moltbot/docs/plugins/voice-call.md

---
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).

<Note>
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.
</Note>

## Quick start

<Steps>
  <Step title="Install the plugin">
    <Tabs>
      <Tab title="From npm (recommended)">
        ```bash
        openclaw plugins install @openclaw/voice-call
        ```
      </Tab>
      <Tab title="From a local folder (dev)">
        ```bash
        PLUGIN_SRC=./path/to/local/voice-call-plugin
        openclaw plugins install "$PLUGIN_SRC"
        cd "$PLUGIN_SRC" && pnpm install
        ```
      </Tab>
    </Tabs>

    Restart the Gateway afterwards so the plugin loads.

  </Step>
  <Step title="Configure provider and webhook">
    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.
  </Step>
  <Step title="Verify setup">
    ```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.

  </Step>
  <Step title="Smoke test">
    ```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
    ```

  </Step>
</Steps>

<Warning>
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.
</Warning>

## 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.

```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 */ },
        },
      },
    },
  },
}
```

<AccordionGroup>
  <Accordion title="Provider exposure and security notes">
    - 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.
  </Accordion>
  <Accordion title="Streaming connection caps">
    - `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).
  </Accordion>
  <Accordion title="Legacy config migrations">
    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`

  </Accordion>
</AccordionGroup>

## 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.

<Warning>
`realtime.enabled` cannot be combined with `streaming.enabled`. Pick one
audio mode per call.
</Warning>

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.<providerId>`.
- 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

<Tabs>
  <Tab title="Google Gemini Live">
    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",
                  },
                },
              },
            },
          },
        },
      },
    }
    ```

  </Tab>
  <Tab title="OpenAI">
    ```json5
    {
      plugins: {
        entries: {
          "voice-call": {
            config: {
              realtime: {
                enabled: true,
                provider: "openai",
                providers: {
                  openai: { apiKey: "${OPENAI_API_KEY}" },
                },
              },
            },
          },
        },
      },
    }
    ```
  </Tab>
</Tabs>

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.<providerId>`.
- 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

<Tabs>
  <Tab title="OpenAI">
    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,
                  },
                },
              },
            },
          },
        },
      },
    }
    ```

  </Tab>
  <Tab title="xAI">
    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",
                  },
                },
              },
            },
          },
        },
      },
    }
    ```

  </Tab>
</Tabs>

## 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",
      },
    },
  },
}
```

<Warning>
**Microsoft speech is ignored for voice calls.** Telephony audio needs PCM;
the current Microsoft transport does not expose telephony PCM output.
</Warning>

Behavior notes:

- Legacy `tts.<provider>` keys inside plugin config (`openai`, `elevenlabs`, `microsoft`, `edge`) are repaired by `openclaw doctor --fix`; committed config should use `tts.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

<Tabs>
  <Tab title="Core TTS only">
```json5
{
  messages: {
    tts: {
      provider: "openai",
      providers: {
        openai: { voice: "alloy" },
      },
    },
  },
}
```
  </Tab>
  <Tab title="Override to ElevenLabs (calls only)">
```json5
{
  plugins: {
    entries: {
      "voice-call": {
        config: {
          tts: {
            provider: "elevenlabs",
            providers: {
              elevenlabs: {
                apiKey: "elevenlabs_key",
                voiceId: "pMsXgVXv3BLzUgSXRplE",
                modelId: "eleven_multilingual_v2",
              },
            },
          },
        },
      },
    },
  },
}
```
  </Tab>
  <Tab title="OpenAI model override (deep-merge)">
```json5
{
  plugins: {
    entries: {
      "voice-call": {
        config: {
          tts: {
            providers: {
              openai: {
                model: "gpt-4o-mini-tts",
                voice: "marin",
              },
            },
          },
        },
      },
    },
  },
}
```
  </Tab>
</Tabs>

## Inbound calls

Inbound policy defaults to `disabled`. To enable inbound calls, set:

```json5
{
  inboundPolicy: "allowlist",
  allowFrom: ["+15550001234"],
  inboundGreeting: "Hello! How can I help?",
}
```

<Warning>
`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.
</Warning>

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 `<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`–`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:

<ParamField path="webhookSecurity.allowedHosts" type="string[]">
  Allowlist hosts from forwarding headers.
</ParamField>
<ParamField path="webhookSecurity.trustForwardingHeaders" type="boolean">
  Trust forwarded headers without an allowlist.
</ParamField>
<ParamField path="webhookSecurity.trustedProxyIPs" type="string[]">
  Only trust forwarded headers when the request remote IP matches the list.
</ParamField>

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:

```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 <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
```

`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?` |
| `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)