TeenFiAllowance POC: Empowering Parental Allowance with ERC-7715 Actions

Project Overview

TeenFiAllowance is a proof-of-concept (POC) decentralized application (dApp) that enables parents to manage weekly allowances for teens using blockchain technology. Built on the Sepolia testnet, leveraging MetaMask Delegation Toolkit’s ERC-7715 Actions and ERC-7710 delegations, it supports two ERC-20 tokens: a custom TST token and PayPal USD (PYUSD). Parents can configure allowances, set spending caps, and transfer tokens, while teens can spend their allowance within approved categories (e.g., Education, Entertainment). For testing, spent tokens are transferred back to the parent. A minimal HTML front-end supports TST and PYUSD, with clear descriptions, headings, compact side-by-side labeled inputs, pre-filled Teen Address, "Connect MetaMask Flask", "Disconnect Wallet", and "Transfer TST" buttons.

This repository contains simplified code without demo-specific styling (e.g., Bootstrap) used in the live demo at www.skytiger.tech/TeenFiAllowance/, which includes a styled interface for presentation purposes.

This project was developed for the "MetaMask Delegation Toolkit (DTK) Dev Cook-Off", showcasing blockchain-based financial education for teens, with a user-friendly interface: a demo is hosted at www.skytiger.tech/TeenFiAllowance/. The live demo is non-working, as the Infura API key has been removed for security reasons. To run the dApp, users must provide their own Infura API key and set up SSL locally, as the frontend requires SSL (HTTPS) to run locally due to MetaMask Flask’s security requirements.

Hackathon Objective Alignment

Aligns with Track 1: Best Use of ERC-7715 Actions by implementing redeemDelegations and offering a family-oriented use case.

Key Features

• Automated Allowances: Token streaming via IERC7715TokenStreaming.

• Delegated Spending: ERC-7715 Actions with redeemDelegations (testing in full contract, but bypassed in POC).

• Security: OpenZeppelin’s Ownable, ReentrancyGuard, SafeERC20, emergency pause functionality.

• Front-End: HTML/JavaScript with Viem (ESM), supporting TST and PYUSD.

Features

• Parent Features:

  • Registers a parent’s wallet and links it to a teen’s wallet to have delegation authority, enabling the parent to configure allowances and manage spending via the TeenFiAllowance smart contract.

  • Configure weekly allowance and spending cap for a teen’s wallet.

  • Transfer TST or PYUSD tokens to the teen.

• Teen Features:

  • View allowance balance and token balance.

  • Spend allowance in approved categories (Education, Entertainment, Savings, Food).

• Blockchain Integration:

  • Uses Sepolia testnet for secure, low-cost transactions.

  • Interacts with TeenFiAllowance smart contract and ERC-20 tokens (TST, PYUSD).

• Responsive UI:

  • Built with Bootstrap 5 and custom CSS for mobile and desktop compatibility.

Problem Statement

Traditional allowances lack automation, and Web3 dApps require complex approvals. TeenFiAllowance automates payments and delegates spending with a simple UX.

Revolut allows parents to create an account and card for their teenagers, and then transfer funds over to it.

They can also view the transactions, however there is no control over their spending.

With the recent release of the MetaMask credit card, the delegation toolkit offers possibilities for setting spending caps on the teenagers funds.

Solution

• Contract: 0x2161e095ec52d9B02AdeADFe6cE2A07deF17FF95 (full) or 0x4a631b162D58756C2568F03744d63037Bd4348d9 (POC).

• MockDelegationManager: 0xD464A84c5ed04d34B0431464c173b782ae5602F6.

• ERC20StreamingEnforcer) (_caveatEnforcer) 0x56c97aE02f233B29fa03502Ecc0457266d9be00e

• MockActionsContract (_actionsContract): 0x3A4A2B75FA0e9c8dB60bC92A6B0616A3b473def6

• MockStreamingContract (_streamingContract): 0x65e302187f01745Eb8D9bc44CDC361f68d3339d7

• Test ERC-20 Tokens:

  • TST: 0x1230591e26044F0AA562c24b4d7Fd002b227E69c

  • PYUSD: 0xCaC524BcA292aaade2DF8A05cC58F0a65B1B3bB9

• Accounts (used only via MetaMask Flask):

  • Parent: 0x86110B44E8580905749Eea2A972D15704A914cE5

  • Teen: 0x3674473C7BDAf922f68a0232509049aBD37Da7A9

  • TST Owner: 0xbb81ae1ca1f3a47fA5CA0A3a44Cd1b195Df65B38

• Front-End: Homepage with TST/PYUSD links, served over HTTPS.

