Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints across data analytics, AI/ML inference, finance/Web3, and utility services. All endpoints are paid per request using USDC on the Base network, with no API keys, no rate limits, and no commitments required. The specific endpoint at `/api/v1/charges/73` is labeled "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per call (USDC uses 6 decimals).
The platform advertises a broad catalog of endpoints including sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, geocoding, validation, conversion, and data export — all at the same $0.02 price point. Payment is handled via the x402 protocol's "exact" scheme, settling on the Base L2 network. The 402 challenge specifies a 300-second timeout and accepts POST requests.
Documentation is extremely sparse. The /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no examples of what any endpoint actually returns. The endpoint at `/api/v1/charges/73` has a generic name and no indication of what data or functionality it provides beyond the label "Premium API Access."
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Programmatic pay-as-you-go access to data, AI, finance, or utility endpoints
Fit
Best for
- —Developers wanting zero-commitment, pay-per-use API access
- —AI agents that can settle x402 payments autonomously on Base
- —Users who prefer crypto-native micropayments over subscription billing
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —Applications requiring high-throughput with predictable flat-rate pricing
- —Users without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/73 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no documentation, no OpenAPI spec, no request/response examples, and the endpoint name 'Premium API Access' is entirely generic with no indication of what it actually does. The docs, pricing, and README pages are all empty beyond a wallet-connect prompt.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format
- —The endpoint name 'Premium API Access' is generic; actual functionality is unknown
- —No examples of successful responses available anywhere in the crawl
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/charges/73
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/charges/73