[Home](./index.md) > [puppeteer](./puppeteer.md) > [Protocol](./puppeteer.protocol.md) > [BackgroundService](./puppeteer.protocol.backgroundservice.md) > [BackgroundServiceEvent](./puppeteer.protocol.backgroundservice.backgroundserviceevent.md) > [instanceId](./puppeteer.protocol.backgroundservice.backgroundserviceevent.instanceid.md) ## Protocol.BackgroundService.BackgroundServiceEvent.instanceId property An identifier that groups related events together. Signature: ```typescript instanceId: string; ```