Pay-per-call API platform on Base network via x402 — $0.02/request, no API keys required.
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 paid per-request at $0.02 each using USDC on the Base network, with no API keys, rate limits, or upfront commitments required. Payment is handled inline via the x402 protocol's HTTP 402 challenge-response flow.
The specific endpoint at `/api/v1/transactions/90` 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. The endpoint accepts POST requests and returns JSON. However, the exact functionality of this particular `/transactions/90` path is not documented — the site's landing page lists categories like analytics, AI, finance, and utilities, but does not include a transactions endpoint in its public catalog.
Documentation is extremely sparse. The /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no substantive 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 knowing what this specific endpoint does beyond "Premium API Access," agents should treat it as an opaque paid endpoint until more documentation surfaces.
Capabilities
Use cases
- —Programmatic access to paid API services without managing API keys or subscriptions
- —Agent-driven workflows that need to pay per-call using USDC on Base
- —Exploring x402 protocol integration for pay-as-you-go API consumption
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that need keyless, pay-per-request API access on Base
- —Low-volume consumers who want no commitments or minimums
Not for
- —Users needing well-documented, schema-specified API contracts
- —High-volume use cases where $0.02/request adds up without bulk discounts
- —Anyone requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/90 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live with a valid 402 challenge, but there is no documentation, no request/response schema, and the specific purpose of /api/v1/transactions/90 is unclear. The site's docs pages are empty beyond a wallet-connect prompt. This is effectively a stub listing.
Warnings
- —The exact functionality of /api/v1/transactions/90 is undocumented — 'Premium API Access' is the only description available.
- —All documentation pages (/docs, /pricing, /api, /README) render only 'Connect wallet' with no content.
- —No OpenAPI spec, request schema, or response schema is available.
- —This endpoint does not appear in the site's public API catalog, which lists analytics, AI, finance, and utility endpoints but not a 'transactions' category.
Citations
- —All endpoints priced at $0.02 per request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —Payment via USDC on Base networkhttps://lowpaymentfee.com
- —402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transactions/90
- —Endpoint accepts POST method and returns application/jsonhttps://lowpaymentfee.com/api/v1/transactions/90