bx-jsonrpc-py 0.2.0

JSON-RPC Python client with streaming support

JSON-RPC Python Client

Library for interacting with JSON-RPC servers. Implements the JSON-RPC 2.0 spec, as well as first-class support for the subscription streaming endpoints exposed by most blockchain RPC interfaces (e.g. Ethereum, Solana) for JSON-RPC websockets connections.

Features

• Websockets connection wrapper with full support for matching request IDs to responses and subscription updates to subscription IDs
• Classes for (de)serializing JSON-RPC spec compliant message types

Installation

$ pip install bx-jsonrpc-py

Websockets Streaming

Many blockchains use a subscription RPC endpoint with JSON-RPC notifications to provide real-time event streams of updates in the network. They usually look something like this:

// create subscription
>> {"id": 1, "method": "subscribe", "params": ["feedName"]}
<< {"jsonrpc":"2.0","id":1,"result":"subscriptionID"}

// incoming notifications
<< {"jsonrpc":"2.0","method":"subscribe","params":{"subscription":"subscriptionID","result":"data"}}}
<< {"jsonrpc":"2.0","method":"subscribe","params":{"subscription":"subscriptionID","result":"data}}}

// cancel subscription
>> {"id": 1, "method": "unsubscribe", "params": ["subscriptionID"]}
<< {"jsonrpc":"2.0","id":1,"result":true}

Some examples: go-ethereum, solana

The included jsonrpc.WsRpcConnection class fully implements this feature.

Usage

import jsonrpc

async with jsonrpc.WsRpcConnection("ws://...") as ws:
    print(await ws.call("method", {"param": "value"}))
    
    subscription_id = await ws.subscribe(
        "feedname", {"option": "value"}
    )
    async for notification in ws.notifications_for_id(subscription_id):
        print(notification)

See examples/client.py for a working sample.

Anticipated Future Work

• Reconnection support for websockets to reconnect and resubscribe to former feeds

Comments / Questions

Feel free to open up a Github issue to discuss enhancements or problems.

MIT License

Copyright (c) 2022 bloXroute Labs

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.