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 catalog of endpoints spanning data analytics, AI/ML inference, finance/crypto data, and utility services. All endpoints are paid per-request at $0.02 each using USDC on the Base network, with no API keys, rate limits, or upfront commitments required. Payment is handled via the x402 protocol: callers attach an X-PAYMENT header to each request to settle in USDC.
The specific endpoint at `/api/v1/charges/390` 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 challenge specifies an exact payment scheme with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
The broader platform advertises categories including 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). However, documentation beyond the landing page is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawled material.
Capabilities
Use cases
- —Agents needing on-demand AI inference (sentiment, summarization, classification) without managing API keys
- —Fetching real-time crypto token quotes and gas estimates via micropayment
- —Running geocoding or data validation as a utility service with per-call billing
- —Exporting analytics data or generating insights on a pay-as-you-go basis
Fit
Best for
- —AI agents that can settle x402 payments in USDC on Base
- —Developers wanting zero-setup, keyless API access at low per-call cost
- —Prototyping workflows that need diverse API capabilities without subscription commitments
Not for
- —High-volume production workloads where per-call pricing at $0.02 adds up significantly
- —Users who need detailed API documentation, schemas, or SLAs before integration
- —Teams that cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/390 \
-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 it accepts USDC payments on Base at $0.02/request. However, there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page listing, and no examples. The docs/pricing/README pages are all empty (just 'Connect wallet'). The specific purpose of '/api/v1/charges/390' beyond 'Premium API Access' is unclear.
Warnings
- —No OpenAPI or schema documentation available — request and response formats are unknown
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no content
- —The specific functionality of /api/v1/charges/390 ('Premium API Access') is not described anywhere — it may be a generic or placeholder endpoint
- —No examples of successful responses are available from crawled material
- —The platform lists many endpoint categories but none could be verified beyond the landing page descriptions
Citations
- —The endpoint returns a 402 challenge requesting 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/charges/390
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints in Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Documentation pages render only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs