Pay-per-call API platform on Base network via x402 — $0.02/request, no API keys required.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad set of endpoints across data analytics, AI/ML inference, finance/Web3, and utility services. Every endpoint costs $0.02 per request, paid in USDC on the Base network using the x402 payment protocol. There are no API keys, no rate limits, and no subscription commitments — callers simply attach an X-PAYMENT header with a valid x402 payment proof to access any endpoint.
The specific endpoint at `/api/v1/payments/10` is listed as "Premium API Access" and accepts POST requests. The x402 challenge advertises a maxAmountRequired of 20000 base units of USDC (contract 0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The platform also exposes 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 spec, no request/response schema documentation, and no usage examples available from the crawled pages. The endpoint is confirmed live (returns 402 with a valid x402 challenge), but without documentation it is unclear what request body this specific endpoint expects or what response it returns.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time crypto token quotes and gas estimates with per-call payment
- —Running geocoding or data validation utilities on a pay-as-you-go basis
- —Exporting analytics data or generating reports without a subscription
Fit
Best for
- —Agents and developers who want zero-setup, pay-per-call API access
- —Use cases requiring no rate limits and no upfront commitments
- —Crypto-native workflows already operating on the Base network
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume production workloads where $0.02/request adds up significantly
- —Developers who cannot or prefer not to pay in USDC on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/10 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, and the landing page lists available endpoints with pricing. However, documentation pages are empty (just 'Connect wallet'), there is no OpenAPI spec, no request/response schemas, and no examples. The specific purpose of /api/v1/payments/10 is unclear beyond 'Premium API Access'. This is effectively a stub listing.
Warnings
- —Documentation pages (/docs, /pricing, /api, /README) all return only 'Connect wallet' with no usable content
- —No OpenAPI or schema documentation available for any endpoint
- —The specific purpose and expected request/response format of /api/v1/payments/10 is undocumented
- —No examples or sample responses are available from the provider
Citations
- —All endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The x402 challenge for /api/v1/payments/10 advertises maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/payments/10
- —Available endpoint categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —Documentation pages render only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs