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 set of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. Every endpoint costs $0.02 per request, paid in USDC on the Base network using the x402 payment protocol. There are no API keys, no rate limits, and no upfront commitments — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/transactions/180` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) on Base. The payment is settled to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` with a 300-second timeout. The endpoint accepts POST requests and returns `application/json`.
The broader platform advertises categories including: metrics, reports, data export, insights, sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation. However, documentation beyond the landing page is essentially empty (all doc/pricing/API pages only show a "Connect wallet" prompt), so the actual behavior and response schemas of individual endpoints are unknown. Without documentation or example responses, the precise functionality of the `/api/v1/transactions/180` endpoint cannot be confirmed beyond its title.
Capabilities
Use cases
- —Agents needing on-demand API access without pre-registration or API keys
- —Micropayment-gated data retrieval or utility calls
- —Programmatic access to analytics, AI inference, or financial data endpoints
Fit
Best for
- —AI agents that can settle x402 payments in USDC on Base
- —Developers wanting zero-signup, pay-as-you-go API access
- —Low-cost per-request workloads at $0.02 each
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume batch workloads where per-request pricing adds up quickly
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/180 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it is operational. However, there is no OpenAPI schema, no documentation, no example requests or responses, and the actual functionality behind 'Premium API Access' at /api/v1/transactions/180 is completely opaque. All non-landing pages returned only 'Connect wallet' with no content.
Warnings
- —No documentation available — all doc/pricing/API pages are empty beyond a 'Connect wallet' prompt
- —The specific functionality of /api/v1/transactions/180 ('Premium API Access') is undocumented and unclear
- —No response schema or example responses are available for any endpoint
- —The platform lists many endpoint categories but none have verifiable documentation
Citations
- —The endpoint returns a 402 challenge requesting 20,000 base units of USDC on Base (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913)https://lowpaymentfee.com/api/v1/transactions/180
- —All endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com