Casper Go SDK

The Casper Go SDK provides a convenient way to interact with the Casper Network using Go.

Get started

go get github.com/make-software/casper-go-sdk

Base usage

RPC client

Package rpc provides access to the exported methods of RPC Client and data structures where the response is serialized. See more details here

Example:

package main

import (
	"context"
	"fmt"
	"net/http"

	"github.com/make-software/casper-go-sdk/v2/casper"
)

func main() {
	handler := casper.NewRPCHandler("http://<Node Address>:7777/rpc", http.DefaultClient)
	client := casper.NewRPCClient(handler)
	deployHash := "62972eddc6fdc03b7ec53e52f7da7e24f01add9a74d68e3e21d924051c43f126"
	deploy, err := client.GetDeploy(context.Background(), deployHash)
	if err != nil {
		return
	}
	fmt.Println(deploy.Deploy.Hash)
}

SSE

The SSE package provides basic functionality to work with Casper events that streamed by SSE server. See more details here

Example:

package main

import (
	"context"
	"log"

	"github.com/make-software/casper-go-sdk/v2/sse"
)

func main() {
	client := sse.NewClient("http://<Node Address>:9999/events/main")
	defer client.Stop()
	client.RegisterHandler(
		sse.DeployProcessedEventType,
		func(ctx context.Context, rawEvent sse.RawEvent) error {
			deploy, err := rawEvent.ParseAsDeployProcessedEvent()
			if err != nil {
				return err
			}
			log.Printf("Deploy hash: %s", deploy.DeployProcessed.DeployHash)
			return nil
		})
	lastEventID := 1234
	client.Start(context.TODO(), lastEventID)
}

Work with Casper types

SDK implements base functionality that allows to work with native Casper types.

• High-level types declaration and the base functions to construct them. details
• Low level types (CLValue) with base functionality details
• Identifiers, hashes and related functions details
• Cryptography public and private keys functionality details

Example of how to construct a deploy and push it to the network:

package main

import (
	"context"
	"encoding/hex"
	"log"
	"math/big"
	"net/http"

	"github.com/make-software/casper-go-sdk/v2/casper"
	"github.com/make-software/casper-go-sdk/v2/types/clvalue"
)

func main() {
	accountPublicKey, err := casper.NewPublicKey("012488699f9a31e36ecf002675cd7186b48e6a735d10ec1b308587ca719937752c")
	if err != nil { return }
	amount := big.NewInt(100000000)
	session := casper.ExecutableDeployItem{
		ModuleBytes: &casper.ModuleBytes{
			ModuleBytes: hex.EncodeToString([]byte("<Contract WASM>")),
			Args: (&casper.Args{}).
				AddArgument("target", clvalue.NewCLByteArray(accountPublicKey.AccountHash().Bytes())).
				AddArgument("amount", *clvalue.NewCLUInt512(amount)),
		},
	}

	payment := casper.StandardPayment(amount)

	deployHeader := casper.DefaultHeader()
	deployHeader.Account = accountPublicKey
	deployHeader.ChainName = "casper-test"

	newDeploy, err := casper.MakeDeploy(deployHeader, payment, session)

	handler := casper.NewRPCHandler("http://<Node Address>:7777/rpc", http.DefaultClient)
	client := casper.NewRPCClient(handler)
	result, err := client.PutDeploy(context.Background(), *newDeploy)
	
	log.Println(result.DeployHash)
}

Advanced usage

It is crucial to have a clear understanding of the SDK structure and its functionalities in order to avoid common mistakes or misuse of functionality. The SDK consists of several packages that have strict dependencies.

If we were to present the packages in different layers, the structure would be as follows (in ascending order, from low to high):

1. Lowest layer: cltype and keypair
2. key
3. clvalue
4. types
5. Services rpc and sse
6. The highest level is a facade that provides popular interfaces through the casper package

The Dependency tree can help to visualise:

Links to package documentation and examples:

1. cltype examples
2. clvalue doc | examples
3. keypair doc | examples
4. types doc | examples
5. rpc doc | examples
6. sse doc | examples

Lint and test

To install necessary Go tools, use the following commands:

go install -v github.com/incu6us/goimports-reviser/v3@latest
go install github.com/golangci/golangci-lint/cmd/golangci-lint@v1.50.1

Run linters:

go fmt ./...
go vet ./...
goimports-reviser ./...
golangci-lint run

Run tests:

go test ./...

Get Involved

We hope you find this SDK to be a useful tool for interacting with the Casper Network using Go. We've strived to make it as intuitive and user-friendly as possible, but we understand that there's always room for improvement.

Should you have any questions, issues, or suggestions, please don't hesitate to open an issue in our GitHub repository. If you are interested in contributing to the Casper Go SDK, we would be thrilled to welcome you to our community. Please check out the CONTRIBUTING.md guide for more information.

Remember, the power of blockchain networks is in their communities. Every question you ask, issue you open, or contribution you make, helps to improve the Casper Go SDK and benefits the entire Casper ecosystem.

Thank you for your interest in our project, and we look forward to building the future of the Casper Network together!