Defining gRPC Services

1. Creating Service Definitions

Element	Convention
Service name	PascalCase + `Service` suffix
Method name	PascalCase verb-first: `CreateUser`, `ListUsers`
Request/Response	`MethodName + Request` / `+ Response`

rpc GetUser(GetUserRequest) returns (GetUserResponse);

Property	Detail
Pattern	1 request → 1 response
Use	Default for CRUD-like ops

rpc ListEvents(ListEventsRequest) returns (stream Event);

Use Case	Detail
Large result set	Avoid huge single response
Real-time feed	Push updates as they happen

rpc UploadFile(stream FileChunk) returns (UploadResult);

Use Case	Detail
File upload	Chunked transfer
Telemetry ingest	Batch metrics

rpc Chat(stream ChatMessage) returns (stream ChatMessage);

Use Case	Detail
Chat / collaboration	Full-duplex
Real-time pricing	Subscribe + send updates

Best Practice	Reason
Always use a dedicated request message	Future-proof — can add fields
Avoid scalar parameters	Not extensible
Include pagination fields	`page_size`, `page_token`

Best Practice	Reason
Dedicated response message	Extensibility
Include `next_page_token`	Pagination cursor
Avoid leaking server internals	Stable contract

service UserService { rpc GetUser(...) returns (...); }
service AdminService { rpc DeleteUser(...) returns (...); }

Tip	Detail
Split by audience	Public vs internal services
One service per file	Easier ownership & versioning

Option	Trade-off
`google.protobuf.Empty`	Shortest, but cannot evolve
Custom empty message	Recommended — extensible later