Premium API access via x402 micropayment on Base — $0.02 per request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities. Each request is paid for individually via the x402 protocol on the Base network using USDC, with no API keys, subscriptions, or rate limits required.
The specific endpoint at `/api/v1/apikeys/31` is listed as "Premium API Access" and accepts POST requests. The x402 challenge advertises a maximum cost of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per call (USDC uses 6 decimals). The platform's landing page confirms a flat $0.02/request pricing model across all listed endpoints. Payment is settled on-chain to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 price point. However, documentation beyond the landing page is essentially empty (all doc/pricing/API pages only show a "Connect wallet" prompt), so the actual request/response schemas, supported parameters, and output formats for any of these endpoints are unknown.
Capabilities
Use cases
- —Acquiring API keys or premium access tokens via a single micropayment
- —Agent-driven on-demand API access without pre-registration
- —Programmatic pay-per-call access to a multi-category API platform
Fit
Best for
- —Agents or developers who want zero-signup, pay-per-use API access
- —x402-compatible clients on the Base network
- —Use cases requiring low-friction, no-commitment API consumption
Not for
- —Users needing detailed API documentation or guaranteed SLAs before purchasing
- —High-volume consumers who would benefit from bulk/subscription pricing
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/apikeys/31 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing. However, there is no OpenAPI schema, no documentation of request parameters or response format, and all doc pages are empty stubs. The purpose of this specific endpoint ('Premium API Access' at /apikeys/31) is ambiguous — it may generate API keys or grant access, but this is unverifiable from available material.
Warnings
- —All documentation pages (/docs, /api, /pricing, /README) return only a 'Connect wallet' prompt with no actual content.
- —No OpenAPI or schema definition is available for any endpoint.
- —The exact purpose and response format of /api/v1/apikeys/31 is unclear — 'Premium API Access' is vague.
- —The broader platform lists many endpoint categories (AI, finance, utilities) but none have documented schemas or examples.
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units of USDC on Base network with a 300-second timeout.https://lowpaymentfee.com/api/v1/apikeys/31
- —The platform charges $0.02 per request with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.https://lowpaymentfee.com/api/v1/apikeys/31
- —All documentation pages only display 'Connect wallet' with no further content.https://lowpaymentfee.com/docs