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 hosts a broad collection of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and general utility services. Every endpoint is priced at $0.02 per request, settled in USDC on the Base network via the x402 payment protocol. There are no API keys, no rate limits, and no minimum commitments — callers simply attach an X-PAYMENT header with a valid payment proof to each request.
The specific endpoint at `/api/v1/inbox/126` is listed as "Premium API Access" but its exact functionality is not documented beyond that label. The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation. All endpoints accept POST requests and return JSON.
Pricing is uniform: the x402 challenge for this endpoint shows a maxAmountRequired of 20000 base units of USDC (0x8335… on Base), which equals $0.02 given USDC's 6 decimals. The payment timeout is 300 seconds. No OpenAPI schema, detailed documentation, or example request/response payloads were found during the crawl — the /api, /pricing, and /README pages all returned only a "Connect wallet" prompt with no additional content.
Capabilities
Use cases
- —Accessing premium API services with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, on-demand API access
- —Prototyping integrations without signup or subscription commitments
Fit
Best for
- —Developers wanting zero-friction, keyless API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer pay-as-you-go pricing with no minimums
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk/subscription pricing
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/126 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no example requests or responses, and the specific purpose of /api/v1/inbox/126 is unknown beyond the generic label 'Premium API Access'. The /api, /pricing, and /README pages returned no useful content.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —The exact functionality of /api/v1/inbox/126 is undocumented — 'Premium API Access' is the only description
- —All documentation pages (/api, /pricing, /README) returned only a 'Connect wallet' prompt with no content
- —Cannot verify what data or service this specific endpoint provides
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/inbox/126
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com