Pay-per-call API key generation on Base via x402 — $0.02 per request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. All endpoints are priced at $0.02 per request, payable in USDC on the Base network with no API keys, rate limits, or commitments required.
The specific endpoint at `/api/v1/apikeys/30` is listed as "Premium API Access." Based on the x402 challenge, it accepts POST requests and charges up to 20,000 base units of USDC (0x8335…on Base), which equals $0.02 given USDC's 6 decimals. Payment is settled on-chain to the specified payTo address using the x402 "exact" scheme.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02 per-call price point. Documentation pages exist but appear to require a wallet connection to view, so detailed request/response schemas for individual endpoints are not publicly available from the crawl.
Capabilities
Use cases
- —Acquiring API access tokens via a single micropayment without traditional subscription signup
- —Agents autonomously purchasing API calls for analytics, AI inference, or financial data
- —Programmatic pay-as-you-go access to utility services like geocoding and validation
Fit
Best for
- —Developers wanting zero-commitment, per-call API access settled in USDC on Base
- —AI agents that need to autonomously pay for API endpoints without pre-provisioned keys
- —Projects needing low-cost micropayment-gated access to diverse utility and AI endpoints
Not for
- —Users who need high-volume bulk pricing or enterprise SLAs
- —Those without a Base-compatible wallet or USDC holdings
- —Applications requiring detailed upfront API documentation before integration
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/apikeys/30 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, documentation pages are gated behind wallet connection, no OpenAPI schema is available, and no request/response examples exist. The purpose of the specific /apikeys/30 endpoint is unclear beyond the generic 'Premium API Access' label.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) all appear to require wallet connection and returned no useful content during crawl.
- —No OpenAPI or request/response schema is available for this endpoint.
- —The exact functionality of /api/v1/apikeys/30 ('Premium API Access') is not clearly documented — it may generate API keys or serve as a generic access endpoint, but this is unconfirmed.
- —Many endpoints listed on the homepage (AI, finance, utils) could not be independently verified for functionality.
Citations
- —Endpoint returns HTTP 402 with x402 challenge, maxAmountRequired 20000 USDC base units on Base networkhttps://lowpaymentfee.com/api/v1/apikeys/30
- —All endpoints priced at $0.02 per request with no API keys, rate limits, or commitmentshttps://lowpaymentfee.com
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/apikeys/30