---
title: "Contracts Usage Patterns"
canonical: "https://support.apollographql.com/space/ETKB/655622200/Contracts%20Usage%20Patterns"
format: markdown
---
[Contracts](https://www.apollographql.com/docs/studio/contracts/) enable teams to contribute to a single unified graph while also delivering use-case-specific schemas to different types of consumers. Graph administrators define filter rules to generate **contract schemas **that are a strict subset of the source supergraph.

There are three different filtering strategies you can use for a contract:

- Selective exclusion (pruning)
- Selective inclusion (deny by default)
- Combined exclusion and inclusion

[Learn more on the dev docs](https://www.apollographql.com/docs/technotes/TN0014-contracts-patterns/).