Types & Interfaces

This document describes the common types and interfaces used throughout the Artico ecosystem.

Core Types

SignalingState

The state of the signaling connection:

type SignalingState =
  | "disconnected" // Not connected to the server
  | "connecting" // Attempting to connect
  | "connected" // Connected but no ID assigned yet
  | "ready"; // Connected and ready to make calls

LogLevel

The logging level for debugging:

enum LogLevel {
  None = 0, // No logs
  Errors = 1, // Error logs only
  Warnings = 2, // Errors and warnings
  Info = 3, // Errors, warnings, and info
  Debug = 4, // All logs including debug
}

Signal Messages

InSignalMessage

Messages received from other peers through the signaling server:

type InSignalMessage = {
  source: string; // ID of the peer sending the signal
  target: string; // ID of the target peer (should be your ID)
  session: string; // Session ID for the call/room
  signal: Signal; // The WebRTC signal data
  metadata?: string; // Optional metadata attached to the signal
};

OutSignalMessage

Messages sent to other peers through the signaling server:

type OutSignalMessage = {
  target: string; // ID of the peer to send the signal to
  session: string; // Session ID for the call/room
  signal: Signal; // The WebRTC signal data
  metadata?: string; // Optional metadata to attach
};

Signal

WebRTC signaling data:

type Signal =
  | {
      type: "candidate";
      data: RTCIceCandidate;
    }
  | {
      type: "sdp";
      data: RTCSessionDescription;
    };

Interfaces

Signaling Interface

The interface that all signaling implementations must follow:

interface Signaling extends EventEmitter<SignalingEvents> {
  get id(): string;
  get state(): SignalingState;

  connect(): void;
  disconnect(): void;
  signal(message: OutSignalMessage): void;
  join(roomId: string, metadata?: string): Promise<void>;
}

type SignalingEvents = {
  connect: (id: string) => void;
  disconnect: () => void;
  error: (err: Error) => void;
  signal: (message: InSignalMessage) => void;
  join: (roomId: string, peerId: string, metadata?: string) => void;
};

Peer Data Types

PeerData

Data that can be sent through a peer connection:

type PeerData = string | ArrayBuffer | Blob | ArrayBufferView;

Default Configurations

Default RTCConfiguration

Artico uses the following default RTCConfiguration:

const defaultRTCConfig: RTCConfiguration = {
  iceServers: [
    { urls: "stun:stun.l.google.com:19302" },
    { urls: "stun:stun1.l.google.com:19302" },
  ],
};

Default SocketSignaling URL

The default signaling server URL:

const defaultSignalingURL = "https://0.artico.dev:443";

Error Types

Common Error Messages

Artico uses specific error messages for common scenarios:

• "id-taken" - The requested peer ID is already in use
• "invalid-id" - The provided peer ID is invalid
• "Cannot call peers until signaling is ready." - Attempted to make a call before signaling is ready
• "Cannot join room until signaling is ready." - Attempted to join a room before signaling is ready
• "Only non-initiators can answer calls" - Attempted to answer a call as the initiator