--- summary: "Place outbound and accept inbound voice calls via Twilio, Telnyx, or Plivo, with optional realtime voice and streaming transcription" read_when: - You want to place an outbound voice call from OpenClaw - You are configuring or developing the voice-call plugin - You need realtime voice or streaming transcription on telephony title: "Voice call plugin" sidebarTitle: "Voice call" --- Voice calls for OpenClaw via a plugin. Supports outbound notifications, multi-turn conversations, full-duplex realtime voice, streaming transcription, and inbound calls with allowlist policies. **Current providers:** `twilio` (Programmable Voice + Media Streams), `telnyx` (Call Control v2), `plivo` (Voice API + XML transfer + GetInput speech), `mock` (dev/no network). The Voice Call plugin runs **inside the Gateway process**. If you use a remote Gateway, install and configure the plugin on the machine running the Gateway, then restart the Gateway to load it. ## Quick start ```bash openclaw plugins install @openclaw/voice-call ``` ```bash PLUGIN_SRC=./path/to/local/voice-call-plugin openclaw plugins install "$PLUGIN_SRC" cd "$PLUGIN_SRC" && pnpm install ``` If npm reports the OpenClaw-owned package as deprecated, that package version is from an older external package train; use a current packaged OpenClaw build or the local folder path until a newer npm package is published. Restart the Gateway afterwards so the plugin loads. Set config under `plugins.entries.voice-call.config` (see [Configuration](#configuration) below for the full shape). At minimum: `provider`, provider credentials, `fromNumber`, and a publicly reachable webhook URL. ```bash openclaw voicecall setup ``` The default output is readable in chat logs and terminals. It checks plugin enablement, provider credentials, webhook exposure, and that only one audio mode (`streaming` or `realtime`) is active. Use `--json` for scripts. ```bash openclaw voicecall smoke openclaw voicecall smoke --to "+15555550123" ``` Both are dry runs by default. Add `--yes` to actually place a short outbound notify call: ```bash openclaw voicecall smoke --to "+15555550123" --yes ``` For Twilio, Telnyx, and Plivo, setup must resolve to a **public webhook URL**. If `publicUrl`, the tunnel URL, the Tailscale URL, or the serve fallback resolves to loopback or private network space, setup fails instead of starting a provider that cannot receive carrier webhooks. ## Configuration If `enabled: true` but the selected provider is missing credentials, Gateway startup logs a setup-incomplete warning with the missing keys and skips starting the runtime. Commands, RPC calls, and agent tools still return the exact missing provider configuration when used. Voice-call credentials accept SecretRefs. `plugins.entries.voice-call.config.twilio.authToken`, `plugins.entries.voice-call.config.realtime.providers.*.apiKey`, `plugins.entries.voice-call.config.streaming.providers.*.apiKey`, and `plugins.entries.voice-call.config.tts.providers.*.apiKey` resolve through the standard SecretRef surface; see [SecretRef credential surface](/reference/secretref-credential-surface). ```json5 { plugins: { entries: { "voice-call": { enabled: true, config: { provider: "twilio", // or "telnyx" | "plivo" | "mock" fromNumber: "+15550001234", // or TWILIO_FROM_NUMBER for Twilio toNumber: "+15550005678", sessionScope: "per-phone", // per-phone | per-call twilio: { accountSid: "ACxxxxxxxx", authToken: "...", }, telnyx: { apiKey: "...", connectionId: "...", // Telnyx webhook public key from the Mission Control Portal // (Base64; can also be set via TELNYX_PUBLIC_KEY). publicKey: "...", }, plivo: { authId: "MAxxxxxxxxxxxxxxxxxxxx", authToken: "...", }, // Webhook server serve: { port: 3334, path: "/voice/webhook", }, // Webhook security (recommended for tunnels/proxies) webhookSecurity: { allowedHosts: ["voice.example.com"], trustedProxyIPs: ["100.64.0.1"], }, // Public exposure (pick one) // publicUrl: "https://example.ngrok.app/voice/webhook", // tunnel: { provider: "ngrok" }, // tailscale: { mode: "funnel", path: "/voice/webhook" }, outbound: { defaultMode: "notify", // notify | conversation }, streaming: { enabled: true /* see Streaming transcription */ }, realtime: { enabled: false /* see Realtime voice */ }, }, }, }, }, } ``` - Twilio, Telnyx, and Plivo all require a **publicly reachable** webhook URL. - `mock` is a local dev provider (no network calls). - Telnyx requires `telnyx.publicKey` (or `TELNYX_PUBLIC_KEY`) unless `skipSignatureVerification` is true. - `skipSignatureVerification` is for local testing only. - On ngrok free tier, set `publicUrl` to the exact ngrok URL; signature verification is always enforced. - `tunnel.allowNgrokFreeTierLoopbackBypass: true` allows Twilio webhooks with invalid signatures **only** when `tunnel.provider="ngrok"` and `serve.bind` is loopback (ngrok local agent). Local dev only. - Ngrok free-tier URLs can change or add interstitial behaviour; if `publicUrl` drifts, Twilio signatures fail. Production: prefer a stable domain or a Tailscale funnel. - `streaming.preStartTimeoutMs` closes sockets that never send a valid `start` frame. - `streaming.maxPendingConnections` caps total unauthenticated pre-start sockets. - `streaming.maxPendingConnectionsPerIp` caps unauthenticated pre-start sockets per source IP. - `streaming.maxConnections` caps total open media stream sockets (pending + active). Older configs using `provider: "log"`, `twilio.from`, or legacy `streaming.*` OpenAI keys are rewritten by `openclaw doctor --fix`. Runtime fallback still accepts the old voice-call keys for now, but the rewrite path is `openclaw doctor --fix` and the compat shim is temporary. Auto-migrated streaming keys: - `streaming.sttProvider` → `streaming.provider` - `streaming.openaiApiKey` → `streaming.providers.openai.apiKey` - `streaming.sttModel` → `streaming.providers.openai.model` - `streaming.silenceDurationMs` → `streaming.providers.openai.silenceDurationMs` - `streaming.vadThreshold` → `streaming.providers.openai.vadThreshold` ## Session scope By default, Voice Call uses `sessionScope: "per-phone"` so repeat calls from the same caller keep conversation memory. Set `sessionScope: "per-call"` when each carrier call should start with fresh context, for example reception, booking, IVR, or Google Meet bridge flows where the same phone number may represent different meetings. ## Realtime voice conversations `realtime` selects a full-duplex realtime voice provider for live call audio. It is separate from `streaming`, which only forwards audio to realtime transcription providers. `realtime.enabled` cannot be combined with `streaming.enabled`. Pick one audio mode per call. Current runtime behaviour: - `realtime.enabled` is supported for Twilio Media Streams. - `realtime.provider` is optional. If unset, Voice Call uses the first registered realtime voice provider. - Bundled realtime voice providers: Google Gemini Live (`google`) and OpenAI (`openai`), registered by their provider plugins. - Provider-owned raw config lives under `realtime.providers.`. - Voice Call exposes the shared `openclaw_agent_consult` realtime tool by default. The realtime model can call it when the caller asks for deeper reasoning, current information, or normal OpenClaw tools. - `realtime.fastContext.enabled` is default-off. When enabled, Voice Call first searches indexed memory/session context for the consult question and returns those snippets to the realtime model within `realtime.fastContext.timeoutMs` before falling back to the full consult agent only if `realtime.fastContext.fallbackToConsult` is true. - If `realtime.provider` points at an unregistered provider, or no realtime voice provider is registered at all, Voice Call logs a warning and skips realtime media instead of failing the whole plugin. - Consult session keys reuse the stored call session when available, then fall back to the configured `sessionScope` (`per-phone` by default, or `per-call` for isolated calls). ### Tool policy `realtime.toolPolicy` controls the consult run: | Policy | Behavior | | ---------------- | ---------------------------------------------------------------------------------------------------------------------------------------- | | `safe-read-only` | Expose