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/75` is listed as "Premium API Access" and costs up to $0.02 per request (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 endpoint 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 listed endpoints share the same $0.02/request pricing with no rate limits or minimum commitments.
The specific `/api/v1/inbox/75` endpoint does not clearly map to any of the named categories on the landing page, and no documentation, OpenAPI schema, or example payloads are available. The endpoint accepts POST requests and returns `application/json`. Without further documentation it is unclear what input this particular endpoint expects or what data it returns.
Capabilities
Use cases
- —Accessing data analytics and reporting endpoints without subscription commitments
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) on a per-call basis
- —Fetching real-time financial data such as crypto quotes, gas estimates, and exchange rates
- —Using utility services like geocoding, validation, and data conversion
Fit
Best for
- —Developers wanting zero-signup, pay-per-use API access
- —AI agents that can settle payments via x402 on Base
- —Projects needing low-cost micropayment-gated endpoints
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/75 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no documentation, no example request/response, and the specific purpose of /api/v1/inbox/75 is undocumented. The landing page lists many endpoints but provides no detail on inputs or outputs for any of them.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The specific endpoint /api/v1/inbox/75 does not appear in the site's listed API catalog — its purpose is unknown
- —No example requests or responses are documented anywhere on the site
- —The /api, /pricing, and /README pages all returned only a 'Connect wallet' prompt with no useful content
Citations
- —The endpoint returns a 402 challenge requesting USDC payment on Base network with maxAmountRequired of 20000 base unitshttps://lowpaymentfee.com/api/v1/inbox/75
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/inbox/75
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Four endpoint categories listed: Data & Analytics, AI & Machine Learning, Finance & Web3, Infrastructurehttps://lowpaymentfee.com