Hosted voice platforms charge a fee for every minute of every call, on top of what you already pay for speech-to-text, the model, the voice and the phone line. OpenRing does the same job on your own computer or server, with your own provider keys, and speaks the same JSON as Vapi.

• 💸 No platform fee, ever. You pay Deepgram, OpenAI, Twilio or whoever you pick, directly, at their price.
• 🔁 Vapi-compatible. Same assistant JSON, provider names, tool calls and webhooks: a Vapi client moves over by changing its base URL, and Import copies an account in one click.
• 🖥️ Yours. Keys, calls and transcripts stay on your machine. No telemetry.
• 🆓 Free to try. A free local voice (Kokoro) is built in, so your first test call costs nothing.

⚡ Quick start

You need Node.js 18 or later. Everything else, Python included, installs itself:

npx openring

The dashboard opens at http://localhost:8000. From there:

1. Choose a password. The first visit asks for one (only from this computer).
2. Connect providers on the Providers page: Deepgram for speech (new accounts get US$200 of credit) and a model, for example Groq's free tier or one-click sign-in with OpenRouter. Each key is checked with the provider before it's saved.
3. Create an assistant on Assistants: a greeting, instructions, a model and a voice.
4. Talk to it. Press Test and speak into your microphone. No phone number needed.
5. Give it a number when you're ready: see Phone calls.

Settings live in ~/.openring/.env, created on the first run with a generated API key for apps that call the API (it's under Settings). The free Kokoro voice downloads itself on the first start (about 120 MB).

🧭 How it works

flowchart LR
  caller["Caller<br/>phone or browser"] <-->|audio| line["Twilio or WebRTC"]
  line <--> openring
  subgraph openring["OpenRing, on your server"]
    direction LR
    stt["Speech-to-text<br/>Deepgram, Whisper, ..."] --> llm["Model<br/>OpenAI, Groq, Ollama, ..."] --> tts["Voice<br/>ElevenLabs, Kokoro, ..."]
  end
  llm <-->|"tools and webhooks, in Vapi's format"| app["Your app"]

Each call runs a Pipecat pipeline: the caller's speech becomes text, the model answers (and can call your tools), and the voice speaks the answer back. Every turn's latency is recorded, step by step, and shown in the dashboard.

📊 How it compares

	OpenRing	Vapi	Retell	Dograh
Source code	✅ Open (MIT)	❌ Closed	❌ Closed	✅ Open core (BSD-2)
Platform fee	✅ None	US$0.05/min	Per-minute pricing	None self-hosted, US$0.01/min in its cloud
Vapi-compatible API	✅	(it's Vapi)	❌	❌
Run it yourself	✅ npx openring, no Docker needed (Docker works too)	Sign up for their cloud	Sign up for their cloud	✅ With Docker

On every platform you also pay for speech-to-text, the model, the voice and the phone line. Prices are from each company's public pricing page in October 2026; check them before you decide. OpenRing isn't affiliated with any of them.

✨ What works today

Works today	Next
Browser test calls from the dashboard (WebRTC)	Routing speech-to-text and voices by cost
Model routes: Fastest, Cheapest, Reliable or Custom; the next model takes over when one fails or is slow (beta)
A 100% local, free stack: Whisper, Ollama and Kokoro, one click in the editor
Provider fallback in Vapi's format, across providers (beta)
Callers in any language: the assistant answers in theirs ("language": "multi")
Phone calls in and out through Twilio (beta: tell us how it goes)	Outbound calls through Telnyx and Genesys; Plivo
Campaigns: one assistant calls a list or CSV, a few at a time, greeting each person by name (beta)
Incoming calls through Telnyx (beta, see Telnyx)
Genesys Cloud calls through its Audio Connector, inside your Architect flows (beta, see Genesys)
Vapi-style /assistant, /phone-number, /call, /campaign and /tool APIs
Cost per call in dollars, per provider, at list prices (cost and costBreakdown)	The phone line's cost
Vapi tools: function, endCall, transferCall
Vapi webhooks: status-update, conversation-update, end-of-call-report, assistant-request	Calls over WhatsApp
Import assistants, tools and numbers from a Vapi account
16 models, 6 speech-to-text and 9 voice providers, with Vapi's names
Per-turn latency, time to first word, tokens and voice characters per call, with traffic lights
Credit left on OpenRouter, Deepgram, ElevenLabs, Twilio and Telnyx, on the Providers page
Call history with transcripts, light and dark themes

The full plan is in the roadmap.

