Get started with 0x API

This is a repo containing toy examples of filling 0x-API quotes either directly with web3 or through a smart contract.

Installation

Clone this repo then, from inside the project, run:

yarn -D
# or
npm install --dev

This will also compile the contracts in contracts/ and produce artifacts in build/.

Examples

The following example scripts are included:

Script	Guide	Description
src/direct-swap.js	Swap tokens with 0x API	Perform a token swap with web3.
src/swap-contract.js	Use 0x API liquidity in your smart contracts	Perform a token swap in a smart contract.

Running the examples locally (forked mainnet)

The examples can be run locally (without actually mining transactions) through the magic of ganache forking. You will first need to start a forked ganache instance with the following command, replacing ETHEREUM_RPC_URL with the HTTP or websocket RPC URL of your mainnet ethereum node (e.g., Infura mainnet):

RPC_URL=ETHEREUM_RPC_URL npm run start-fork

Direct swap

To run the direct swap example, in a separate terminal run:

npm run swap-fork

Contract swap

To run the contract swap example, in a seperate terminal run:

npm run deploy-fork # Only need to do this once per ganache instance.
npm run swap-contract-fork

Running the examples on mainnet

You can also run the examples and perform actual swaps that will get mined with a little effort:

1. Modify the mnemonic in package.json to one only you know. Do not use the default mnemonic on mainnet!
2. Fund the first HD wallet account associated with that mnemonic with some ETH. You can run npm run print-hd-wallet-accounts to list the addresses associated with the configured mnemonic.

Direct swap

To run the direct swap example live, run the following:

# Replace ETHEREUM_RPC_URL with your mainnet node RPC endpoint.
RPC_URL=ETHEREUM_RPC_URL npm run swap-live
# You can also configure how much WETH is sold with the -a option, e.g.
RPC_URL=ETHEREUM_RPC_URL npm run swap-live -a 0.1

Contract swap

To run the contract swap example live, first deploy the contract to mainnet.

# Replace ETHEREUM_RPC_URL with your mainnet node RPC endpoint.
RPC_URL=ETHEREUM_RPC_URL npm run deploy-live --network main

Note the address to which the contract has been deployed. You can now run the script to perform the swap.

# Replace ETHEREUM_RPC_URL with your mainnet node RPC endpoint
# and CONTRACT_ADDRESS with the deployed address of the contract.
RPC_URL=ETHEREUM_RPC_URL npm run swap-contract-live CONTRACT_ADDRESS
# You can also configure how much WETH is sold with the -a option, e.g.
RPC_URL=ETHEREUM_RPC_URL npm run swap-contract-live -a 0.1 CONTRACT_ADDRESS

Keep in mind that tokens will remain in the contract after the swap and can only be retrieved by your first HD wallet account through withdrawToken() or withdrawETH().

Running the examples on mainnet with Foundry

forge build
forge test --fork-url RPC_URL

Need help?

• Refer to our 0x API specification for detailed documentation.
• 0x API is open source! Look through the codebase and deploy your own 0x API instance.
• Don’t hesitate to reach out on Discord for help! The 0x Core team is active on Discord to help teams building with all things 0x.