Cloak is a privacy-preserving exit router on Solana. This repo hosts the whole system, with a strong focus on the Zero-Knowledge layer:

• ZK Notes (UTXO-style): commitments, nullifiers, Merkle proofs
• Withdraw circuit (SP1): inclusion + nullifier + conservation
• On-chain verification: Pinocchio program shield-pool
• Indexer API: append-only Merkle tree & proofs
• Relay: submits withdraw txs (no Jito in MVP)

Required Tools:

• Rust (stable or nightly)
• Solana CLI tools
• SP1 toolchain (for ZK proving)

Installation:

# 1. Install Rust
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
rustup install nightly

# 2. Install Solana CLI
sh -c "$(curl -sSfL https://release.solana.com/v1.18.4/install)"
export PATH="$HOME/.local/share/solana/install/active_release/bin:$PATH"

# 3. Install SP1 toolchain (REQUIRED for ZK functionality)
curl -L https://sp1.succinct.xyz | bash
source ~/.zshenv  # or ~/.bashrc depending on your shell
sp1up

# 4. Install the succinct toolchain
cargo prove install-toolchain

# 5. RISC-V target is automatically installed with SP1
# No manual installation needed - SP1 handles this automatically

# 6. Verify installations
rustc --version
solana --version
cargo prove --version

Build the project:

git clone <repo-url>
cd cloak
cargo build --release

SP1 Toolchain Error: If you see error: override toolchain 'succinct' is not installed, run:

# Install SP1 and the succinct toolchain
curl -L https://sp1.succinct.xyz | bash
source ~/.zshenv  # or ~/.bashrc depending on your shell
sp1up
cargo prove install-toolchain

RISC-V Target Error: If you see error: toolchain 'nightly-aarch64-apple-darwin' does not support target 'riscv32im-succinct-zkvm-elf', this is normal! SP1 automatically handles the RISC-V target installation. Just run:

# Build the project - SP1 will handle the RISC-V target automatically
cargo build --release

Build Issues:

• Ensure all prerequisites are installed
• Try cargo clean before rebuilding
• Check that RUSTUP_TOOLCHAIN environment variable is not set incorrectly

• ZK overview: docs/docs/zk/README.md
• Circuit spec: docs/docs/zk/circuit-withdraw.md
• Encoding contract: docs/docs/zk/encoding.md
• Merkle tree & proofs: docs/docs/zk/merkle.md
• SP1 prover details: docs/docs/zk/prover-sp1.md
• On-chain verifier & program: docs/docs/zk/onchain-verifier.md
• API contracts (Indexer/Relay): docs/docs/zk/api-contracts.md
• Threat model: docs/docs/zk/threat-model.md
• Roadmap: docs/docs/roadmap.md

Build order (MVP): Merkle+Indexer → Deposit tx/event → SP1 withdraw circuit → On-chain verifier → Relay → Web wiring.

• Run yarn inside docs-site/ and yarn start to launch the Docusaurus portal backed by the markdown docs in docs/.
• Generated site covers architecture, workflows, on-chain programs, services, PoW, tooling, and operations.