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 broad catalog of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are paid per-request using USDC on the Base network at a flat rate of $0.02 per call, with no API keys, no rate limits, and no subscriptions required.
The specific endpoint at `/api/v1/transactions/218` is listed as "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. Payment is made via the x402 exact scheme with a 300-second timeout. The platform advertises additional endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, gas estimates, geocoding, validation, conversion, and data export — all at the same $0.02 price point.
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 crawled content. The endpoint is live (402 challenge confirmed), but without documentation it is unclear what input the POST body expects or what the response payload looks like for this particular transactions endpoint.
Capabilities
Use cases
- —Accessing analytics metrics and reports without subscription commitments
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) on a per-call basis
- —Fetching real-time crypto token quotes, gas estimates, and exchange rates
- —Geocoding, data validation, and format conversion utilities
Fit
Best for
- —Developers who want zero-setup, keyless API access paid in USDC
- —Agents and bots that need pay-per-call endpoints without rate limits
- —Prototyping and low-volume use cases where subscription APIs are overkill
Not for
- —High-volume production workloads needing SLAs and guaranteed uptime documentation
- —Users who need detailed API documentation and response schemas before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/218 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, documentation is effectively absent — all doc pages show only 'Connect wallet' with no schemas, examples, or descriptions of what this specific endpoint does. The listing title 'Premium API Access' is generic and uninformative. Without request/response schemas this is essentially a stub.
Warnings
- —No OpenAPI spec or any machine-readable schema available
- —All documentation pages (/docs, /api, /pricing, /README) render only 'Connect wallet' with no content
- —The purpose and expected input/output of /api/v1/transactions/218 is completely undocumented
- —No response examples or error documentation found
- —Cannot verify what data or service this specific endpoint actually provides
Citations
- —Flat pricing of $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (6 decimals = $0.02) on Basehttps://lowpaymentfee.com/api/v1/transactions/218
- —Platform offers endpoints for analytics, AI/ML, finance, crypto, and utility serviceshttps://lowpaymentfee.com
- —Documentation pages render only 'Connect wallet' with no technical contenthttps://lowpaymentfee.com/docs