V10.5 Task B.1: Frontend — Attach Token for reconnection

[up-guillaume]

Problem

When mobile user switches apps and returns, WebSocket reconnects but loses execution context.

Solution

Store attach token in localStorage to rejoin ongoing execution:

// When execution starts
const attachToken = uuid();
localStorage.setItem(`chat_${agentId}_${sessionId}`, attachToken);

// On reconnect
const existingToken = localStorage.getItem(`chat_${agentId}_${sessionId}`);
if (existingToken) {
  ws.send(JSON.stringify({ type: 'attach', token: existingToken }));
}

Acceptance Criteria

• Token stored when execution starts
• Token used on reconnect
• Token cleaned up when execution ends

Related

• Plan: PLAN_V10_5.md