| encoding/json | Package json implements encoding and decoding of JSON as defined in RFC 7159. |
| errors | Package errors implements functions to manipulate errors. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| github.com/open-policy-agent/opa/metrics | 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. |
| net/http | Package http provides HTTP client and server implementations. |
| strconv | Package strconv implements conversions to and from string representations of basic data types. |