Contracts reference

@shh/contracts is a Hardhat (TypeScript) project. Verifiers are generated from the circuits and never hand-edited; everything else is purpose-written and tested against the SDK.

#Pools & tree

PrivacyPool.sol

Fixed-denomination pool with ASP-gated withdrawals. deposit(commitment) and withdraw(proof, roots, nullifierHash, recipient, relayer, fee, refund).

ShieldedPool.sol

UTXO commitments and join-split via transact. Computes publicAmount from the external amount and fee, emits encrypted outputs.

MerkleTreeWithHistory.sol

On-chain incremental Poseidon tree with a ring buffer of recent roots; isKnownRoot accepts the current or a recent historical root.

#Compliance

AssociationSetProvider.sol

Publishes the associationRoot the Privacy Pool checks against.

IAssociationSetProvider.sol

The interface the pool consumes — decoupling pool logic from a specific ASP implementation.

#Bridges

bridge/L1ShieldedBridge.sol

The Base-side lock that messages the L3 via the OP portal.

bridge/L2ShieldedBridge.sol

The L3-side finalizer; finalizeShieldedDeposit accepts only the aliased L1 bridge address.

libraries/AddressAliasHelper.sol

OP-style L1→L2 address aliasing used to authenticate deposits.

#Verifiers (generated)

verifiers/PoolWithdrawVerifier.sol

Groth16 verifier exported from poolWithdraw.circom.

verifiers/Transaction2x2Verifier.sol

Groth16 verifier exported from the 2-in/2-out transaction circuit.

#Interfaces & mocks

• interfaces/ — IHasher, IVerifiers, IOptimismPortal, IL2StandardBridge, IAssociationSetProvider.
• mocks/ — MockOptimismPortal, MockL2StandardBridge for unit-testing the bridge without a live OP stack.

#Build & test

pnpm contracts:build   # hardhat compile
pnpm contracts:test    # 10/10 — both pools, double-spend, ASP gating,
                       #         bidirectional bridge, front-running
pnpm deploy:local      # deploy the core to the local node