🔁 Moving from Vapi

Copy every assistant, tool and Twilio number of an account in one request, or press Import on the Assistants page. The key is used once and never stored; importing again updates what came in before.

curl -X POST http://localhost:8000/import \
  -H "Authorization: Bearer $OPENRING_API_KEY" -H "Content-Type: application/json" \
  -d '{"baseUrl": "https://api.vapi.ai", "apiKey": "YOUR_VAPI_PRIVATE_KEY"}'

The answer lists each assistant with anything that keeps it from taking calls here yet (for example a provider OpenRing doesn't support yet). Documents keep their full JSON, so nothing is lost. Then point your client's base URL at your server, and each imported Twilio number's voice webhook at $PUBLIC_URL/twilio/voice.

📖 API guide

Every request takes Authorization: Bearer $OPENRING_API_KEY.

Assistants

Same shape as Vapi:

curl -X POST http://localhost:8000/assistant \
  -H "Authorization: Bearer $OPENRING_API_KEY" -H "Content-Type: application/json" \
  -d '{
    "name": "Front desk",
    "firstMessage": "Hi! How can I help you today?",
    "model": {"provider": "openai", "model": "gpt-4.1-mini",
              "messages": [{"role": "system", "content": "You are a friendly receptionist."}]},
    "voice": {"provider": "11labs", "voiceId": "YOUR_VOICE_ID"},
    "transcriber": {"provider": "deepgram", "model": "nova-3", "language": "en"}
  }'

Phone calls

Twilio has to reach your server, so it needs a public https URL. On your own computer, start a tunnel (cloudflared tunnel --url http://localhost:8000), put its URL in PUBLIC_URL in ~/.openring/.env and restart. Then attach your Twilio number and point its Voice webhook (HTTP POST) at $PUBLIC_URL/twilio/voice:

curl -X POST http://localhost:8000/phone-number \
  -H "Authorization: Bearer $OPENRING_API_KEY" -H "Content-Type: application/json" \
  -d '{"number": "+15551234567", "assistantId": "ASSISTANT_ID"}'

Call the number. Transcripts are at GET /call and on the Calls page.

To have the assistant call someone, send the same body as Vapi's POST /call (or use Call a phone in the dashboard). Only call people who expect it: automated calls are regulated (the TCPA in the US, Anatel's rules in Brazil). A Twilio trial account can only call numbers verified in its console.

curl -X POST http://localhost:8000/call \
  -H "Authorization: Bearer $OPENRING_API_KEY" -H "Content-Type: application/json" \
  -d '{"phoneNumberId": "PHONE_NUMBER_ID", "customer": {"number": "+5511912345678"}}'

Campaigns (beta)

A campaign has one assistant call a list of people, a few at a time, with the body of Vapi's POST /campaign. Each person gets an ordinary outbound call that carries the campaignId, so transcripts and webhooks work as for any call. In the dashboard, Campaigns > New campaign takes a pasted list or a CSV; the CSV's other columns become variables.

curl -X POST http://localhost:8000/campaign \
  -H "Authorization: Bearer $OPENRING_API_KEY" -H "Content-Type: application/json" \
  -d '{"name": "Appointment reminders", "phoneNumberId": "PHONE_NUMBER_ID", "assistantId": "ASSISTANT_ID",
       "maxConcurrency": 3,
       "schedulePlan": {"earliestAt": "2026-11-03T12:00:00Z", "latestAt": "2026-11-03T20:00:00Z"},
       "customers": [{"number": "+5511912345678", "name": "Maria",
                      "assistantOverrides": {"variableValues": {"time": "3 pm"}}}]}'

The assistant's first message and instructions can use {{customer.name}}, {{customer.number}} and any key of variableValues: "firstMessage": "Hi {{customer.name}}, I'm calling to confirm your {{time}} visit.". POST /call takes assistantOverrides too. Calling starts at earliestAt (or right away), and no new call starts after latestAt. GET /campaign/{id} has Vapi's counters (callsCounterScheduled, callsCounterEnded, ...) and each call; PATCH with {"status": "cancelled"} stops it. A restarted server picks its campaigns back up without calling anyone twice. Workflows, squads and campaign webhooks are not supported yet.

