[Home](./index.md) > [puppeteer](./puppeteer.md) > [Protocol](./puppeteer.protocol.md) > [Accessibility](./puppeteer.protocol.accessibility.md) > [QueryAXTreeRequest](./puppeteer.protocol.accessibility.queryaxtreerequest.md) > [backendNodeId](./puppeteer.protocol.accessibility.queryaxtreerequest.backendnodeid.md) ## Protocol.Accessibility.QueryAXTreeRequest.backendNodeId property Identifier of the backend node for the root to query. Signature: ```typescript backendNodeId?: DOM.BackendNodeId; ```