privacy-protocol

Privacy Protocol is a relayer-first privacy middleware for EVM dApps.

Package exports:

• privacy-protocol/core: low-level SDK

• privacy-protocol/hooks: React hooks

No manual circuit import is required. The Noir circuit is bundled.

Install

npm install privacy-protocol ethers

For React apps:

npm install react

Core SDK (Quickstart)

import { ethers } from "ethers";
import { PrivacyProtocolSDK } from "privacy-protocol/core";

const provider = new ethers.JsonRpcProvider(process.env.RPC_URL);
const signer = await provider.getSigner();

const sdk = new PrivacyProtocolSDK(provider, process.env.PRIVACY_PROTOCOL_POOL_ADDRESS!);

Relayer transport is built in by default. You only pass options.relayer if you want to override the default endpoint or relayer metadata.

const sdkWithCustomRelayer = new PrivacyProtocolSDK(
  provider,
  process.env.PRIVACY_PROTOCOL_POOL_ADDRESS!,
  undefined,
  {
    relayer: {
      url: process.env.PRIVACY_PROTOCOL_RELAYER_URL,
      relayerAddress: process.env.PRIVACY_PROTOCOL_RELAYER_ADDRESS,
    },
  },
);

Typical Flow

1. Approve token spend to poolAddress.

2. Deposit with sdk.deposit(...).

3. Build leaves with sdk.getLeaves().

4. Execute private action (sdk.executeAction(...)) or withdraw (sdk.withdraw(...)).

5. Persist returned note fields (secret, nullifier, commitment).

Relay Lifecycle

Private executeAction/withdraw initially return:

• txHash: "relay:<request_id>"

As relayer submission progresses:

• request is queued (queued)

• on-chain tx is submitted (submitted)

• tx confirms (success/reverted)

Use:

const details = await sdk.getPrivateTransactionDetails(txHash);

If relayer has already submitted, this resolves to actual on-chain metadata (tx.from, gas payer, status, etc).

React Hooks

import {
  useDeposit,
  useExecuteAction,
  useWithdraw,
  useCommitments,
  usePrivateTransactionDetails,
  useLocalNotes,
} from "privacy-protocol/hooks";

Minimal hook setup:

const common = {
  poolAddress,
  provider,
  signer,
};

const { deposit } = useDeposit(common);
const { executeAction } = useExecuteAction(common);
const { withdraw } = useWithdraw(common);

You can still pass relayer in hook options to override defaults per app.

Required Inputs

• Deployed PrivacyProtocolPool address

• Ethers provider + signer

• Supported token address in pool

• Storage for note material and tx metadata

Common Errors

• InvalidRootHash: stale leaves/root; refresh leaves and ensure latest SDK build.

• InvalidProof: mismatched note inputs or action context.

• NullifierUsed: note already spent.

• TokenNotSupported: token not added to pool.