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 pay-per-request endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are priced at $0.02 per request, paid in USDC on the Base network with no API keys, no rate limits, and no commitments required.
The specific endpoint at `/api/v1/transactions/243` is listed as "Premium API Access" and accepts POST requests. The x402 challenge confirms it is live, requesting a maximum of 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) on Base (asset contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913). Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
The platform also 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 price point. However, documentation beyond the landing page is extremely sparse: the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available, making it difficult to determine what inputs the endpoints expect or what outputs they return.
Capabilities
Use cases
- —Accessing AI inference (sentiment, summarization, classification, embeddings) on a per-call basis without API keys
- —Fetching real-time crypto quotes, gas estimates, and exchange rates via micropayments
- —Performing geocoding, validation, or data conversion with no subscription commitment
- —Integrating pay-as-you-go data analytics and reporting into agent workflows
Fit
Best for
- —Developers wanting zero-commitment, keyless API access paid in USDC
- —AI agents that need on-demand inference endpoints purchasable via x402
- —Web3-native applications needing micropayment-gated utility services
Not for
- —Users who need detailed API documentation and well-defined schemas before integrating
- —High-volume production workloads where per-request pricing at $0.02 may not be cost-effective
- —Users without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/243 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but there is zero documentation on request/response schemas, no OpenAPI spec, and all doc pages render only 'Connect wallet'. The actual functionality behind 'Premium API Access' at /api/v1/transactions/243 is unclear.
Warnings
- —No OpenAPI or schema documentation available — all doc/pricing/README pages show only 'Connect wallet'
- —The specific purpose of /api/v1/transactions/243 ('Premium API Access') is not explained anywhere
- —No request or response examples are available; integration requires guesswork
- —The breadth of advertised endpoints (AI, finance, geo, etc.) cannot be verified from available material
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0.02 USD) on Basehttps://lowpaymentfee.com/api/v1/transactions/243
- —Platform advertises endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilitieshttps://lowpaymentfee.com
- —Documentation pages (/docs, /api, /pricing, /README) render only 'Connect wallet'https://lowpaymentfee.com/docs