Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. It is one of many endpoints offered by the platform, which spans data & analytics, AI & machine learning, finance & Web3, and infrastructure utility categories — all priced at $0.02 per request settled in USDC on the Base network.
The specific endpoint `/api/v1/payments/129` is labeled "Premium API Access" in the x402 challenge but its exact functionality is not documented beyond that label. The platform advertises a simple pay-per-use model: no API keys, no rate limits, no commitments, and instant access. Payment is handled via the x402 protocol where callers attach an `X-PAYMENT` header with a signed USDC payment on Base. The max amount required per call is 20,000 base units of USDC (6 decimals), which equals $0.02.
The probe confirms the endpoint is live, returning a proper 402 challenge with x402 version 1. The payment is directed to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using the USDC contract on Base (`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`). The endpoint accepts POST requests and returns `application/json`. However, documentation is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. The actual request body schema and response format for this specific endpoint are unknown.
Capabilities
Use cases
- —Accessing premium data or services with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Testing x402 payment protocol integrations
Fit
Best for
- —Developers experimenting with x402 pay-per-call patterns
- —Agents that can sign USDC payments on Base
- —Users who want keyless, commitment-free API access
Not for
- —Users who need detailed API documentation or schemas before integrating
- —High-volume use cases where per-request pricing may add up
- —Anyone without a Base-compatible wallet holding USDC
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/129 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is essentially no documentation for what this specific endpoint does, what request body it expects, or what it returns. The label 'Premium API Access' is generic and uninformative. Docs pages are empty beyond a wallet connect prompt.
Warnings
- —The exact functionality of /api/v1/payments/129 ('Premium API Access') is undocumented — it is unclear what data or service it provides.
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no usable content.
- —No request body schema or response schema is available for this endpoint.
- —This endpoint path (/api/v1/payments/129) does not match any of the listed API categories on the homepage, raising questions about what it actually does.
Citations
- —The endpoint returns a 402 challenge with x402 version 1, requiring USDC payment on Basehttps://lowpaymentfee.com/api/v1/payments/129
- —maxAmountRequired is 20000 base units of USDC (USD Coin, 6 decimals) = $0.02https://lowpaymentfee.com/api/v1/payments/129
- —Platform advertises $0.02/request, no API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —Payment address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3, USDC asset contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/payments/129