Only call people who agreed to get the call, at hours the law allows: automated calls are regulated (the TCPA in the US, Anatel's rules in Brazil). The dashboard asks you to confirm that for every campaign.

Tools

Tools use Vapi's format, so a server written for Vapi works unchanged. Put them in model.tools, or save them once with POST /tool and list their ids in model.toolIds:

"model": {
  "provider": "groq", "model": "openai/gpt-oss-20b",
  "tools": [
    {"type": "function",
     "function": {"name": "book_appointment", "description": "Book a cleaning",
                  "parameters": {"type": "object", "properties": {"day": {"type": "string"}}, "required": ["day"]}},
     "server": {"url": "https://your-app.com/tools"},
     "messages": [{"type": "request-start", "content": "One moment, let me check."}]},
    {"type": "endCall"},
    {"type": "transferCall", "destinations": [{"type": "number", "number": "+15551230000",
      "description": "front desk", "message": "Transferring you now."}]}
  ]
}

When the model calls book_appointment, OpenRing POSTs {"message": {"type": "tool-calls", "toolCallList": [...], "call": {...}}} to the tool's server.url (or the assistant's) and reads back {"results": [{"toolCallId": "...", "result": "..."}]}. server.headers, server.secret (sent as X-Vapi-Secret), server.timeoutSeconds, async and the request-start / request-failed messages work as on Vapi. endCall hangs up after the goodbye; transferCall moves a phone call to the chosen number (Twilio) once the assistant stops talking. Tool calls and results show up in the call's transcript.

Server messages

Your assistant's server.url gets Vapi's messages in Vapi's shape ({"message": {"type": ..., "call": {...}}}), with server.headers and server.secret (as X-Vapi-Secret):

• status-update when the call starts (in-progress), is transferred (forwarding) and ends (ended, with endedReason);
• conversation-update after each answer, with the transcript so far;
• end-of-call-report with the transcript and per-turn latency.

Pick which ones with serverMessages, as on Vapi. A phone number without an assistant but with its own server.url asks it on each incoming call (assistant-request) and uses the assistantId or the transient assistant it answers. POST /call also takes a transient assistant instead of an assistantId.

Provider fallback (beta)

Same fields as Vapi. When a provider fails during a call in a way a retry won't fix (a rejected key, no credit left, the provider down), the next one in the list takes over for the rest of the call. Unlike Vapi, a fallback model can come from another provider:

"transcriber": {"provider": "deepgram", "fallbackPlan": {"transcribers": [{"provider": "assembly-ai"}]}},
"model": {"provider": "groq", "model": "openai/gpt-oss-20b",
          "fallbackModels": ["openai/gpt-oss-120b", {"provider": "openai", "model": "gpt-4.1-mini"}]},
"voice": {"provider": "cartesia", "voiceId": "YOUR_VOICE_ID",
          "fallbackPlan": {"voices": [{"provider": "kokoro", "voiceId": "af_heart"}]}}

When the model switches, the new one answers the caller's last message, so the turn isn't lost. A fallback whose key is missing is skipped, and each switch is listed in the call's providerFallbacks and on its page.

Model routes (beta)

A model route is a saved list of models, in order, that several assistants can share, like OmniRoute's combos. Make one on the Model routes page (or POST /model-route) and pick it in the assistant editor ("model": {"routeId": "ROUTE_ID", ...}; the assistant keeps its own instructions and tools):

{"name": "Fast, then cheap", "preset": "fastest",
 "models": [{"provider": "groq", "model": "openai/gpt-oss-20b"},
            {"provider": "openrouter", "model": "openai/gpt-4.1-mini"},
            {"provider": "ollama", "model": "llama3.2"}]}

A call starts on the first model in the route's order. The next one takes over when a model fails (a rejected key, no credit left, a rate limit, an outage) or when it hasn't started answering after maxLatencyMs: the slow request is cancelled and the next model answers the same turn. The model that let the route down rests for cooldownMinutes, so new calls start on the next one until it's back.

