Can Helix make phone calls?
No. Helix is for written communication — email, calendar, contacts. For voice calls, pair Helix with a voice platform like Vapi or a similar provider.
Compare
Helix vs Vapi
Vapi is for voice agents that pick up the phone — telephony, real-time transcription, latency-tuned LLM stacks. Helix is for agents that own an inbox and a calendar with human approval on every send. The surfaces are complementary, not competing.
Vapi is a developer platform for building voice AI agents that make and take phone calls. Vapi site
Feature-by-feature
| Feature | Helix | Vapi |
|---|---|---|
| Primary channel | Email, calendar, contacts | Phone (PSTN + WebRTC) |
| Latency profile | Async — drafts queued for approval | Real-time — sub-second turn-taking |
| Sender identity | Real mailbox or agent inbox | Phone number provisioned by Vapi |
| Human approval | First-class on every send | Live human-in-the-loop transfer |
| Driving model | Any MCP client | Vapi assistant config + tools |
| Free tier | Free, no credit card | Pay-as-you-go credits |
In plain prose
Vapi’s strength is the voice channel — provisioning numbers, streaming audio, sub-second response, and a battle-tested telephony stack.
Helix’s strength is async written communication. An agent has a real inbox, a real calendar, and a human-approval queue. An MCP client (Claude, Cursor, ChatGPT, n8n) drives the agent end-to-end.
A common pattern: a Vapi agent qualifies inbound calls and hands off to a Helix agent for follow-up email and meeting scheduling — async, with human approval before any send.
FAQ
Can Vapi call Helix?
Yes. Helix exposes an MCP endpoint and a JSON API. From a Vapi assistant, you can draft a follow-up, book a meeting, or queue an approval on a Helix identity.
Which is cheaper to start?
Helix is free with no credit card. Vapi runs on pay-as-you-go credits — cheap to test, scales with minutes used.
Next step
Try the workflow this comparison points at: Lead-qualifier after-hours template. Free, no credit card.
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