@nativeharness/protocol

The versioned event contract your frontend renders, and the HTTP/SSE binding that carries it: start a turn, watch it, reconnect, replay.

npm install @nativeharness/protocol

import { SessionService, createHandler } from "@nativeharness/protocol";

const service = new SessionService({ agent, store, events });
server.on("request", createHandler({ service }));

No UI is imposed. Nineteen event types — tokens, tool starts and results, output as it is produced, approvals, questions, done — and your own components decide what they look like.

Reconnection is a cursor, not a hope: events are persisted before they are emitted, so a client that drops picks up exactly where it left off.

Part of nativeharness — the agent harness native to your app. Apache-2.0 · docs · source