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-protocol API marketplace that gates access to a variety of endpoints behind per-request micropayments settled in USDC on the Base network. The specific endpoint at `/api/v1/trades/51` is listed as "Premium API Access" and accepts POST requests. The x402 challenge advertises a maximum cost of 20,000 base units of USDC (0x8335…), which equals $0.02 per request (USDC uses 6 decimals). No API keys or rate limits are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader platform advertises four categories of endpoints: 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 listed endpoints share the same $0.02/request pricing.
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 example payloads available. The specific functionality behind `/api/v1/trades/51` is unclear — the path suggests trade data retrieval but no schema or description beyond the generic "Premium API Access" label is provided. The endpoint is confirmed live (returns a proper 402 challenge), but without documentation it is difficult to know what request body to send or what response to expect.
Capabilities
Use cases
- —Fetching trade data via a single micropayment without needing an API key
- —Programmatic access to premium data endpoints settled on-chain
- —Agent-driven API consumption where each call is independently paid
Fit
Best for
- —Developers wanting keyless, pay-per-call API access
- —AI agents that can settle x402 payments on Base
- —Users who need low-cost single-request access without subscriptions
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone unable to pay with USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/trades/51 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and the specific purpose of /api/v1/trades/51 is undocumented. This is effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — request and response formats are unknown
- —All documentation pages (/docs, /pricing, /api, /README) render only 'Connect wallet' with no content
- —The specific functionality of /api/v1/trades/51 is unclear; 'Premium API Access' is a generic label
- —Cannot verify what data or service this endpoint actually provides
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/trades/51
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/trades/51