Skip to content

README.md

Latest commit

 

History

History
237 lines (161 loc) · 5.81 KB

README.md

File metadata and controls

237 lines (161 loc) · 5.81 KB
Raw

quasar_vault

A Solana smart contract built with Quasar that lets users deposit and withdraw SOL into a personal vault secured by a PDA (Program Derived Address).

⚡ What is Quasar?

Quasar is a Solana program development framework for writing blazing fast SVM programs. Programs are #![no_std] by default — accounts are pointer-cast directly from the SVM input buffer with no deserialization, no heap allocation, and no copies.

You write #[program], #[account], and #[derive(Accounts)] like Anchor, but the generated code compiles down to near-hand-written CU efficiency.

Built by @blueshift — github.com/blueshift-gg/quasar

📁 Project Structure

quasar_vault/
├── src/
│   ├── lib.rs                  # Program entrypoint — declares instructions
│   ├── instructions/
│   │   ├── mod.rs              # Exports all instructions
│   │   ├── deposit.rs          # Deposit instruction logic
│   │   └── withdraw.rs         # Withdraw instruction logic
│   └── tests.rs                # Integration tests using QuasarSvm
├── Cargo.toml
├── Quasar.toml
└── README.md

⚙️ How It Works

Each user gets their own vault — a PDA derived from their wallet address:

vault PDA = ["vault", user_pubkey]  owned by quasar_vault program
  • Deposit — User transfers SOL from their wallet into their vault via the system program
  • Withdraw — Program transfers SOL back from the vault to the user

📜 Instructions

Deposit

#[instruction(discriminator = 0)]
pub fn deposit(ctx: Ctx<Deposit>, amount: u64) -> Result<(), ProgramError>
Account Type Description
user Signer The user depositing SOL
vault UncheckedAccount PDA vault — seeds: ["vault", user]
system_program Program<System> Solana system program for CPI transfer

Withdraw

#[instruction(discriminator = 1)]
pub fn withdraw(ctx: Ctx<Withdraw>, amount: u64) -> Result<(), ProgramError>
Account Type Description
user Signer The user withdrawing SOL
vault UncheckedAccount PDA vault — seeds: ["vault", user]

🚀 Getting Started

Prerequisites

Install

git clone https://github.com/mishalturkane/quasar_vault
cd quasar_vault

🛠️ CLI Commands

Build

Compiles the program to a .so binary:

quasar build

Output: target/deploy/quasar_vault.so

Test

Runs integration tests using the local QuasarSvm simulator. No real SOL is used:

quasar test

Note: Always run quasar build before quasar test so the .so file exists.

Profile

Gives a per-instruction CU (Compute Unit) breakdown with an interactive flamegraph:

quasar profile

Output example:

quasar_vault  484 CU
     441  91.1%  entrypoint
      43   8.9%  [unknown]

flamegraph  http://127.0.0.1:7777/?program=quasar_vault

Deploy

# Get free devnet SOL first
solana airdrop 2 --url devnet

# Deploy to devnet
quasar deploy --devnet

# Deploy to mainnet
quasar deploy --mainnet

🧪 Tests

Tests are written using QuasarSvm — a local Solana VM that runs entirely in memory. No real SOL is used during tests.

Located in src/tests.rs.

test_deposit

User  starts : 10 SOL
Deposits     :  1 SOL  →  vault
──────────────────────────────────
User  after  :  9 SOL
Vault after  :  1 SOL

test_withdraw

User  starts : 10 SOL
Deposits     :  1 SOL  →  vault
Withdraws    :  0.5 SOL ← vault
──────────────────────────────────
User  after  :  9.5 SOL
Vault after  :  0.5 SOL

Key Points About Tests

  • Account::from_pair creates fake in-memory accounts with any balance
  • Vault must be owned by crate::ID so the program can debit it on withdraw
  • PDA derived with Pubkey::find_program_address(&[b"vault", user.as_ref()], &crate::ID)
  • assert_eq! verifies exact lamport values after each operation

🔑 Key Concepts

PDA (Program Derived Address)

A special account address with no private key — only the owning program can sign for it:

let (vault, _bump) = Pubkey::find_program_address(
    &[b"vault", user.as_ref()],
    &crate::ID,
);

Why vault owner must be crate::ID

Only the owner of an account can debit its lamports. Setting vault owner to your program ID ensures only your program can withdraw from it — not any random caller.

Lamports ↔ SOL

1 SOL = 1,000,000,000 lamports

📦 Dependencies

[dependencies]
quasar-lang        = { git = "https://github.com/blueshift-gg/quasar" }
solana-instruction = { version = "3.2.0" }

[dev-dependencies]
quasar_vault-client = { path = "target/client/rust/quasar_vault-client" }
quasar-svm          = { git = "https://github.com/blueshift-gg/quasar-svm" }
solana-account      = { version = "3.4.0" }
solana-address      = { version = "2.2.0", features = ["decode"] }
solana-instruction  = { version = "3.2.0", features = ["bincode"] }
solana-pubkey       = { version = "4.1.0" }

🛠️ Built With

📄 License

MIT