# Farcaster User Profile Lookup

> Farcaster User Profile Lookup is a paid API for AI agents from api.web3identity.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-13).

Retrieve a Farcaster user's profile data (FID, username, display name, followers) by FID, username, or connected wallet address

## Facts

- Endpoint: GET https://api.web3identity.com/api/farcaster/v
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-web3identity-com-13f9a9b0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lNUrt3HrKZXssjG3oHTpr

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability api-web3identity-com-13f9a9b0
```

Example prompt: Can you look up the Farcaster profile for the username 'vitalik.eth' and tell me their FID, display name, and how many followers they have?

## When to prefer this

Use this endpoint when you need to resolve a Farcaster identity from a known FID, username, or Ethereum wallet address — especially useful for enriching on-chain data with social identity context, verifying Farcaster presence, or displaying human-readable profile information in a web3 context.

## Known failure modes

- User not found for given FID/username/address — returns empty or 404-style response
- Invalid input type or missing required 'type' field — schema validation error
- Wallet address not connected to any Farcaster account — empty result
- Rate limiting or payment failure — 402 payment required or 429 too many requests
- Malformed FID (non-numeric) or username format error

## How this service works

Get Farcaster user profile by FID, username, or connected address

## Output

Returns a JSON object containing the user's Farcaster ID (FID), username, display name, and follower count for the matched Farcaster account.

## Example request

```json
{
 "input": {
  "type": "http",
  "method": "GET",
  "queryParams": {
   "identifier": "vitalik.eth",
   "identifierType": "username"
  }
 }
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "fid": {
       "type": "number"
      },
      "username": {
       "type": "string"
      },
      "followers": {
       "type": "number"
      },
      "displayName": {
       "type": "string"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-web3identity-com-13f9a9b0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.web3identity.com](https://www.zero.xyz/host/api.web3identity.com/llms.txt)