bodhi

@acala-network/bodhi.js

bodhi.js SDK provides utils for interaction with Acala EVM+:

• a BodhiProvider that extends ethers.js Provider
• a BodhiSigner that extends ethers.js Signer

Getting Started

install

yarn add @acala-network/bodhi
# or
npm install @acala-network/bodhi

create a wallet

import { WsProvider } from "@polkadot/api";
import { createTestPairs } from "@polkadot/keyring/testingPairs";
import { SubstrateSigner, BodhiProvider, BodhiSigner } from "@acala-network/bodhi";

const provider = new BodhiProvider({
  provider: new WsProvider("ws://localhost:9944")
});

// create a substrate payload signer, dapps will use an extension signer
const { alice } = createTestPairs();
const signer = new SubstrateSigner(provider.api.registry, alice);

const wallet = new BodhiSigner(provider, alice.address, signer);
// or from pair
const wallet = BodhiSigner.fromPair(provider, alice);

alternatively, for a quick testing setup, we can use the getTestUtils helper, which basically encapsulates the above setup.

import { getTestUtils } from '@acala-network/bodhi';
const { wallets, provider, pairs } = await getTestUtils('ws://localhost:9944');
const alice = pairs[0];
const wallet = wallets[0];

use the wallet

now that we have an eth compatible wallet (signer), we can use it with any eth toolings.

For example we can use it with waffle to deploy a contract

import { deployContract } from "ethereum-waffle";
const instance = await deployContract(wallet, contractAbi, params);

or use with ethers to interact with existing contracts

const instance = new ethers.Contract(address, contractAbi, wallet);
await instance.callSomeFunction();

Concepts

You may notice there are so many "providers" and "signers", basically there are two from substrate world (WsProvider, SubstrateSigner), and two from traditional eth world (Signer, Provider).

Here is a brief hierachy of how they work together:

• BodhiSigner: top level eth signer (wallet), compatible with ethers.js AbstractSigner, can be directly used by any eth toolings, such as ethers, waffle, etc.
  • SubstrateSigner: substrate payload signer, usually from keyring pair or an extension wallet, such as polkadotjs or talisman
  • Provider (BodhiProvider): eth provider for eth related communications, mostly compatible with ethers.js AbstractProvider
    • WsProvider: provides websocket connection with substrate based chains, used by BodhiProvider internally

TODO: maybe a graph is better.

Evm+ Specific Features

besides classic signer methods, we have some additional features available only for Evm+. For a comprehensive list please checkout here

await wallet.claimEvmAccounts(evmAddress);  // bind an evm address to the signer substrate address
await wallet.claimDefaultAccount();         // bind default evm address to the signer substrate address
wallet.computeDefaultEvmAddress();          // you know it
await wallet.queryEvmAddress();             // Get the signers EVM address if it has claimed one.

Examples

Checkout bodhi-examples for some real apps that integrate bodhi signers, with some extra cool features (such as batch transactions).