# ENSIndexer Overview

ENSIndexer is a reference implementation of an [ENSDb Writer](/docs/services/ensdb/concepts/glossary#ensdb-writer). It uses [Ponder](https://ponder.sh) for indexing ENS state from contracts across multiple chains. It processes events from each relevant chain and transforms the data, storing it in your ENSDb instance.

:::note
While ENSIndexer can be run independently in certain scenarios, it is designed to work as part of the complete ENSNode system, and we recommend following the [ENSNode Contribution Guide](/docs/reference/contributing) if you'd like to run ENSIndexer locally, or the [ENSNode Deployment Guide](/docs/self-host) if you'd like to run ENSIndexer in the cloud.
:::

## Configuration

ENSIndexer can be configured via environment variables.

[ENSIndexer Configuration Options](/docs/services/ensindexer/usage/configuration)