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 minimum commitments required.
The specific endpoint `/api/v1/payments/155` is labeled "Premium API Access" but its exact functionality is not documented beyond that label. The x402 challenge confirms it is live, accepts POST requests, and requires a payment of up to 20,000 base units of USDC (0.02 USD) on Base (asset contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913). The payment scheme is "exact" with a 300-second timeout. No detailed input/output schema, request parameters, or response format documentation was found in the crawl.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, geocoding, validation, conversion, and data export — all at the same $0.02 price point. However, the docs, pricing, and API pages returned only a "Connect wallet" prompt with no further content, so detailed documentation for any individual endpoint is unavailable.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Programmatic pay-as-you-go access to a multi-category API platform
Fit
Best for
- —Developers or agents wanting zero-signup, pay-per-call API access
- —x402-compatible agents that can settle USDC on Base
- —Exploring low-cost micropayment API patterns
Not for
- —Users needing detailed API documentation or guaranteed SLAs
- —Use cases requiring free or fiat-only payment methods
- —Production workloads that need well-documented input/output schemas
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/155 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no documentation of what this specific endpoint actually does, no input/output schema, no example requests or responses, and the docs/pricing/API pages are empty beyond a wallet connect prompt. The listing is effectively a stub with confirmed liveness.
Warnings
- —The exact functionality of /api/v1/payments/155 ('Premium API Access') is undocumented — it is unclear what data or service it provides.
- —All documentation pages (docs, pricing, API, README) returned only 'Connect wallet' with no substantive content.
- —No OpenAPI spec, no input schema, and no response examples are available.
- —The platform lists many endpoints but none have detailed documentation in the crawl.
Citations
- —Endpoint returns 402 with x402 challenge, confirming it is live on Base with USDC payment of 20000 base units (0.02 USD)https://lowpaymentfee.com/api/v1/payments/155
- —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/155
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com