# Subgraphs

DFX leverages subgraphs which listens for events from one or more data sources (*Smart Contracts*) on Ethereum Mainnet and Layer 2 Solutions. Subgraphs are powerful because they can index and cache contract data which can be queried with GraphQL.

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## Resources

* [Subgraph Source Code](https://github.com/dfx-finance/subgraph)
* [Mainnet Subgraph](https://thegraph.com/hosted-service/subgraph/dfx-finance/dfx-v1)
* [Polygon Subgraph](https://thegraph.com/hosted-service/subgraph/dfx-finance/dfx-v1-polygon)