[Home](./index.md) > [puppeteer](./puppeteer.md) > [Protocol](./puppeteer.protocol.md) > [BackgroundService](./puppeteer.protocol.backgroundservice.md) > [EventMetadata](./puppeteer.protocol.backgroundservice.eventmetadata.md) ## Protocol.BackgroundService.EventMetadata interface A key-value pair for additional event information to pass along. Signature: ```typescript export interface EventMetadata ``` ## Properties | Property | Type | Description | | --- | --- | --- | | [key](./puppeteer.protocol.backgroundservice.eventmetadata.key.md) | string | | | [value](./puppeteer.protocol.backgroundservice.eventmetadata.value.md) | string | |