# JSON-RPC 2.0

Golang implementation of JSON-RPC 2.0 server with generics.

Go 1.18+ required

## Features:

- [x] HTTP/HTTPS transport
- [x] TCP transport
- [ ] WebSocket transport

## Usage (http transport)

1. Create JSON-RPC server:
```go
    import "go.neonxp.dev/jsonrpc2/rpc"
    ...
    s := rpc.New()
```

2. Add required transport(s):
```go
    import "go.neonxp.dev/jsonrpc2/transport"
    ...
    s.AddTransport(&transport.HTTP{Bind: ":8000"})
    s.AddTransport(&transport.TCP{Bind: ":3000"})
```

3. Write handler:
```go
    func Multiply(ctx context.Context, args *Args) (int, error) {
        return args.A * args.B, nil
    }
```

   Handler must have exact two arguments (context and input of any json serializable type) and exact two return values (output of any json serializable type and error)
3. Wrap handler with `rpc.Wrap` method and register it in server:
```go
    s.Register("multiply", rpc.H(Multiply))
```

4. Run RPC server:
```go
    s.Run(ctx)
```

## Custom transport

Any transport must implement simple interface `transport.Transport`:

```go
type Transport interface {
	Run(ctx context.Context, resolver Resolver) error
}
```

## Complete example

[Full code](/example)

```go
package main

import (
   "context"

   "go.neonxp.dev/jsonrpc2/rpc"
   "go.neonxp.dev/jsonrpc2/transport"
)

func main() {
   s := rpc.New()

   s.AddTransport(&transport.HTTP{Bind: ":8000"}) // HTTP transport
   s.AddTransport(&transport.TCP{Bind: ":3000"}) // TCP transport

   s.Register("multiply", rpc.H(Multiply))
   s.Register("divide", rpc.H(Divide))

   s.Run(context.Background())
}

func Multiply(ctx context.Context, args *Args) (int, error) {
    //...
}

func Divide(ctx context.Context, args *Args) (*Quotient, error) {
    //...
}

type Args struct {
	A int `json:"a"`
	B int `json:"b"`
}

type Quotient struct {
	Quo int `json:"quo"`
	Rem int `json:"rem"`
}

```

## Author

Alexander Kiryukhin <i@neonxp.dev>

## License

![GPL v3](https://www.gnu.org/graphics/gplv3-with-text-136x68.png)