> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cognite.com/llms.txt
> Use this file to discover all available pages before exploring further.

# RequiresConstraintCycle validation rule

> Validates that requires constraints between containers do not form cycles. Deployment will fail if cycles exist.

This rule checks whether the requires constraints between containers form a cycle.
For example, if container `A` requires `B`, `B` requires `C`, and `C` requires `A`, this forms
a cycle.

## Why it matters

Cycles in requires constraints will be rejected by the CDF API. The deployment
of the data model will fail if any such cycle exists.

## Example

Container `my_space:OrderContainer` requires `my_space:CustomerContainer`, which
requires `my_space:OrderContainer`. This creates a cycle and will be rejected.

## Further reading

* [Validation rules](/cdf/deploy/neat/validation/index)