| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| github.com/open-policy-agent/opa/ast | Deprecated: This package is intended for older projects transitioning from OPA v0.x and will remain for the lifetime of OPA v1.x, but its use is not recommended. |
| github.com/open-policy-agent/opa/storage | Package storage exposes the policy engine's storage layer. |
| github.com/open-policy-agent/opa/util | Package util provides generic utilities used throughout the policy engine. |
| github.com/pkg/errors | Package errors provides simple error handling primitives. |
| io | Package io provides basic interfaces to I/O primitives. |
| math | Package math provides basic constants and mathematical functions. |
| regexp | Package regexp implements regular expression search. |
| strconv | Package strconv implements conversions to and from string representations of basic data types. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |