x402-gated API suite on Base: analytics, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com offers a collection of pay-per-call API endpoints gated by the x402 protocol, settling payments in USDC on the Base network. The specific endpoint at `/api/v1/charges/395` is labeled "Premium API Access" and requires a maximum of 20,000 base units of USDC (i.e., $0.02) per request. No API keys or accounts are needed — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader platform advertises four categories of endpoints: 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 listed endpoints share the same $0.02/request pricing with no rate limits or minimum commitments.
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 crawled material. The x402 challenge is live and well-formed, confirming the endpoint is operational, but the lack of documentation makes it impossible to determine what data or functionality this specific `/charges/395` endpoint actually returns.
Capabilities
Use cases
- —Paying per-call for analytics metrics or data exports without needing an API key
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) with micropayments
- —Fetching real-time crypto gas estimates or token price quotes via x402
- —Geocoding or data validation as a utility service with no subscription
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously on Base
- —Projects needing low-cost micropayment-gated endpoints without rate limits
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume production workloads where per-request pricing at $0.02 may add up
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/395 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint works and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, and all documentation pages are empty stubs showing only 'Connect wallet'. The actual functionality of /api/v1/charges/395 is undocumented, making this effectively a stub listing.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README pages all render only 'Connect wallet' with no content
- —No OpenAPI or schema definition found; request and response formats are unknown
- —The specific endpoint /api/v1/charges/395 is labeled 'Premium API Access' but its actual functionality is undocumented
- —The platform lists many endpoint categories (AI, analytics, finance, utilities) but none have documented input/output schemas
Citations
- —The endpoint requires a maximum of 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/charges/395
- —All listed endpoints are priced at $0.02/request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Documentation pages (/docs, /pricing, /api, /README) render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs