# warp-grpc

A gRPC server implementation on top of Warp's HTTP2 handler.  The lib also
contains a demo sever using the awesome `grpcb.in` Proto. The current release
is an advanced technical demo, expect a few breaking changes.

## Design

The library implements gRPC using a WAI middleware for a set of gRPC endpoints.
Endpoint handlers differ depending of the streaming/unary-ty of individual
RPCs. Bidirectional streams will be supported next.

There is little specification around the expected allowed observable states in
gRPC, hence the types this library presents make conservative choices: unary
RPCs expect an input before providing an output. Client stream allows to return
an output only when the client has stopped streaming. Server streams wait for
an input before starting to iterate sending outputs.

## Usage

Generate some `proto-lens` code from `.proto` files, ideally in a separate
library.  Import this library and the generated proto-lens code to implement
handlers for the `service` stanzas defined in the `.proto` files (see
Haddocks). Finally, serve `warp` over TLS`.

## Next steps

* Handler type for bidirectional streams.

## Limitations

* Only supports "h2" with TLS (I'd argue it's a feature, not a bug. Don't @-me)