# Farcaster Profile Lookup by Username or FID

> Farcaster Profile Lookup by Username or FID is a paid API for AI agents from agent402.tools, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Looks up a Farcaster user profile by username or numeric FID, returning identity metadata including bio, follower counts, and Warpcast URL.

## Facts

- Endpoint: POST https://agent402.tools/api/farcaster-profile
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/farcaster-profile-lookup-by-username-or-fid-90d5b7f6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_n9qh29Gz9voE7HUPgf0bK

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 farcaster-profile-lookup-by-username-or-fid-90d5b7f6 -d '<json body>'
```

Example prompt: Can you pull up the Farcaster profile for the username 'dwr.eth' — I want to see their display name, bio, follower count, and profile picture?

## When to prefer this

Use this endpoint when you need to resolve a Farcaster username or FID to a full profile record, enrich cast or event data with author identity, validate whether a Farcaster handle exists, or display human-readable profile info from a known identifier. Prefer this over generic social lookup tools when specifically working within the Farcaster/Warpcast ecosystem.

## Known failure modes

- Username or FID not found — returns error indicating no matching profile
- Neither fid nor username provided — returns validation error requiring at least one identifier
- Invalid FID type (non-integer) — returns schema validation error
- Network or upstream Farcaster hub unavailability — returns timeout or 5xx error
- Rate limiting — returns 429 if call quota exceeded

## How this service works

Lookup a Farcaster profile by username or FID. Returns FID, username, display name, bio, profile picture URL, follower/following counts, and the canonical Warpcast URL. Use to label cast authors, validate a Farcaster handle, or fetch a profile for display.

## Output

Returns a structured object containing the user's FID, username, display name, bio text, profile picture URL, follower count, following count, and the canonical Warpcast profile URL.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "fid": {
   "type": "number",
   "description": "Farcaster ID (integer; one of fid/username required)."
  },
  "username": {
   "type": "string",
   "description": "Farcaster handle, with or without leading @ (one of fid/username required)."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "bio": "Working on Farcaster.",
  "fid": 3,
  "pfpUrl": "https://...",
  "source": "neynar",
  "username": "dwr",
  "venueUrl": "https://warpcast.com/dwr",
  "powerBadge": true,
  "displayName": "Dan Romero",
  "followerCount": 500000,
  "followingCount": 1000,
  "activeOnFcNetwork": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/farcaster-profile-lookup-by-username-or-fid-90d5b7f6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.tools](https://www.zero.xyz/host/agent402.tools/llms.txt)