Pay-per-call API platform on Base network via x402 — $0.02/request in USDC, no API keys required.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to accept USDC payments on the Base network. The specific endpoint at `/api/v1/payments/318` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD) per call. No API keys, rate limits, or upfront commitments are required — each request is paid individually via an X-PAYMENT header.
The broader platform advertises multiple API 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). All endpoints are listed at the same $0.02/request price point. However, the specific functionality behind the `/api/v1/payments/318` endpoint is not documented beyond its "Premium API Access" label.
Payments settle on Base via USDC (contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3`. The x402 challenge specifies version 1 with an "exact" payment scheme and a 300-second timeout. The endpoint accepts POST requests and returns `application/json`.
Capabilities
Use cases
- —Agents that need on-demand API access without managing API keys or subscriptions
- —Programmatic access to premium endpoints with per-call USDC micropayments
- —Testing x402 protocol integrations on Base network
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents with crypto wallets that can settle x402 payments automatically
- —Users who prefer no rate limits and instant access without signup
Not for
- —Users without a Base-network USDC wallet
- —High-volume consumers who need bulk pricing or subscription discounts
- —Anyone needing detailed documentation — the docs pages are essentially empty
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/318 \
-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 pricing and payment details. However, the actual functionality behind '/api/v1/payments/318' is undocumented — there is no OpenAPI schema, no request/response examples, and the docs/pricing/README pages are all blank ('Connect wallet' only). The listing is essentially a stub with confirmed liveness but unknown utility.
Warnings
- —The specific functionality of /api/v1/payments/318 ('Premium API Access') is not documented anywhere — it is unclear what data or service it returns.
- —All documentation pages (docs, api, pricing, README) render only a 'Connect wallet' prompt with no actual content.
- —No OpenAPI spec, request schema, or response examples are available.
- —The endpoint path '/api/v1/payments/318' does not match any of the advertised API categories on the homepage, suggesting it may be a generic or test endpoint.
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD) on Base networkhttps://lowpaymentfee.com/api/v1/payments/318
- —All endpoints are listed at $0.02/request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/payments/318
- —Platform offers Data & Analytics, AI & ML, Finance & Web3, and Infrastructure API categorieshttps://lowpaymentfee.com