Why people look for a Vapi alternative
Vapi gives developers genuine control - you choose and wire every layer, often with your own provider keys. The people who search for an alternative usually loved that at first and then grew tired of being the integrator: provider accounts, latency tuning, and a bill that is only knowable after you have built it. Nixflex is the finished engine that removes that job.
THE 1,000-MINUTE BILL · LIVE
Nixflex — flat, all-in$80
Vapi`$? — depends on your build
Sources: Nixflex flat `$0.08/min. Vapi's real total is not computable from published pricing - the base is advertised, but model, voice and telephony meters depend on the providers you wire in.
What you get on Nixflex
One flat price with the whole stack inside: $0.08 per minute of voice covers speech recognition, the AI, the voice, real calendar booking, the two-way SMS agent, webhooks and post-call analysis. No monthly platform fee, no per-feature meters, no gated tiers. Your own Twilio or Telnyx numbers carry the calls at carrier rates with zero markup - and they stay in your account, so there is no lock-in by design.
Underneath sits an engine that enforces the things prompts can only request: a booking cannot be confirmed unless the calendar truly accepted it, outbound voicemail is recognised by the engine itself on any carrier, and a failing custom-API tool never crashes a live call. Data lives on EU infrastructure (Ireland) with automatic 90-day deletion - a straight answer for GDPR questionnaires.
Switching, honestly: four steps
1Sign up
Free, $10 credit, no card - about 125 minutes of testing.
2Import your numbers
Your Twilio or Telnyx numbers, one API call each - no porting, they never leave your carrier account.
3Recreate your agent
Paste your prompt, pick a voice, connect your calendar and webhooks - the concepts map one-to-one.
4Test side by side
Run real calls on both platforms with the same prompt. Keep whichever wins - your numbers repoint with one webhook change.
Frequently asked
Do I have to port my phone numbers?
No - this is the key difference from most migrations. Nixflex is bring-your-own-carrier: your numbers stay in your Twilio or Telnyx account, you import them with one API call, and switching direction later is a webhook change.
Will my prompts work?
Prompts are plain instructions and transfer directly. The concepts - agents, numbers, tools, webhooks - map one-to-one, so an afternoon is usually enough for a working replica of your current agent.
I liked choosing my own models on Vapi - do I lose that?
You stop choosing vendors - Nixflex chose and tunes the stack continuously. You keep every product control: prompts, voices, your own numbers, per-number config, custom functions calling your APIs mid-call, and webhooks everywhere.
Can I run both platforms during the switch?
Yes, and you should: point one number at Nixflex, keep the rest where they are, and compare real calls for a week. $10 of free credit covers the pilot without a card.
Try the alternative in your browser - right now
A live Nixflex agent is on the homepage. No signup, no meeting, no card.