Go wrapper for the StreamrProxyClient

This is a Go wrapper for the StreamrProxyClient C++ library. It is used to publish data to the Streamr network.

Installation

go get github.com/streamr-dev/goproxyclient

The package is distributed with a precompiled shared library and is available for MacOS (arm64 and x86_64) and Linux (arm64 and x86_64).

Usage

package main

import (
	"log"

	streamrproxyclient "github.com/streamr-dev/goproxyclient"
)

func main() {
	// This is a widely-used test account
	ownEthereumAddress :=
	 "0xa5374e3c19f15e1847881979dd0c6c9ffe846bd5";
	ethereumPrivateKey :=
	 "23bead9b499af21c4c16e4511b3b6b08c3e22e76e0591f5ab5ba8d4c3a5b1820";

	// A Proxy server run by Streamr
	proxyUrl := "ws://95.216.15.80:44211"
	proxyEthereumAddress := "0xd0d14b38d1f6b59d3772a63d84ece0a79e6e1c1f"
	
	// The stream to publish to
	streamPartId := "0xd2078dc2d780029473a39ce873fc182587be69db/low-level-client#0"
	
	// Create a new library instance
	lib := streamrproxyclient.NewLibStreamrProxyClient()
	defer lib.Close()

	
	// Create a new ProxyClient instance
	client, err := streamrproxyclient.NewProxyClient(ownEthereumAddress, streamPartId)
	if err != nil {
			log.Fatalf("Error creating ProxyClient: %v", err)
	}
	defer client.Close()

	// Create definition of the proxy server to connect to
	proxies := []streamrproxyclient.Proxy{
		*streamrproxyclient.NewProxy(proxyUrl, proxyEthereumAddress),
	}

	// Connect to the proxy server
	result := client.Connect(proxies)
	if len(result.Errors) != 0 {
		log.Fatalf("Errors during connection: %v", result.Errors)
	}
	if len(result.Successful) != 1 {
		log.Fatalf("Unexpected number of successful connections: %d", len(result.Successful))
	}

	// Publish a message to the test stream
	// You should see the result in the Streamr HUB web UI at
	// https://streamr.network/hub/streams/0xd2078dc2d780029473a39ce873fc182587be69db%2Flow-level-client/live-data
	data := []byte("Hello from Go!")
	result = client.Publish(data, ethereumPrivateKey)
	if len(result.Errors) != 0 {
		log.Fatalf("Errors during publish: %v", result.Errors)
	}
	if len(result.Successful) != 1 {
		log.Fatalf("Unexpected number of successful publishes: %d", len(result.Successful))
	}
}

API documentation

LibStreamrProxyClient

The main library class that initializes the native library.

Methods

• NewLibStreamrProxyClient() *LibStreamrProxyClient - Creates a new library instance and initializes the native library
• Close() - Cleans up and closes the native library

ProxyClient

Client for connecting to proxy servers and publishing messages.

Methods

• NewProxyClient(ownEthereumAddress string, streamPartId string) (*ProxyClient, *ProxyClientError) - Creates a new proxy client instance

  • ownEthereumAddress - Ethereum address of the publisher
  • streamPartId - ID of the stream partition to publish to
  • Returns the client instance and any error that occurred

• Close() *ProxyClientError - Closes and cleans up the proxy client

  • Returns any error that occurred during cleanup

• Connect(proxies []Proxy) *ProxyClientResult - Connects to the specified proxy servers

  • proxies - Array of proxy servers to connect to
  • Returns result containing successful connections and any errors

• Publish(data []byte, ethereumPrivateKey string) *ProxyClientResult - Publishes data to the stream

  • data - Byte array of data to publish
  • ethereumPrivateKey - Optional private key for signing messages
  • Returns result containing successful publishes and any errors

Proxy

Contains information about a proxy server.

Methods

• NewProxy(websocketUrl string, ethereumAddress string) *Proxy - Creates a new proxy definition
  • websocketUrl - WebSocket URL of the proxy server
  • ethereumAddress - Ethereum address of the proxy server

ProxyClientResult

Result of proxy client operations containing successes and failures.

Fields

• Errors []*ProxyClientError - Array of errors that occurred
• Successful []*Proxy - Array of successful proxy operations

ProxyClientError

Error type for proxy client operations.

Fields

• Message string - Error message
• Code string - Error code
• Proxy *Proxy - Associated proxy if applicable

Error Codes

• ERROR_INVALID_ETHEREUM_ADDRESS - Invalid Ethereum address provided
• ERROR_INVALID_STREAM_PART_ID - Invalid stream partition ID
• ERROR_PROXY_CLIENT_NOT_FOUND - Proxy client instance not found
• ERROR_INVALID_PROXY_URL - Invalid proxy WebSocket URL
• ERROR_NO_PROXIES_DEFINED - No proxy servers defined
• ERROR_PROXY_CONNECTION_FAILED - Failed to connect to proxy
• ERROR_PROXY_BROADCAST_FAILED - Failed to broadcast message