28 KiB
summary, read_when, title, sidebarTitle
| summary | read_when | title | sidebarTitle | |||
|---|---|---|---|---|---|---|
| Place outbound and accept inbound voice calls via Twilio, Telnyx, or Plivo, with optional realtime voice and streaming transcription |
|
Voice call plugin | 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).
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.
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.
Both are dry runs by default. Add `--yes` to actually place a short
outbound notify call:
```bash
openclaw voicecall smoke --to "+15555550123" --yes
```
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.
{
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 */ },
},
},
},
},
}
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.
Current runtime behaviour:
realtime.enabledis supported for Twilio Media Streams.realtime.provideris 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.<providerId>. - Voice Call exposes the shared
openclaw_agent_consultrealtime tool by default. The realtime model can call it when the caller asks for deeper reasoning, current information, or normal OpenClaw tools. realtime.fastContext.enabledis default-off. When enabled, Voice Call first searches indexed memory/session context for the consult question and returns those snippets to the realtime model withinrealtime.fastContext.timeoutMsbefore falling back to the full consult agent only ifrealtime.fastContext.fallbackToConsultis true.- If
realtime.providerpoints 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: "${GEMINI_API_KEY}",
model: "gemini-2.5-flash-native-audio-preview-12-2025",
voice: "Kore",
},
},
},
},
},
},
},
}
```
See Google provider and OpenAI provider for provider-specific realtime voice options.
Streaming transcription
streaming selects a realtime transcription provider for live call audio.
Current runtime behavior:
streaming.provideris optional. If unset, Voice Call uses the first registered realtime transcription provider.- Bundled realtime transcription providers: Deepgram (
deepgram), ElevenLabs (elevenlabs), Mistral (mistral), OpenAI (openai), and xAI (xai), registered by their provider plugins. - Provider-owned raw config lives under
streaming.providers.<providerId>. - After Twilio sends an accepted stream
startmessage, Voice Call registers the stream immediately, queues inbound media through the transcription provider while the provider connects, and starts the initial greeting only after realtime transcription is ready. - If
streaming.providerpoints at an unregistered provider, or none is registered, Voice Call logs a warning and skips media streaming instead of failing the whole plugin.
Streaming provider examples
Defaults: API key `streaming.providers.openai.apiKey` or `OPENAI_API_KEY`; model `gpt-4o-transcribe`; `silenceDurationMs: 800`; `vadThreshold: 0.5`.```json5
{
plugins: {
entries: {
"voice-call": {
config: {
streaming: {
enabled: true,
provider: "openai",
streamPath: "/voice/stream",
providers: {
openai: {
apiKey: "sk-...", // optional if OPENAI_API_KEY is set
model: "gpt-4o-transcribe",
silenceDurationMs: 800,
vadThreshold: 0.5,
},
},
},
},
},
},
},
}
```
```json5
{
plugins: {
entries: {
"voice-call": {
config: {
streaming: {
enabled: true,
provider: "xai",
streamPath: "/voice/stream",
providers: {
xai: {
apiKey: "${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.
{
tts: {
provider: "elevenlabs",
providers: {
elevenlabs: {
voiceId: "pMsXgVXv3BLzUgSXRplE",
modelId: "eleven_multilingual_v2",
},
},
},
}
Behavior notes:
- Legacy
tts.<provider>keys inside plugin config (openai,elevenlabs,microsoft,edge) are repaired byopenclaw doctor --fix; committed config should usetts.providers.<provider>. - 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
<Say>. 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:
{
inboundPolicy: "allowlist",
allowFrom: ["+15550001234"],
inboundGreeting: "Hello! How can I help?",
}
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:
{"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
listeningand 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
<Say>TwiML update for that initial message, so outbound<Connect><Stream>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:
120–300seconds for notify-style flows. - Keep this value higher than
maxDurationSecondsso normal calls can finish. A good starting point ismaxDurationSeconds + 30–60seconds.
{
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
<Gather>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:
{
plugins: {
entries: {
"voice-call": {
config: {
publicUrl: "https://voice.example.com/voice/webhook",
webhookSecurity: {
allowedHosts: ["voice.example.com"],
},
},
},
},
},
}
CLI
openclaw voicecall call --to "+15555550123" --message "Hello from OpenClaw"
openclaw voicecall start --to "+15555550123" # alias for call
openclaw voicecall continue --call-id <id> --message "Any questions?"
openclaw voicecall speak --call-id <id> --message "One moment"
openclaw voicecall dtmf --call-id <id> --digits "ww123456#"
openclaw voicecall end --call-id <id>
openclaw voicecall status --call-id <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 <path> to point at a different log and --last <n> 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:
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 <Say> 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:
{
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:
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, andfromNumber, orTWILIO_ACCOUNT_SID,TWILIO_AUTH_TOKEN, andTWILIO_FROM_NUMBER. - Telnyx:
telnyx.apiKey,telnyx.connectionId,telnyx.publicKey, andfromNumber. - Plivo:
plivo.authId,plivo.authToken, andfromNumber.
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:
https://voice.example.com/voice/webhook
Then inspect runtime state:
openclaw voicecall status --call-id <id>
openclaw voicecall tail
openclaw logs --follow
Common causes:
publicUrlpoints at a different path thanserve.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
publicUrlwhen the tunnel hostname changes. - Ensure the proxy preserves the original host and proto headers, or configure
webhookSecurity.allowedHosts. - Do not enable
skipSignatureVerificationoutside local testing.
Google Meet Twilio joins fail
Google Meet uses this plugin for Twilio dial-in joins. First verify Voice Call:
openclaw voicecall setup
openclaw voicecall smoke --to "+15555550123"
Then verify the Google Meet transport explicitly:
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.provideris unset or names a registered provider.- The provider API key is available to the Gateway process.
openclaw logs --followshows realtime TwiML served, the realtime bridge started, and the initial greeting queued.