x402-gated Premium API Access endpoint on Base, paying $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" behind an x402 paywall. It is one of many endpoints offered by the lowpaymentfee.com platform, which advertises a broad catalog spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities — all priced at $0.02 per request, settled in USDC on the Base network.
The specific endpoint `/api/v1/apikeys/94` is live and returns a valid x402 challenge (version 1, scheme "exact") requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
However, the actual functionality behind this particular path (`/apikeys/94`) is unclear. The site's landing page lists many other endpoints (metrics, reports, sentiment analysis, summarization, etc.) but does not specifically describe what `/api/v1/apikeys/94` does. The docs, pricing, and API pages all render only a "Connect wallet" prompt with no further documentation. Without an OpenAPI spec, request/response schemas, or detailed documentation, the precise input parameters and output format remain unknown. The platform's value proposition is low-friction, pay-per-call API access with no API keys or rate limits required.
Capabilities
Use cases
- —Programmatic access to a pay-per-call API without needing traditional API keys
- —Agent-driven workflows that need on-demand API access settled in USDC on Base
- —Testing x402 payment flows against a live endpoint
Fit
Best for
- —Developers exploring x402 payment protocol integrations
- —Agents that need keyless, pay-per-request API access
- —Users who want to avoid subscription commitments for occasional API calls
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone who needs to understand the exact response schema before paying
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/apikeys/94 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no OpenAPI spec, no documentation beyond a wallet-connect prompt, and the specific functionality of /api/v1/apikeys/94 is not described anywhere. Request/response schemas are completely unknown, making this effectively a stub listing.
Warnings
- —The exact functionality of /api/v1/apikeys/94 is undocumented — the path name suggests API key generation but this is speculative.
- —No OpenAPI spec, no request schema, and no response schema are available.
- —All documentation pages (docs, pricing, API, README) render only a 'Connect wallet' prompt with no useful content.
- —The site lists many other endpoints but none match this specific path, raising questions about what this endpoint actually does.
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/apikeys/94
- —The platform advertises $0.02 per request with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/apikeys/94
- —The site lists endpoints across data & analytics, AI & ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com