Pay-per-call API suite on Base via x402 — data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad collection of endpoints spanning data analytics, AI/ML inference, finance/Web3, and general utility services. All endpoints are paid per request using USDC on the Base network via the x402 protocol, with no API keys, no rate limits, and no commitments required.
The specific endpoint at `/api/v1/charges/329` is listed as "Premium API Access" and accepts POST requests. The x402 challenge indicates a maximum cost of 20,000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base), which equals $0.02 per call (USDC uses 6 decimals). The platform advertises a uniform $0.02/request pricing across all its endpoints.
The broader platform lists endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation. However, documentation beyond the landing page is essentially empty (all sub-pages only show "Connect wallet"), so the actual request/response schemas, supported parameters, and output formats for any of these endpoints are unknown. The endpoint is confirmed live via a valid 402 challenge.
Capabilities
Use cases
- —Accessing various API services (analytics, AI, finance, utilities) without needing API key registration
- —Making one-off paid API calls settled in USDC on Base
- —Integrating agent-driven workflows that pay per request via x402
Fit
Best for
- —Developers wanting frictionless, keyless API access with crypto micropayments
- —AI agents that can autonomously pay for API calls via x402
- —Users who prefer pay-as-you-go pricing with no subscriptions
Not for
- —Users who need detailed API documentation and well-defined schemas before integrating
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Users without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/329 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live (valid 402 challenge captured) and pricing is clear ($0.02/request in USDC on Base). However, there is no documentation, no OpenAPI schema, no request/response examples, and all doc pages are empty stubs. The purpose of this specific '/charges/329' endpoint is unclear beyond the generic label 'Premium API Access'. This is effectively a stub listing.
Warnings
- —All documentation pages (/docs, /api, /pricing, /README) return only 'Connect wallet' with no actual content
- —No OpenAPI or schema available — request parameters and response format are completely unknown
- —The specific function of /api/v1/charges/329 ('Premium API Access') is not explained anywhere
- —The platform lists many endpoints but none have documented input/output contracts
Citations
- —Uniform pricing of $0.02 per request across all endpoints, no API keys, no rate limitshttps://lowpaymentfee.com
- —Endpoint returns 402 with x402 challenge requiring 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/charges/329
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/charges/329
- —Platform offers endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilitieshttps://lowpaymentfee.com