the consult tool and limit the regular agent to `read`, `web_search`, `web_fetch`, `x_search`, `memory_search`, and `memory_get`. | | `owner` | Expose the consult tool and let the regular agent use the normal agent tool policy. | | `none` | Do not expose the consult tool. Custom `realtime.tools` are still passed through to the realtime provider. | ### Realtime provider examples Defaults: API key from `realtime.providers.google.apiKey`, `GEMINI_API_KEY`, or `GOOGLE_GENERATIVE_AI_API_KEY`; model `gemini-2.5-flash-native-audio-preview-12-2025`; voice `Kore`. ```json5 { plugins: { entries: { "voice-call": { config: { provider: "twilio", inboundPolicy: "allowlist", allowFrom: ["+15550005678"], realtime: { enabled: true, provider: "google", instructions: "Speak briefly. Call openclaw_agent_consult before using deeper tools.", toolPolicy: "safe-read-only", providers: { google: { apiKey: "${GEMINI_API_KEY}", model: "gemini-2.5-flash-native-audio-preview-12-2025", voice: "Kore", }, }, }, }, }, }, }, } ``` ```json5 { plugins: { entries: { "voice-call": { config: { realtime: { enabled: true, provider: "openai", providers: { openai: { apiKey: "${OPENAI_API_KEY}" }, }, }, }, }, }, }, } ``` See [Google provider](/providers/google) and [OpenAI provider](/providers/openai) for provider-specific realtime voice options. ## Streaming transcription `streaming` selects a realtime transcription provider for live call audio. Current runtime behavior: - `streaming.provider` is optional. If unset, Voice Call uses the first registered realtime transcription provider. - Bundled realtime transcription providers: Deepgram (`deepgram`), ElevenLabs (`elevenlabs`), Mistral (`mistral`), OpenAI (`openai`), and xAI (`xai`), registered by their provider plugins. - Provider-owned raw config lives under `streaming.providers.`. - After Twilio sends an accepted stream `start` message, Voice Call registers the stream immediately, queues inbound media through the transcription provider while the provider connects, and starts the initial greeting only after realtime transcription is ready. - If `streaming.provider` points at an unregistered provider, or none is registered, Voice Call logs a warning and skips media streaming instead of failing the whole plugin. ### Streaming provider examples Defaults: API key `streaming.providers.openai.apiKey` or `OPENAI_API_KEY`; model `gpt-4o-transcribe`; `silenceDurationMs: 800`; `vadThreshold: 0.5`. ```json5 { plugins: { entries: { "voice-call": { config: { streaming: { enabled: true, provider: "openai", streamPath: "/voice/stream", providers: { openai: { apiKey: "sk-...", // optional if OPENAI_API_KEY is set model: "gpt-4o-transcribe", silenceDurationMs: 800, vadThreshold: 0.5, }, }, }, }, }, }, }, } ``` Defaults: API key `streaming.providers.xai.apiKey` or `XAI_API_KEY`; endpoint `wss://api.x.ai/v1/stt`; encoding `mulaw`; sample rate `8000`; `endpointingMs: 800`; `interimResults: true`. ```json5 { plugins: { entries: { "voice-call": { config: { streaming: { enabled: true, provider: "xai", streamPath: "/voice/stream", providers: { xai: { apiKey: "${XAI_API_KEY}", // optional if XAI_API_KEY is set endpointingMs: 800, language: "en", }, }, }, }, }, }, }, } ``` ## TTS for calls Voice Call uses the core `messages.tts` configuration for streaming speech on calls. You can override it under the plugin config with the **same shape** — it deep-merges with `messages.tts`. ```json5 { tts: { provider: "elevenlabs", providers: { elevenlabs: { voiceId: "pMsXgVXv3BLzUgSXRplE", modelId: "eleven_multilingual_v2", }, }, }, } ``` **Microsoft speech is ignored for voice calls.** Telephony audio needs PCM; the current Microsoft transport does not expose telephony PCM output. Behavior notes: - Legacy `tts.` keys inside plugin config (`openai`, `elevenlabs`, `microsoft`, `edge`) are repaired by `openclaw doctor --fix`; committed config should use `tts.providers.