Should you build your own Vapi?
API-first platform for inbound and outbound phone and web voice agents
A focused inbound agent is a credible weekend build with LiveKit Agents or Pipecat. Replacing Vapi as a product is much larger: it combines realtime orchestration, provider abstraction, phone-number and SIP workflows, outbound campaigns, tool calls, testing, observability, scaling, support, and compliance options. Self-hosting can remove Vapi's $0.05 per-minute platform fee, but model, carrier, number, infrastructure, failed-call, monitoring, and engineering costs remain.
ENOriginal research content in English. Original prompt preserved in English.
Build me a focused, self-hosted alternative to Vapi for one inbound support number.
Requirements:
- Use Python 3.12 and livekit-agents~=1.5 with one named AgentServer worker.
Use direct provider plugins, not LiveKit Inference or another managed agent host.
- Run LiveKit Server, Redis, and LiveKit SIP with Docker Compose on one Ubuntu VM.
Put Caddy in front of HTTPS/WSS; expose only the documented SIP and UDP media ports.
- Provision one Telnyx DID and credential-authenticated SIP trunk. Include checked-in
LiveKit inbound-trunk and dispatch-rule JSON that sends calls to support-agent.
- Build an AgentSession with Silero VAD, Deepgram Nova-3 STT, gpt-5-mini through
the OpenAI plugin, and Cartesia Sonic-3 TTS. Load every secret from .env.
- Give the agent one narrow support prompt, interruption handling, and two tools:
look up an order in SQLite and save a callback request after caller confirmation.
- Persist call id, timestamps, transcript, tool results, and outcome to SQLite.
Add structured JSON logs and /healthz; recording is off by default.
- Include unit tests for both tools and scripted agent tests for lookup, refusal to
invent an order, callback confirmation, and a caller interruption.
- Provide make setup, make dev, make smoke, and docker compose up -d commands.
The smoke test must work in the LiveKit agent console before a real PSTN call.
- README: DNS, TLS, firewall, Telnyx, trunk, dispatch, provider-key, and test-call
steps, plus common one-way-audio and SIP authentication checks.
- The cost section must say the Vapi fee is removed, while the DID, SIP minutes,
model usage, VM, failed calls, monitoring, and operator time remain. Link the
source-backed calculator at https://voice.oss.codes for changing rates.
- Out of scope: outbound campaigns, a multi-tenant dashboard, squads, billing,
automatic provider failover, call recording, compliance claims, and high availability.The prompt opens pre-filled in your agent. Review it before running.
What would building your own look like?
Route a SIP trunk into a realtime agent, stream speech through STT, LLM, and TTS with interruption handling, run a server-side tool, and save the call outcome.
What you will need
- public Linux VM, domain, TLS, and correctly restricted SIP, WebRTC, and RTP ports
- SIP trunk and phone number from a carrier such as Telnyx
- STT, LLM, and TTS provider API keys
- country-specific consent, recording, caller-ID, and outbound-calling review before real traffic
They pay to move from a working voice demo to dependable production calling without operating SIP, RTP, WebRTC, agent workers, provider fallbacks, observability, and capacity themselves.
xmanaged realtime infrastructure, scaling, provider failover, and support
xassistant, squad, workflow, phone-number, and provider configuration APIs
xoutbound campaigns, carrier integrations, spam mitigation, and production telephony debugging
xhosted simulations, evaluations, call logs, recordings, analytics, and retention controls
xenterprise SLAs, compliance add-ons, role controls, and data-residency options
Prefer something ready-made?
DograhA Vapi-shaped workflow builder you can Docker-compose; phone and model meters remain.Open source↗License, setup, and limitations for each alternative.
How much does Vapi cost?
- Monthly billing
- $29/mo$29/mo
- Per year
- $348/yr$348/yr
- On a Brazilian card, with 3.5% IOF
- R$152/moR$1,819/yr
Saved to My list. You will see a notice on this site when the price changes.
You complete the purchase on Vapi’s site. Vibe Radar does not handle payments.
| Plan | Monthly | Annual (per month) | What is included |
|---|---|---|---|
| build | $0 | - | At least 60 promotional call minutes at signup and 10 concurrent calls; ongoing calls are fully usage based. |
| scale | custom | - | Custom annual usage commitment, concurrency, support and volume terms. |
Free tierno permanent free tier; signup includes a promotional allowance of at least 60 call minutes
Billing termsusage based with no base subscription for Build; Scale uses a custom annual commitment
Additional costsVoice calls add a $0.05/minute Vapi platform fee plus separate speech-to-text, model, text-to-speech and telephony charges; SMS/chat is $0.005/message; extra concurrency is $10/line/month; HIPAA is $2,000/month and zero-data-retention is $1,000/month.
verified 2026-08-14 · source ↗
Is it cheaper to build or buy Vapi?
Adjust the numbers: hours to build, your hourly rate, running costs and the subscription price.
Over 24 months, subscribing is cheaper.
Starting hours estimated from the analysis (weekend for one inbound agent; ongoing production operations). Does not price what you give up (support, integrations, security).
Can I rebuild Vapi?
Kinda. The core of Vapi is buildable in a weekend with the prompt on this page, but there are real gaps: managed realtime infrastructure, scaling, provider failover, and support, assistant, squad, workflow, phone-number, and provider configuration APIs. Read the honest list above before committing.
How much does Vapi cost?
Vapi costs about $29/mo (Core, checked 10/20/2026), which is $348 per year.
What do I lose by replacing Vapi?
Honestly: managed realtime infrastructure, scaling, provider failover, and support; assistant, squad, workflow, phone-number, and provider configuration APIs; outbound campaigns, carrier integrations, spam mitigation, and production telephony debugging; hosted simulations, evaluations, call logs, recordings, analytics, and retention controls; enterprise SLAs, compliance add-ons, role controls, and data-residency options. If any of those are load-bearing for you, keep paying.
Is there an open-source alternative to Vapi?
Yes: Dograh (A Vapi-shaped workflow builder you can Docker-compose; phone and model meters remain.) The prompt is for when you want it exactly your way.