Pay-per-call API platform on Base (USDC) offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that provides a broad catalog of pay-per-request endpoints across 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 utilities (geocoding, validation, conversion, generation). All endpoints are priced at $0.02 per request, settled in USDC on the Base network via the x402 protocol.
The specific endpoint at `/api/v1/keys/84` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02) on Base. It accepts POST requests and returns application/json. The platform advertises no API keys, no rate limits, and instant access — payment is the only authentication mechanism. There is no OpenAPI schema, detailed documentation, or example request/response bodies available from the crawled pages, so the exact input parameters and response format for this specific endpoint are unknown.
The platform's wallet-gated pages (pricing, README, API docs) did not yield additional content during crawling, which limits the ability to describe request schemas or response formats in detail. The endpoint is confirmed live via a valid x402 402 challenge.
Capabilities
Use cases
- —Accessing AI inference (sentiment, summarization, classification, embeddings) on a per-call basis without subscriptions
- —Fetching real-time crypto token quotes and gas estimates for DeFi applications
- —Running geocoding or data validation as lightweight utility calls
- —Exporting analytics data or generating reports with pay-as-you-go pricing
- —Integrating low-cost API calls into autonomous agents via x402 payment protocol
Fit
Best for
- —Developers or agents needing low-cost, no-signup API access
- —x402-compatible autonomous agents that settle payments in USDC on Base
- —Prototyping and low-volume use cases where per-request pricing is economical
Not for
- —High-volume production workloads where subscription pricing would be cheaper
- —Users who need detailed SLAs, rate-limit guarantees, or enterprise support
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/keys/84 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, and the landing page provides a catalog overview with pricing. However, there is no OpenAPI schema, no documentation of request/response formats, and wallet-gated pages yielded no content. The specific purpose of /api/v1/keys/84 ('Premium API Access') is vague and undocumented beyond its title.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The exact purpose and input/output format of /api/v1/keys/84 is undocumented — 'Premium API Access' is ambiguous
- —Wallet-gated docs pages (pricing, README, API) returned no useful content
- —No examples of request bodies or response payloads could be found
Citations
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The /api/v1/keys/84 endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on Basehttps://lowpaymentfee.com/api/v1/keys/84
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Payment asset is USDC at contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/keys/84