`. - Core TTS is used when Twilio media streaming is enabled; otherwise calls fall back to provider-native voices. - If a Twilio media stream is already active, Voice Call does not fall back to TwiML ``. If telephony TTS is unavailable in that state, the playback request fails instead of mixing two playback paths. - When telephony TTS falls back to a secondary provider, Voice Call logs a warning with the provider chain (`from`, `to`, `attempts`) for debugging. - When Twilio barge-in or stream teardown clears the pending TTS queue, queued playback requests settle instead of hanging callers awaiting playback completion. ### TTS examples ```json5 { messages: { tts: { provider: "openai", providers: { openai: { voice: "alloy" }, }, }, }, } ``` ```json5 { plugins: { entries: { "voice-call": { config: { tts: { provider: "elevenlabs", providers: { elevenlabs: { apiKey: "elevenlabs_key", voiceId: "pMsXgVXv3BLzUgSXRplE", modelId: "eleven_multilingual_v2", }, }, }, }, }, }, }, } ``` ```json5 { plugins: { entries: { "voice-call": { config: { tts: { providers: { openai: { model: "gpt-4o-mini-tts", voice: "marin", }, }, }, }, }, }, }, } ``` ## Inbound calls Inbound policy defaults to `disabled`. To enable inbound calls, set: ```json5 { inboundPolicy: "allowlist", allowFrom: ["+15550001234"], inboundGreeting: "Hello! How can I help?", } ``` `inboundPolicy: "allowlist"` is a low-assurance caller-ID screen. The plugin normalizes the provider-supplied `From` value and compares it to `allowFrom`. Webhook verification authenticates provider delivery and payload integrity, but it does **not** prove PSTN/VoIP caller-number ownership. Treat `allowFrom` as caller-ID filtering, not strong caller identity. Auto-responses use the agent system. Tune with `responseModel`, `responseSystemPrompt`, and `responseTimeoutMs`. ### Spoken output contract For auto-responses, Voice Call appends a strict spoken-output contract to the system prompt: ```text {"spoken":"..."} ``` Voice Call extracts speech text defensively: - Ignores payloads marked as reasoning/error content. - Parses direct JSON, fenced JSON, or inline `"spoken"` keys. - Falls back to plain text and removes likely planning/meta lead-in paragraphs. This keeps spoken playback focused on caller-facing text and avoids leaking planning text into audio. ### Conversation startup behavior For outbound `conversation` calls, first-message handling is tied to live playback state: - Barge-in queue clear and auto-response are suppressed only while the initial greeting is actively speaking. - If initial playback fails, the call returns to `listening` and the initial message remains queued for retry. - Initial playback for Twilio streaming starts on stream connect without extra delay. - Barge-in aborts active playback and clears queued-but-not-yet-playing Twilio TTS entries. Cleared entries resolve as skipped, so follow-up response logic can continue without waiting on audio that will never play. - Realtime voice conversations use the realtime stream's own opening turn. Voice Call does **not** post a legacy `` TwiML update for that initial message, so outbound `` sessions stay attached. ### Twilio stream disconnect grace When a Twilio media stream disconnects, Voice Call waits **2000 ms** before auto-ending the call: - If the stream reconnects during that window, auto-end is canceled. - If no stream re-registers after the grace period, the call is ended to prevent stuck active calls. ## Stale call reaper Use `staleCallReaperSeconds` to end calls that never receive a terminal webhook (for example, notify-mode calls that never complete). The default is `0` (disabled). Recommended ranges: - **Production:** `120`–`300` seconds for notify-style flows. - Keep this value **higher than `maxDurationSeconds`** so normal calls can finish. A good starting point is `maxDurationSeconds + 30–60` seconds. ```json5 { plugins: { entries: { "voice-call": { config: { maxDurationSeconds: 300, staleCallReaperSeconds: 360, }, }, }, }, } ``` ## Webhook security When a proxy or tunnel sits in front of the Gateway, the plugin reconstructs the public URL for signature verification. These options control which forwarded headers are trusted: