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 lowpaymentfee.com platform, which hosts a catalog of pay-per-request APIs spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. All endpoints are priced at $0.02 per request, settled in USDC on the Base network, with no API keys, no rate limits, and no commitments required.
The specific endpoint `/api/v1/payments/140` is labeled "Premium API Access" in the x402 challenge. The probe confirms it is live, returning a 402 challenge with an exact-payment scheme requiring up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) on Base (asset contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913). The endpoint accepts POST requests and returns application/json. However, the actual functionality behind this specific endpoint path (`/payments/140`) is not documented beyond the generic "Premium API Access" label — it is unclear what data or service it returns once payment is made.
The platform also advertises sibling endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, geocoding, validation, conversion, and more, all at the same $0.02 price point. Documentation pages (/docs, /pricing, /api, /README) all rendered only a "Connect wallet" prompt with no further content, so detailed request/response schemas are unavailable.
Capabilities
Use cases
- —Accessing premium API services without needing API keys or subscriptions
- —Making one-off paid API calls settled instantly in USDC on Base
- —Agent-driven workflows that need frictionless per-request payment
Fit
Best for
- —Developers wanting zero-commitment pay-per-use API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer crypto micropayments over traditional billing
Not for
- —Users who need detailed documentation or OpenAPI schemas before integrating
- —High-volume use cases where $0.02/request adds up and bulk pricing is preferred
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/140 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no documentation, no OpenAPI schema, no request/response examples, and the actual functionality behind '/api/v1/payments/140' is completely opaque — the label 'Premium API Access' is generic and uninformative.
Warnings
- —The actual service or data returned by /api/v1/payments/140 is undocumented — 'Premium API Access' is a generic label with no specifics.
- —All documentation pages (/docs, /pricing, /api, /README) render only 'Connect wallet' with no usable content.
- —No OpenAPI spec, no request schema, and no response schema are available.
- —Cannot verify what you actually receive after payment without making a paid request.
Citations
- —Endpoint returns 402 with x402 challenge requiring 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/payments/140
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/payments/140
- —Documentation pages render only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs