What is this?

This is a (hopefully) easy to use example of how you can use Hybrid Compute with Account Abstraction to build powerful Web3 Apps!

This "Hello World" example allows you to fetch the current price of any cryptocurrency from an off-chain API such as CoinRanking into your smart contract within 1 single, atomic transaction!

You can run this repo in 2 ways:

• On our official testnet "Boba Sepolia"
• or spin up the local stack end-to-end (including the local chain, the bundler for Account Abstraction, the snap, etc.)

Get started

Clone this repo with git clone --recurse-submodules -j8 [email protected]:bobanetwork/aa-hc-example.git

Installation

You will need a handful of tools to run the full stack (local):

• cargo [Download]
• forge [Download]
• npm | yarn or pnpm [Download]
• golang [Download]
• Metamask Flask (Development build of Metamask) [Download]

To run the stack on Boba Sepolia you can skip cargo and golang which is only required to run the local stack.

Local

All contracts and services are deployed and environment variables are substituted across all services automatically to ensure a convenient developer experience.

1. Make sure you have the dependencies as outlined above installed and Docker running.
2. Run pnpm start:local to spin the local stack up. Make sure you have Docker running.
3. Head over to localhost:8001 to create your Smart Wallet.
4. Once you created your account, try it out by using the "Transfer Funds" section. Make sure you funded your new "Snap Account" with some ETH on Boba Sepolia.
5. Congrats you sent your first UserOp on your local devnet using Account Abstraction! This is the moment your smart account gets deployed on-chain (on the first UserOp).
6. Navigate now to localhost:8000 to interact with your local DApp which utilizes Hybrid Compute via Account Abstraction to fetch off-chain data to your smart contract! In our example we fetch the current price of a cryptocurrency asset.

Please note, that the local stack actually spins up the Boba L2 locally, the Bundler ("Rundler") along with other local services. This might take a while to startup.

Boba Sepolia

1. Copy /contracts/.env-example and name it .env. All necessary variables are pre-filled except of PRIVATE_KEY.
2. Add your own private key, that contains some ETH on Boba Sepolia in order to deploy the contracts on testnet. You can obtain some SepETH on Sepolia (L1) from any faucet and bridge them to L2 through our Gateway.
3. Run pnpm start:sepolia to spin up the reduced local stack to use the existing infrastructure on Boba Sepolia.
4. Head over to hc-wallet.sepolia.boba.network to create your Smart Wallet.
5. Once you created your account, try it out by using the "Transfer Funds" section. Make sure you funded your new "Snap Account" with some ETH on Boba Sepolia.
6. Congrats you sent your first UserOp on Boba Sepolia using Account Abstraction! If you navigate to the Block-Explorer you should see your contract wallet.
7. Navigate now to localhost:8000 to interact with your local DApp which utilizes Hybrid Compute via Account Abstraction to fetch off-chain data to your smart contract! In our example we fetch the current price of a cryptocurrency asset.

When you follow the steps above your application will use the already deployed backend below for simplification. If you want to deploy your own backend instead follow these steps:

1. Deploy the backend to your cloud of your choosing [here is more documentation on that]. We've provided you with a Dockerfile and Docker Compose to make this as easy as possible.
2. Once your backend is live, change the BACKEND_URL in your .env (if the file doesn't exist, you skipped the steps above) within your contracts folder.
3. Rerun the script pnpm start:sepolia and try it out as described above.

Name	Address	Explainer
BACKEND	https://aa-hc-example.onrender.com/hc
FRONTEND	https://aa-hc-example-fe.onrender.com
HC_HELPER_ADDR	0x1c64EC0A5E2C58295c3208a63209A2A719dF68D8	HC Helper is system-wide available
TOKEN_PRICE_ADDR	0xcad49c0381c1B0779A318c2326Db43A6073adC1e
RPC_URL	https://gateway.tenderly.co/public/boba-sepolia
-> More RPC URls	https://chainlist.org/chain/28882

This is what a successful transaction will look like: 0x30056b3ff720f4d824422bd077b88c4333e86fbe5522bcdba96cfc8fa2a69b52

This is what it will look like on the frontend provided:

How does it work?

This example utilizes Hybrid Compute 2.0 based on Account Abstraction.

Here is a high level overview of what happens:

The actual API call happens when the gas estimation happens (click for full page view):

If the gas estimation was successful, then we can submit our user operation (click for full page view):

Testing

Whenever you make changes and push to main on your Github repository relevant tests are being run by Github actions to make sure everything works as expected.

If you want to run tests locally, execute pnpm test.