Pay-per-call premium API on Base via x402 — $0.02/request in USDC, no API keys required.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints accessible via the x402 payment protocol on the Base network. This specific endpoint (`/api/endpoint-22`) is listed as "Premium API Access" and accepts USDC payments on Base. The x402 challenge confirms the endpoint is live and charges a maximum of 20,000 base units of USDC (i.e., $0.02 per request, since USDC uses 6 decimals). Payment is sent to `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` and the endpoint accepts POST requests returning `application/json`.
The broader site advertises multiple API 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 (geocoding, validation, conversion, generation) — all at the same $0.02/request price point. However, this particular endpoint (`/api/endpoint-22`) does not map to any of the named endpoints listed on the site, so its specific functionality is unclear. No OpenAPI schema, detailed documentation, or example request/response payloads were found in the crawl; the docs, API, pricing, and README pages all returned only a "Connect wallet" prompt with no substantive content.
The service emphasizes simplicity: no API keys, no rate limits, no commitments, and instant access. Settlement occurs on the Base L2 network using USDC. Without documentation for this specific endpoint, callers should treat it as an opaque premium endpoint and test with a single request to determine the actual response format.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API key management
- —Testing x402 payment protocol integrations against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment-gated APIs
- —AI agents that need keyless, pay-as-you-go API access
- —Users who want to avoid subscriptions and pay only per request
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription plans
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/endpoint-22 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The x402 challenge confirms the endpoint is live and pricing is clear ($0.02 USDC on Base). However, the specific endpoint /api/endpoint-22 is not documented anywhere on the site, no OpenAPI schema exists, no example requests or responses are available, and all documentation pages return only a wallet-connect prompt. The actual functionality of this endpoint is unknown.
Warnings
- —Endpoint /api/endpoint-22 does not correspond to any named API listed on the provider's homepage — its actual functionality is unknown.
- —No documentation, OpenAPI spec, or example payloads are available for this endpoint.
- —All doc/pricing/API pages return only a 'Connect wallet' prompt with no substantive content.
- —The site lists many endpoint categories but none match this specific path, raising questions about what this endpoint actually does.
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/endpoint-22
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/endpoint-22
- —Site advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Site lists Data & Analytics, AI & ML, Finance & Web3, and Infrastructure API categorieshttps://lowpaymentfee.com