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 one of many endpoints offered by the lowpaymentfee.com platform, which hosts a broad catalog of pay-per-call APIs 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/58` is listed under the title "Premium API Access." The x402 challenge confirms it is live, accepting POST requests, and requires an exact payment of 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals → $0.02) per call. Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. No API key or account registration is needed; access is granted purely through the x402 payment header.
Documentation is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema, and no description of what this particular endpoint actually returns beyond its title. The broader site lists other endpoints (sentiment analysis, summarization, geocoding, etc.) but provides no detailed documentation for any of them. Without knowing the expected request body or response format, callers will need to experiment or contact the provider.
Capabilities
Use cases
- —Acquiring API keys or access tokens via micropayment without account registration
- —Programmatic pay-per-call access for AI agents needing on-demand API credentials
- —Demonstrating x402 payment protocol integration for developers
Fit
Best for
- —Developers exploring x402 payment-gated APIs
- —AI agents that need keyless, pay-as-you-go API access
- —Projects requiring low-friction API access without subscriptions
Not for
- —Users who need detailed API documentation before integrating
- —High-volume consumers who want bulk pricing or rate-limit guarantees
- —Anyone requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/apikeys/58 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a title, and the docs pages are empty. The purpose of this specific endpoint ('apikeys/58') is unclear — it could generate API keys or grant access, but nothing is documented.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no content
- —The exact purpose and response format of /api/v1/apikeys/58 is undocumented
- —Cannot confirm what 'Premium API Access' actually returns without testing
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/apikeys/58
- —All APIs on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/apikeys/58