Embed a Relay in another runtime

Use RelayCore when @olimsaidov/icdp/relay/node does not match your server runtime.

import { RelayCore } from "@olimsaidov/icdp/relay";

const core = new RelayCore({
  product: "my-shell/1.0",
  browserWsUrl: "wss://debug.example.com/devtools/browser",
  targetWsUrl: (targetId) =>
    `wss://debug.example.com/devtools/page/${encodeURIComponent(targetId)}`,
});

Wrap each WebSocket in one stable object:

type SocketLike = {
  send(data: string): void;
  close(code?: number, reason?: string): void;
};

Do not create a new wrapper per event; RelayCore uses object identity to match connections.

Wire socket events

For the single Host-uplink route:

core.hostConnected(hostSocket);
core.hostMessage(hostSocket, rawText);
core.hostDisconnected(hostSocket);

For every Client CDP socket:

core.clientConnected(clientSocket); // browser endpoint
core.clientMessage(clientSocket, rawText);
core.clientDisconnected(clientSocket);

For /devtools/page/<targetId>, decode the path segment and pass the Target:

core.clientConnected(clientSocket, targetId);

RelayCore rejects an unknown Target, assigns Client ids, and transports raw CDP to the Host. Do not parse or route CDP in the adapter.

Serve discovery

Expose these JSON payload builders on the browser-side HTTP server:

Path	Value
/json/version	core.jsonVersion()
/json, /json/list	core.jsonList()
/icdp/status	core.status()

jsonVersion() advertises browserWsUrl. Each jsonList() entry uses targetWsUrl(targetId) and is backed by an implicit Host Session.

A new Host socket remains a contender until RelayCore validates its ready frame. It cannot alter Targets or reach Clients before promotion. Once valid, it replaces the old Host socket, closes that socket with code 1008, and replaces the cached Target summaries.