Establishing a JSON-RPC connection

Transports

A JSON-RPC connection communicates over an existing transport, such as HTTP, Sockets and pipes, and Websockets:

• HTTP POST: unidirectional, one request/response pair per call.
• Sockets and pipes, via chronos' StreamTransport: bidirectional, persistent connection, custom message framing.
  • Framing.httpHeader: Content-Length prefix specifying the length of the payload, compatible with vscode-jsonrpc.
  • Framing.lengthHeaderBE32: Big-endian, 32-bit binary prefix - most efficient option.
• Websockets: bidirectional, persistent connection.

Server (and possibly client also)

Create the server instance using one of the available transports:

HTTP:

let srv = newRpcHttpServer(["127.0.0.1:0"])

Sockets:

const framing = Framing.lengthHeaderBE32()
let srv = newRpcSocketServer(["127.0.0.1:0"], framing = framing)

Websockets:

let srv = newRpcWebSocketServer("127.0.0.1", Port(0))

After registering the RPC methods, the server can start serving clients:

srv.start()

Then usually runForever() or waitFor a program termination signal waitSignal(SIGINT). This will run the Chronos async event loop until the program is terminated.

Client

Create the client instance using one of the available transports:

HTTP:

let client = newRpcHttpClient()
await client.connect("http://" & $srv.localAddress()[0])

Sockets:

const framing = Framing.lengthHeaderBE32()
let client = newRpcSocketClient(framing = framing)
await client.connect(srv.localAddress()[0])

Websockets:

let client = newRpcWebSocketClient()
await client.connect("ws://" & $srv.localAddress())

You can then proceed to send requests.

Disconnecting

Close the client connection:

await client.close()

Stop the RPC server and clean-up resources:

await srv.stop()
await srv.closeWait()