Pay-per-call API platform on Base via x402 — $0.02/request, no API keys required.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of pay-per-request endpoints across data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are settled on the Base network using USDC, with a uniform price of $0.02 per request. The x402 protocol eliminates the need for API keys, accounts, or rate limits — callers simply attach an X-PAYMENT header with a signed USDC payment to each request.
The specific endpoint at `/api/v1/charges/110` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02) on Base. The platform advertises additional endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 price point.
Documentation is extremely sparse. The /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what the `/api/v1/charges/110` endpoint actually returns. The landing page lists endpoint names and prices but provides no parameter documentation or response format details. Prospective users should be aware that without documentation, the actual behavior of each endpoint is unknown and must be discovered experimentally.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time crypto token quotes, gas estimates, and exchange rates on a per-call basis
- —Running geocoding, validation, or data conversion tasks with instant pay-per-use pricing
- —Integrating analytics metrics and data export into agent workflows via x402 payments
Fit
Best for
- —Agents or developers who want zero-signup, pay-as-you-go API access
- —Use cases requiring small, infrequent API calls where subscription pricing is wasteful
- —Crypto-native applications already operating on the Base network with USDC
Not for
- —High-volume production workloads where per-request costs add up (no bulk discounts documented)
- —Users who need detailed API documentation, SLAs, or guaranteed uptime
- —Applications requiring non-USDC or non-Base payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/110 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-signed-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it accepts USDC on Base at $0.02/request. However, documentation is effectively nonexistent — no OpenAPI schema, no request/response examples, no parameter descriptions, and no explanation of what 'Premium API Access' at /api/v1/charges/110 actually returns. The listing is essentially a stub.
Warnings
- —Documentation pages (/docs, /pricing, /api, /README) all render only 'Connect wallet' with no usable content
- —No OpenAPI or schema available — request parameters and response format are completely unknown
- —The specific endpoint /api/v1/charges/110 ('Premium API Access') has no description of what it does or returns
- —No SLA, rate limit, or uptime guarantees documented
Citations
- —Uniform pricing of $0.02 per request across all endpointshttps://lowpaymentfee.com
- —No API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units USDC ($0.02) on Basehttps://lowpaymentfee.com/api/v1/charges/110
- —Asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 is USDC on Basehttps://lowpaymentfee.com/api/v1/charges/110
- —Platform lists endpoints for analytics, AI/ML, finance, and utility categorieshttps://lowpaymentfee.com