Pay-per-call API platform on Base network via x402 — $0.02/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 utility services. Every endpoint costs $0.02 per request, paid in USDC on the Base network with no API keys, no rate limits, and no commitments required. The x402 protocol handles payment inline: callers attach a payment header to each HTTP request and receive the response immediately upon settlement.
The specific endpoint at `/api/v1/transactions/74` is listed as "Premium API Access" and accepts POST requests. The x402 challenge confirms it is live, requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is sent 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 sub-pages just show "Connect wallet"), so the actual request/response schemas for individual endpoints are unknown. Without OpenAPI specs or usage examples, callers will need to experiment to discover input formats and response structures.
Capabilities
Use cases
- —Agent-driven data retrieval with inline USDC micropayments
- —On-demand AI inference (sentiment, summarization, classification) without API keys
- —Fetching real-time crypto price feeds and gas estimates
- —Geocoding and data conversion utilities paid per call
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go API access
- —AI agents that can settle x402 payments on Base
- —Projects needing low-cost micropayment-gated endpoints
Not for
- —Users who need detailed API documentation and OpenAPI schemas before integrating
- —High-throughput batch workloads where per-request pricing adds up
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/74 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI spec, no documentation beyond the landing page, no request/response schemas, and no usage examples. The specific endpoint path '/api/v1/transactions/74' has no description beyond 'Premium API Access', making it unclear what it actually does. All doc/pricing/README pages are empty stubs.
Warnings
- —No OpenAPI or schema documentation available — request/response formats are unknown
- —All documentation pages (/docs, /api, /pricing, /README) return only 'Connect wallet' with no content
- —The specific endpoint /api/v1/transactions/74 is not listed on the landing page catalog; its purpose is unclear
- —No examples or error handling documentation provided
Citations
- —Platform charges $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge confirms USDC asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base with maxAmountRequired of 20000 base units ($0.02)https://lowpaymentfee.com/api/v1/transactions/74
- —Platform offers endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilitieshttps://lowpaymentfee.com