| github.com/open-policy-agent/opa/v1/ast | Package ast declares Rego syntax tree types and also includes a parser and compiler for preparing policies for execution in the policy engine. |
| github.com/open-policy-agent/opa/v1/metrics | Package metrics contains helpers for performance metric management inside the policy engine. |
| github.com/open-policy-agent/opa/v1/topdown | Package topdown provides low-level query evaluation support. |
| sort | Package sort provides primitives for sorting slices and user-defined collections. |
| time | Package time provides functionality for measuring and displaying time. |