Pay-per-call API platform on Base (USDC) offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that provides a broad collection of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and general utility services. All endpoints are pay-per-request using the x402 protocol, settling payments in USDC on the Base network. There are no API keys, no rate limits, and no subscription commitments — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/transactions/32` is listed as "Premium API Access" and requires a maximum payment of 20,000 base units of USDC (0.02 USD) per call. The platform advertises a uniform $0.02 per request price across all its endpoints. Categories of available APIs include: metrics and reports (Data & Analytics), sentiment analysis, text summarization, classification, and embeddings (AI & ML), price feeds, exchange rates, token quotes, and gas estimates (Finance & Web3), and geocoding, validation, conversion, and generation utilities (Infrastructure).
Documentation beyond the landing page 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 detailed documentation for any individual endpoint. The x402 challenge was successfully captured (HTTP 402 with valid accepts block), confirming the endpoint is live.
Capabilities
Use cases
- —Querying real-time financial data (prices, exchange rates, gas estimates) without API key management
- —Running AI inference tasks (sentiment analysis, summarization, classification, embeddings) on a per-call basis
- —Accessing utility services like geocoding, validation, and data conversion with micropayments
- —Agents autonomously purchasing API calls using x402 USDC payments on Base
Fit
Best for
- —AI agents that need frictionless, keyless API access via x402
- —Developers prototyping with pay-as-you-go endpoints at very low cost
- —Web3-native applications that prefer on-chain payment settlement
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume production workloads where $0.02/request adds up significantly
- —Users without USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/32 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but there is no OpenAPI schema, no request/response examples, and all documentation pages are empty beyond a wallet connect prompt. The purpose of the specific /api/v1/transactions/32 endpoint is unclear, and no input/output schemas are available for any endpoint.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet' with no content
- —No OpenAPI or JSON schema describing request/response formats for any endpoint
- —The specific endpoint /api/v1/transactions/32 is labeled 'Premium API Access' but its actual function is undocumented
- —No request or response examples are available anywhere in the crawled material
- —The broad range of claimed capabilities (AI, finance, data, utilities) cannot be verified from available material
Citations
- —Uniform pricing of $0.02 per request across all endpointshttps://lowpaymentfee.com
- —No API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units USDC (0.02 USD) on Basehttps://lowpaymentfee.com/api/v1/transactions/32
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/transactions/32
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com