x402-gated API platform on Base offering data, AI, finance, and utility endpoints at $0.02/request via USDC.
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/backups/13` is listed as "Premium API Access" and accepts POST requests with an x402 payment challenge. The site advertises a flat $0.02 per request across all its endpoints, paid in USDC (contract 0x8335…2913 on Base). No API keys, rate limits, or subscriptions are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader platform organizes its endpoints into 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 appear to follow the same x402 payment scheme.
Note that the specific endpoint probed (`/api/v1/backups/13`) does not correspond to any of the publicly listed API categories on the landing page, and its actual functionality is unclear — the description is simply "Premium API Access" with no further documentation. The docs, pricing, and API pages all render only a "Connect wallet" prompt with no additional content, so there is no detailed documentation available for any endpoint.
Capabilities
Use cases
- —Accessing premium API data with per-call USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Testing x402 protocol integrations against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing keyless API access with crypto micropayments
- —Users who want pay-per-use pricing without subscriptions
Not for
- —Users who need detailed API documentation or schemas before integrating
- —Anyone without a Base-network USDC wallet
- —High-volume use cases where per-request payment overhead matters
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/backups/13 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no request/response schema, and the specific endpoint path (/api/v1/backups/13) doesn't match any publicly listed API. The docs pages are empty beyond a wallet-connect prompt.
Warnings
- —The endpoint path /api/v1/backups/13 does not match any of the publicly listed API endpoints on the landing page — its actual functionality is unknown.
- —All documentation pages (docs, pricing, API, README) render only a 'Connect wallet' prompt with no usable content.
- —No request or response schema is available; callers cannot know what to send or what to expect back.
- —The platform lists many endpoint categories (AI, finance, data, utils) but none have documented schemas or example payloads.
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, which equals $0.02.https://lowpaymentfee.com/api/v1/backups/13
- —The site advertises $0.02 per request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —Documentation pages render only a 'Connect wallet' prompt with no additional content.https://lowpaymentfee.com/docs