Pay-per-call API key generation on Base via x402, settled in USDC at $0.02/request.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints accessible via the x402 payment protocol on the Base network. The specific endpoint at `/api/v1/apikeys/98` is labeled "Premium API Access" and accepts POST requests with an x402 payment header. Payment is settled in USDC (contract 0x8335…2913 on Base) with a maximum amount of 20,000 base units, which equals $0.02 per call (USDC uses 6 decimals). No API keys, subscriptions, or rate limits are required — each call is individually paid for at the protocol level.
The broader platform advertises endpoints across four categories: Data & Analytics (metrics, reports, data export, insights), 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 listed endpoints share the same $0.02/request pricing. However, the specific endpoint being listed here (`/api/v1/apikeys/98`) is described only as "Premium API Access" — its exact functionality beyond that label is not documented in the crawled material.
The endpoint is live and returns a valid x402 challenge (HTTP 402) with version 1 of the protocol. Documentation pages on the site (/docs, /pricing, /api, /README) all returned minimal content (just a "Connect wallet" prompt), so detailed request/response schemas, parameter descriptions, and usage examples are unavailable.
Capabilities
Use cases
- —Acquiring premium API access tokens via a single micropayment
- —Agent-driven API consumption without pre-registration or API keys
- —Programmatic pay-as-you-go access to data, AI, finance, or utility endpoints
Fit
Best for
- —AI agents needing instant, keyless API access on Base
- —Developers who want per-call billing without subscriptions
- —x402-compatible clients looking for low-cost endpoints
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who prefer bulk/subscription pricing
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/apikeys/98 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but documentation pages are effectively empty ('Connect wallet' only). There is no OpenAPI spec, no request/response schema, and no description of what 'Premium API Access' actually returns. The listing is largely a stub with pricing and protocol details only.
Warnings
- —All documentation pages (/docs, /pricing, /api, /README) returned no useful content — only a 'Connect wallet' prompt.
- —The exact functionality of /api/v1/apikeys/98 ('Premium API Access') is undocumented; it is unclear what data or service is returned upon successful payment.
- —No request body schema or response schema is available; integration requires trial-and-error or contacting the provider.
Citations
- —Endpoint returns HTTP 402 with x402 version 1 challenge advertising USDC on Basehttps://lowpaymentfee.com/api/v1/apikeys/98
- —maxAmountRequired is 20000 base units of USDC (6 decimals) = $0.02https://lowpaymentfee.com/api/v1/apikeys/98
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/apikeys/98
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com