> For the complete documentation index, see [llms.txt](https://docs.vechain.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.vechain.org/developer-resources/index-with-graph-node/index-with-openzeppelin.md).

# Index with OpenZeppelin

OpenZeppelin is a trusted source of well-tested contract libraries and provides matching subgraphs for its contracts.

Read more about it on [docs.openzeppelin.com](https://docs.openzeppelin.com/subgraphs/0.1.x/).

This example will show how to index the ERC20 tokens B3TR and VOT3.