Pay-per-call premium API on Base via x402 — $0.02/request in USDC, no API keys required.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints accessible via the x402 payment protocol on the Base network. This specific endpoint (`/api/endpoint-77`) is listed as "Premium API Access" and accepts USDC payments on Base. The x402 challenge confirms the endpoint is live and requires a maximum of 20,000 base units of USDC (i.e., $0.02) per request. No API keys, rate limits, or subscriptions are needed — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com 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 listed endpoints share the same $0.02/request pricing. However, this particular endpoint path (`/api/endpoint-77`) does not match any of the documented API paths on the site, so its exact functionality is unclear.
The endpoint accepts POST requests and returns `application/json`. Settlement occurs on the Base L2 network using USDC (contract `0x8335…2913`). The x402 challenge specifies a 300-second payment timeout. Documentation on the site is extremely thin — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Integrating x402-compatible endpoints into automated pipelines without subscription management
Fit
Best for
- —Developers or agents already set up with x402 payment flows on Base
- —Use cases requiring low-friction, no-signup API access at $0.02/call
- —Crypto-native applications that prefer on-chain settlement over traditional billing
Not for
- —Users who need detailed API documentation or well-defined input/output schemas before integrating
- —High-volume callers who would benefit from bulk pricing or subscription plans
- —Anyone without a Base-compatible wallet or x402 payment client
Quick start
curl -X POST https://lowpaymentfee.com/api/endpoint-77 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Endpoint
Quality
The x402 challenge confirms the endpoint is live and priced at $0.02 USDC on Base, but the endpoint path (/api/endpoint-77) doesn't match any documented API on the site. Documentation pages are empty (just 'Connect wallet'). No input/output schema, no examples, and no description of what this specific endpoint actually does.
Warnings
- —Endpoint path /api/endpoint-77 does not match any of the documented API paths on lowpaymentfee.com — actual functionality is unknown
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no substantive content
- —No input schema or output schema is documented; callers cannot know what request body to send or what response to expect
- —The 'Premium API Access' description is generic and does not explain what the endpoint does
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base (= $0.02)https://lowpaymentfee.com/api/endpoint-77
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/endpoint-77
- —Site advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Documented API categories include Data & Analytics, AI & ML, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages show only 'Connect wallet'https://lowpaymentfee.com/docs