AgentSession | SignalWire

AgentSession<UserData> is the orchestrator that binds an Agent to the SignalWire platform. When start() is called, it translates the LiveWire agent definition into a SignalWire AgentBase instance, mapping instructions to prompts, tools to SWAIG functions, and LLM model settings to SignalWire AI parameters.

import { Agent, AgentSession } from '@signalwire/sdk/livewire';
const agent = new Agent({ instructions: 'You are a helpful assistant.' });
const session = new AgentSession();
await session.start({ agent });

Constructor

new AgentSession<UserData>(options?: {
  stt?: any;
  tts?: any;
  llm?: any;
  vad?: any;
  turnDetection?: any;
  tools?: FunctionTool[] | Record<string, FunctionTool>;
  mcpServers?: unknown;
  userData?: UserData;
  allowInterruptions?: boolean;
  minInterruptionDuration?: number;
  minEndpointingDelay?: number;
  maxEndpointingDelay?: number;
  maxToolSteps?: number;
  preemptiveGeneration?: boolean;
})

stt

any

STT provider instance. Accepted for API compatibility; SignalWire handles speech recognition automatically. Logs an informational message on first use.

tts

any

TTS provider instance. Accepted for API compatibility; SignalWire handles text-to-speech automatically. Logs an informational message on first use.

llm

any

A model name, or an LLM plugin object such as plugins.OpenAILLM whose model is used. Sets the model param on the underlying SignalWire agent, with any provider/ prefix (like "openai/") removed.

vad

any

VAD provider instance. Accepted for API compatibility; SignalWire handles voice activity detection automatically.

turnDetection

any

Turn detection configuration. Accepted for API compatibility; SignalWire handles turn detection automatically.

tools

FunctionTool[] | Record<string, FunctionTool>

Optional additional tools, as an array or an object keyed by name, merged with the agent’s tools when start() is called.

mcpServers

unknown

Accepted for LiveKit parity. MCP servers are not yet supported in LiveWire — logs a one-time advisory and has no effect.

userData

UserDataDefaults to {}

Arbitrary data attached to the session. Accessible from tool handlers via RunContext.userData.

allowInterruptions

booleanDefaults to true

false sets the enable_barge AI param to false when the session starts, which turns barge-in off.

minInterruptionDuration

numberDefaults to 0.5

Accepted for LiveKit parity. Forwarded to the SignalWire AI params when the session starts.

minEndpointingDelay

numberDefaults to 0.5

Minimum endpointing delay in seconds. Forwarded to the SignalWire AI params when the session starts.

maxEndpointingDelay

numberDefaults to 3.0

Maximum endpointing delay in seconds. Forwarded to the SignalWire AI params when the session starts.

maxToolSteps

numberDefaults to 3

Accepted for LiveKit parity. SignalWire handles tool-execution depth automatically — logs a one-time advisory if set to a non-default value.

preemptiveGeneration

booleanDefaults to false

Accepted for LiveKit parity. Stored on the session but not currently used.

Properties

userData

UserData

Getter/setter for the session’s user data. Defaults to an empty object.

Methods

start

Bind an Agent and prepare the underlying SignalWire AgentBase.

say

Queue text to be spoken by the agent.

generateReply

Trigger the agent to generate a reply.

interrupt

No-op. SignalWire handles barge-in automatically.

updateAgent

Swap in a new Agent mid-session.

getSwAgent

getSwAgent(): AgentBase | undefined

Returns the underlying SignalWire AgentBase instance, or undefined if start() has not been called yet. Useful for testing or advanced configuration.