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 suite of 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.
The specific endpoint `/api/v1/keys/100` is listed as "Premium API Access" and carries a maximum charge of 20,000 base units of USDC (0.02 USDC = $0.02), consistent with the platform's uniform pricing. Payment is handled via the x402 protocol: callers send an X-PAYMENT header with a signed payment payload, and the server verifies on-chain settlement before returning the response. There are no API keys, no rate limits, and no subscription commitments — each call is independently paid.
Documentation is minimal. The landing page lists available endpoints and pricing but provides no request/response schemas, parameter descriptions, or usage examples. The `/api`, `/pricing`, and `/README` pages all resolve to a bare "Connect wallet" prompt with no additional content. The exact functionality of the `/api/v1/keys/100` endpoint is unclear — the name "Premium API Access" suggests it may provision or return API keys, but this is unconfirmed. Agents should treat this endpoint with caution until more documentation is available.
Capabilities
Use cases
- —Agents needing on-demand AI inference (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time financial data such as token quotes, exchange rates, and gas estimates via micropayment
- —Running utility operations like geocoding, validation, or data conversion with per-call billing
Fit
Best for
- —AI agents that need stateless, pay-per-call access to diverse API categories
- —Developers prototyping with no commitment or subscription overhead
- —Crypto-native workflows already operating on Base with USDC
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
- —Non-crypto users who cannot settle payments in USDC on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/keys/100 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no request/response examples, and no documentation beyond a landing page listing. The specific purpose of /api/v1/keys/100 is ambiguous. Effectively a stub listing.
Warnings
- —No API documentation, OpenAPI spec, or request/response schemas available
- —The exact functionality of /api/v1/keys/100 ('Premium API Access') is unclear — it may provision keys or serve as a generic access endpoint
- —All secondary pages (/api, /pricing, /README) return only a 'Connect wallet' prompt with no useful content
- —No rate limit or uptime guarantees documented
Citations
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories, all at $0.02/requesthttps://lowpaymentfee.com
- —Pricing is $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0.02 USD) on Base for /api/v1/keys/100https://lowpaymentfee.com/api/v1/keys/100