Query NFT ownership data via x402 micropayment on Base for $0.02 per request.
What it does
This endpoint at lowpaymentfee.com returns the owner of NFT #21 via a pay-per-call x402 protocol. The endpoint accepts POST requests and is settled in USDC on the Base network. The x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (6 decimals), which equals $0.02 per request. No API keys, rate limits, or subscriptions are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com platform offers a suite of x402-gated APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/Web3 data (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are listed at $0.02 per request and settle on Base via USDC.
This specific endpoint (/api/v1/nfts/21/owner) is narrowly scoped to returning ownership information for a single NFT (ID 21). The response MIME type is application/json. No OpenAPI schema, request body schema, or response body schema is published, so the exact request and response formats must be inferred or discovered by calling the endpoint.
Capabilities
Use cases
- —Querying the current owner of a specific NFT programmatically
- —Integrating NFT ownership checks into agent workflows without API key management
- —Verifying NFT provenance or ownership as part of a Web3 application
Fit
Best for
- —Agents needing one-off NFT ownership lookups with no subscription overhead
- —Developers prototyping Web3 apps that need pay-per-call NFT data
- —x402-compatible wallets and agents on the Base network
Not for
- —Bulk or batch NFT ownership queries across many token IDs (only NFT #21 is served by this endpoint)
- —Users who need free or pre-paid API access without crypto wallet integration
- —Querying NFTs on networks other than Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/nfts/21/owner \
-H "X-PAYMENT: <x402_payment_proof>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no documented request/response format, no examples, and the endpoint is narrowly scoped to a single NFT ID. The crawled pages beyond the homepage returned only 'Connect wallet' with no additional documentation.
Warnings
- —No OpenAPI or request/response schema is published — callers must discover the expected body format by trial.
- —This endpoint is hardcoded to NFT ID 21; it is unclear whether other NFT IDs are available at different paths.
- —Documentation pages (/api, /pricing, /README) returned no useful content beyond 'Connect wallet'.
- —The nature and source of the NFT data (which collection, which chain for the NFT itself) is not documented.
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/nfts/21/owner
- —All endpoints on lowpaymentfee.com are listed at $0.02 per request with no API keys, no rate limits, and instant access on Basehttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/nfts/21/owner