Support grpc-web

[jzelinskie]

Despite a general trend of grpc-web becoming less popular over time, there are still environments, such as Cloudflare Workers, that make sense to leverage grpc-web rather than grpc-gateway.

In the past, we've ran a small proxy that embeds Improbable's grpc-web implementation -- there's no reason why we couldn't build this directly into SpiceDB.

[RichiCoder1]

I believe this would allow using this: https://github.com/timostamm/protobuf-ts/tree/main/packages/grpcweb-transport

Which appears to be WinterCG env compatible (e.g. it uses fetch and no node deps)

[RichiCoder1]

Another option I've recently discovered that might be interesting for ya'll is Buf's connect: https://connect.build/docs/introduction

Their JS/HTTP API implementation seems excellent and compatible w/ fetch/WinterCG environments.

(and supports grpc-web too)

[rikkuness]

In my own servers I've added a configurable option to enable the improbable grpc-web server listed above. It's useful for convenience but in production type deployments I'll instead offload this to an Envoy reverse proxy/sidecar using the GrpcWeb filter https://www.envoyproxy.io/docs/envoy/latest/configuration/http/http_filters/grpc_web_filter

I've also used both of these with the above mentioned protobuf-ts and both work perfectly well together.