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/infrastructure 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/transfers/45` is listed as "Premium API Access" and its x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The endpoint accepts POST requests and returns application/json. The broader 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 per call.
Documentation is extremely sparse. The /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawl. The actual functionality behind `/api/v1/transfers/45` and the other listed endpoints cannot be verified beyond the x402 challenge metadata.
Capabilities
Use cases
- —Agents needing on-demand AI inference (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time crypto token quotes, gas estimates, or exchange rates via pay-per-call
- —Geocoding, data validation, or format conversion as lightweight utility calls
- —Exporting analytics data or generating reports on a per-request billing basis
Fit
Best for
- —AI agents that need keyless, pay-as-you-go API access
- —Developers who want to avoid subscription commitments for low-volume usage
- —Crypto-native applications already operating on the Base network
Not for
- —High-volume production workloads where per-request pricing becomes expensive
- —Users who need detailed documentation or SLA guarantees before integrating
- —Applications requiring non-USDC or non-Base-network payment settlement
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transfers/45 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02/request in USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page listing, and no examples. The actual functionality behind the endpoints is unverifiable from available material.
Warnings
- —No OpenAPI or schema documentation available — all endpoint functionality is unverifiable
- —All doc/pricing/README pages render only 'Connect wallet' with no content
- —The specific endpoint /api/v1/transfers/45 has no description beyond 'Premium API Access' — its actual purpose is unclear
- —No request body schema or response schema documented anywhere
Citations
- —All endpoints priced at $0.02 per request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/transfers/45
- —Platform lists endpoints for analytics, AI/ML, finance/Web3, and infrastructure categorieshttps://lowpaymentfee.com
- —Docs, pricing, API, and README pages show only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs