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 set of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities. All endpoints are pay-per-request using USDC on the Base network, settled via the x402 protocol. There are no API keys, no rate limits, and no minimum commitments — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/transactions/261` is listed as "Premium API Access" and requires a maximum of 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) per call. The platform also advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02 price point.
Documentation is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no detailed documentation for any endpoint. The x402 challenge is live and well-formed, confirming the endpoint accepts POST requests and returns application/json, but without further documentation it is unclear what request body this specific endpoint expects or what response it returns.
Capabilities
Use cases
- —Accessing premium API data without managing API keys or subscriptions
- —Making one-off paid API calls from autonomous agents using x402
- —Paying for API access with USDC on Base L2
Fit
Best for
- —Developers wanting zero-friction, keyless API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume callers who would benefit from bulk/subscription pricing
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/261 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint exists and accepts payment. However, documentation is effectively nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI schema, no request/response examples, and no description of what this specific endpoint does beyond the generic label 'Premium API Access'. The endpoint's actual functionality cannot be determined from available material.
Warnings
- —No documentation available — all doc/pricing/README pages render only 'Connect wallet'
- —No OpenAPI or request/response schema provided for any endpoint
- —The specific purpose of /api/v1/transactions/261 ('Premium API Access') is unclear and may be a generic or placeholder endpoint
- —Cannot verify what data or service this endpoint actually returns
Citations
- —The endpoint returns a 402 challenge requiring USDC payment of 20000 base units (0.02 USD) on Base networkhttps://lowpaymentfee.com/api/v1/transactions/261
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/261
- —Available endpoint categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com