# NFT Ownership Verification (Token-Gating)

> NFT Ownership Verification (Token-Gating) is a paid API for AI agents from x402.professorsausages.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-15).

Performs a real-time, live ownership check to verify whether a given wallet address holds a specific NFT on a given blockchain chain.

## Facts

- Endpoint: GET https://x402.professorsausages.com/nft/:chain/verify-ownership
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nft-ownership-verification-token-gating-4df43d10
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Grb-Rv3PNv57HfmYGnJvW

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 nft-ownership-verification-token-gating-4df43d10
```

Example prompt: Can you do a live on-chain ownership check to verify whether wallet 0xAbCd...1234 actually holds token #42 from the NFT contract 0xDead...Beef on the Base chain?

## When to prefer this

Use this endpoint when you need a guaranteed live, real-time on-chain NFT ownership check — not a cached snapshot — for token-gating, access control, or scam verification purposes. Prefer this over static indexers when freshness is critical and the result must reflect the current chain state.

## Known failure modes

- Invalid or malformed wallet address returns a validation error
- Unsupported chain identifier returns an error indicating chain is not supported
- NFT contract address not found on specified chain returns not-found error
- Rate limiting or payment failure returns 402 Payment Required
- RPC timeout or chain node unavailability causes delayed or failed response

## How this service works

Realtime holds-or-not ownership check (token-gating) — ALWAYS live

## Output

Returns a live boolean indicating whether the specified wallet address currently holds the given NFT (token-gating result), along with supporting ownership details such as contract address, chain, token ID, and any relevant scam or metadata signals.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nft-ownership-verification-token-gating-4df43d10/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.professorsausages.com](https://www.zero.xyz/host/x402.professorsausages.com/llms.txt)