| 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. |
| google.golang.org/grpc | Package grpc implements an RPC system called gRPC. |
| google.golang.org/grpc/balancer | Package balancer defines APIs for load balancing in gRPC. |
| google.golang.org/grpc/codes | Package codes defines the canonical error codes used by gRPC. |
| google.golang.org/grpc/connectivity | Package connectivity defines connectivity semantics. |
| google.golang.org/grpc/grpclog | Package grpclog defines logging for grpc. |
| google.golang.org/grpc/health/grpc_health_v1 | |
| google.golang.org/grpc/internal | Package internal contains gRPC-internal code, to avoid polluting the godoc of the top-level grpc package. |
| google.golang.org/grpc/internal/backoff | Package backoff implement the backoff strategy for gRPC. |
| google.golang.org/grpc/status | Package status implements errors returned by gRPC. |
| io | Package io provides basic interfaces to I/O primitives. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| time | Package time provides functionality for measuring and displaying time. |