shh

A privacy L3 on Base, built on the OP Stack.

𝕏 @privashhgg · shh.gg

A privacy L3 on Base, built on the OP Stack. shh ships in two profiles that share one cryptographic core:

• Full privacy chain — every transfer is a shielded UTXO note (Circom + Groth16).
• Open L3 + Privacy Pool — a transparent EVM L3 with an opt-in, compliance-compatible Privacy Pool (fixed denomination + Association Sets, so withdrawals are "unlockable" by an Association Set Provider).

It runs locally with a single sequencer via Docker Compose, and is live as a public testnet L3 settling to Base Sepolia — see Live testnet.

Layout

packages/
  circuits/   Circom circuits + trusted-setup tooling (the zk core)
  contracts/  Hardhat: pools, Poseidon Merkle tree, bridges, generated verifiers
  sdk/        TypeScript: notes, Merkle tree, witness + proof generation (npm: @privashh/sdk)
  asp-publisher/  daemon: publishes the Privacy Pool association-set root on-chain
infra/
  op-stack/   Docker Compose single-sequencer L3 (live; settles to Base Sepolia)
  explorer/   Blockscout
apps/
  web/        Next.js wallet backend (route handlers; local dev)
docs/
  workflow.md          phased build plan + verification gates
  architecture.md      system architecture
  privacy-design.md    cryptographic source of truth (hashes, circuits, signals)

Quick start

pnpm install
pnpm setup        # compile circuits + Groth16 trusted setup + build sdk & contracts
pnpm dev          # local chain + deploy + copy artifacts + wallet backend (http://localhost:3000)

pnpm dev is the turn-key local stack: it starts a local node, deploys the privacy core, copies circuit artifacts into the web app, and runs the wallet backend. Then:

node apps/web/scripts/demo-deposit.mjs          # make a Privacy Pool deposit
curl http://localhost:3000/api/pool/leaves      # see it indexed

Run the full verification gate directly:

pnpm --filter @privashh/sdk test       # 9/9  notes, Merkle, value conservation
pnpm --filter @shh/circuits test  # 4/4  valid witness proves+verifies; tampered fails
pnpm contracts:test               # 10/10 deposit→prove→withdraw, double-spend, ASP gating,
                                  #       bidirectional shielded bridge, front-running

Real L3 + explorer (Docker; chain boot is optional — see each README):

cd infra/op-stack && cp .env.example .env && make generate && docker compose up -d
cd infra/explorer && cp .env.example .env && docker compose up -d

Status: live on a public testnet — the L3, privacy core, ASP publisher, and public RPC are up, and the client SDK is published to npm. The wallet UI (in-browser proving) is in progress. See docs/workflow.md.

Live testnet

shh runs as a public OP Stack L3 settling to Base Sepolia.

Chain ID	55666
RPC	https://rpc.shh.gg
Settlement (L1)	Base Sepolia (84532)
Profile	open-pool (transparent L3 + Privacy Pool)
Pool denomination	0.1 ETH

Deployed contracts (open-pool profile):

Contract	Address
PrivacyPool	0x06f7F1539030D116AecCC7a32eF35D71b572dc3c
ShieldedPool	0xFf0186cb30cF970F1911760e2fc2b37ED5114520
AssociationSetProvider	0x37C5550c8baF1015f0a469b7C4d6D63065965aeF
PoolWithdrawVerifier	0xc3A5f03b0b1BeD88A50BadAf0C83b9c04f5ede56
Transaction2x2Verifier	0xc26C4e92f2c48dC9dC45e02e81092c15f3caC25e
Poseidon hasher	0x17071fFB640DB06aE3568050a9E0217c51899e64

An ASP publisher keeps the association-set root current on-chain, so deposits become withdrawable. The client SDK is published as @privashh/sdk:

npm install @privashh/sdk

Security

The trusted setup shipped for development is single-contributor and must not secure real funds. Mainnet requires a multi-party ceremony and an external audit (Phase 8). See docs/privacy-design.md.