• Functions: configureAllowance, spendAllowance, createStreamingAllowance, addParent.

Technical Details

• Standards: ERC-7715, ERC-7710, ERC-20.

• Dependencies: OpenZeppelin, Viem (ESM).

• Delegation: Live redeemDelegations tested; bypassed in POC.

• Testing: TestTeenFi.s.sol passed.

Frontend

• HTML5, CSS3, JavaScript (ES6): Core web technologies.

• Bootstrap 5: Responsive UI framework.

• Viem (2.21.25): Ethereum client library for contract interactions.

• MetaMask Flask: Wallet for Sepolia testnet connectivity.

• Minimal CSS: Basic styling for usability, without Bootstrap or external frameworks.

• lite-server: Local development server with SSL support.

• mkcert: Tool for generating local SSL certificates.

Blockchain

• Solidity: Smart contracts (TeenFiAllowance, TST).

• Sepolia Testnet: Ethereum test network (chain ID: 0xaa36a7).

• Infura RPC: https://sepolia.infura.io/v3/<API-KEY>.

• Hardhat/Foundry: Contract deployment tools.

• ERC-20: Standard for TST and PYUSD tokens.

Deployment

• Hosting: Repository code is simplified; disabled demo with styling hosted on SkyTiger.Tech (removed the API key).

• Contracts: Deployed on Sepolia, verified on Etherscan.

Contract Details

• TeenFiAllowance Contract:

  • Address: 0x4a631b162D58756C2568F03744d63037Bd4348d9

  • Functions:

    • addParent(address parent, address teen): Registers a parent’s wallet and links it to a teen’s wallet, granting delegation authority for allowance management.

    • configureAllowance(address teen, address token, uint256 weeklyAmount, uint256 spendingCap, bytes delegationTerms): Sets allowance parameters.

    • spendAllowance(address parent, uint256 amount, uint8 category): Allows teens to spend tokens.

    • teenBalances(address): Returns teen’s allowance balance.

  • Verified on Sepolia Etherscan.

• TST Token (Custom ERC-20):

  • Address: 0x1230591e26044F0AA562c24b4d7Fd002b227E69c

  • Decimals: 18

  • Verified on Sepolia Etherscan.

• PYUSD Token (PayPal USD):

  • Address: 0xCaC524BcA292aaade2DF8A05cC58F0a65B1B3bB9

  • Decimals: 18

  • Not been verified on Sepolia Etherscan.

Etherscan Links:

• TeenFiAllowance: https://sepolia.etherscan.io/address/0xC77223d1bDEa392Da996E6f9a4aab174fc3aD71F

• MockActionsContract: https://sepolia.etherscan.io/address/0x3A4A2B75FA0e9c8dB60bC92A6B0616A3b473def6

• MockStreamingContract: https://sepolia.etherscan.io/address/0x65e302187f01745Eb8D9bc44CDC361f68d3339d7

• TestToken: https://sepolia.etherscan.io/address/0x1230591e26044F0AA562c24b4d7Fd002b227E69c -

Innovation and Impact

• Innovation: Family-oriented Web3 with dual-token support.

• Impact: Simplifies Web3 for non-technical users.

• Boundaries Pushed: Full delegation lifecycle with compact UI.

Challenges and Solutions

• Challenge: Contract revert ("Caller is not a parent of the teen").

  • Solution: Called addParent.

• Challenge: Could not get the Delegation Framework to install and work

  • Solution: Created the MockDelegationManager

• Challenge: Contract revert ("Delegation terms cannot be empty").

  • Solution: Set delegationTerms to 0x1234.

• Challenge: teenBalances timeout.

  • Solution: Used Infura RPC with retries.

• Challenge: Teen wallet connection failure.

  • Solution: Added "Disconnect Wallet" button.

• Challenge: Teen has no TST tokens.

  • Solution: Added "Transfer TST" button and backend script.

Future Enhancements

• Achievement rewards, Gator SDK, ERC-4337, NextJS.

• Gasless Transactions: ERC-4337 user operations with a paymaster cover gas fees, enhancing teen accessibility

Contract Deployments and Testing

Contract Deployment Settings:

• Script: DeployTeenFiAllowance.s.sol

• Parameters:

  • _delegationManager: 0xdb9B1e94...

  • _caveatEnforcer: 0x56c97aE0...

  • _actionsContract: 0x3A4A2B75...

  • _streamingContract: 0x65e30218...

