Solana Escrow

A trustless token swap program built on Solana using the Anchor framework. Two parties can exchange SPL tokens without needing to trust each other — the program acts as a neutral intermediary.

How it works

1. Maker creates an escrow, deposits token A into a vault, and specifies how much token B they want in return
2. Taker fulfils the deal by sending token B to the maker and receiving token A from the vault
3. Maker can cancel at any time and get their tokens back via a refund

Instructions

Instruction	Signer	Description
make	Maker	Creates the escrow PDA, creates vault, deposits token A
take	Taker	Sends token B to maker, receives token A from vault, closes escrow
refund	Maker	Cancels the escrow, returns token A, closes all accounts

Project structure

programs/escrow/src/
├── lib.rs                  ← entry point
├── constants.rs            ← PDA seeds
├── error.rs                ← custom errors
├── state/
│   ├── mod.rs
│   └── escrow.rs           ← Escrow account struct
└── instructions/
    ├── mod.rs
    ├── make.rs             ← make instruction
    ├── take.rs             ← take instruction
    └── refund.rs           ← refund instruction

Security practices

• PDA-owned vault — no human controls the locked tokens
• has_one constraints prevent token substitution attacks
• TransferChecked used for all transfers — prevents decimal manipulation
• Bump stored on-chain — prevents bump substitution attacks
• overflow-checks = true in release profile — prevents integer overflow
• Anchor discriminators — prevent account type confusion

Getting started

anchor build
anchor test

Stack

• Anchor 0.32.1
• anchor-spl 0.32.0
• Solana Token Interface (supports both Token and Token-2022)