Solana Escrow Program

This project implements a secure, trustless escrow protocol on Solana using the Anchor framework. Two parties can safely swap SPL tokens using program-derived addresses (PDAs) and on-chain logic, with all flows enforced by the smart contract.

Features

• Trustless Escrow: Securely swap SPL tokens between two parties with no intermediaries.
• Offer/Take/Refund: Makers create offers, deposit tokens, and can refund if not taken. Takers can accept offers and atomically swap tokens.
• Anchor Framework: Built with Anchor for safety, clarity, and easy testing.
• TypeScript Tests: Comprehensive tests using Mocha/Chai and Anchor’s TypeScript client.
• Deterministic PDAs: All state and vault accounts are derived using seeds for uniqueness and security.

How It Works

PDA Structure

• Escrow State PDA: Stores offer details and bump. Derived as:
  • seeds = [b"escrow", maker_pubkey, seed (u64 le)]
• Vault ATA: Associated token account for the escrow PDA, holds the offered tokens.
• Maker/Taker ATAs: Standard SPL token accounts for each user.

Program Instructions

• make: Initializes a new escrow offer and vault for the maker.
• deposit: Deposits the offered tokens into the vault.
• take: Taker accepts the offer, swaps tokens, and closes the vault.
• refund: Maker cancels the offer and reclaims escrowed tokens if not taken.

Setup

1. Install dependencies:

   yarn install
   # or
   npm install

2. Configure Solana CLI:

   • Set up your wallet and localnet/devnet as needed.
   • Update Anchor.toml with your wallet path and cluster.

3. Build and Deploy the Program:

   anchor build
   anchor deploy

4. Run Tests:

   yarn test
   # or
   anchor test

Usage Example (Test Flow)

The test suite in tests/escrow.ts demonstrates the full lifecycle:

1. Make Offer:

   • Derives PDAs for the maker and vault.
   • Calls make to create the escrow state and vault accounts.

2. Deposit Tokens:

   • Calls deposit to transfer tokens from the maker to the vault.
   • Checks vault balance after deposit.

3. Take Offer (Swap):

   • Taker calls take to send their tokens to the maker and receive the escrowed tokens.
   • Checks balances and asserts vault is closed.

4. Refund:

   • Maker calls refund to reclaim tokens if the offer is not taken.
   • Asserts that the vault is closed and tokens are returned.

File Structure

• programs/escrow/src/lib.rs — Anchor program logic (Rust, entrypoint)
• programs/escrow/src/instructions/ — Instruction handlers (make.rs, deposit.rs, take.rs, refund.rs)
• programs/escrow/src/state/ — State definitions (Escrow struct)
• tests/escrow.ts — TypeScript tests using Anchor client
• Anchor.toml — Anchor configuration
• Cargo.toml, Xargo.toml — Rust and Solana BPF build setup
• package.json, tsconfig.json — TypeScript and test setup

Requirements

• Solana CLI
• Anchor CLI
• Node.js, Yarn or npm

Security Notes

• All escrow and vault accounts are PDAs, so only the program can move funds from vaults.
• Bump seeds are stored in the escrow state PDA for secure PDA derivation and signing.
• Only the maker can refund, and only if the offer has not been taken.
• All swaps and refunds are atomic and enforced by on-chain logic.

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For full usage and API details, see the test suite in tests/escrow.ts.

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