Making a WebSocket survive Chrome's Manifest V3

Short summary

A detailed engineering post on keeping WebSockets alive inside Chrome Manifest V3 extensions, where service workers are terminated after ~30s of idle time. The fix involves three parts: a 20-second heartbeat to keep the worker active, auto-reconnect that pulls a fresh state snapshot so drops are invisible to users, and try/catch around every port message since the worker can die mid-operation. The article includes concrete code examples and explains the CSP and lifecycle constraints that led to the bug.

• •Manifest V3 service workers terminate after ~30s idle, killing any WebSocket living in them
• •Fix requires heartbeat to reset idle timer, auto-reconnect with state snapshot, and defensive try/catch on port messages
• •Content scripts can't open WebSockets on GitHub due to strict CSP in Firefox, forcing socket into the background worker

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