farcaster-auth

Setup

First, ensure that the following are installed globally on your machine:

• Node.js 16+
• Yarn

yarn add @zachterrell57/farcaster-auth

Usage

Generating a signature

import { generateSignature, verifyUser } from '@zachterrell57/farcaster-auth';

const credentials = generateSignature();

const signature = credentials.signature;
const address = credentials.address;

Casting the signature to Farcaster

It is now up to the user to post the signature to Farcaster. Until v2 of the protocol, it is probably easiest to post from the Merkle Manufactory app. Clients can help the user achieve this by helping them copy the signature to the clipboard, and providing an Open Farcaster button that will open the Merkle app for the user. Users should make sure not to edit the signature, as this will result in a failed authentication

Verifying the user

const username = 'username';

const verified = verifyUser(username, address);

Persistence

After the user is verified, the client is free to store this information in any way. Some options include:

• Creating an authed property on a User object in a centralized DB. This will allow the user to log in via a traditional email and password flow (or magic link), which means the user will remain authenticated across devices and sessions
• Using cookies to persist authentication. This will work if the user only wishes to use the client from one device, but will fail if the client is accessed from a different device (as the cookies are device-specific)