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 set of endpoints across data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are pay-per-request at $0.02 each, settled in USDC on the Base network. No API keys, no rate limits, and no sign-up required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/charges/15` 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 given USDC's 6 decimals. The x402 challenge specifies the `exact` payment scheme with a 300-second timeout. The endpoint accepts POST requests and returns `application/json`.
The broader platform advertises endpoints in four categories: 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 (geocoding, validation, conversion, generation). Documentation pages exist at /docs, /pricing, and /api but currently render only a "Connect wallet" prompt with no substantive content, so the actual request/response schemas for individual endpoints are unknown.
Capabilities
Use cases
- —Agents that need on-demand AI inference (sentiment, summarization, classification, embeddings) without managing API keys
- —Fetching real-time crypto gas estimates, token quotes, or exchange rates with per-call USDC micropayments
- —Geocoding or data validation as a utility service within automated workflows
- —Exporting analytics data or generating reports on a pay-as-you-go basis
Fit
Best for
- —AI agents and bots that can settle x402 payments in USDC on Base
- —Developers who want zero-signup, zero-rate-limit API access
- —Micropayment use cases where $0.02/request is cost-effective
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —High-volume batch workloads where per-request pricing at $0.02 may add up quickly
- —Users without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/15 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, documentation pages are empty (only 'Connect wallet'), there is no OpenAPI spec, no request/response schema, and no examples. The specific purpose of /api/v1/charges/15 ('Premium API Access') is vague and undifferentiated from the other endpoints. Significant inference is required.
Warnings
- —Documentation pages (/docs, /pricing, /api, /README) all render only 'Connect wallet' with no actual content
- —No OpenAPI or schema available — request and response formats for all endpoints are unknown
- —The specific endpoint /api/v1/charges/15 is labeled 'Premium API Access' but its function is unclear; it does not appear in the site's listed API catalog
- —Cannot verify that the advertised AI, finance, and utility endpoints actually function as described
Citations
- —All endpoints priced at $0.02/request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/charges/15
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Documentation pages render only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs