Pay-per-call API suite on Base (USDC) covering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com offers a collection of x402-enabled API endpoints spanning data analytics, AI/ML inference, finance/crypto market data, and general utility services. Every endpoint costs $0.02 per request, paid in USDC on the Base network via the x402 protocol — no API keys, no rate limits, and no subscriptions required.
The specific endpoint at `/api/v1/transactions/112` is listed as "Premium API Access" and accepts POST requests. Its x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made via the `exact` scheme to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
The broader platform 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 pages exist but appear to require a wallet connection to view, so detailed request/response schemas for individual endpoints are not available from the crawl. The exact functionality behind the `/api/v1/transactions/112` path is unclear from the available material; it may be a transaction-related data endpoint or a generic premium access route.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time crypto token quotes and gas estimates on a per-call basis
- —Running geocoding or data validation tasks with instant pay-per-use billing
- —Exporting data or generating analytics reports via micropayment-gated endpoints
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents that can settle USDC payments on Base autonomously
- —Projects needing quick access to diverse utility endpoints without subscription overhead
Not for
- —High-volume production workloads where per-request pricing becomes expensive at scale
- —Users without a Base-compatible USDC wallet or x402 client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/112 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02/request in USDC on Base). However, there is no OpenAPI schema, no documentation content (all doc pages just show 'Connect wallet'), no request/response examples, and the specific purpose of the /api/v1/transactions/112 endpoint is ambiguous. The listing is effectively a stub with confirmed liveness.
Warnings
- —Documentation pages (/docs, /api, /pricing, /README) all render only 'Connect wallet' with no visible content — detailed API docs are inaccessible without wallet auth.
- —The exact functionality of /api/v1/transactions/112 ('Premium API Access') is not described anywhere in the crawled material; its purpose is unclear.
- —No OpenAPI spec, request schema, or response schema is available for any endpoint.
- —The platform lists many endpoints but none have documented input/output contracts in the crawl.
Citations
- —All endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base with exact schemehttps://lowpaymentfee.com/api/v1/transactions/112
- —Platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com