x402-payable 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 platform that exposes a broad catalog of endpoints across four categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are priced at $0.02 per request, paid in USDC on the Base network via the x402 protocol — no API keys, no rate limits, no subscriptions required.
The specific endpoint `/api/v1/trades/143` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made via the x402 exact scheme with a 300-second timeout. The endpoint accepts POST requests and returns application/json. Note that this particular path (`/trades/143`) does not appear in the site's public catalog of endpoints, so its exact functionality is unclear — it may be a trade-related data endpoint or an unlisted resource.
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 crawled material. The endpoint is confirmed live (402 challenge captured), but without documentation it is difficult to know what request body to send or what response to expect.
Capabilities
Use cases
- —Accessing trade or financial data without API key registration
- —Agent-driven workflows that need on-demand data or AI inference with crypto micropayments
- —Prototyping integrations against low-cost, no-commitment API endpoints
- —Paying per request for geocoding, text summarization, or sentiment analysis
Fit
Best for
- —Developers who want zero-signup, pay-as-you-go API access
- —AI agents with x402-compatible wallets on Base
- —Projects needing low-cost ($0.02) micropayment-gated endpoints
Not for
- —Users without USDC on the Base network
- —Applications requiring detailed API documentation or SLAs
- —High-throughput production workloads needing guaranteed uptime and support
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/trades/143 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is confirmed live with a valid 402 challenge and clear pricing ($0.02 USDC on Base). However, documentation is essentially nonexistent — no OpenAPI spec, no request/response schemas, no examples. The specific /trades/143 path is not listed in the site's public catalog, making its purpose unclear. Score reflects a live but poorly documented stub.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet'
- —The endpoint path /api/v1/trades/143 does not appear in the site's public endpoint catalog
- —No OpenAPI spec or request/response schema provided
- —No examples of expected request body or response format
Citations
- —All endpoints priced at $0.02/request with no API keys, no rate limits, on Base networkhttps://lowpaymentfee.com
- —402 challenge requests maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/trades/143
- —Site offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Documentation pages render only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs