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 set 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 at `/api/v1/inbox/200` is listed as "Premium API Access." Its x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (0x8335… on Base), which equals $0.02 given USDC's 6 decimals. Payment is made per-call via the x402 exact scheme with no API keys, no rate limits, and no upfront commitments required. The endpoint accepts HTTP POST requests and returns application/json.
Documentation beyond the landing page is sparse — the /api, /pricing, and /README routes all resolve to a wallet-connect prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema, and no usage examples available from the crawled material. The exact functionality of the `/api/v1/inbox/200` path is unclear; it does not map to any of the named endpoints on the landing page. Agents should treat this as a live but under-documented endpoint.
Capabilities
Use cases
- —Agents needing on-demand API access without pre-registration or API keys
- —Programmatic pay-per-call access to data, AI, finance, or utility services
- —Testing x402 payment flows on Base with low-cost endpoints
Fit
Best for
- —AI agents that settle payments in USDC on Base
- —Developers exploring x402 protocol integrations
- —Low-volume, no-commitment API consumption at $0.02/call
Not for
- —High-volume workloads where per-call pricing becomes expensive compared to subscription plans
- —Users who need detailed API documentation or guaranteed SLAs before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/200 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Example
Request
{}Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page, and the specific /api/v1/inbox/200 path is not described among the listed endpoints. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available
- —The /api/v1/inbox/200 path does not correspond to any named endpoint on the provider's landing page — its actual functionality is unknown
- —All documentation pages (/api, /pricing, /README) return only a wallet-connect prompt with no content
- —No request body schema or response examples are available
Citations
- —All endpoints priced at $0.02 per request with no minimums or commitmentshttps://lowpaymentfee.com
- —Payment settled in USDC on Base network via x402 protocolhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/inbox/200
- —No API keys, no rate limits, instant access advertisedhttps://lowpaymentfee.com
- —Endpoint categories include Data & Analytics, AI & ML, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com