> ## Documentation Index > Fetch the complete documentation index at: https://docs.near.org/llms.txt > Use this file to discover all available pages before exploring further. # Tutorial: State Changes > This tutorial will guide you through building a simple indexer using the NEAR Lake Framework. The indexer will listen for StateChange events and print relevant data about account changes. This tutorial will guide you through building a simple indexer using the NEAR Lake Framework. The indexer will listen for `StateChange` events and print relevant data about account changes. **Source code for the tutorial** [`near-examples/near-lake-accounts-watcher`](https://github.com/near-examples/near-lake-accounts-watcher/tree/0.2.0): source code for a video tutorial on how to use the NEAR Lake Framework **Version 0.2.0** The video is based on the [`near-lake-framework`](/data-infrastructure/near-lake-framework) version 0.2.0 At the same time we're keeping the source code up to date with the latest version of the published crate. We've created a video tutorial to empower the release announcement of [NEAR Lake Framework](/data-infrastructure/near-lake-framework). In this tutorial you will build an indexer application to watch for any `StateChange`s affecting the account or a list of account provided.