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. All endpoints are pay-per-request at $0.02 each, settled in USDC on the Base network. No API keys, accounts, or rate limits are required — callers simply attach an x402 payment header to each request.
The specific endpoint `/api/v1/products/25` is listed as "Premium API Access" and returns `application/json` via POST. Its x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913, 6 decimals), which equals $0.02. The payment scheme is "exact" with a 300-second timeout, settling to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3.
The broader platform advertises additional endpoints including 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 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 data returned by these endpoints is unknown beyond the MIME type (application/json).
Capabilities
Use cases
- —Accessing AI inference (sentiment, summarization, classification, embeddings) without API key signup
- —Fetching real-time crypto token quotes and gas estimates via micropayment
- —Running geocoding or data validation calls on a per-request billing model
- —Exporting data or generating analytics reports with no subscription commitment
Fit
Best for
- —Developers who want instant API access without account creation
- —Agents and bots that can settle x402 payments in USDC on Base
- —Low-volume or sporadic API consumers who prefer pay-per-use over subscriptions
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription discounts
- —Developers without a Base-network USDC wallet
Quick start
# 1. Send a POST to discover the x402 payment challenge:
curl -X POST https://lowpaymentfee.com/api/v1/products/25
# Returns 402 with x402 challenge JSON.
# 2. Construct an X-PAYMENT header per x402 spec (scheme: exact,
# asset: USDC on Base, amount: 20000 base units = $0.02)
# 3. Resend with the payment header attached.Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint exists and pricing is clear ($0.02 USDC). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and no examples. The actual functionality of /api/v1/products/25 is entirely opaque — 'Premium API Access' is a generic label with no detail on what data or service it provides.
Warnings
- —No API documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet' with no technical content
- —No OpenAPI or schema definition found for any endpoint
- —The specific purpose and expected input/output of /api/v1/products/25 ('Premium API Access') is undocumented
- —The broad catalog of advertised endpoints (AI, finance, utilities) cannot be verified for actual functionality from available crawl data
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 (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base network with exact schemehttps://lowpaymentfee.com/api/v1/products/25
- —Platform advertises endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilitieshttps://lowpaymentfee.com
- —/docs, /api, /pricing, and /README pages render only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs