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-request 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/89` is live and returns a valid x402 challenge (HTTP 402) with a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals), which equals $0.02. Payment is made via the x402 exact scheme to the specified payTo address. The platform advertises no API keys required, no rate limits, and instant access — the x402 payment header serves as the sole authentication mechanism.
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 spec, no request/response schema documentation, and no examples of what this particular endpoint returns. The endpoint path (`/api/v1/apikeys/89`) suggests it may provision or return an API key, but this is speculative. Without documentation or sample responses, the actual behavior of this endpoint remains unclear.
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-subscription API access with crypto micropayments
- —AI agents that need to autonomously purchase API keys
- —Users on the Base L2 network who hold USDC
Not for
- —Users who need detailed API documentation before purchasing
- —Anyone without USDC on Base network
- —High-volume consumers who prefer flat-rate pricing
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/apikeys/89 \
-H "X-PAYMENT: <x402-payment-header>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but documentation is essentially nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response examples, and no explanation of what the endpoint actually returns. The endpoint path and description are vague ('Premium API Access'). Pricing is clear ($0.02 USDC on Base), but the lack of any schema or behavioral documentation makes this a near-stub listing.
Warnings
- —No documentation available — all doc/pricing/API/README pages render only 'Connect wallet'
- —No OpenAPI or output schema provided; actual response format is unknown
- —The endpoint path '/api/v1/apikeys/89' is ambiguous — it is unclear what 'apikeys/89' returns or whether it provisions a key
- —The broader platform lists many endpoints but none have documented schemas or examples
Citations
- —Endpoint returns HTTP 402 with x402 challenge, maxAmountRequired 20000 USDC base units on Basehttps://lowpaymentfee.com/api/v1/apikeys/89
- —Platform lists endpoints at $0.02/request across data, AI, finance, and infrastructure categorieshttps://lowpaymentfee.com
- —Platform advertises no API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/apikeys/89