NFT metadata endpoint on Base, pay-per-call via x402 with USDC (~$0.02/request).
What it does
This endpoint at lowpaymentfee.com returns NFT metadata for token ID 20 via a POST request, gated by the x402 payment protocol. The endpoint is live and returns a 402 challenge advertising payment in USDC on the Base network. The maximum amount required per call is 20,000 base units of USDC (6 decimals), which equals $0.02 USD. Payment is settled on-chain to the specified wallet address using the "exact" scheme.
The broader lowpaymentfee.com platform advertises a suite of pay-per-request APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are listed at $0.02 per request with no API keys, no rate limits, and no minimum commitments. However, this specific listing covers only the `/api/v1/nfts/20/metadata` endpoint.
No OpenAPI schema, detailed documentation, or example responses were found in the crawl. The endpoint's output format is described only as `application/json`. Without sample payloads or schema definitions, the exact structure of the NFT metadata response is unknown. The platform requires an x402-compatible payment header (X-PAYMENT) to access the resource.
Capabilities
Use cases
- —Retrieving metadata for a specific NFT (token ID 20) programmatically
- —Integrating NFT metadata into a dApp or marketplace without managing API keys
- —Demonstrating x402 pay-per-call patterns for Web3 data endpoints
Fit
Best for
- —Agents or apps that need on-demand NFT metadata with crypto micropayments
- —Developers exploring x402 protocol integrations on Base
- —Use cases where keyless, pay-as-you-go API access is preferred
Not for
- —Bulk retrieval of metadata across many NFT collections (only token ID 20 is served at this path)
- —Users who need fiat-only payment options
- —Applications requiring detailed OpenAPI documentation or guaranteed SLAs
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/nfts/20/metadata \
-H "X-PAYMENT: <x402-payment-token>" \
-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 example request/response, and no documentation beyond the landing page listing. The specific NFT metadata content and input parameters are entirely unknown.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —No example request or response bodies found; output structure is unknown
- —This endpoint serves metadata for a single token ID (20); generalizability to other token IDs is unclear
- —The broader platform lists many endpoints but none have detailed docs in the crawl
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/nfts/20/metadata
- —All endpoints on the platform are listed at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/nfts/20/metadata