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/33` 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 up to 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.
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 documentation, and no examples of what the endpoint returns. The platform advertises no API keys required, no rate limits, and instant access, but the actual behavior and response format of this particular endpoint remain undocumented.
Capabilities
Use cases
- —Programmatically obtaining API keys or access tokens via a single paid POST request
- —Agents purchasing API access on-the-fly without pre-registration
- —Demonstrating x402 payment-gated endpoint patterns on Base
Fit
Best for
- —Developers experimenting with x402 payment protocol on Base
- —AI agents that need to acquire API access autonomously
- —Low-cost per-request API consumption without subscriptions
Not for
- —Production workloads requiring documented request/response schemas
- —Users who need detailed API documentation before integrating
- —High-volume use cases where per-request pricing may add up
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/apikeys/33 \
-H "X-PAYMENT: <x402-payment-token>" \
-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 schema, and no examples. The purpose of the specific /api/v1/apikeys/33 endpoint is unclear beyond its title.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) are all empty, showing only 'Connect wallet'
- —No OpenAPI or schema documentation available for this endpoint
- —No request body schema or response schema documented — actual behavior is unknown
- —The endpoint path '/api/v1/apikeys/33' suggests API key provisioning but this is inferred from the name alone
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/apikeys/33
- —All endpoints on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/apikeys/33