NFT metadata endpoint on Base, pay-per-call via x402 with USDC at $0.02/request.
What it does
This endpoint serves NFT metadata for token ID 44 via a pay-per-request x402 protocol on the Base network. It accepts POST requests and returns JSON. Payment is settled in USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, with a maximum cost of $0.02 per call (20,000 base units at 6 decimals). No API keys or rate limits are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The endpoint is part of a broader platform at lowpaymentfee.com that offers dozens of x402-gated APIs spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities, all priced uniformly at $0.02 per request. This specific endpoint (/api/v1/nfts/44/metadata) is focused on NFT metadata retrieval, though the platform does not document the exact schema of the returned metadata object.
The endpoint was confirmed live via a 402 challenge response. The x402 challenge specifies version 1, scheme "exact", a 300-second payment timeout, and outputs application/json. No OpenAPI spec, detailed documentation, or example responses were found in the crawl, so the exact structure of the metadata payload is unknown.
Capabilities
Use cases
- —Retrieving metadata for NFT token ID 44 from this provider
- —Integrating pay-per-call NFT data into agent workflows without API key management
- —Demonstrating x402 micropayment protocol usage on Base
Fit
Best for
- —Agents needing NFT metadata with zero signup friction
- —Developers experimenting with x402 payment protocol on Base
- —Low-volume, on-demand NFT data retrieval
Not for
- —Bulk NFT metadata indexing across many collections (only serves token 44)
- —Users who need free or pre-paid API access without crypto wallets
- —Production systems requiring documented response schemas and SLAs
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/nfts/44/metadata \
-H "X-PAYMENT: <x402-payment-proof>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI spec, no documentation of the request body or response schema, no example responses, and the endpoint only serves a single NFT token ID. The crawl pages beyond the homepage returned only 'Connect wallet' with no useful content.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —Response payload structure is completely undocumented
- —Endpoint appears to serve metadata for only a single NFT (token ID 44) — unclear if other token IDs are available at different paths
- —Most site pages (pricing, README, api) returned no meaningful content beyond 'Connect wallet'
- —The platform lists many API categories but none appear to have detailed docs
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/nfts/44/metadata
- —All APIs on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/nfts/44/metadata