grapesy: industrial strength gRPC library for Haskell

Haskell library providing gRPC client and server.

Interoperability matrix

The gRPC framework comes with a test suite that tests interoperability between implementations as well compliance to the gRPC specification. As the table below shows, grapesy passes all of these tests, apart from the Open Request Cost Aggregation (ORCA) tests, which is not yet supported by grapesy.

Legend and version information

Legend:

• ✅ passed
• ❌ failed
• ❔ not supported by the reference (or reference does not conform to the gRPC specification)
• 🚫 not supported by grapesy

We last tested against version v1.83.0 (released July 21, 2026).

grapesy server versus reference client

grapesy client versus reference server

Unsupported tests

There are additional tests that are not supported by grapesy, but since these are not supported by most (or indeed any) of the reference implementations that we tested, we did not consider them any further. The full list is:

• cacheable_unary
• channel_soak
• compute_engine_channel_credentials
• compute_engine_creds
• concurrent_large_unary
• google_default_credentials
• jwt_token_creds
• long_lived_channel
• max_concurrent_streams_connection_scaling
• oauth2_auth_token
• per_rpc_creds
• rpc_soak

Memory profiles

Screenshots of the "Area Chart" display of the eventlog2html output for selected RPC communication patterns.

Many connections

Client opens many connections and does a single non-streaming RPC.

Client profile:

Server profile:

Many calls

Client opens a single connection and does many RPCs.

Client profile:

Server profile:

Many messages

Client opens a single connection and does a single RPC that sends many messages.

Client profile:

Server profile:

Benchmarks