x402-gated API key endpoint on Base, paying $0.02 in USDC per request.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. It is part of a broader platform that offers a variety of pay-per-call API endpoints spanning data & analytics, 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 priced at $0.02 per request, settled in USDC on the Base network.
The specific endpoint `/api/v1/apikeys/69` appears to be an API key provisioning or access endpoint. The x402 challenge confirms it is live, accepting POST requests, and requires a payment of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. No API keys or rate limits are advertised — the payment itself serves as the access credential.
Documentation is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no detailed description of what this particular endpoint returns. The platform's landing page lists many endpoints but provides no technical documentation for any of them.
Capabilities
Use cases
- —Acquiring API access credentials via a single micropayment
- —Programmatic pay-per-use API consumption without subscription
- —Agent-driven API key provisioning on Base network
Fit
Best for
- —Developers wanting no-signup, pay-per-call API access
- —AI agents that can settle x402 payments in USDC on Base
- —Users who prefer crypto micropayments over traditional API key management
Not for
- —Users needing detailed API documentation or OpenAPI specs before purchasing
- —Anyone without a Base-compatible USDC wallet
- —High-volume consumers who need bulk pricing or SLAs
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/apikeys/69 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is zero documentation beyond the landing page listing. No OpenAPI schema, no request/response examples, and no explanation of what the endpoint actually returns. The docs/pricing/README pages are all empty wallet-connect stubs.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema describing request parameters or response format
- —Unclear what /api/v1/apikeys/69 actually returns upon successful payment
- —Platform lists many endpoints but none have documented behavior or examples
Citations
- —Endpoint returns HTTP 402 with x402 challenge requiring 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/apikeys/69
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/apikeys/69