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, and no upfront commitments.
The specific endpoint `/api/v1/trades/61` is listed as "Premium API Access" and was probed live, returning a valid 402 challenge. The challenge specifies payment of 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 to the payTo address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3, with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
Documentation beyond the landing page is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no additional technical content. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available. The exact functionality behind `/api/v1/trades/61` (labeled "Premium API Access") is unclear; it does not appear in the landing page's listed catalog, so its purpose must be inferred from the path — likely trade-related data. Prospective users should be aware that without documented schemas, integration requires experimentation.
Capabilities
Use cases
- —Fetching real-time financial or trade data with per-call USDC micropayments
- —Running AI inference (sentiment, summarization, classification) without API key management
- —Accessing utility services like geocoding or data conversion on a pay-as-you-go basis
- —Integrating crypto gas estimates or token quotes into trading bots
- —Agent-driven workflows that need keyless, on-demand API access
Fit
Best for
- —Developers wanting zero-commitment, pay-per-request API access
- —AI agents that can settle x402 payments autonomously on Base
- —Projects needing lightweight access to multiple API categories without subscription overhead
Not for
- —Users who need detailed API documentation and request/response schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or rate-limited subscription plans
- —Users without USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/trades/61 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page catalog, and the specific /api/v1/trades/61 endpoint is not even listed in the catalog. The docs, pricing, and README pages are all empty beyond a wallet-connect prompt.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The /api/v1/trades/61 endpoint is not listed in the site's public catalog — its exact functionality is unknown
- —All documentation pages (/docs, /pricing, /README) render only 'Connect wallet' with no technical content
- —No example request or response payloads are documented anywhere
Citations
- —All endpoints priced at $0.02/request with no API keys, no rate limits, on Base networkhttps://lowpaymentfee.com
- —Endpoint returns 402 with maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/trades/61
- —Categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com