backend

tap Backend

tap's Backend has several main components required to run the tap app:

Protocol	Description	Requirements
tap On-Chain Program	Solana program that manages user accounts and multi-sign USDC wallets	Solana CLI & Anchor CLI
Google Cloud	Google Cloud Functions based backend that handles user authentication, credit card onramp, and
other backend services	Google Cloud CLI & Google Cloud Account
Google Firestore	Database for storing user public info	Google Cloud CLI & Google Cloud Account
Circle SDK	Circle SDK for credit card onramp	Circle Developer Sandbox Account
Web3 Auth SDK	Single sign-in with Google and non-custodial signing wallet	Web3 Auth Developer Account

• Make sure you have the requirements for each component before proceeding.
• Copy .env.example.yml to .env.local.yml and fill out the environment variables for the correct environment(s).
  • For FAKE_USDC and BANK_AUTH you can generate a new keypair with solana-keygen grind --starts-with USDC:1 (or BANK:1) to generate an easy to track public key and use the public key as the value. Make sure to update values in the front end .env.local as well.
• Open the backend directory cd backend and run npm install to install the dependencies.

tap On-Chain Program

Set Up

• Install the Solana CLI https://docs.solana.com/cli/install-solana-cli-tools
• Install the Anchor CLI https://www.anchor-lang.com/docs/cli
• Create a new Solana wallet solana-keygen new --outfile ~/.config/solana/id.json
• Set the Solana CLI to use the new wallet and localhost solana config set --keypair ~/.config/solana/id.json --url localhost

Build the Program

• Open the program directory cd program/tap_cash
• Build the program with anchor build

Deploy the Program

• Launch a local Solana cluster solana-test-validator -r
• Airdrop your wallet some SOL solana airdrop 100
• Deploy the program to the local cluster anchor deploy
• Your program should now be deployed to the local cluster and you can start interacting with it

Google Cloud Functions

based on https://github.com/GoogleCloudPlatform/functions-framework-nodejs/blob/master/docs/typescript.md

Getting Started

• Install Google Cloud CLI https://cloud.google.com/sdk/docs/install.
• When asked if you want to set up your account, do so and follow the steps. Select your organization/project as the organization/project when prompted.
• Copy .env.example.yml to .env.local.yml (and .env.prod.yml if you are deploying functions) and fill out the environment variables for the correct environment(s).

Contributing

Adding a function

1. Create the function code where appropriate inside src.
2. Add the function to the set of function definitions/handlers in src/index.ts
3. Add the function's deploy script to package.json by copying one of the lines named deploy-xxx and changing the name after deploy (in both the script name and script command) based on what you put in src/index.ts.
4. Add that script to deploy-all.
5. Follow instructions below on deploying a function.

Deploy Functions

Use the appropriate script in package.json, e.g. npm run deploy-hello-world, or npm run deploy-all to deploy everything.

The output of the script will tell you the URL of the new/updated function to use for the app to call, e.g. https://hello-world-7pi36k236a-uc.a.run.app

Running Functions locally

• Change directory to backend: cd backend
• npm run start to start the functions locally
• Run sample curl scripts (start with save-member to initiate a bank and user account)

Devnet Implementation of TAP

Program: TAPAPp2YoguQQDkicGyzTzkA3t4AgECvR1eL1hbx9qz USDC: USDCMGr4yKJju4p6r229yeWmKSsBLicUcZ2T1Ggx9sk Bank Auth: BaNkRi9z8s8y93KixtteuLXRxrL8Ph5XaXZs8HEvCda1 Bank PDA: 61t7eqKRX4y4og7N3viKsNrc6Hp9AMWSa6Ym4jt82g23