x402-gated API platform on Base offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-protocol API marketplace that gates access to a variety of endpoints behind per-request USDC micropayments on the Base network. The specific endpoint at `/api/v1/carts/96` is listed as "Premium API Access" and requires a payment of up to 20,000 base units of USDC (i.e., $0.02) per call. The platform advertises no API keys, no rate limits, and instant access — callers simply attach an x402 payment header to each request.
The broader site offers endpoints across four categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All listed endpoints share the same $0.02/request pricing.
However, the specific `/api/v1/carts/96` endpoint's purpose is unclear — the path suggests a cart resource (ID 96), but the description is simply "Premium API Access" with no further documentation. The docs, pricing, and API pages on the site returned only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no detailed documentation available from the crawl.
Capabilities
Use cases
- —Accessing premium API resources with per-call USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Exploring x402 protocol integration for automated micro-transactions
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that need keyless API access with crypto micropayments
- —Low-volume consumers who prefer pay-per-request over subscriptions
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/carts/96 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (returns a valid 402 x402 challenge) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and the purpose of the /api/v1/carts/96 resource is unexplained. The docs pages returned only wallet-connect prompts with no content.
Warnings
- —No OpenAPI schema or detailed documentation available for this endpoint
- —The purpose of /api/v1/carts/96 ('Premium API Access') is not explained — the path suggests a cart resource but no further context is provided
- —All documentation pages (docs, pricing, API, README) returned only 'Connect wallet' with no substantive content
- —No request body schema or response schema is documented anywhere in the crawl
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/carts/96
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/carts/96