Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to accept USDC payments on the Base network. The specific endpoint `/api/v1/transactions/382` is listed as "Premium API Access" and returns a 402 challenge requiring payment of up to 20,000 base units of USDC (i.e., $0.02) per call. The platform advertises no API keys, no rate limits, and instant access — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com platform offers endpoints across four 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 endpoints are priced at $0.02 per request. However, the specific endpoint being listed here (`/api/v1/transactions/382`) is described only as "Premium API Access" with no further documentation on what data or functionality it returns.
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 description of what the `/api/v1/transactions/382` endpoint actually does beyond its generic title. The endpoint is live and responds with a valid x402 challenge, but the lack of documentation makes it difficult to know what payload to send or what response to expect.
Capabilities
Use cases
- —Accessing premium data or transaction information via a single paid API call
- —Integrating pay-per-use API access into agent workflows without API key management
- —Programmatic access to platform services settled in USDC on Base
Fit
Best for
- —Developers wanting keyless, pay-per-call API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/382 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, confirming it accepts USDC on Base at $0.02/request. However, there is no documentation, no OpenAPI schema, no request/response examples, and the endpoint's actual functionality ('Premium API Access') is completely undescribed. The docs pages are empty beyond a wallet-connect prompt.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema describing request parameters or response format for this endpoint
- —The purpose of /api/v1/transactions/382 is unclear — 'Premium API Access' is a generic label with no specifics
- —Cannot verify what data or service is returned after payment without actually paying
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/transactions/382
- —All endpoints priced at $0.02/request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/transactions/382
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com