TAP Protocol ICP/Azle Boilerplate Canister

• Installation
• Deployment

This boilerplate enables you to start with a smart contract (canister) on ICP for TAP Protocol related computations.

You can use your canister as both, privilege and token authority and use ICP's Bitcoin integration to perform computations on L1.

To allow the development with a familiar platform, this boilerplate utilizes Azle.

Azle helps you to build secure decentralized/replicated servers in TypeScript or JavaScript, as well as NodeJS on ICP. The current replication factor is 13-40 times.

Please remember that Azle is in beta and thus it may have unknown security vulnerabilities due to the following:

• Azle is built with various software packages that have not yet reached maturity
• Azle does not yet have multiple independent security reviews/audits
• Azle does not yet have many live, successful, continuously operating applications deployed to ICP

A great Azle resource is located at The Azle Book.

Make sure to read the comments in the boilerplace code. Especially the files index.ts, lib/incoming.ts, lib/queue.ts and lib/ticker.ts give an insight on how to utilize the concepts of this canister boilerplate.

Installation

Windows is only supported through a Linux virtual environment of some kind, such as WSL

You will need Node.js 20 (or later) and dfx to develop ICP applications with Azle:

Node.js 20

It's recommended to use nvm to install Node.js 20:

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash

Restart your terminal and then run:

nvm install 20

Check that the installation went smoothly by looking for clean output from the following command:

node --version

dfx

Install the dfx command line tools for managing ICP applications:

DFX_VERSION=0.22.0 sh -ci "$(curl -fsSL https://internetcomputer.org/install.sh)"

Check that the installation went smoothly by looking for clean output from the following command:

dfx --version

Deployment

To create and deploy a simple sample application called tap-icp-boilerplate:

# cd into this project's root folder
cd tap-icp-boilerplate

# copy and rename the config-dist.ts file
cp src/config-dist.ts src/config.ts

# adjust the config file to your needs (totally fine to start with default setup)
vi src/config.ts

# install all npm dependencies including azle
npm install

# install the azle dfx extension
npx azle install-dfx-extension

# start up a local ICP replica
dfx start --clean

In a separate terminal in the tap-icp-boilerplate directory:

# deploy your canister
dfx deploy

To allow built-in ETH RPC calls on your local ICP replica, perform the below in a separate terminal inside the tap-icp-boilerplate directory:

// add this in your dfx.json to enable evm_rpc IF not existing yet
{
  "canisters": {
    "evm_rpc": {
      "type": "pull",
      "id": "7hfb6-caaaa-aaaar-qadga-cai"
    }
  }
}

# perform this once for evm_rpc to work with your local ICP replica (assuming dfx start above has been done already)
dfx deps pull
dfx deps init evm_rpc --argument '(record { nodesInSubnet = 34 })'
dfx deps deploy

Please note that you won't need to perform the step above on ICP's mainnet.

Once the initial setup is done, you'd want to take care of the following things:

• Setup a TAP Reader instance as oracle for your canister. The path (without http:// or https://) goes into the "API_HOST" value of the config. Please note that SSL is required for local replicas and mainnet. On ICP mainnet, your api host location must support IPV6 (including SSL support).
• Authority setup:
  • In your canister site, call "signCreateTokenAuthority" and/or "signCreatePrivilegeAuthority" manually.
  • Copy the resulting text and inscribe it TO the Bitcoin address of your canister.
  • Confirm each authorities by calling "tap" and add the utxo data of the inscriptions (txhash, vout and value).
  • If you use both authority types, make sure to tap one at a time (=wait for conformation before tapping the next).
• After your canister is completed and you want to go live, make sure to remove all update queries in index.ts to prevent cycle drainage from your canister and update the canister.
• If you are using token-auth with your canister, it is HIGHLY recommended to disable transferables. Please see the Tap Protocol specs