x402-gated API suite on Base: analytics, AI, finance, and utility endpoints at $0.02/request via USDC.
What it does
lowpaymentfee.com hosts a collection of pay-per-call API endpoints gated by the x402 protocol on the Base network. The specific endpoint at `/api/v1/stripe/charges/188` is listed as "Premium API Access" and accepts payment in USDC (contract 0x8335…2913 on Base) using the x402 "exact" scheme. The maximum amount required is 20,000 base units of USDC, which equals $0.02 (USDC uses 6 decimals). Payment is settled on-chain to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
The broader platform advertises 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 endpoints are listed at $0.02 per request with no API keys, no rate limits, and no minimum commitments.
Documentation is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawl. The exact functionality behind the `/api/v1/stripe/charges/188` path is unclear; the name "Premium API Access" and the path segment "stripe/charges" suggest it may relate to Stripe charge creation or lookup, but this is speculative given the lack of documentation.
Capabilities
Use cases
- —Accessing analytics metrics and reports without API key management
- —Running AI inference (sentiment, summarization, classification, embeddings) on a per-call payment basis
- —Fetching real-time crypto prices, gas estimates, and exchange rates
- —Geocoding and data validation via utility endpoints
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go API access via crypto
- —Agents that can settle x402 payments in USDC on Base
- —Use cases requiring low-cost ($0.02) per-call pricing without rate limits
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Applications requiring fiat-only payment rails with no crypto wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/stripe/charges/188 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live (returns a valid x402 402 challenge), but documentation is essentially nonexistent — every doc page shows only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, and no examples. The purpose of this specific endpoint (/api/v1/stripe/charges/188) is unclear. Pricing is clear ($0.02 USDC on Base).
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) are all empty beyond a 'Connect wallet' prompt — no technical docs available.
- —No OpenAPI or schema documentation exists for any endpoint.
- —The specific purpose of /api/v1/stripe/charges/188 ('Premium API Access') is unclear — the path suggests Stripe charge operations but this is unconfirmed.
- —No request body schema or response schema is documented; integration requires trial-and-error.
- —The outputSchema in the x402 challenge only specifies HTTP POST with no input/output field definitions.
Citations
- —The endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 USDC base units on Base networkhttps://lowpaymentfee.com/api/v1/stripe/charges/188
- —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
- —Documentation pages render only a 'Connect wallet' prompt with no technical contenthttps://lowpaymentfee.com/docs