Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. Every endpoint costs $0.02 per request, paid in USDC on the Base network with no API keys, no rate limits, and no subscriptions required. The x402 protocol handles payment inline: callers attach a cryptographic payment header and receive the response immediately.
The specific endpoint at `/api/v1/transactions/348` is listed as "Premium API Access" and returns `application/json`. Based on the x402 challenge, it accepts POST requests and charges a maximum of 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) per call, settled to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` on Base. The broader platform advertises additional endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, geocoding, validation, and more — all at the same $0.02 price point.
Documentation is extremely sparse. The /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawl. The exact functionality behind the `/api/v1/transactions/348` path is unclear — the name "Premium API Access" is generic and does not describe what data or service is returned.
Capabilities
Use cases
- —Accessing on-demand API services without subscription or API key management
- —Making micropayment-gated API calls settled in USDC on Base
- —Integrating pay-per-use endpoints into agent workflows via x402 protocol
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously on Base
- —Projects needing low-cost per-request pricing without rate limits
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Applications requiring non-crypto payment methods
- —High-volume use cases where a flat subscription would be cheaper
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/348 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI spec, no request/response schema, and the specific purpose of /api/v1/transactions/348 is entirely unclear. The docs pages are empty beyond a wallet-connect prompt.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README all render only 'Connect wallet' with no content.
- —No OpenAPI or schema definition found for any endpoint.
- —The purpose of /api/v1/transactions/348 ('Premium API Access') is vague and undocumented — it is unclear what data or service this endpoint provides.
- —The broader platform lists many endpoints (AI, analytics, finance, utils) but none have documented request/response formats.
Citations
- —Endpoint returns 402 with x402 challenge requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/transactions/348
- —maxAmountRequired is 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913), which equals $0.02https://lowpaymentfee.com/api/v1/transactions/348
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com