| container/list | Package list implements a doubly linked list. |
| context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| 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/util | Package util provides generic utilities used throughout the policy engine. |
| math | Package math provides basic constants and mathematical functions. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| time | Package time provides functionality for measuring and displaying time. |