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 set 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 commitments required. The specific endpoint at `/api/v1/transfers/154` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02, since USDC uses 6 decimals) on Base.
The platform advertises categories including 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 follow the x402 payment protocol: callers receive a 402 challenge with payment details, submit an X-PAYMENT header with a signed USDC transaction, and receive the API response upon settlement.
Documentation 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 usage examples available from the crawled material. The exact functionality behind the `/api/v1/transfers/154` path labeled "Premium API Access" is unclear, as it does not map to any of the publicly listed endpoint categories.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time financial data and crypto quotes with per-request USDC micropayments
- —Running utility operations like geocoding or data validation on a pay-as-you-go basis
- —Integrating agent-driven workflows that autonomously pay for API calls via x402
Fit
Best for
- —Developers wanting zero-commitment, pay-per-use API access
- —AI agents that can autonomously settle micropayments on Base
- —Projects needing quick access to diverse endpoints without signup or rate limits
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription plans
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transfers/154 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <signed-x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it accepts USDC on Base at $0.02/request. However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and the specific purpose of /api/v1/transfers/154 ('Premium API Access') is unexplained and doesn't match any listed category. This is effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — all /docs, /pricing, /api, /README pages return only 'Connect wallet'
- —The endpoint path /api/v1/transfers/154 does not correspond to any of the publicly listed API categories; its actual functionality is unknown
- —No request body schema or response schema is documented anywhere
- —No examples of successful responses are available
Citations
- —All endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The x402 challenge for /api/v1/transfers/154 requests maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transfers/154
- —Platform offers endpoints in Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com