# Policies

| Reference | What it covers |
| [OPA policies](/products/affinidi-trust-fabric/agent-stream/reference/policies/opa-policies.md) | Writing and enforcing Rego policies: the three policy types and their Rego packages, the policy editor’s fields, the data a policy evaluates against, and how to test a policy before enforcing it. |

## Pages in this section
- [OPA policies](/products/affinidi-trust-fabric/agent-stream/reference/policies/opa-policies.md): Field reference for the three policy types and their Rego packages, the policy editor, global assignments, the input document a policy evaluates against, the surface-level OPA Policy block, and VP evidence.