This repository will serve dApp developers, interested in developing for Aleph Zero network, to boostrap their work. It will include:

• an example set of smart contracts, showcasing all basic building blocks required to build a dApp
• accompanying frontend, together with Aleph Zero branding, for interacting with the contracts
• integration with the PolkadotJS signer extension

How to run locally

Prerequisities

1. Rust in version 1.69.0 with the nightly-2023-02-07 toolchain.
2. substrate-contracts-node version v0.26.0.
3. cargo-contract version 3.0.1.

To install Rust, run:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

This will install rustup, the Rust version and toolchain management tool. Next, use it to install Rust and the appropriate toolchain:

rustup install 1.69.0
rustup install nightly-2023-02-07-x86_64-unknown-linux-gnu

To install the substrate-contracts-node, simply download it from the release page, unpack the archive and put the binary on your path (remember to reload the shell for this to take effect).

To install cargo contract, run:

cargo install --force --locked cargo-contract --version 3.0.1

You can verify your versions using:

rustup show
substrate-contracts-node --version
cargo contract --version

Running chain

In the root directory of the project, run make chain-start. To stop the chain, just exit the process in your terminal.

To clean the chain's run make chain-clean. This will remove chain's database files (like blocks and contracts).

To restart the chain (and purge the state) run make chain-restart.

By default, node will bind its websocket endpoint to port 9944. Make sure that the chain is running WS on port 9944. In the logs, look for:

2023-01-10 19:23:40.475  INFO main sc_rpc_server: Running JSON-RPC HTTP server: addr=127.0.0.1:9933, allowed origins=None
2023-01-10 19:23:40.475  INFO main sc_rpc_server: Running JSON-RPC WS server: addr=127.0.0.1:9944, allowed origins=None

If it bound to a different port your frontend instance will not connect properly - it tries to connect to the 9944 port. In that case, either make sure there are no other substrate-contracts-node running (by killing them with make chain-stop) or change the port in the frontend app.

Building contracts

In the /contracts directory run make build-all to build both contracts.

Deploying contracts

In the root directory, run make setup. This will:

• deploy both contracts to the local chain
• instantiate them
• record their addresses
• update the addresses and contracts' metadata files in the frontend directory

If you need to upload the contracts many times, you have two options:

• run the make chain-restart command, which will remove the old contracts,
• set the BULLETIN_BOARD_VERSION variable to different two-digit numbers with each run, which will allow you to upload different instances of the same contract.

Option 1 is the recommended one for most use cases.

Running the frontend

In the /frontend directory, run export REACT_APP_PROVIDER_URL=ws://localhost:9944 && npm start. This should open a new tab in your default browser that connects to your local chain.

Working with the polkadot.js wallet extension

To sign transactions, we will be using the polkadot extension. Follow the instructions about how to install it in the official documentation.

substrate-contracts-node ships with bunch of pre-funded accounts - we need to import them into the extension:

1. Open the browser extension modal.
2. Click on the + icon.
3. Then Import account from pre-existing seed.
4. In the EXISTING 12 OR 24-WORD MNEOMNIC SEED form add bottom drive obey lake curtain smoke basket hold race lonely fit walk -- this it the seed for the default accounts. You can find it on https://docs.substrate.io/reference/command-line-tools/subkey/#subkey-generate-node-key .
5. Click ADVANCED and use one of the derivation paths:

• //Bob//stash
• //Charlie//stash
• //Dave//stash
• //Eve//stash
• //Ferdie//stash

6. Finish the account setup.

Now, you can use the newly-added account with the example frontend.