README.md

Farcaster Neynar API Client

A tool for interacting with Farcaster via Neynar APIs.

• Setup
• Examples
  • Create a Signer
  • Publish a Cast
  • Reply to a Cast
  • Like and Recast a Cast
  • Follow a User
  • Get a User's Casts and Likes
• Contributing

Setup

Install the library:

npm install axios @standard-crypto/farcaster-js-neynar

Examples

Create a Signer

import { NeynarAPIClient, waitForNeynarSignerApproval } from '@standard-crypto/farcaster-js-neynar';
import QRCode from 'qrcode';

const client = new NeynarAPIClient('apiKey');

const developerMnemonic = 'your farcaster recovery phrase';

// create signer
const signer = await client.v2.createSigner(
  developerMnemonic,
);

console.log('Scan the QR code below on a logged in device to approve signer');
console.log(await QRCode.toString(signer.signer_approval_url ?? '', { type: 'terminal', small: true }));
console.log(`url: ${signer.signer_approval_url}`);
console.log('Once approved, you can start using your signer to write data to Farcaster');
console.log(`signer uuid: ${signer.signer_uuid}`);
console.log('waiting for signer to be approved...');
await waitForNeynarSignerApproval(client, signer.signer_uuid);

Publish a Cast

import { NeynarAPIClient } from '@standard-crypto/farcaster-js-neynar';

const signerUuid = 'approvedSignerUUID';
const client = new NeynarAPIClient('apiKey');

const publishedCast = await client.v2.publishCast(signerUuid, 'This is a test cast.');

console.log(`New cast hash: ${publishedCast.hash}`);

Reply to a Cast

import { NeynarAPIClient } from '@standard-crypto/farcaster-js-neynar';

const signerUuid = 'approvedSignerUUID';
const client = new NeynarAPIClient('apiKey');

const existingCastHash = 'existingCastHash';
const publishedCast = await client.v2.publishCast(signerUuid, 'This is a reply cast.', { replyTo: existingCastHash });

console.log(`Reply hash:${publishedCast.hash}`);

Like and Recast a Cast

import { NeynarAPIClient } from '@standard-crypto/farcaster-js-neynar';

const signerUuid = 'approvedSignerUUID';
const client = new NeynarAPIClient('apiKey');

const existingCastHash = 'existingCastHash';
await client.v2.reactToCast(signerUuid, 'like', existingCastHash); // Like Cast
await client.v2.reactToCast(signerUuid, 'recast', existingCastHash); // Recast Cast

Follow a User

import { NeynarAPIClient } from '@standard-crypto/farcaster-js-neynar';

const signerUuid = 'approvedSignerUUID';
const client = new NeynarAPIClient('apiKey');

const userToFollowFid = 13525;
await client.v2.followUsers(signerUuid, [userToFollowFid]);

Get a User's Casts and Likes

import { NeynarAPIClient } from '@standard-crypto/farcaster-js-neynar';

const client = new NeynarAPIClient('apiKey');

const username = 'dwr';

const user = await client.v1.lookupUserByUsername(username);
if (user === null) throw new Error(`No user ${username} found.`);

const numCastsToFetch = 100;
let castsFetched = 0;
console.log('User Casts:');
for await (const cast of await client.v1.fetchCastsForUser(user.fid)) {
  console.log(cast.text);
  castsFetched++;
  if (castsFetched === numCastsToFetch) break;
}

const numLikesToFetch = 100;
let likesFetched = 0;
console.log('User Likes:');
for await (const like of await client.v1.fetchUserCastLikes(user.fid)) {
  console.log(`${like.cast_author?.username} : ${like.cast?.cast_text}`);
  likesFetched++;
  if (likesFetched === numLikesToFetch) break;
}

Contributing

See CONTRIBUTING.md