| context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| 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/prometheus/client_golang/api | Package api provides clients for the HTTP APIs. |
| github.com/prometheus/common/model | Package model contains common data structures that are shared across Prometheus components and libraries. |
| net/http | Package http provides HTTP client and server implementations. |
| strconv | Package strconv implements conversions to and from string representations of basic data types. |
| time | Package time provides functionality for measuring and displaying time. |