Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol on the Base network. It accepts POST requests and charges 0.02 USDC per call (maxAmountRequired of 20000 base units with 6 decimals = $0.02). Payment is settled in USDC (contract 0x8335…2913) on Base to the payee address 0x1A2B…85F3.
The provider's landing page advertises a broad suite of APIs 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 (geocoding, validation, conversion, generation). All endpoints are listed at $0.02/request with no API keys, no rate limits, and instant access.
However, the specific endpoint probed here is `/api/v1/transactions/75`, which does not appear in the provider's listed catalog. Its purpose is unclear — it may be a transaction-related endpoint or a generic premium access gate. No OpenAPI schema, request/response examples, or detailed documentation were found. The docs, pricing, and API pages all returned only a "Connect wallet" prompt with no substantive content.
Capabilities
Use cases
- —Accessing premium API services without subscription or API key management
- —Making one-off paid API calls settled in USDC on Base
- —Agent-driven programmatic access to paid endpoints via x402 protocol
Fit
Best for
- —Developers wanting no-commitment pay-per-use API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer crypto micropayments over traditional billing
Not for
- —Users needing detailed API documentation or guaranteed SLAs
- —Anyone without a Base-compatible USDC wallet
- —High-volume users who would benefit from bulk pricing
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/75 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (returns 402 challenge correctly) and pricing is clear ($0.02 USDC on Base). However, there is no documentation, no OpenAPI schema, no request/response examples, and the specific endpoint path (/api/v1/transactions/75) is not listed in the provider's catalog. The docs pages are empty beyond a wallet-connect prompt.
Warnings
- —The endpoint /api/v1/transactions/75 does not appear in the provider's advertised API catalog — its actual functionality is unknown.
- —No documentation, OpenAPI spec, or example payloads are available.
- —All documentation pages (docs, pricing, API, README) return only a 'Connect wallet' prompt with no content.
- —The purpose and response format of this specific endpoint cannot be verified.
Citations
- —The endpoint returns a 402 challenge requesting 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/transactions/75
- —The provider advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transactions/75