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 marketplace that offers a variety of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are priced at $0.02 per request, payable in USDC on the Base network with no API keys, rate limits, or subscriptions required. The specific endpoint at `/api/v1/transactions/184` is listed as "Premium API Access" and returns an x402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02, since USDC uses 6 decimals) on Base.
The 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 (geocoding, validation, conversion, generation). However, the crawled documentation pages (docs, api, pricing, README) all returned only a "Connect wallet" prompt with no substantive content, so the actual functionality behind these endpoints is unverified. There is no OpenAPI schema, no example request/response documentation, and no detailed description of what the `/api/v1/transactions/184` endpoint specifically does.
The x402 challenge is live and well-formed: it specifies the USDC contract on Base (`0x8335...`), a pay-to address, and a 300-second timeout. The endpoint accepts POST requests and is discoverable. Given the lack of documentation beyond the landing page listing, the actual data returned by this and other endpoints remains unclear.
Capabilities
Use cases
- —Accessing premium API data with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Programmatic pay-as-you-go access to analytics, AI, or finance endpoints
Fit
Best for
- —Developers wanting zero-commitment, pay-per-call API access
- —AI agents that can settle x402 payments autonomously on Base
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/184 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint exists and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no documentation beyond a landing page listing, no example requests or responses, and the specific purpose of `/api/v1/transactions/184` ("Premium API Access") is entirely opaque. The docs/pricing/README pages are all empty wallet-connect stubs.
Warnings
- —No documentation available — docs, pricing, and README pages all return only a 'Connect wallet' prompt with no content
- —The specific functionality of /api/v1/transactions/184 ('Premium API Access') is undocumented and unclear
- —No OpenAPI schema or example request/response payloads are provided
- —The broad range of advertised endpoints (AI, analytics, finance, utils) is unverified — actual functionality behind them is unknown
Citations
- —All endpoints priced at $0.02 per request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (6 decimals = $0.02) on Base networkhttps://lowpaymentfee.com/api/v1/transactions/184
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/184
- —Platform advertises Data & Analytics, AI & ML, Finance & Web3, and Infrastructure endpoint categorieshttps://lowpaymentfee.com