Pay-per-call API platform on Base (USDC) covering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of pay-per-request endpoints settled in USDC on the Base network. The specific endpoint at `/api/v1/transactions/322` is listed as "Premium API Access" and costs up to $0.02 per call (maxAmountRequired of 20,000 base units of USDC with 6 decimals). Payment is handled via the x402 protocol — no API keys, accounts, or rate limits are required; callers simply attach an X-PAYMENT header with a valid payment proof.
The wider platform advertises four endpoint categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All listed endpoints share the same $0.02/request pricing. The x402 challenge confirms the endpoint is live, uses the "exact" payment scheme on Base, accepts USDC (contract 0x8335…2913), and responds with application/json.
Documentation beyond the landing page is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available. The exact functionality behind the `/api/v1/transactions/322` path is unclear; the generic "Premium API Access" label does not describe what data or service is returned.
Capabilities
Use cases
- —Accessing data analytics or AI inference endpoints without creating an account or managing API keys
- —Making one-off API calls with instant USDC micropayments on Base
- —Integrating pay-per-request finance or utility services into agent workflows
Fit
Best for
- —Developers who want zero-signup, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously on Base
- —Projects needing low-cost per-call pricing without subscriptions
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk/subscription pricing
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/322 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The x402 challenge is live and confirms pricing and network details, but there is no OpenAPI spec, no request/response schema, and no documentation beyond a landing page listing. The specific purpose of /api/v1/transactions/322 is undocumented, making this effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — all /docs, /pricing, /api, and /README pages return only a wallet-connect prompt
- —The exact functionality of /api/v1/transactions/322 ('Premium API Access') is not described anywhere in the crawled material
- —No example request or response payloads are available; integration requires trial-and-error
- —The broad catalog of endpoints (AI, finance, data, utils) is listed on the homepage but none have documented input/output schemas
Citations
- —Endpoint returns 402 with x402 challenge, confirming it is live on Base with USDChttps://lowpaymentfee.com/api/v1/transactions/322
- —maxAmountRequired is 20000 base units of USDC (6 decimals) = $0.02 per requesthttps://lowpaymentfee.com/api/v1/transactions/322
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/322
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Four endpoint categories listed: Data & Analytics, AI & Machine Learning, Finance & Web3, Infrastructurehttps://lowpaymentfee.com