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 15 via a POST request, gated behind 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 response.
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 share the same $0.02-per-request pricing model and settle on the Base L2 network using USDC. The specific endpoint probed here (/api/v1/nfts/15/metadata) returns NFT metadata, though the exact schema of the response is not documented.
Because there is no OpenAPI specification, no detailed documentation of request/response schemas, and the crawled docs and pricing pages returned only a wallet-connect prompt, the actual capabilities and response format of this endpoint remain unclear. The endpoint is confirmed live (402 challenge captured), but consumers should expect to experiment with the POST body to discover the full behavior.
Capabilities
Use cases
- —Retrieve on-chain NFT metadata for token ID 15 without managing API keys
- —Integrate NFT metadata lookups into agent workflows with automatic micropayments
- —Demonstrate x402 payment protocol usage for gated API access
Fit
Best for
- —Developers experimenting with x402 pay-per-call protocols
- —Agents needing NFT metadata with no-signup, instant access
- —Projects already operating on the Base L2 network with USDC
Not for
- —Bulk NFT metadata retrieval across many token IDs (only token 15 is documented)
- —Users who need detailed API documentation or guaranteed SLAs
- —Applications requiring non-USDC or non-Base payment rails
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/nfts/15/metadata \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_proof>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge, but there is no OpenAPI spec, no request/response schema documentation, and the crawled pages beyond the landing page returned only wallet-connect stubs. The specific NFT metadata endpoint is not mentioned on the landing page. Effectively a stub listing with confirmed liveness.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —Response format is unknown — no example responses documented
- —Only token ID 15 is referenced; unclear if other token IDs are supported at this path
- —Crawled /api, /pricing, and /README pages returned no useful content (wallet-connect only)
- —The NFT metadata endpoint is not listed among the provider's advertised APIs on the landing page
Citations
- —The endpoint returns HTTP 402 with x402 challenge requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/nfts/15/metadata
- —maxAmountRequired is 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913), equaling $0.02https://lowpaymentfee.com/api/v1/nfts/15/metadata
- —The provider advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The provider lists APIs across data analytics, AI/ML, finance/Web3, and infrastructure categorieshttps://lowpaymentfee.com