# brine-tree
[](https://crates.io/crates/brine-tree)
A fast, low-overhead, **Blake3** Merkle tree library for the Solana programs.
---
## Features
- Zero-copy
- Support for add, remove, replace
- Low compute unit (CU) consumption
- Can be stored in account state
- Includes proof generation and verification
- Includes cached proof generation
---
## Quick Start
```rust
use brine_tree::{MerkleTree, Leaf};
fn main() {
const TREE_DEPTH: usize = 18;
let mut tree = MerkleTree::<{TREE_DEPTH}>::new(&[b"empty_leaf_seed"]);
let data = &[b"hello", b"world"];
let leaf = Leaf::new(data);
tree.try_add_leaf(leaf)?;
// Off-chain proof generation
let db = &[leaf, ...]; // your database of leaves
let leaf_index = 0; // index of the leaf you want to prove
let proof = tree.get_merkle_proof(db, leaf_index)?;
assert!(tree.contains(&proof, data));
Ok(())
}
```
Returns `Ok(())` for successful operations or `Err(ProgramError)` if invalid.
---
## Use Cases
- State compression for large datasets
- Whitelist or access control verification
- Off-chain data integrity checks
- Cross-chain state proofs
- Decentralized identity claims
- Oracle data validation
---
### But why?
**Q: Why not use an off-chain Merkle tree?**
**A:** Solana programs often need to verify inclusion or manage state on-chain efficiently. Off-chain Merkle trees require additional infrastructure and trust assumptions.
**Q: Why not use something else?**
**A:** There definitely are a few [other](https://github.com/anza-xyz/agave/blob/master/merkle-tree/src/merkle_tree.rs) implementations worth looking into, like [concurrent merkle tree](https://github.com/solana-labs/solana-program-library/blob/master/libraries/concurrent-merkle-tree/src/concurrent_merkle_tree.rs), but this one is simple and easy to work with.
---
## Contributing
Contributions are welcome! Please open issues or PRs on the GitHub repo.