[verdict][curated prompt][source: vapi.ai]
Can I vibecode Vapi?
// buildable in a weekend, but real gaps stay open
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.
confidence: high
what it is: API-first platform for inbound and outbound phone and web voice agents
Buildability index · an editorial game
- Price usage-based weight: zero
- Time weekend for one inbound agent; ongoing production operations weight: plus 2
- Category developer tools no weight
- Moat infrastructure scale · integrations weight: minus 3
- Confidence high weight: plus 1
- What you lose 5 items weight: minus 2
- Site vapi.ai (si apre in una nuova scheda) no weight
The moat outweighs the price: rebuilding this is a project, not an evening.
Gioco editoriale: il verdetto dice se un agente può, l’indice se conviene.
What you build
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 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
The orchestration fee is replaceable; dependable managed telephony operations are the harder product.
The prompt
A weekend with a coding agent. The gaps that stay are right below, under “what you lose”.
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.Curated prompt: written and reviewed by hand for this app. In English on purpose — it is the language coding agents work best in.
What you lose
- 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
Why people still pay
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.
moat: Infrastructure scale Integrations what a moat is
managed realtime and telephony operations plus control plane
Free alternatives
Not in the mood to build it? These already exist, they are free or open source, and we checked them one by one.
Rejected (1) — and why
- Pipecat (si apre in una nuova scheda) — A well-maintained framework for building voice agents, not an install-and-use voice-agent product.
Who has already built it
Starting from here is still vibecoding: the prompt is for when you want it exactly your way.
- LiveKit Agents + SIP (opens in a new tab) — Apache-2.0 realtime agent framework. Pair it with the separately deployed LiveKit Server and SIP service for a self-hosted phone stack. (alive)
- Pipecat (opens in a new tab) — BSD-2-Clause Python framework with composable voice pipelines and broad model, transport, and telephony integrations. You still own deployment and carrier operations. (alive)
- Voice OSS cost planner (opens in a new tab) — Source-linked calculator and deployment reference for platform, model, SIP, number, infrastructure, and operational costs. It is a planning companion, not an agent runtime. (alive)
Do you agree?
The vote balance
Ancora nessun voto: il tuo è il primo.
Nessun voto ancora — il primo pesa.