Allowlist hosts from forwarding headers. Trust forwarded headers without an allowlist. Only trust forwarded headers when the request remote IP matches the list. Additional protections: - Webhook **replay protection** is enabled for Twilio and Plivo. Replayed valid webhook requests are acknowledged but skipped for side effects. - Twilio conversation turns include a per-turn token in `` callbacks, so stale/replayed speech callbacks cannot satisfy a newer pending transcript turn. - Unauthenticated webhook requests are rejected before body reads when the provider's required signature headers are missing. - The voice-call webhook uses the shared pre-auth body profile (64 KB / 5 seconds) plus a per-IP in-flight cap before signature verification. Example with a stable public host: ```json5 { plugins: { entries: { "voice-call": { config: { publicUrl: "https://voice.example.com/voice/webhook", webhookSecurity: { allowedHosts: ["voice.example.com"], }, }, }, }, }, } ``` ## CLI ```bash openclaw voicecall call --to "+15555550123" --message "Hello from OpenClaw" openclaw voicecall start --to "+15555550123" # alias for call openclaw voicecall continue --call-id --message "Any questions?" openclaw voicecall speak --call-id --message "One moment" openclaw voicecall dtmf --call-id --digits "ww123456#" openclaw voicecall end --call-id openclaw voicecall status --call-id openclaw voicecall tail openclaw voicecall latency # summarize turn latency from logs openclaw voicecall expose --mode funnel ``` When the Gateway is already running, operational `voicecall` commands delegate to the Gateway-owned voice-call runtime so the CLI does not bind a second webhook server. If no Gateway is reachable, the commands fall back to a standalone CLI runtime. `latency` reads `calls.jsonl` from the default voice-call storage path. Use `--file ` to point at a different log and `--last ` to limit analysis to the last N records (default 200). Output includes p50/p90/p99 for turn latency and listen-wait times. ## Agent tool Tool name: `voice_call`. | Action | Args | | --------------- | ------------------------------------------ | | `initiate_call` | `message`, `to?`, `mode?`, `dtmfSequence?` | | `continue_call` | `callId`, `message` | | `speak_to_user` | `callId`, `message` | | `send_dtmf` | `callId`, `digits` | | `end_call` | `callId` | | `get_status` | `callId` | This repo ships a matching skill doc at `skills/voice-call/SKILL.md`. ## Gateway RPC | Method | Args | | -------------------- | ------------------------------------------ | | `voicecall.initiate` | `to?`, `message`, `mode?`, `dtmfSequence?` | | `voicecall.continue` | `callId`, `message` | | `voicecall.speak` | `callId`, `message` | | `voicecall.dtmf` | `callId`, `digits` | | `voicecall.end` | `callId` | | `voicecall.status` | `callId` | `dtmfSequence` is only valid with `mode: "conversation"`. Notify-mode calls should use `voicecall.dtmf` after the call exists if they need post-connect digits. ## Troubleshooting ### Setup fails webhook exposure Run setup from the same environment that runs the Gateway: ```bash openclaw voicecall setup openclaw voicecall setup --json ``` For `twilio`, `telnyx`, and `plivo`, `webhook-exposure` must be green. A configured `publicUrl` still fails when it points at local or private network space, because the carrier cannot call back into those addresses. Do not use `localhost`, `127.0.0.1`, `0.0.0.0`, `10.x`, `172.16.x`-`172.31.x`, `192.168.x`, `169.254.x`, `fc00::/7`, or `fd00::/8` as `publicUrl`. Twilio notify-mode outbound calls send their initial `` TwiML directly in the create-call request, so the first spoken message does not depend on Twilio fetching webhook TwiML. A public webhook is still required for status callbacks, conversation calls, pre-connect DTMF, realtime streams, and post-connect call control. Use one public exposure path: ```json5 { plugins: { entries: { "voice-call": { config: { publicUrl: "https://voice.example.com/voice/webhook", // or tunnel: { provider: "ngrok" }, // or tailscale: { mode: "funnel", path: "/voice/webhook" }, }, }, }, }, } ``` After