cpix18 / paymaster-bundler-examples

Coinbase Developer Platform Paymaster & Bundler Examples

This repo has code examples on how to request tokens from an ERC20 token [SWING] faucet (https://basescan.org/address/0xcC7817DCc0965DDE3B4a9340ec35A21b23393013) on Base using Coinbase Developer Platform's Paymaster & Bundler.

I currently have one example using the pimlico SDK, but contributions are always welcome!

Supported SDKs

• Pimlico (permissionless.js)

Supported Account Types

• SimpleAccount (default)
• Safe
• Kernel

Compatibility

SDK	Simple	Safe	Kernel
permissionless.js	✅	✅	✅

Getting Started

Prerequisites: you'll need to have node and yarn installed.

1. Clone this repo locally

git clone https://github.com/CPix18/paymaster-bundler-examples.git

2. Get into the right folder

cd paymaster-bundler-examples

3. Set up environment variables

• Copy the env example

cp .env.example .env

• Install dotenv

yarn

• This will setup dotenv to load the env file for private values

• Get your Node RPC URL

  • Navigate to https://www.coinbase.com/developer-platform/products/base-node
  • Sign up for a Coinbase Developer Platform account, if you don't have one already.
  • Under the Build Onchain section in the Portal, select Node
  • In the dropdown on the top right of Configuration, select Base Mainnet
  • Copy your RPC endpoint, and paste it into .env as the RPC_URL variable.
    • The RPC URL should look like https://api.developer.coinbase.com/rpc/v1/base/<api_key>

• Add a signer

  You'll need to add a private key to initialize and sign for your ERC-4337 smart contract account

  • Since the faucet request is free and gas will be sponsored by our Paymaster, you can use a new account without any funds
  • You can create a new private key with Foundry
    • To install Foundry, run curl -L https://foundry.paradigm.xyz | bash in Terminal for mac users
    • To generate a new key pair, run cast wallet new
  • Copy your private key, and paste it into .env as the PRIVATE_KEY variable
  • YOU CAN ALSO JUST USE A NEW PRIVATE KEY GENERATED FROM A WALLET APP

4. Navigate to the directory of the SDK you want to run the example with.

Example for swing

cd examples/pimlico

5. Install the dependencies with yarn

yarn

6. Run the example

yarn dev

7. See your sponsored transaction live!

You should receive an Etherscan link with your sponsored transaction in the terminal output. Example

Minting to 0x923a5B9864726a67E1B2a0839c9b698b84dD4B80
Waiting for transaction...
 ⛽ Successfully sponsored gas for mintTo transaction with Coinbase Developer Platform!
 🔍 View on Etherscan: https://basescan.org/tx/0x94e27c21b8f8e3a288cbeff022a6c921aa49d7a945e340b05c3141a72da63183
✨  Done in 5.66s.