for HIPAA?
Retell AI lists HIPAA and GDPR compliance plus SOC 2 Type I and Type II on its pricing page. Vapi offers HIPAA eligible data handling as a $2,000 per month add-on per organization. Ask either vendor for a BAA before you handle patient data.