| encoding/json | Package json implements encoding and decoding of JSON as defined in RFC 7159. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| net/http | Package http provides HTTP client and server implementations. |
| net/http/httptest | Package httptest provides utilities for HTTP testing. |
| net/url | Package url parses URLs and implements query escaping. |
| 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. |