1gRPC Internationalization 2========================= 3 4As a universal RPC framework, gRPC needs to be fully usable within/across different international environments. 5This document describes gRPC API and behavior specifics when used in a non-english environment. 6 7## API Concepts 8 9While some API elements need to be able to represent non-english content, some are intentionally left as ASCII-only 10for simplicity & performance reasons. 11 12### Method name (in RPC Invocation) 13Method names are ASCII-only and may only contain characters allowed by HTTP/2 text header values. That should not 14be very limiting as most gRPC services will use protobuf which only allows method names from an even more restricted ASCII subset. 15Also, handling method names is a very hot code path so any additional encoding/decoding step is to be avoided. 16 17Recommended representation in language-specific APIs: string type. 18 19### Host name (in RPC Invocation) 20Host names are punycode encoded, but the user is responsible for providing the punycode-encoded string if she wishes to use an internationalized host name. 21 22Recommended representation in language-specific APIs: string/unicode string. 23 24NOTE: overriding host name when invoking RPCs is only supported by C-core based gRPC implementations. 25 26### Status detail/message (accompanies RPC status code) 27 28Status messages are expected to contain national-alphabet characters. 29Allowed values are unicode strings (content will be percent-encoded on the wire). 30 31Recommended representation in language-specific APIs: unicode string. 32 33### Metadata key 34Allowed values are defined by HTTP/2 standard (metadata keys are represented as HTTP/2 header/trailer names). 35 36Recommended representation in language-specific APIs: string. 37 38### Metadata value (text-valued metadata) 39Allowed values are defined by HTTP/2 standard (metadata values are represented as HTTP/2 header/trailer text values). 40 41Recommended representation in language-specific APIs: string. 42 43### Channel target (in channel creation) 44 45TBD 46