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 micropayments settled in USDC on the Base network. The specific endpoint at `/api/v1/carts/86` is listed as "Premium API Access" and costs up to $0.02 per call (20,000 base units of USDC with 6 decimals). Payment is handled via the x402 exact scheme — no API keys, no rate limits, and no subscriptions required.
The broader platform advertises four categories of endpoints: 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 endpoints are listed at the same $0.02 per request price point. The x402 challenge confirms the endpoint is live, accepts POST requests, and returns application/json responses.
Note that the specific functionality behind the `/api/v1/carts/86` path is unclear — the name "Premium API Access" and the carts-style URL do not map obviously to any of the documented API categories. Documentation pages (docs, pricing, README) all returned only a "Connect wallet" prompt with no substantive content, so the actual request/response schemas for this or any other endpoint are unknown.
Capabilities
Use cases
- —Agents that need on-demand API access without pre-registration or API keys
- —Micropayment-gated data retrieval where per-call billing is preferred over subscriptions
- —Programmatic access to utility or data endpoints settled on Base L2
Fit
Best for
- —AI agents with x402-compatible wallets looking for frictionless API access
- —Developers who want pay-as-you-go pricing with no commitments
- —Use cases requiring low-cost per-request billing on Base network
Not for
- —Users who need detailed API documentation or guaranteed SLAs before purchasing
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/carts/86 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but the actual functionality behind /api/v1/carts/86 is undocumented. No OpenAPI schema, no request/response examples, and all documentation pages return only a wallet-connect prompt. The listing is effectively a stub with pricing info.
Warnings
- —The specific functionality of /api/v1/carts/86 ('Premium API Access') is unclear — the carts-style path does not match any documented API category
- —All documentation pages (/docs, /pricing, /README, /api) returned only 'Connect wallet' with no substantive content
- —No request or response schema is available for any endpoint on the platform
- —The platform lists many endpoint categories (AI, finance, data, infrastructure) but none could be verified for actual functionality
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/carts/86
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints in four categories: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/carts/86