Subtitle: If your APIs speak protobuf and gRPC, a JSON-first client will fight you at every step.
Most API clients were built for a world of REST and JSON.
That works fine until your service returns application/x-protobuf, your contracts live in .proto files, and your real traffic is gRPC—including streaming. At that point, the “universal” API client stops feeling universal.
This post breaks down where Postman (and tools like it) tend to break down for protobuf workflows—and what a protobuf-native workflow looks like instead.
1. Protobuf is a contract, not a blob
