Pay-per-request API suite on Base via x402 — data, AI, finance, and utility endpoints at $0.02/call.
What it does
lowpaymentfee.com offers a collection of pay-per-request API endpoints accessible via the x402 payment protocol on the Base network. The specific endpoint at `/api/v1/charges/206` is labeled "Premium API Access" and requires a payment of up to 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals = $0.02) per request. No API keys, rate limits, or subscriptions are needed — callers simply attach an x402 payment header to each POST request.
The broader platform advertises four categories of endpoints: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All listed endpoints are priced at $0.02 per request and settle in USDC on Base.
Documentation is extremely sparse — the /docs, /pricing, /api, 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 material. The endpoint is confirmed live (returns a valid 402 challenge), but without documentation it is unclear what request body the `/api/v1/charges/206` endpoint expects or what response payload it returns.
Capabilities
Use cases
- —Agents that need on-demand AI inference (sentiment, summarization, classification, embeddings) without managing API keys
- —Fetching real-time financial data like token quotes, gas estimates, or exchange rates with per-call payment
- —Running data analytics or export tasks paid per request via USDC on Base
- —Geocoding or data validation as a utility microservice with no subscription commitment
Fit
Best for
- —AI agents with Base USDC wallets needing keyless API access
- —Developers prototyping with low-cost, no-commitment API calls
- —Web3-native applications that prefer on-chain payment settlement
Not for
- —High-volume production workloads where per-call pricing at $0.02 adds up quickly
- —Users who need detailed API documentation, SLAs, or guaranteed uptime
- —Callers without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/206 \
-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 network. However, documentation is essentially nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, and no examples. The specific purpose of /api/v1/charges/206 ('Premium API Access') is undefined beyond its label. This is effectively a stub listing.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README all render only 'Connect wallet'
- —No OpenAPI or schema definition found for any endpoint
- —The specific function of /api/v1/charges/206 is unclear; 'Premium API Access' is a generic label
- —Request and response formats are entirely unknown
- —The breadth of advertised endpoints (AI, finance, data, geo) could not be independently verified
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/charges/206
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Basehttps://lowpaymentfee.com
- —The platform advertises Data & Analytics, AI & ML, Finance & Web3, and Infrastructure endpoint categorieshttps://lowpaymentfee.com
- —Documentation pages (/docs, /pricing, /api, /README) render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs