---
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` 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",
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`
## 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.
- 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 existing voice session when available, then fall back to the caller/callee phone number so follow-up consult calls keep context during the call.
### 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.`.
- 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
```
`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?` |
| `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?` |
| `voicecall.continue` | `callId`, `message` |
| `voicecall.speak` | `callId`, `message` |
| `voicecall.dtmf` | `callId`, `digits` |
| `voicecall.end` | `callId` |
| `voicecall.status` | `callId` |
## Related
- [Talk mode](/nodes/talk)
- [Text-to-speech](/tools/tts)
- [Voice wake](/nodes/voicewake)