# MarketDataKeyRule

- [OpenAPI fragment](https://www.lusid.com/docs/api/lusid/schemas/MarketDataKeyRule.json)
- [Rendered page](https://www.lusid.com/docs/api/lusid/schemas/MarketDataKeyRule)

When performing analytics, instruments and models have dependencies on market data.
A market data key rule essentially tells lusid to "resolve dependencies matching the pattern 'X' using data of the form 'Y'".
The parameter 'X' is defined by the key of the key rule, and might specify "all USD rates curves" or "all RIC-based prices".
The parameter 'Y' is defined by the remaining fields of the key rule, and allows the user to configure things such as
where to look for data, what sort of data should be looked for (e.g. bid/mid/ask), and how old the data is allowed to be.

## Used by schemas

- [MarketContext](https://www.lusid.com/docs/api/lusid/schemas/MarketContext.txt)
- [GroupOfMarketDataKeyRules](https://www.lusid.com/docs/api/lusid/schemas/GroupOfMarketDataKeyRules.txt)

[< Schemas](https://www.lusid.com/docs/api/lusid/schemas/llms.txt)