• Network: Sepolia

Contract Deployment Steps:

1. Clone Repository:

   git clone [[Repo URL]](https://github.com/SkyTiger2024/TeenFiAllowance.git)
   cd TeenFiAllowance/TeenFi
   npm install

2. Install Dependencies: Using Node.JS 22.13.0 npm install yarn pnpm npm install metamask/delegation-toolkit forge install install metamask/delegation-framework@v1.3.0 --no-commit forge install create .yarnmc.yml create .npmrc

3. Setup:

   • Install MetaMask Flask, enable Snaps.

   • Set Sepolia RPC in .env. 3.Deploy MockActions & MockStreaming Contracts:

_actionsContract: 0x234202b7EEC7B243fc854c865EAab181B91575D8, _streamingContract: 0x65e302187f01745Eb8D9bc44CDC361f68d3339d7```

4. Verify Mock Contracts on Sepolia Etherscan:

forge verify-contract <STREAMING_CONTRACT_ADDRESS> src/MockStreamingContract.sol:MockStreamingContract --chain-id 11155111```

5. Deploy the MockDelegationManager: `forge script script/DeployMockDelegationManager.s.sol --rpc-url https://sepolia.infura.io/v3/68be52d1c6a64ef3b9d7ae3401415bd4 --private-key (key) --broadcast

Logs MockDelegationManager deployed to: 0x`

6. Update DeployTeenFiAllowance.s.sol with Mock Addresses: TeenFiAllowance teenFiAllowance = new TeenFiAllowance( 0xD464A84c5ed04d34B0431464c173b782ae5602F6, // _delegationManager (MockDelegationManager) 0x56c97aE02f233B29fa03502Ecc0457266d9be00e, // _caveatEnforcer (ERC20StreamingEnforcer) 0x3A4A2B75FA0e9c8dB60bC92A6B0616A3b473def6, // _actionsContract (MockActionsContract) 0x65e302187f01745Eb8D9bc44CDC361f68d3339d7 // _streamingContract (MockStreamingContract)

7. Deploy the TeenFiAllowance Contract: forge script script/DeployTeenFiAllowance.s.sol --rpc-url https://sepolia.infura.io/v3/<APIKEY> --private-key (key) --broadcast Note down contract addres: TeenFiAllowance deployed to: 0x

8. Verify TeenFiAllowance Contract on Etherscan: forge flatten src/TeenFiAllowance.sol > FlatTeenFiAllowance.sol Slect Single Solidity file, and paste this contents.

9. Update script/TestTeenFi.s.sol with Contract Address: address constant TEENFI_ADDRESS = 0x<TeenFiAllownaceContractAddress>;

10. Run Tests:

forge script script/TestTeenFi.s.sol --rpc-url https://sepolia.infura.io/v3/<APIKEY> --private-key [YOUR_PRIVATE_KEY] --broadcast

== Logs ==
Registering parent for teen...
Parent registered
Approving TeenFiAllowance for configureAllowance...
Approval successful
Calling configureAllowance...
configureAllowance successful
Verifying delegation...
Delegation status: true
Calling modifyAllowance...
modifyAllowance successful

11. Run dApp:

npm run dev

12. Query Contract:

• Get parents:

  cast call 0x724e4fbe886aC69AE6E4866de4D53639b3723BED "getParents(address)(address[])" 0xfFF8f28f6E86C72FB3c11003dC6c3a05E9ea3E91 --rpc-url https://sepolia.infura.io/v3/<APIKEY>

• Get allowance:

  cast call 0x724e4fbe886aC69AE6E4866de4D53639b3723BED "parentTeenAllowances(address,address)(address,uint256,uint256,uint256,bool,uint256)" 0xbB81ae1ca1f3a47fA5CA0A3a44Cd1b195Df65B38 0xfFF8f28f6E86C72FB3c11003dC6c3a05E9ea3E91 --rpc-url https://sepolia.infura.io/v3/生まれ

13. View Events: https://sepolia.etherscan.io/address/0x724e4fbe886aC69AE6E4866de4D53639b3723BED#events

14. Run Contract Tests:

forge script script/TestTeenFi.s.sol --rpc-url https://sepolia.infura.io/v3/[YOUR_INFURA_KEY] --private-key [YOUR_PRIVATE_KEY] --broadcast

15. Set Parent-Teen Relationship:

cast send 0x4a631b162D58756C2568F03744d63037Bd4348d9 "addParent(address,address)" 0x86110B44E8580905749Eea2A972D15704A914cE5 0x3674473C7BDAf922f68a0232509049aBD37Da7A9 --rpc-url https://sepolia.infura.io/v3/[YOUR_INFURA_KEY] --private-key [DEVAC_PRIVATE_KEY]

Front-End Setup Instructions

Front-EndPrerequisites

• MetaMask Flask: Installed and configured for Sepolia testnet.

