jat-program

On-chain programs for Jat, private payments on Solana. This repo is the Anchor workspace: the shielded pool with its on-chain Poseidon Merkle tree and Groth16 verifier, and the stealth announcer. The original code lives in programs/; everything under programs/*/src is first-party. The zero-knowledge circuits are in jat-circuits and the client SDK and services are in jat-sdk.

What is here

• Pool program: an incremental Poseidon (BN254) Merkle tree of depth twenty, a Groth16 withdraw verifier over the alt_bn128 syscalls, single-use nullifier accounts, and a trustless vault payout that signs with a program derived address. No authority sets the root; the root is a deterministic function of deposits.
• Announcer program: one write-once record per payment holding the ephemeral key R, a one-byte view tag, and the scheme, keyed by a program derived address. Holds no funds and has no authority.

Features

Capability	Program	Status
Incremental Poseidon Merkle tree (depth 20)	pool	stable
Fixed-denomination deposits	pool	stable
Proof-of-receipt gate (seal_verify, CPI-able)	pool	stable
ZK withdraw with recipient binding	pool	beta
Single-use nullifier accounts	pool	stable
Stealth announcement index	announcer	stable

Architecture

flowchart LR
  D[depositor] -->|deposit lamports + precommit| T[(pool: Poseidon tree)]
  T -->|leaf, root| H[on-chain root history]
  P[prover] -->|groth16 proof| V[seal_verify / withdraw]
  V -->|root in history?| H
  V -->|consume nullifier| N[(nullifier PDA)]
  V -->|invoke_signed| Vault[(vault PDA)]
  Vault -->|payout| R[recipient]
  Pay[payer] -->|announce R, view_tag| A[(announcer PDA)]

Loading

A deposit pins the leaf's value to the lamports actually moved in and inserts leaf = Poseidon(value, label, precommit) into the program's own tree. A withdraw proves membership under a recent root, binds the payout to the recipient by Poseidon(hi16, lo16), consumes a global nullifier, and pays out of the vault PDA. No operator, no upgrade-time root injection.

Deployments

Network: Solana devnet.

Program	Address
Pool	seuH78RmBPVzoKToLQVEZrDvuL5jDNBSbptozWK9PEm
Announcer	seaWHA64tVzN8yfa33bE6cvqKRSxVp3R6c7Ts5NXPM9

Verify on an explorer with the cluster set to devnet: https://explorer.solana.com/address/seuH78RmBPVzoKToLQVEZrDvuL5jDNBSbptozWK9PEm?cluster=devnet

Build

git clone --recurse-submodules https://github.com/Jatcotcash/jat-program
cd peepy
anchor build
# or, for a devnet SBPFv3 deploy:
cargo-build-sbf --arch v3

Host tests run without a validator:

cargo test --workspace

cargo test checks that a real circom/snarkjs proof verifies through groth16-solana, and that the on-chain Poseidon insert reproduces the proof's Merkle root. If either fails, the program and the circuits have drifted apart.

Program keypairs and wallets are gitignored and never committed.

Instructions

Instruction	Program	What it does
init_tree	pool	Seed the empty Poseidon tree; no authority field
deposit	pool	Move lamports in, insert a commitment leaf
seal_verify	pool	Verify a proof-of-receipt, consume a scoped nullifier
withdraw	pool	Prove ownership, pay out of the vault, consume a global nullifier
announce	announcer	Write a stealth announcement PDA keyed by R

Project structure

peepy/
  programs/
    seal/
      src/lib.rs        init_tree, deposit, seal_verify, withdraw + Poseidon helpers
      src/vk.rs         gate verifying key (BN254)
      src/vk_withdraw.rs withdraw verifying key (BN254)
    announcer/
      src/lib.rs        announce + Announcement account
      tests/announce.rs wire-format pins against the IDL
  Anchor.toml           toolchain, program ids per cluster, scripts
  Cargo.toml            workspace, release profile
  CEREMONY.md           trusted-setup ceremony for mainnet keys
  SECURITY.md           threat model, hardening, roadmap

Status

Runs on devnet. The full round-trip works end to end. No third-party audit yet, and the pool uses a Groth16 trusted setup, so treat the current parameters as devnet-grade. Do not use with real funds. The path to mainnet is in CEREMONY.md and SECURITY.md.

Contributing

See CONTRIBUTING.md and CODE_OF_CONDUCT.md.

License

MIT, see LICENSE.

Links

• Circuits: https://github.com/Jatcotcash/jat-circuits
• SDK and services: https://github.com/Jatcotcash/jat-sdk