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 variety 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 resource at `/api/v1/apikeys/28` appears to be an API-key provisioning or access endpoint. 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) to the payee address 0x1A2B…85F3. No traditional API keys or rate limits are advertised; access is granted per-request via the x402 payment header.
Documentation beyond the landing page is extremely thin — the /docs, /api, /pricing, and /README pages all resolve to a minimal "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no usage examples. The platform's value proposition is simplicity (no API keys, no rate limits, instant access), but the lack of documentation makes it difficult to know what request body to send or what response to expect from this particular endpoint.
Capabilities
Use cases
- —Programmatically obtaining or activating an API key via a single micropayment
- —Agent-driven access to gated API resources without pre-registration
- —Paying per-request for premium API features using USDC on Base
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who want bulk pricing or subscription discounts
- —Developers who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/apikeys/28 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI spec, no request/response schema, and all documentation pages return only a 'Connect wallet' stub. The purpose of this specific endpoint (/api/v1/apikeys/28) is unclear beyond the label 'Premium API Access'. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — request/response formats are unknown
- —All doc pages (/docs, /api, /pricing, /README) return only a 'Connect wallet' prompt with no content
- —The exact purpose and behavior of /api/v1/apikeys/28 is not documented; 'Premium API Access' is the only description
- —No examples of successful responses are available
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/apikeys/28
- —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 USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/apikeys/28