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 exposes a broad catalog of endpoints across four categories: 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 endpoints are priced at $0.02 per request, settled in USDC on the Base network via the x402 protocol.
The specific endpoint `/api/v1/inbox/148` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals = $0.02). Payment is made via the x402 exact scheme with no API keys, no rate limits, and no upfront commitments required. The endpoint accepts HTTP POST and returns application/json.
Documentation is minimal — the site's /api, /pricing, and /README pages all resolve to a wallet-connect prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available. The purpose of the `/api/v1/inbox/148` endpoint specifically is unclear; it does not map to any of the named endpoints on the landing page, so its actual functionality cannot be confirmed from available materials.
Capabilities
Use cases
- —Programmatic access to data analytics, AI inference, finance, or utility endpoints without API key management
- —Agent-driven workflows that need on-demand API calls settled in USDC on Base
- —Prototyping integrations where per-call pricing avoids subscription overhead
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents with Base USDC wallets needing low-friction endpoint access
- —Projects that prefer crypto-native micropayments over traditional billing
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume production workloads where $0.02/request adds up quickly
- —Teams that require SLA guarantees or support contracts
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/148 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page listing, and the specific /api/v1/inbox/148 path does not correspond to any named endpoint on the site. The actual functionality of this endpoint is unknown.
Warnings
- —The endpoint path /api/v1/inbox/148 does not match any of the named endpoints listed on the landing page; its actual functionality is unclear.
- —No OpenAPI spec, request schema, or response schema is available.
- —Documentation pages (/api, /pricing, /README) all resolve to a wallet-connect prompt with no content.
- —No usage examples or error documentation found.
Citations
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —The x402 challenge for /api/v1/inbox/148 requests up to 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, which equals $0.02.https://lowpaymentfee.com/api/v1/inbox/148
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categories.https://lowpaymentfee.com