NFT metadata endpoint on Base, pay-per-call via x402 with USDC at $0.02/request.
What it does
This endpoint at lowpaymentfee.com serves NFT metadata for token ID 9 via a POST request, gated by the x402 payment protocol. Each call costs $0.02 in USDC on the Base network (maxAmountRequired of 20,000 base units with 6 decimals = $0.02). No API keys or accounts are needed — callers attach an X-PAYMENT header with a valid x402 payment proof and receive JSON metadata in return.
The provider, lowpaymentfee.com, hosts a broader suite of pay-per-call APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/Web3 data (price feeds, exchange rates, gas estimates), and infrastructure utilities (geocoding, validation, conversion). All endpoints appear to share the same $0.02/request pricing and x402 payment model on Base. However, the specific endpoint being listed here is `/api/v1/nfts/9/metadata`, which returns NFT metadata.
No OpenAPI schema, detailed documentation, or example responses were found in the crawl. The endpoint is confirmed live — it returns a proper 402 challenge with x402 version 1 headers. The output is declared as application/json. Without sample responses or schema details, the exact structure of the returned NFT metadata is unknown.
Capabilities
Use cases
- —Retrieving metadata for a specific NFT (token ID 9) programmatically
- —Integrating NFT metadata into a dApp or marketplace without managing API keys
- —Agent-driven NFT data retrieval with micropayment settlement on Base
Fit
Best for
- —Developers needing keyless, pay-per-call NFT metadata access
- —AI agents that can settle x402 payments on Base
- —Projects wanting low-friction NFT data without subscription commitments
Not for
- —Bulk retrieval of metadata across many NFT collections (only token 9 is exposed at this path)
- —Users who cannot settle USDC payments on the Base network
- —Applications requiring detailed NFT provenance or transaction history beyond metadata
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/nfts/9/metadata \
-H "X-PAYMENT: <x402-payment-proof>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is confirmed live with a valid 402 challenge, but there is no OpenAPI schema, no example request/response, and no documentation beyond a brief landing page. The specific NFT metadata structure is entirely unknown, and only a single token ID (9) is exposed at this path. Effectively a stub listing.
Warnings
- —No OpenAPI or JSON schema available for request or response bodies
- —No example responses found — NFT metadata structure is unknown
- —Only token ID 9 is addressable at this specific path; unclear if other token IDs are supported at sibling paths
- —Provider landing page lists many API categories but no detailed docs were crawlable
Citations
- —Endpoint returns 402 with x402 version 1 challenge, confirming it is livehttps://lowpaymentfee.com/api/v1/nfts/9/metadata
- —maxAmountRequired is 20000 base units of USDC (asset 0x8335…) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/nfts/9/metadata
- —Provider advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Basehttps://lowpaymentfee.com
- —Provider lists additional API categories including AI/ML, finance, data analytics, and infrastructure utilitieshttps://lowpaymentfee.com