[drunner]

Do you have a preferred message protocol?

[VHRanger]

JSON with a good schema if you're doing it across languages?

[swatcoder]

XML, JSON, and YAML belong to a totally diffent class of use than protobuf, flatbuffers, capnproto, etc

It's like comparing apples and screwdrivers.

[hot_gril]

They're comparable for a lot of use cases. In fact many protobuf-based APIs will also have a JSON mode.

[swatcoder]

Exactly because the consumers of those API's exhibit a strong preference for one or the other.

Library/module/API developers often seek to deliver maximimum adaptibility in their interfaces so that consumers of them can satisfy their own more specific/pressing requirements.

[dilyevsky]

imo it's mainly because protos are unusable on the web without something like grpc-web (which requires a proxy) and in general web support in protobufs always seemed like an afterthought, just barely working (if at all) which is kind of ironic considering it came out of Google

[hot_gril]

I've never used protobufs with web, but I don't see why not. gRPC, on the other hand, requires HTTP/2 which can be a luxury. I remember making a side project that uses gRPC a while ago and trying to deploy on GCP AppEngine, only to find out it doesn't support gRPC.

[TillE]

I'm sure there's some great schema implementation that you can bolt onto JSON, but personally I have never seen anyone actually using one in the wild.

With protobuf the schema is essential, it is the foundation. I feel this is a huge advantage especially for communication protocols.

[VHRanger]

We've used it. It's useful to define the contract between teams.

So you have 2 teams do a meeting, we work out a contract we like, dump that into a jsonschema and you can enforce by unit tests that schema is respected on each side (producer/consumer)

[sagarm]

JSON is the serialization format. What's the IDL?

[hot_gril]

I've seen OpenAPI/Swagger in the wild a few times. It's a good way to specify the API for an HTTP server, whether it's JSON or something else. Biggest downside is the confusing name change.