changing config, restart or reload the Gateway, then run: ```bash openclaw voicecall setup openclaw voicecall smoke ``` `voicecall smoke` is a dry run unless you pass `--yes`. ### Provider credentials fail Check the selected provider and the required credential fields: - Twilio: `twilio.accountSid`, `twilio.authToken`, and `fromNumber`, or `TWILIO_ACCOUNT_SID`, `TWILIO_AUTH_TOKEN`, and `TWILIO_FROM_NUMBER`. - Telnyx: `telnyx.apiKey`, `telnyx.connectionId`, `telnyx.publicKey`, and `fromNumber`. - Plivo: `plivo.authId`, `plivo.authToken`, and `fromNumber`. Credentials must exist on the Gateway host. Editing a local shell profile does not affect an already running Gateway until it restarts or reloads its environment. ### Calls start but provider webhooks do not arrive Confirm the provider console points at the exact public webhook URL: ```text https://voice.example.com/voice/webhook ``` Then inspect runtime state: ```bash openclaw voicecall status --call-id openclaw voicecall tail openclaw logs --follow ``` Common causes: - `publicUrl` points at a different path than `serve.path`. - The tunnel URL changed after the Gateway started. - A proxy forwards the request but strips or rewrites host/proto headers. - Firewall or DNS routes the public hostname somewhere other than the Gateway. - The Gateway was restarted without the Voice Call plugin enabled. When a reverse proxy or tunnel is in front of the Gateway, set `webhookSecurity.allowedHosts` to the public hostname, or use `webhookSecurity.trustedProxyIPs` for a known proxy address. Use `webhookSecurity.trustForwardingHeaders` only when the proxy boundary is under your control. ### Signature verification fails Provider signatures are checked against the public URL OpenClaw reconstructs from the incoming request. If signatures fail: - Confirm the provider webhook URL exactly matches `publicUrl`, including scheme, host, and path. - For ngrok free-tier URLs, update `publicUrl` when the tunnel hostname changes. - Ensure the proxy preserves the original host and proto headers, or configure `webhookSecurity.allowedHosts`. - Do not enable `skipSignatureVerification` outside local testing. ### Google Meet Twilio joins fail Google Meet uses this plugin for Twilio dial-in joins. First verify Voice Call: ```bash openclaw voicecall setup openclaw voicecall smoke --to "+15555550123" ``` Then verify the Google Meet transport explicitly: ```bash openclaw googlemeet setup --transport twilio ``` If Voice Call is green but the Meet participant never joins, check the Meet dial-in number, PIN, and `--dtmf-sequence`. The phone call can be healthy while the meeting rejects or ignores an incorrect DTMF sequence. Google Meet passes the Meet DTMF sequence and intro text to `voicecall.start`. For Twilio calls, Voice Call serves the DTMF TwiML first, redirects back to the webhook, then opens the realtime media stream so the saved intro is generated after the phone participant has joined the meeting. Use `openclaw logs --follow` for the live phase trace. A healthy Twilio Meet join logs this order: - Google Meet delegates the Twilio join to Voice Call. - Voice Call stores pre-connect DTMF TwiML. - Twilio initial TwiML is consumed and served before realtime handling. - Voice Call serves realtime TwiML for the Twilio call. - The realtime bridge starts with the initial greeting queued. `openclaw voicecall tail` still shows persisted call records; it is useful for call state and transcripts, but not every webhook/realtime transition appears there. ### Realtime call has no speech Confirm only one audio mode is enabled. `realtime.enabled` and `streaming.enabled` cannot both be true. For realtime Twilio calls, also verify: - A realtime provider plugin is loaded and registered. - `realtime.provider` is unset or names a registered provider. - The provider API key is available to the Gateway process. - `openclaw logs --follow` shows realtime TwiML served, the realtime bridge started, and the initial greeting queued. ## Related - [Talk mode](/nodes/talk) - [Text-to-speech](/tools/tts) - [Voice wake](/nodes/voicewake)