Milestone Escrow Smart Contract

This project implements a Milestone-based Escrow System on the Cardano blockchain using Aiken. It is designed to demonstrate the technical competencies required for a Cardano Catalyst Milestone Reviewer.

Project Overview

The core functionality ensures that funds allocated for a project are only released when specific milestones are achieved and verified by a designated reviewer.

• Actors:

  • Funder: The entity providing the funds (e.g., Catalyst Treasury).
  • Contractor: The entity doing the work (e.g., Proposal Team).
  • Reviewer: The trusted entity verifying the milestone (e.g., Value Milestone Reviewer).

• Logic:

  • Funds are locked in the contract with a Datum specifying the milestone schedule.
  • Release: Requires a signature from the Reviewer. Releases amount_per_milestone to the Contractor and updates the Datum to increment the current_milestone.
  • Cancel: Allows the Funder to reclaim remaining funds, but requires Reviewer approval (simulating dispute resolution or agreement).

Technical Relevance to Milestone Reviewer Role

This project serves as a proof-of-work for the following skills:

1. Understanding of E-UTxO Model:

   • The contract verifies state transitions (Datum updates) to ensure legitimate progress through milestones.
   • It handles UTxO consumption and creation (spending script input, creating continuing output).

2. Smart Contract Security:

   • Implements checks for signatures, output values, and correct addresses.
   • Prevents unauthorized access to funds.

3. Off-Chain Integration (MeshSDK v1.9.0):

   • Includes TypeScript scripts (offchain/src) to interact with the contract.
   • Demonstrates ability to use the latest MeshTxBuilder to construct complex Plutus V3 transactions.
   • Implements robust wallet management and transaction signing.

Directory Structure

• validators/: Aiken smart contract code.
• offchain/: Node.js project for off-chain interaction using MeshSDK.
• plutus.json: Generated CIP-57 blueprint.

How to Run

1. Install Aiken: aiken --version
2. Build Contract:

   aiken build

3. Run Tests:

   aiken check

4. Off-chain Interaction:
   • Navigate to offchain/
   • npm install
   • (Optional) Configure .env with a Blockfrost Key (see offchain/src/common.ts for setup)
   • Run npx ts-node src/release.ts to see the transaction builder in action (mock mode).