Transport

The ChatTransportAdapter delivers streaming events (text deltas, tool calls, thinking steps) to connected clients in real-time.

Interface

interface ChatTransportAdapter {
  publishEvents(runId: string, events: AnyChatEvent[]): Promise<void>;
  getReplayState(runId: string): Promise<StreamingStateReplayEvent | null>;
  getEvents(runId: string, afterSeq?: number): Promise<{ events: AnyChatEvent[]; latestSeq: number }>;
  markComplete(runId: string, result: ProcessMessageResult): Promise<void>;
  markError(runId: string, error: string): Promise<void>;
  getConnectionUrl(runId: string): string;
  readonly provider: string;
}

Built-in Implementations

Cloudflare Workers

import { AgentsSDKTransportAdapter } from "@aimform/ai";
 
const transport = new AgentsSDKTransportAdapter(
  env.WORKFLOW_CHAPERONE_AGENT,
  "https://api.aimform.com",
);
 
// The WorkflowChaperoneAgent DO handles WebSocket connections.
// Clients connect at: wss://api.aimform.com/api/conversations/ws/:runId

The companion WorkflowChaperoneAgent (extending Agent<Env>) buffers up to 2000 events in memory and auto-broadcasts to all connected WebSocket clients.

Late-Joiner Replay

Clients that reconnect mid-stream receive the full accumulated state:

Client connects → sends { type: "subscribe", runId, afterSeq: 0 }
  → Agent replies with streaming_state_replay event containing:
    - All accumulated text
    - Active tool executions
    - Current streaming blocks
    - Latest sequence number
  → Continues receiving live events

Custom Transport (Node.js WebSocket)

class WebSocketTransport implements ChatTransportAdapter {
  readonly provider = "ws";
  private wss: WebSocketServer;
 
  async publishEvents(runId: string, events: AnyChatEvent[]) {
    for (const client of this.wss.clients) {
      if (client.readyState === WebSocket.OPEN) {
        for (const event of events) {
          client.send(JSON.stringify(event));
        }
      }
    }
  }
 
  // ... implement other methods
}
 
// Usage on VPS
import { WebSocketServer } from "ws";
const wss = new WebSocketServer({ port: 8080 });
const transport = new WebSocketTransport(wss);

AWS API Gateway

class APIGatewayTransport implements ChatTransportAdapter {
  readonly provider = "aws-api-gateway";
 
  constructor(private apiGateway: ApiGatewayManagementApi) {}
 
  async publishEvents(runId: string, events: AnyChatEvent[]) {
    const connections = await this.getConnections(runId);
    for (const conn of connections) {
      await this.apiGateway.postToConnection({
        ConnectionId: conn.id,
        Data: JSON.stringify({ events }),
      }).promise();
    }
  }
}