Introduction

Neynar provides APIs to easily interact with the Farcaster decentralized social protocol. These APIs let you query user data, social graphs, and content (casts), enabling you to build decentralized social apps quickly.

Core Concepts

Farcaster has a few key primitives you’ll interact with via the Neynar API:
  • User — Each user has a permanent FID (Farcaster ID) that identifies them. Profile details such as username, display name, bio, and linked accounts are stored on-chain and mapped to this FID.
  • Cast — A unit of content posted to Farcaster, similar to a tweet on X. Each cast has a unique hash and may contain text, media, embeds, and metadata.
  • Social Graph — The network of follower/following relationships between users.
  • Feeds — Collections of casts, often based on a user’s social graph, channel membership, or other filters.
All data is open and decentralized, available on Farcaster hubs. Neynar abstracts away the complexity of querying these hubs.

Base URL

All requests to the Neynar API must be made to:
https://api.neynar.com
HTTPS is required for all requests. HTTP requests will be rejected.

Authentication

All API endpoints require an API key. Include the following header with every request:
x-api-key
string
required
Your Neynar API key as a string.
You can obtain your API key from the Developer Portal after signing up.
Neynar APIs support payment per API request via x402. API requests missing an API key header will see an x402 error to pay per request.

Examples

fetch('https://api.neynar.com/v2/farcaster/user/bulk?fids=1', {
  method: 'GET',
  headers: {
    'x-api-key': 'insert-your-api-key',
    'Content-Type': 'application/json'
  }
})
.then(response => response.json())
.then(data => console.log(data));