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 catalog of pay-per-request endpoints settled in USDC on the Base network. The specific endpoint at `/api/v1/inbox/182` is listed as "Premium API Access" and costs up to $0.02 per call (20,000 base units of USDC with 6 decimals). No API keys or accounts are required; callers authenticate and pay via the x402 protocol's X-PAYMENT header.
The platform advertises four categories of APIs: 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.
The specific `/api/v1/inbox/182` endpoint does not clearly map to any of the named API categories on the landing page, so its exact functionality is uncertain. The endpoint accepts HTTP POST requests and returns `application/json`. The x402 challenge is live and well-formed, settling payments to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC (`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) on Base.
Capabilities
Use cases
- —Accessing data analytics and reports on a per-request basis without subscription
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) with per-call payment
- —Fetching real-time financial data such as crypto prices, exchange rates, and gas estimates
- —Using utility services like geocoding, validation, and data conversion
Fit
Best for
- —Agents or developers who want instant API access without signup or API keys
- —Low-volume or bursty workloads where per-request pricing is more economical than subscriptions
- —Crypto-native applications that can settle payments in USDC on Base
Not for
- —High-volume production workloads where per-request costs would accumulate significantly
- —Users who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/182 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint is operational. However, the specific endpoint /api/v1/inbox/182 has no documentation explaining its purpose, expected input, or output schema. The landing page lists many APIs but this path doesn't match any of them. No OpenAPI spec, no examples, and crawled subpages returned only 'Connect wallet' with no useful content.
Warnings
- —The endpoint path /api/v1/inbox/182 does not correspond to any documented API on the landing page; its actual functionality is unknown.
- —No request or response schema is documented; callers must experiment to discover the expected payload.
- —Crawled /api, /pricing, and /README pages returned no meaningful content (only 'Connect wallet').
- —No OpenAPI specification or machine-readable documentation is available.
Citations
- —The endpoint returns a 402 x402 challenge requesting up to 20,000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/inbox/182
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 (6 decimals), so 20000 base units = $0.02https://lowpaymentfee.com/api/v1/inbox/182
- —The platform lists APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories all at $0.02/requesthttps://lowpaymentfee.com
- —No API keys, no rate limits, instant access, Base network settlementhttps://lowpaymentfee.com