I want to deploy pre-compiled Smart Contract bytecode using Truffle migrations. Specifically, it is the Uniswap V2 Factory contract.

In the Uniswap V2 documentation there is a cliffhanger, where they mention to use:

const UniswapV2FactoryBytecode = require('@uniswap/v2-core/build/UniswapV2Factory.json').bytecode

And then deploy it using Truffle (but do not include an example). However, I cannot get the deployment to work. Here is my migration script:

const UniswapV2FactoryBytecode = require('@uniswap/v2-core/build/UniswapV2Factory.json').bytecode
module.exports = function(_deployer, network, accounts) {
    _deployer.deploy(UniswapV2FactoryBytecode, accounts[0])

Note the UniswapV2Factory constructor requires a _feeToSetter address which is why I pass accounts[0] as a parameter.

When I run using truffle migrate --reset the following error is returned:

TypeError: contract.detectNetwork is not a function

Can anyone help point to a solution get this to work?

2 Answers 2


One solution appears to be to install @truffle/contract package like so:

npm install @truffle/contract

Then in the migration file you will need to grab the full contract JSON (not just the bytecode as mentioned in the question) and use the @truffle/contract to create a contract instance from the JSON. You will also need to set the provider manually, and set the deployer account manually too.

const json = require('@uniswap/v2-core/build/UniswapV2Factory.json')
const contract = require('@truffle/contract');
const UniswapV2Factory = contract(json);


module.exports = function(_deployer, network, accounts) {
    _deployer.deploy(UniswapV2Factory, accounts[0], {from: accounts[0]})

Given all the extra hoops to jump through this might not be the best approach but it does produce what I was after - an instance of the contract deployed in my development environment.


My solution was copying the UniswapV2Factory contract's JSON file into build/contracts folder. Then I just used it as any other artifact with artifacts.require("UniswapV2Factory");.

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