[Home](./index.md) > [puppeteer](./puppeteer.md) > [Protocol](./puppeteer.protocol.md) > [DOMDebugger](./puppeteer.protocol.domdebugger.md) > [EventListener](./puppeteer.protocol.domdebugger.eventlistener.md) > [once](./puppeteer.protocol.domdebugger.eventlistener.once.md) ## Protocol.DOMDebugger.EventListener.once property `EventListener`'s once flag. Signature: ```typescript once: boolean; ```