# Indexer In addition to the [subgraph](https://thegraph.com/legacy-explorer/subgraph/ourzora/zora-v1) on Graph Protocol, Zora maintains its own indexer that serves a GraphQL API full of useful information about the Zora protocol and the entire NFT universe. The Indexer watches the Zora Media, Market, and Auction House contracts as well as a set of arbitrary ERC-721 contracts. Indexer also regularly fetches and refreshes ERC-721 metadata json data, so clients can query NFTs by their metadata properties. Currently Indexer only watches Ethereum networks, but is extensible to include other EVM networks. Begin making example queries in our hosted GraphQL [**playground**](https://ourzora.github.io/indexer-playground/) on both Rinkeby and Mainnet. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://ourzora.gitbook.io/zoraos/dev/indexer.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.