@uma/contracts-frontend

@uma/contracts-frontend

This package exports all UMA smart contract artifacts specifically meant for consumption in a frontend. These exports are specifically optimized for frontends so they are able to drop any unused artifacts in order to keep the bundle size small.

Installing the package

yarn add @uma/contracts-frontend

Importing artifacts directly

To import artifacts directly into your tool of choice, the index file provides convenient functions for doing so:

import { getVotingAbi, getVotingBytecode, getVotingAddress } from "@uma/contracts-frontend"

// Gets the abi object for the Voting contract.
// This will be needed to interact with the voting contract.
const votingAbi = getAbiVotingAbi()

// Gets the bytecode string for the voting contract.
// This should usually only be required if you need to deploy a voting contract (rare).
const votingBytecode = getVotingBytecode()

// Gets the address of the voting contract for chain id 1 (eth mainnet).
// If there is no single canonical deployment of a particular contract on the network provided, this will fail.
const chainId = 1
const votingAddress = getVotingAddress(chainId)

Typescript!

Typescript is fully supported for all of the above operations:

import { getVotingAbi, getVotingBytecode, getVotingAddress } from "@uma/contracts-frontend";
...

In addition to artifact support, typescript types (and sometimes factories) are available for ethers and web3.

Ethers

The best support is for Ethers contract types. To construct an Ethers contract, import one of the ethers factories:

import { VotingEthers__factory, getVotingAddress } from "@uma/contracts-frontend" // Factory to create ethers instance.
import type { VotingEthers } from "@uma/contracts-frontend" // Type for ethers instance.

const NETWORK_ID = 1
const VOTING_ADDRESS = getVotingAddress(NETWORK_ID)

// Note: the explicit type here isn't necessary -- this is just provided to document what VotingEthers is.
const votingInstance: VotingEthers = VotingEthers__factory.connect(VOTING_ADDRESS, providerOrSigner)

Web3

Web3 factories are not provided, but web3 contract types are. They can be used as follows:

import type { VotingWeb3 } from "@uma/contracts-frontend"
import { getVotingAbi, getVotingAddress, getVotingBytecode } from "@uma/contracts-frontend"

const VOTING_ABI = getVotingAbi()
const NETWORK_ID = 1
const VOTING_ADDRESS = getVotingAddress(NETWORK_ID)

// Create a voting instance to represent a pre-deployed voting contract.
const voting = new web3.eth.Contract(VOTING_ABI, VOTING_ADDRESS) as VotingWeb3

// Or you can create a new voting instance using the bytecode.
const VOTING_BYTECODE = getVotingBytecode()
const newVotingInstance = (await new web3Instance.eth.Contract(VOTING_ABI, undefined)
  .deploy({ data: VOTING_BYTECODE, arguments: VOTING_ARGS })
  .send({ from: YOUR_ADDRESS })) as VotingWeb3

Adding contracts from external packages

To add external package contracts, the external package must be set up in a particular way. Most of it is standard hardhat, but a few exports must be added specifically.

Requirements

The external package must export:

• All hardhat artifacts that it wants this package to re-export.
• Typechain types under /typechain. It must include web3 and ethers typechain exports.
• A special json file at the path /build/artifacts.json that describes the location of all hardhat artifacts. This JSON file is a simple json array of objects, each object having a field called relativePath that is the path from the root to each hardhat artifact. The artifact's filename must match the contract name.
• A folder at /networks following the same structure as /packages/core/networks in this repository for any contract addresses that it wants to add.

Adding an external package

To add an external package:

• Add the external package name to the EXTERNAL_PACKAGES array in /packages/common/hardhat/tasks/artifacts.ts.
• Add the external package to this package as a devDependency.
• Copy the copy-across-types package.json script in this package replacing the name and @across-protocol/contracts with the new package.
• Add your new package.json script to the generate-ts script in package.json similar to how copy-across-types is.