# rpc error: code = Unimplemented desc = unknown method GetUser for service pb.UserService

- **ID:** `go/grpc-unknown-service-method`
- **Domain:** go
- **Category:** module_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

The server has registered the service but not this specific method. Typically caused by an outdated generated server stub or a client using a newer proto than the server.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 1.0+ | active | — | — |

## Workarounds

1. **** (95% success)
   ```
   protoc --go_out=. --go-grpc_out=. user.proto
go build ./...
   ```
2. **** (90% success)
   ```
   grpcurl -plaintext localhost:50051 describe pb.UserService
   ```

## Dead Ends

- **** — The method handler must exist as a generated function; string manipulation on descriptors does not register a callable handler (90% fail)
- **** — The older method may not exist either; the correct fix is aligning proto versions (70% fail)