JSON-RPC 2.0 types and type classes for Haskell.

A lightweight implementation of the JSON-RPC 2.0 protocol types for Haskell with Aeson serialisation. Provides the core request, response, notification, and error types along with type classes for deriving JSON-RPC method dispatch via DerivingVia.

Implements the specification at https://www.jsonrpc.org/specification.

jsonrpc

A lightweight Haskell implementation of JSON-RPC 2.0 protocol types with Aeson serialisation.

Features

• Core message types: requests, responses, notifications, and errors
• IsJSONRPCRequest / IsJSONRPCNotification type classes for automatic method dispatch via DerivingVia
• Standard error codes from the specification
• Spec-compliant JSON encoding (optional params, error data field, etc.)

Quick start

{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE DerivingVia #-}
{-# LANGUAGE DuplicateRecordFields #-}
{-# LANGUAGE TypeFamilies #-}

import JSONRPC
import Data.Aeson (FromJSON, ToJSON)
import GHC.Generics (Generic)

-- Define your request type
data PingRequest = PingRequest
    { id :: RequestId
    , params :: Maybe ()
    }
    deriving stock (Show, Eq, Generic)
    deriving (ToJSON, FromJSON) via ViaJSONRPCRequest PingRequest

instance IsJSONRPCRequest PingRequest where
    requestMethod _ = "ping"

License

MPL-2.0