Voice Call (plugin)

Scope

Use this page when:

• You want to place an outbound voice call from Moltbot
• You are configuring or developing the voice-call plugin

Voice calls for Moltbot via a plugin. Supports outbound notifications and multi-turn conversations with inbound policies.

Current providers:

• twilio (Programmable Voice + Media Streams)
• telnyx (Call Control v2)
• plivo (Voice API + XML transfer + GetInput speech)
• mock (dev/no network)

Quick mental model:

• Install plugin
• Restart Gateway
• Configure under plugins.entries.voice-call.config
• Use moltbot voicecall ... or the voice_call tool

Where it runs (local vs remote)

The Voice Call plugin runs inside the Gateway process.

If you use a remote Gateway, install/configure the plugin on the machine running the Gateway, then restart the Gateway to load it.

Install

Option A: install from npm (recommended)

moltbot plugins install @moltbot/voice-call

Restart the Gateway afterwards.

Option B: install from a local folder (dev, no copying)

moltbot plugins install ./extensions/voice-call
cd ./extensions/voice-call && pnpm install

Restart the Gateway afterwards.

Config

Set config under plugins.entries.voice-call.config:

{
  plugins: {
    entries: {
      "voice-call": {
        enabled: true,
        config: {
          provider: "twilio", // or "telnyx" | "plivo" | "mock"
          fromNumber: "+15550001234",
          toNumber: "+15550005678",

          twilio: {
            accountSid: "ACxxxxxxxx",
            authToken: "..."
          },

          plivo: {
            authId: "MAxxxxxxxxxxxxxxxxxxxx",
            authToken: "..."
          },

          // Webhook server
          serve: {
            port: 3334,
            path: "/voice/webhook"
          },

          // 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,
            streamPath: "/voice/stream"
          }
        }
      }
    }
  }
}

Notes:

• Twilio/Telnyx require a publicly reachable webhook URL.
• Plivo requires a publicly reachable webhook URL.
• mock is a local dev provider (no network calls).
• skipSignatureVerification is for local testing only.

TTS for calls

Voice Call uses the core messages.tts configuration (OpenAI or ElevenLabs) 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",
    elevenlabs: {
      voiceId: "pMsXgVXv3BLzUgSXRplE",
      modelId: "eleven_multilingual_v2"
    }
  }
}

Notes:

• Edge TTS is ignored for voice calls (telephony audio needs PCM; Edge output is unreliable).
• Core TTS is used when Twilio media streaming is enabled; otherwise calls fall back to provider native voices.

More examples

Use core TTS only (no override):

{
  messages: {
    tts: {
      provider: "openai",
      openai: { voice: "alloy" }
    }
  }
}

Override to ElevenLabs just for calls (keep core default elsewhere):

{
  plugins: {
    entries: {
      "voice-call": {
        config: {
          tts: {
            provider: "elevenlabs",
            elevenlabs: {
              apiKey: "elevenlabs_key",
              voiceId: "pMsXgVXv3BLzUgSXRplE",
              modelId: "eleven_multilingual_v2"
            }
          }
        }
      }
    }
  }
}

Override only the OpenAI model for calls (deep‑merge example):

{
  plugins: {
    entries: {
      "voice-call": {
        config: {
          tts: {
            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
• responseTimeoutMs

CLI

moltbot voicecall call --to "+15555550123" --message "Hello from Moltbot"
moltbot voicecall continue --call-id <id> --message "Any questions?"
moltbot voicecall speak --call-id <id> --message "One moment"
moltbot voicecall end --call-id <id>
moltbot voicecall status --call-id <id>
moltbot voicecall tail
moltbot voicecall expose --mode funnel

Agent tool

Tool name: voice_call

Actions:

• initiate_call (message, to?, mode?)
• continue_call (callId, message)
• speak_to_user (callId, message)
• end_call (callId)
• get_status (callId)

This repo ships a matching skill doc at skills/voice-call/SKILL.md.

Gateway RPC

• voicecall.initiate (to?, message, mode?)
• voicecall.continue (callId, message)
• voicecall.speak (callId, message)
• voicecall.end (callId)
• voicecall.status (callId)