[Home](./index.md) > [puppeteer](./puppeteer.md) > [Protocol](./puppeteer.protocol.md) > [Network](./puppeteer.protocol.network.md) > [RequestWillBeSentEvent](./puppeteer.protocol.network.requestwillbesentevent.md) > [loaderId](./puppeteer.protocol.network.requestwillbesentevent.loaderid.md) ## Protocol.Network.RequestWillBeSentEvent.loaderId property Loader identifier. Empty string if the request is fetched from worker. Signature: ```typescript loaderId: LoaderId; ```