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REPLACEMENT BRIEF

dev tools

Can AI replace Vapi?

EDITORIAL ANSWERKINDACurated prompt

Wiring an LLM to a phone call is a buildable voice agent at demo level — Twilio plus a model. The product's moat is the realtime infrastructure: managed low-latency pipelines, provider failover, scaling, and the orchestration layer — the call that does not lag, not the dial.

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.

Build the personal version →

AT A GLANCE

price
varies
replaceable scope
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.
build time
weekend for one inbound agent; ongoing production operations
Build promptreviewed prompt · not run

the prompt

Curated prompt
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.
Copy or open in an agent

The prompt stays readable first. Choose a launch option when you are ready.

$ open in your agent (prompt prefilled, you press enter) or copy it raw

what AI can 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.

The prompt was editor-reviewed; no completed build is recorded.

The honest tradeoff

why people still pay

Developers pay for the realtime pipeline — sub-second latency, provider failover, and scale — because a voice agent that pauses three seconds between turns is a demo, not a product.

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

Start with existing software

prior art · use these instead of building, if you'd rather

LiveKit Agents + SIPApache-2.0 realtime agent framework. Pair it with the separately deployed LiveKit Server and SIP service for a self-hosted phone stack.↗PipecatBSD-2-Clause Python framework with composable voice pipelines and broad model, transport, and telephony integrations. You still own deployment and carrier operations.↗Voice OSS cost plannerSource-linked calculator and deployment reference for platform, model, SIP, number, infrastructure, and operational costs. It is a planning companion, not an agent runtime.↗

EVIDENCE LEDGER

What this page can prove

The verdict judges replaceability. The evidence level records what DeepFeather actually checked.

Read the methodology →
evidence level
Curated prompt

The prompt was editor-reviewed; no completed build is recorded.

replacement boundaryRoute 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.

known limits · managed realtime infrastructure, scaling, provider failover, and support; assistant, squad, workflow, phone-number, and provider configuration APIs

editorial reviewawaiting manual review

BUILD FEEDBACK

Did you try this build?

Report the outcome. Submissions enter a manual evidence queue and never auto-upgrade the verdict.

ElevenLabs
$22/mo · ai audioNOT REALLYReplit
$25/mo · dev toolsKINDAGitHub Copilot
$10/mo · dev toolsKINDA

questions

Can AI replace Vapi?

Possibly for a narrower core workflow, but this catalog judgment is not a verified build. Expected gaps include: managed realtime infrastructure, scaling, provider failover, and support, assistant, squad, workflow, phone-number, and provider configuration APIs. Validate the prompt against your own acceptance criteria before committing.

How much does Vapi cost?

Vapi's pricing is usage-based or varies by plan. Use the linked pricing source for the current amount; the catalog last checked it on 2026-07-31.

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 — LiveKit Agents + SIP (Apache-2.0 realtime agent framework. Pair it with the separately deployed LiveKit Server and SIP service for a self-hosted phone stack.), Pipecat (BSD-2-Clause Python framework with composable voice pipelines and broad model, transport, and telephony integrations. You still own deployment and carrier operations.), Voice OSS cost planner (Source-linked calculator and deployment reference for platform, model, SIP, number, infrastructure, and operational costs. It is a planning companion, not an agent runtime.). Using prior art is also a valid exit; the prompt is for when you want it exactly your way.