x402-gated API suite on Base: analytics, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is a collection of x402-protocol pay-per-request APIs settled in USDC on the Base network. The specific endpoint `/api/v1/carts/94` is listed as "Premium API Access" and returns a standard x402 challenge requiring up to 20,000 base units of USDC (i.e., $0.02) per call. 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 priced at $0.02 per request with no API keys, no rate limits, and no minimum commitments. Payment is handled via the x402 exact-payment scheme, settling in USDC (contract 0x8335…2913) on Base to the payee address 0x1A2B…85F3. The endpoint accepts HTTP POST and returns application/json.
Note that while the landing page lists many endpoints across multiple categories, the specific endpoint being cataloged here (`/api/v1/carts/94`) is described only as "Premium API Access" with no further documentation about its request schema, expected input parameters, or response format. The docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no additional technical content. Without documentation or OpenAPI specs, the actual functionality behind this specific cart endpoint is unclear.
Capabilities
Use cases
- —Paying per-request for API access without API keys or subscriptions
- —Programmatic agent access to analytics, AI, or finance endpoints via x402
- —Integrating crypto-settled microservices into automated workflows
Fit
Best for
- —Agents or developers wanting keyless, pay-per-call API access
- —x402-compatible clients on the Base network
- —Low-volume or bursty usage patterns where subscriptions are wasteful
Not for
- —Users who need detailed API documentation or OpenAPI schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or rate-limited plans
- —Users without USDC on Base or an x402-compatible payment client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/carts/94 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no OpenAPI spec, no documentation beyond a landing page listing, no request/response schema, and no explanation of what '/api/v1/carts/94' actually does. The docs pages are empty (wallet-connect only). Effectively a stub with confirmed liveness.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —The specific endpoint /api/v1/carts/94 has no description beyond 'Premium API Access' — its actual functionality is unknown
- —All documentation pages (docs, pricing, API, README) render only a 'Connect wallet' prompt with no technical content
- —No request body schema or response examples are available 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/94
- —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 across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/carts/94