# Synapse API — Arbitrum NFT Holdings by Owner

> Synapse API — Arbitrum NFT Holdings by Owner is a paid API for AI agents from synapse-api-brown.vercel.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Fetches all NFTs owned by a specific wallet address on the Arbitrum blockchain network

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/arbitrum/nft/by-owner
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-arbitrum-nft-holdings-by-owner-af03d401
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_A_rpeCxdle0IVb4flky2v

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 synapse-api-arbitrum-nft-holdings-by-owner-af03d401 -d '<json body>'
```

Example prompt: Can you pull up all the NFTs owned by wallet address 0xAbc123...def456 on Arbitrum, show me the first 20?

## When to prefer this

Use this endpoint when you need to enumerate all NFT holdings for a specific wallet on the Arbitrum network specifically. It supports pagination for wallets with large collections and is pay-per-call at $0.01 USDC, making it cost-effective for spot lookups. Prefer this over general blockchain explorers when you need structured, machine-readable NFT data programmatically.

## Known failure modes

- Invalid or malformed owner wallet address returns an error or empty result
- Non-existent address returns an empty NFT list
- Rate limiting or service unavailability returns a 429 or 5xx error
- pageKey from a different query context returns invalid pagination results
- Limit value out of accepted range may cause a validation error

## How this service works

High-speed API suite for AI processing, web scraping, and smart data utilities across 57+ blockchain networks. Pay-per-call via x402.

## Output

Returns a paginated list of NFTs owned by the specified wallet on the Arbitrum network, including token IDs, contract addresses, NFT metadata (name, image, traits), and a pageKey for fetching subsequent pages.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "limit": {
   "type": "number"
  },
  "owner": {
   "type": "string"
  },
  "pageKey": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synapse-api-arbitrum-nft-holdings-by-owner-af03d401/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from synapse-api-brown.vercel.app](https://www.zero.xyz/host/synapse-api-brown.vercel.app/llms.txt)