gsrpc

README

Go Substrate RPC Client (GSRPC)

Substrate RPC client in Go. It provides APIs and types around Polkadot and any Substrate-based chain RPC calls. This client is modeled after polkadot-js/api.

State

This package is feature complete, but it is relatively new and might still contain bugs. We advise to use it with caution in production. It comes without any warranties, please refer to LICENCE for details.

Documentation & Usage Examples

Please refer to https://godoc.org/github.com/didaunesp/no-signature-go-substrate-rpc-client-v4

Usage test examples of Dynamic Parsing of events & extrinsics

Registry docs

Contributing

1. Install dependencies by running make
2. Build the project with go build
3. Lint make lint (you can use make lint-fix to automatically fix issues)
4. Run make run-substrate-docker to run the Substrate docker container

Testing

We run our tests against a Substrate Docker image. You can choose to run the tests within a tests-dedicated Docker container or without a container.

1. make test-dockerized Run tests within a docker container of its own against the Substrate docker container.

2. make test Run the tests locally against the Substrate docker container. Note that it expects the Substrate docker container to be up and running to execute the whole test suite properly.

Visit https://polkadot.js.org/apps for inspection

Note: To use a custom Substrate endpoint, first set the environment variable before running the tests: export RPC_URL="http://example.com:9934"

Adding support for new RPC methods

After adding support for new methods, update the RPC mocks.

1. Install mockery
2. Run go generate ./...

Documentation

Overview

Package gsrpc (Go Substrate RPC Client) provides APIs and types around Polkadot and any Substrate-based chain RPC calls. This client is modelled after polkadot-js/api(https://github.com/polkadot-js/api).

Calling RPC methods

Simply instantiate the gsrpc with a URL of your choice, e. g.

api, err := gsrpc.NewSubstrateAPI("wss://poc3-rpc.polkadot.io")

and run any of the provided RPC methods from the api:

hash, err := api.RPC.Chain.GetBlockHashLatest()

Further examples can be found below.

Signing extrinsics

In order to sign extrinsics, you need to have [subkey](https://github.com/paritytech/substrate/tree/master/subkey) installed. Please make sure that you use subkey in the version of your relay chain.

Types

The package [types](https://godoc.org/github.com/didaunesp/no-signature-go-substrate-rpc-client-v4/types/) exports a number of useful basic types including functions for encoding and decoding them.

To use your own custom types, you can simply create structs and arrays composing those basic types. Here are some examples using composition of a mix of these basic and builtin Go types:

1. Vectors, lists, series, sets, arrays, slices: https://godoc.org/github.com/didaunesp/no-signature-go-substrate-rpc-client-v4/types/#example_Vec_simple

2. Structs: https://godoc.org/github.com/didaunesp/no-signature-go-substrate-rpc-client-v4/types/#example_Struct_simple

There are some caveats though that you should be aware of:

1. The order of the values in your structs is of relevance to the encoding. The scale codec Substrate/Polkadot uses does not encode labels/keys.

2. Some types do not have corresponding types in Go. Working with them requires a custom struct with Encoding/Decoding methods that implement the Encodeable/Decodeable interfaces. Examples for that are enums, tuples and vectors with any types, you can find reference implementations of those here: types/enum_test.go , types/tuple_test.go and types/vec_any_test.go

For more information about the types sub-package, see https://godoc.org/github.com/didaunesp/no-signature-go-substrate-rpc-client-v4/types

Index

• type SubstrateAPI
  • func NewSubstrateAPI(url string) (*SubstrateAPI, error)

Types

type SubstrateAPI

type SubstrateAPI struct {
	RPC    *rpc.RPC
	Client client.Client
}

func NewSubstrateAPI

func NewSubstrateAPI(url string) (*SubstrateAPI, error)