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 set of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints are pay-per-request at $0.02 each, settled in USDC on the Base network. No API keys, rate limits, or subscriptions are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/payments/206` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base). Since USDC uses 6 decimals, this equals $0.02 per call, consistent with the site's advertised pricing. Payment is made 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 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 usage examples available from the crawled content. The actual behavior and output format of this specific endpoint (and the others) cannot be verified from the available material.
Capabilities
Use cases
- —Agents needing on-demand API access without managing API keys or subscriptions
- —Pay-per-call AI inference (sentiment, summarization, classification, embeddings)
- —Fetching real-time crypto prices, gas estimates, or exchange rates with micropayments
- —Geocoding or data validation as a utility service with no rate limits
Fit
Best for
- —AI agents that need frictionless, key-free API access via x402
- —Developers wanting to test micropayment-gated endpoints on Base
- —Low-volume or bursty workloads where per-request pricing is preferable to subscriptions
Not for
- —High-volume production workloads where $0.02/request adds up quickly
- —Users who need detailed API documentation, schemas, or SLAs before integrating
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/206 \
-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 is essentially nonexistent — docs/pricing/API/README pages all show only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, no examples, and no description of what this specific 'Premium API Access' endpoint actually does or returns. The listing is effectively a stub.
Warnings
- —No documentation available — all doc pages render only 'Connect wallet'
- —No OpenAPI or schema definition for any endpoint
- —The purpose and output of /api/v1/payments/206 ('Premium API Access') is completely undocumented
- —Cannot verify what data or functionality any of the advertised endpoints actually provide
- —No request body schema or response format documented anywhere
Citations
- —All endpoints priced at $0.02 per request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —x402 challenge requests maxAmountRequired of 20000 base units of USDC on Base (= $0.02)https://lowpaymentfee.com/api/v1/payments/206
- —Payment settles to 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with 300-second timeouthttps://lowpaymentfee.com/api/v1/payments/206
- —Platform advertises endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilitieshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages all render only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs