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. Each call costs $0.02 in USDC on the Base network, settled via the x402 payment protocol. No API keys, accounts, or rate limits are advertised — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The specific endpoint at `/api/v1/payments/169` is listed as "Premium API Access" and accepts POST requests. Its x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The broader platform lists 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 per request price point.
Documentation is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content visible to crawlers. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available. The endpoint is confirmed live (returns a proper 402 challenge), but without documentation it is unclear what request body this specific endpoint expects or what response it returns.
Capabilities
Use cases
- —Agents that need on-demand AI inference (sentiment, summarization, classification, embeddings) without managing API keys
- —Fetching real-time crypto token quotes, gas estimates, or exchange rates with per-call payment
- —Geocoding or data validation as a utility service paid per request via x402
- —Programmatic data export and analytics without subscription commitments
Fit
Best for
- —AI agents and bots that can settle x402 payments on Base
- —Developers wanting zero-signup, pay-as-you-go API access
- —Low-volume or bursty workloads where $0.02/call is cost-effective
Not for
- —High-volume production workloads where per-call costs add up quickly
- —Users who need detailed API documentation or SLAs before integrating
- —Callers who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/169 \
-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, but documentation is essentially nonexistent — docs/pricing/API pages all show only 'Connect wallet'. No OpenAPI spec, no request/response schemas, and no examples are available. The specific purpose of /api/v1/payments/169 ('Premium API Access') is unclear beyond its generic title.
Warnings
- —Documentation pages (docs, pricing, API, README) all render only 'Connect wallet' with no usable content for crawlers.
- —No OpenAPI or schema documentation is available for any endpoint.
- —The specific function of /api/v1/payments/169 ('Premium API Access') is not documented — it is unclear what it does or what request body it expects.
- —The platform lists many endpoint categories but without docs it is impossible to verify they are functional.
Citations
- —The platform advertises $0.02 per request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —The x402 challenge for /api/v1/payments/169 shows maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base.https://lowpaymentfee.com/api/v1/payments/169
- —Listed endpoint categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure.https://lowpaymentfee.com
- —Docs, API, pricing, and README pages render only 'Connect wallet' with no further content.https://lowpaymentfee.com/docs