The preset sets the order and those two numbers. OmniRoute's combos offer many presets and sixteen scoring sliders, for a gateway that serves coding tools; a phone call needs three things (answer fast, keep going, cost little), so OpenRing keeps three presets, plus Custom for everything:

Preset	Order	Switches after	Rests a model
fastest	The quickest measured answer first	1.5 s	5 min
cheapest	The lowest price first, local models before paid ones	3 s	5 min
reliable	Yours, as listed	2 s	15 min
custom	"order": listed, fastest or cheapest	"maxLatencyMs" (or null: errors only)	"cooldownMinutes"

"Fastest" goes by how long each model took to start answering on your recent calls; Measure speed on the route's page (or POST /model-route/{id}/measure) asks each model for one short answer to time it, a few tokens each. "Cheapest" goes by list prices (see What a call costs). Models not measured or priced yet come after the others, in your order. Changing the order or a number on a preset route makes it custom. Without a route, "maxLatencyMs" on an assistant's model does the same for its fallbackModels.

What a call costs

Every call records what its providers charge, at list prices, in Vapi's fields: cost (US$) and costBreakdown.llm, .stt, .tts and .total, next to the tokens, voice characters and seconds of audio it used. A call that switched providers is priced per provider. The dashboard shows it per call and per minute. The phone line (Twilio, Telnyx) isn't included yet.

Model prices ship with OpenRing (openring/llm_prices.json, from LiteLLM's price list and OpenRouter's model list); speech-to-text and voice prices come from each provider's pricing page (openring/prices.py). Local providers cost nothing. A provider without a known price is listed in costBreakdown.unpriced and left out of the total, never guessed. For your own rates, or a model the list doesn't have, write ~/.openring/prices.json and restart OpenRing:

{"llm": {"custom-llm": {"my-model": [0.2, 0.6]}},
 "stt": {"deepgram": {"nova-3": 0.0065}},
 "tts": {"rime-ai": {"*": 30}}}

Models are per 1M tokens (input, output), speech-to-text per minute, voices per 1M characters; "*" is any model of that provider. GET /prices shows every price in use.

Telnyx (beta)

Incoming calls through Telnyx are new and not yet confirmed on a real Telnyx call. In the Telnyx portal, create a TeXML Application whose voice URL is $PUBLIC_URL/telnyx/voice (HTTP POST) and assign your number to it. Add the number in OpenRing with "provider": "telnyx", and set TELNYX_API_KEY and TELNYX_PUBLIC_KEY (Keys & Credentials > Public Key), or connect Telnyx from the Providers page. Every webhook is checked against that public key. Outbound calls and transfers go through Twilio for now.

Genesys Cloud (beta)

If your contact center runs on Genesys Cloud, an assistant can take calls inside your Architect flows, through Genesys's Audio Connector (the AudioHook protocol). Not yet confirmed on a real Genesys call.

1. On the Providers page, connect Genesys Cloud: press Generate for an API key and a client secret, copy both, and save. (Or set GENESYS_API_KEY and GENESYS_CLIENT_SECRET; the secret is base64.)
2. In Genesys, add an Audio Connector integration with the base connection URI wss://YOUR_PUBLIC_HOST/ws/genesys (shown on the Phone numbers page) and those two credentials.
3. In Architect, add a Call Audio Connector action. Pass the assistant as the input variable assistantId, or add the called number in OpenRing with "provider": "genesys" and its assistant. Every other input variable fills the assistant's {{variables}} ({{accountId}}, say); the caller's name fills {{customer.name}}.
4. After the action, the output variable action says what happened: finished, or transfer with the number in transferTo (from a transferCall tool), so the flow can route the call. callId points to the call in OpenRing.

Every connection must carry the API key and Genesys's signature made with the client secret; anything else is refused. Transcripts, latency and webhooks work as for any other call.

🆓 The free stack

Layer	Free option
Speech-to-text	"provider": "whisper": runs on your computer, no key; or Deepgram's US$200 credit for new accounts
Model	"provider": "ollama" (local), "provider": "groq" (free tier) or "provider": "omniroute" (free local gateway to 150+ free providers)
Voice	"provider": "kokoro": runs on your CPU, no key
Phone line	A Twilio trial account, for testing

100% local. Whisper, Ollama and Kokoro together cost nothing per minute, and the call's audio never leaves your computer. In the assistant editor, press Use the free local stack, or:

"transcriber": {"provider": "whisper", "model": "base", "language": "en"},
"model": {"provider": "ollama", "model": "llama3.2"},
"voice": {"provider": "kokoro", "voiceId": "af_heart"}

Install Ollama and run ollama pull llama3.2 first; the Providers page shows whether it is running and which models it has. Whisper downloads its model once, when an assistant first uses it (tiny 75 MB, base 145 MB, small 480 MB; also medium, large-v3 and large-v3-turbo, or any faster-whisper repo on Hugging Face). It runs on an NVIDIA GPU when there is one, otherwise on the CPU: on a 2018 laptop a four-second sentence takes about 0.6 s with tiny and 1.2 s with base, about twice that with "language": "multi", so pick the language when you know it. A local model on a laptop also answers slower than a cloud one; a desktop GPU makes the whole stack quick.

🔌 Providers

Provider names are Vapi's, so an assistant JSON moves between the two unchanged. Connect each one from the dashboard's Providers page, or put its key in ~/.openring/.env.

Layer	provider values	Key
Model	openai, anthropic, google (Gemini), groq, openrouter, deepseek / deep-seek, xai, cerebras, together-ai, deepinfra, perplexity-ai, mistral, fireworks	OPENAI_API_KEY, ANTHROPIC_API_KEY, GOOGLE_API_KEY, GROQ_API_KEY, ... (the provider's name)
Model, local	ollama, omniroute, or custom-llm with model.url (any OpenAI-compatible endpoint)	none
Speech-to-text	deepgram, assembly-ai, gladia, soniox, cartesia, 11labs	DEEPGRAM_API_KEY, ASSEMBLYAI_API_KEY, GLADIA_API_KEY, SONIOX_API_KEY, CARTESIA_API_KEY, ELEVENLABS_API_KEY
Speech-to-text, local	whisper (free; model: tiny, base, small, medium, large-v3, large-v3-turbo)	none
Voice	11labs / elevenlabs, cartesia, deepgram (Aura), openai, rime-ai, neuphonic, smallest-ai, inworld	the provider's key (RIME_API_KEY, NEUPHONIC_API_KEY, SMALLEST_API_KEY, INWORLD_API_KEY, ...)
Voice, local	kokoro (free, runs on CPU)	none

Callers in any language. With "language": "multi" (Follow the caller in the dashboard) the transcriber detects the language, OpenRing tells the model to answer in it and to switch when the caller switches, and an ElevenLabs or OpenAI voice reads whatever language it gets. Kokoro and Deepgram voices speak one language each; the dashboard says so when you pick one. With a Deepgram key you already have a fast cloud voice: {"provider": "deepgram", "voiceId": "thalia"}.

Requests to OpenRouter carry OpenRing's name, so OpenRouter can list it among the apps that use it; OPENRING_ATTRIBUTION=false leaves that out.

🐳 Docker

cp .env.example .env          # fill in your keys and OPENRING_PASSWORD
docker compose up --build     # dashboard and API on http://localhost:8000

On a server, set PUBLIC_URL to its https address so Twilio can reach it.

🧱 Principles

OpenRing never charges per minute, keeps your keys and data on your machine, stays compatible with Vapi clients, runs with one command and says plainly what works and what doesn't. The whole list, and how we decide what to build, is in PRINCIPLES.md.

🤝 Contributing

git clone https://github.com/elifalanrocha/openring && cd openring
pip install -e ".[dev,kokoro,whisper]"
pytest                 # about 20 s, no paid services needed
python -m openring

Small pull requests get merged fastest. Start with CONTRIBUTING.md and the good first issues; see CHANGELOG.md for what shipped.

🔒 Security

Set OPENRING_API_KEY before exposing the server. The dashboard has its own password: the first one can only be chosen from the server's own computer (http://localhost) or with OPENRING_PASSWORD, so a stranger who finds your tunnel URL cannot claim it first. Sessions are HttpOnly, SameSite=Strict cookies, and repeated wrong passwords are slowed down. Forgot it? openring --reset-password. Incoming calls need TWILIO_AUTH_TOKEN: every Twilio webhook is checked against its X-Twilio-Signature, and calls are refused while the token is missing (VALIDATE_TWILIO_SIGNATURE=false turns the check off, for local tests only). Each call accepts a single media stream, so a replayed or second connection is dropped. Found a vulnerability? Please report it privately: see SECURITY.md.

⭐ Star history

📄 License

MIT. Not affiliated with Vapi, Retell, Dograh or Twilio. OpenRing builds on Pipecat and other open-source projects, credited in THIRD_PARTY.md.