| ## RPC (Remote Procedure Call) Types | |
| This package contains [protocol buffer][protobuf] types that represent remote procedure | |
| call concepts. While [gRPC](https://grpc.io) uses these types, we encourage their | |
| use in any interested RPC implementation to promote compatibility and consistency. | |
| ### Key Concepts | |
| - **Code**: An enum that represents an error code returned by an RPC. These error codes | |
| map to HTTP codes, but are slightly finer-grained. Every gRPC code has exactly one | |
| corresponding HTTP code; however, some HTTP codes have more than one corresponding | |
| gRPC code. | |
| - **Error details**: Any of the types contained in `error_details.proto` which provide | |
| extra details about particular types of failures. | |
| - **Status**: Combines a code, message, and error details to represent the success or | |
| failure details of an RPC call. | |
| [protobuf]: https://developers.google.com/protocol-buffers/ | |