Stealth Address SDK

This TypeScript SDK provides tools for working with Ethereum stealth addresses as defined in EIP-5564 and EIP-6538. It aims to offer a comprehensive suite of functionalities for both generating stealth addresses and interacting with stealth transactions.

Features

Generate Ethereum stealth addresses.
Compute stealth address private keys.
Check stealth address announcements to determine if they are intended for a specific user.
Look up the stealth meta address for a registrant
Fetch announcements
Watch announcements for a user
Prepare the payload for announcing stealth address details
Prepare the payload for registering a stealth meta-address on someone's behalf

Installation

npm install @scopelift/stealth-address-sdk
# or
yarn add @scopelift/stealth-address-sdk
# or
bun install @scopelift/stealth-address-sdk

Testing

Tests default to using your local anvil node

anvil
bun run test

Alternatively, run your tests using a fork of your provided (RPC_URL in env) rpc url

bun run anvil-fork
# run all tests
bun run test-fork
# or for a specific file
bun run test-fork FILE={file path}

Quick Start

Generating a Stealth Address

import { generateStealthAddress } from "@scopelift/stealth-address-sdk";

// Your stealth meta-address URI
// Follows the format: "st:<chain>:<stealthMetaAddress>", where <chain> is the chain identifier (https://eips.ethereum.org/EIPS/eip-3770#examples) and <stealthMetaAddress> is the stealth meta-address.
const stealthMetaAddressURI = "...";

// Generate a stealth address using the default scheme (1)
// To learn more about the initial implementation scheme using SECP256k1, please see the reference here (https://eips.ethereum.org/EIPS/eip-5564)
const result = generateStealthAddress({ stealthMetaAddressURI });

// Use the stealth address
console.log(result.stealthAddress);

Computing Stealth Key

import {
  computeStealthKey,
  VALID_SCHEME_ID,
} from "@scopelift/stealth-address-sdk";

// Example inputs
const viewingPrivateKey = "0x..."; // Viewing private key of the recipient
const spendingPrivateKey = "0x..."; // Spending private key of the recipient
const ephemeralPublicKey = "0x..."; // Ephemeral public key from the sender's announcement
const schemeId = VALID_SCHEME_ID.SCHEME_ID_1; // Scheme ID, currently only '1' is supported

// Compute the stealth private key
const stealthPrivateKey = computeStealthKey({
  viewingPrivateKey,
  spendingPrivateKey,
  ephemeralPublicKey,
  schemeId,
});

Checking Stealth Address Announcements

import {
  checkStealthAddress,
  VALID_SCHEME_ID,
} from "@scopelift/stealth-address-sdk";

// Example inputs
const ephemeralPublicKey = "0x..."; // The ephemeral public key from the announcement
const spendingPublicKey = "0x..."; // The user's spending public key
const userStealthAddress = "0x..."; // The user's stealth address
const viewingPrivateKey = "0x..."; // The user's viewing private key
const viewTag = "0x..."; // The view tag from the announcement
const schemeId = VALID_SCHEME_ID.SCHEME_ID_1; // Scheme ID, currently only '1' is supported

// Check if the announcement is intended for the user
const isForUser = checkStealthAddress({
  ephemeralPublicKey,
  schemeId,
  spendingPublicKey,
  userStealthAddress,
  viewingPrivateKey,
  viewTag,
});

console.log(
  isForUser
    ? "Announcement is for the user"
    : "Announcement is not for the user"
);

Fetching announcements, and checking if the associated stealth address is for the user

import {
  ERC5564_CONTRACT,
  VALID_SCHEME_ID,
  createStealthClient,
} from "@scopelift/stealth-address-sdk";

// Example parameters
const chainId = 11155111; // Example chain ID for Sepolia
const rpcUrl = process.env.RPC_URL; // Your env rpc url that aligns with the chainId;
const fromBlock = BigInt(12345678); // Example ERC5564 announcer contract deploy block for Sepolia, or the block in which the user registered their stealth meta address (as an example)

// Initialize the stealth client
const stealthClient = createStealthClient({ chainId, rpcUrl: rpcUrl! });

// Use the address of your calling contract if applicable
const caller = "0xYourCallingContractAddress";

// Your scheme id
const schemeId = BigInt(VALID_SCHEME_ID.SCHEME_ID_1);

// The contract address of the ERC5564Announcer on your target blockchain
// You can use the provided ERC5564_CONTRACT enum to get the singleton contract address for a valid chain ID
const ERC5564Address = ERC5564_CONTRACT.SEPOLIA; // only for Sepolia for now

async function fetchAnnouncementsForUser() {
  // Example call to getAnnouncements action on the stealth client to get all potential announcements
  // Use your preferred method to get announcements if different, and
  // adjust parameters according to your requirements
  const announcements = await stealthClient.getAnnouncements({
    ERC5564Address,
    args: {
      schemeId,
      caller,
      // Additional args for filtering, if necessary
    },
    fromBlock, // Optional fromBlock parameter (defaults to 0, which can be slow for many blocks)
  });

  // Example call to getAnnouncementsForUser action on the stealth client
  // Adjust parameters according to your requirements
  const userAnnouncements = await stealthClient.getAnnouncementsForUser({
    announcements,
    spendingPublicKey: "0xUserSpendingPublicKey",
    viewingPrivateKey: "0xUserViewingPrivateKey",
  });

  return userAnnouncements;
}

License

MIT License

ScopeLift / stealth-address-sdk