[Home](./index.md) > [puppeteer](./puppeteer.md) > [Protocol](./puppeteer.protocol.md) > [Fetch](./puppeteer.protocol.fetch.md) > [AuthChallenge](./puppeteer.protocol.fetch.authchallenge.md) > [source](./puppeteer.protocol.fetch.authchallenge.source.md) ## Protocol.Fetch.AuthChallenge.source property Source of the authentication challenge. Signature: ```typescript source?: ('Server' | 'Proxy'); ```