• Sepolia ETH: Obtain test ETH from a faucet (e.g., Infura Faucet).

• Node.js: For local development (optional).

• Git: For cloning the repository.

• mkcert: For generating local SSL certificates

• Infura Account: Required for Sepolia RPC connectivity.

Front-End Deployment

1. Clone the Repository:

   git clone https://github.com/your-repo/TeenFiAllowance.git
   cd TeenFiAllowance

2. Install Dependencies (if running locally):

   npm install lite-server --save-dev

3. Set Up Infura API Key:

   • Sign up at Infura and create a new Sepolia project.

   • Copy the RPC URL (e.g., https://sepolia.infura.io/v3/YOUR_API_KEY).

   • Update the chain.rpcUrls.default.http field in the JavaScript code of useTSTtokens.html, usePYUSDtokens.html, and addParent2Teen.html with your RPC URL.

4. Generate SSL Certificates:

   • Install mkcert (see mkcert GitHub).

   • Create a certificate authority (CA):

     mkcert create-ca

     • Outputs: ca.key (CA Private Key), ca.crt (CA Certificate).

   • Create a certificate for localhost:

     mkcert create-cert --domains "localhost,127.0.0.1"

     • Outputs: cert.key (Private Key), cert.crt (Certificate).

   • Move certificates to the repository root (or update bs-config.js paths if stored elsewhere).

5. Configure lite-server:

   • Ensure bs-config.js is in the repository root with:

     module.exports = {
       port: 3000,
       open: true,
       server: {
         baseDir: "./",
         https: {
           key: "./cert.key",
           cert: "./ca.crt"
         }
       }
     };

6. Deployed Contracts Details ):

   • Tkae the addresses noted down from when you deplyed TeenFiAllowance.sol and TST.sol.

   • Update contractAddress and tokenAddress in useTSTtokens.html, usePYUSDtokens.html, and addParent2Teen.html.

7. Run the Frontend:

   • Start the server with SSL:

     npx lite-server --config=bs-config.js

   • Access at https://localhost:3000.

FrontEnd Usage

1. Visit the dApp: Open https://localhost:3000 (local)

2. Configure Parent-Teen Relationship:

   • Navigate to the “Configure a new wallet as parent of a teen” page (addParent2Teen.html) via the link on the main index page.

   • Connect MetaMask Flask with the parent wallet 0x<ParentsWalletAddress>

   • Enter the parent wallet address and teen wallet address

   • Click “AddParent” to execute addParent function in the contract and link the wallets.

3. Choose Token:

   • Navigate to TST (useTSTtokens.html) or PYUSD (usePYUSDtokens.html) page.

4. Parent Actions (TST Page):

   • Set teen address , weekly amount (e.g., 100 TST), and spending cap (e.g., 400 TST).

   • Click “Configure Allowance”.

   • Transfer tokens (e.g., 50 TST) via “Transfer TST to Teen”.

5. Teen Actions:

   • Connect teen wallet .

   • View balance and spend allowance (e.g., 25 TST in “Education”).

6. Verify Transactions: Check on Sepolia Etherscan.

FrontEnd Testing

• Test Wallets:

  • Parent: 0x<ParentsWalletAddress>

  • Teen: 0x<TeensWalletAddress>

• Steps:

  1. Ensure wallets have Sepolia ETH and TST/PYUSD tokens.

  2. On Configure a new wallet as parent of a teen, connect parent wallet, enter Parent and Teen addresses, and execute addParent.

  3. Configure allowance (100 TST weekly, 400 TST cap).

  4. Transfer 50 TST to teen.

  5. Spend 25 TST as teen in a category.

  6. Verify balances and transactions.

• Note: Test when gas fees are low (monitor Sepolia Gas Tracker).

Submission Details

• Repository:

• Demo Video: https://github.com/SkyTiger2024/TeenFiAllowance

• Screenshots: [Insert URL]

• Deployed Contracts: 0x2161e095ec52d9B02AdeADFe6cE2A07deF17FF95 (full) 0x4a631b162D58756C2568F03744d63037Bd4348d9 (POC)

• Front-End Demo URL: https://www.skytiger.tech/TeenFiAllowance

• Team: SkyTigers

• Contact: info@skytiger.tech

Contributing

• Fork the repository.

• Create a feature branch (git checkout -b feature/YourFeature).

• Commit changes (git commit -m 'Add YourFeature').

• Push to the branch (git push origin feature/YourFeature).

• Open a pull request.

License

MIT License. See LICENSE for details.

Contact

• Email: info@skytiger.tech

• X: @SkyTigerTech

• Instagram: soratora2024

• YouTube: SkyTiger