x402-gated API platform on Base offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API marketplace that exposes a variety of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are pay-per-request using USDC on the Base network, settled via the x402 protocol — no API keys, no rate limits, and no upfront commitments required.
The specific endpoint at `/api/v1/trades/149` is labeled "Premium API Access" and accepts POST requests. Its x402 challenge advertises a maximum cost of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per request (USDC uses 6 decimals). The broader platform lists endpoints for metrics, reports, data export, insights, 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.
Documentation is extremely sparse: the /docs, /api, /pricing, 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 example payloads available. The endpoint is confirmed live (returns 402 with a valid x402 challenge), but without documentation it is unclear what data `/api/v1/trades/149` specifically returns or what POST body it expects.
Capabilities
Use cases
- —Fetching trade data or analytics via a single paid API call without needing an API key
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) on a per-request basis
- —Retrieving real-time crypto quotes, gas estimates, or exchange rates with micropayments
- —Using utility services like geocoding, validation, or data conversion without subscription commitments
Fit
Best for
- —Developers who want instant, keyless API access paid per request
- —AI agents that can settle x402 payments in USDC on Base
- —Projects needing low-cost micropayment-gated endpoints without rate limits
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription plans
- —Developers not set up for USDC payments on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/trades/149 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live with a valid x402 challenge and clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and no examples. The specific purpose of /api/v1/trades/149 is undocumented. This is effectively a stub listing.
Warnings
- —No API documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet'
- —No OpenAPI or schema definition found for any endpoint
- —The specific function of /api/v1/trades/149 ('Premium API Access') is undocumented — unclear what data it returns or what request body it expects
- —The platform lists many endpoint categories but none have documented request/response formats
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/trades/149
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/trades/149
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com