Installation

Add the Beacon SDK

npm install @privacy-protocol/beacon

The SDK is ESM-only and generates UltraHonk proofs in the browser or in Node. It pulls in the Noir proving stack through pinned peer dependencies you must install at the exact versions:

npm install @noir-lang/noir_js@1.0.0-beta.16 @aztec/bb.js@3.0.0-nightly.20251104

Do not bump the peer dependencies. The proving stack must match the verification key of the deployed on-chain verifier. A different @noir-lang/noir_js or @aztec/bb.js version can produce proofs that fail to verify on-chain. Upgrading them requires regenerating the circuit and verifier together.

viem is a regular dependency and ships with the SDK.

What the SDK exports

• Proving — proveMembershipFromSecrets, proveMembershipFromWitness → { proof, publicInputs, nullifierHash, ... }.
• Catalog — MEMBERSHIP_ID, CATALOG, circuitId(name, version).
• Identity & Merkle — createIdentity, computeNullifier, buildMembershipTree, buildMembershipTreeFromLeaves.
• Field helpers — toField, toBytes32, toBig, requireField, SNARK_SCALAR_FIELD, TREE_HEIGHT.

Generate a proof

import { proveMembershipFromSecrets, MEMBERSHIP_ID } from "@privacy-protocol/beacon";
 
// `scope` is a bytes32 domain separator you choose (e.g. a proposal id, an epoch, an app id).
// The SDK reduces it into the BN254 field and returns the exact publicInputs to pass on-chain.
const { proof, publicInputs, nullifierHash } = await proveMembershipFromSecrets({
  scope,                       // bytes32 / bigint domain separator
  memberSecrets: [s0, s1, s2], // the membership set (leaves = Poseidon2(secret))
  memberIndex: 0,              // which member is proving
});
 
// publicInputs === [scope, root, nullifier] — hand these to your consumer contract.

See Integrate for the on-chain side, and Contracts for the public-input convention.

Next steps

• Contracts — the on-chain surface you call
• Integrate — wire the proof into your contract