| context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| flag | Package flag implements command-line flag parsing. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| google.golang.org/grpc | Package grpc implements an RPC system called gRPC. |
| google.golang.org/grpc/grpclog | Package grpclog defines logging for grpc. |
| google.golang.org/grpc/interop/grpc_testing | |
| google.golang.org/grpc/metadata | Package metadata define the structure of the metadata supported by gRPC library. |
| google.golang.org/grpc/peer | Package peer defines various peer information associated with RPCs and corresponding utils. |
| google.golang.org/grpc/xds | Package xds contains an implementation of the xDS suite of protocols, to be used by gRPC client and server applications. |
| log | Package log implements a simple logging package. |
| net | Package net provides a portable interface for network I/O, including TCP/IP, UDP, domain name resolution, and Unix domain sockets. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| sync/atomic | Package atomic provides low-level atomic memory primitives useful for implementing synchronization algorithms. |
| time | Package time provides functionality for measuring and displaying time. |