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 pay-per-request endpoints settled in USDC on the Base network. The specific endpoint `/api/v1/inbox/77` 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 wider platform advertises four endpoint families: Data & Analytics (metrics, reports, 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.
Note that the specific functionality behind `/api/v1/inbox/77` is not documented beyond the generic "Premium API Access" label. There is no OpenAPI schema, no request/response examples, and the crawled docs pages (pricing, README, API) all resolve to a minimal "Connect wallet" prompt with no additional detail. Treat this listing as a gateway to the platform's capabilities, but verify the actual behavior of this particular inbox endpoint before relying on it in production.
Capabilities
Use cases
- —Calling AI inference endpoints (sentiment, summarization, classification, embeddings) without managing API keys
- —Fetching real-time financial data such as token quotes, exchange rates, and gas estimates
- —Running utility operations like geocoding, validation, and data conversion on a per-request basis
- —Exporting or querying analytics data and insights on demand
Fit
Best for
- —Agents and bots that need keyless, on-demand API access paid per call
- —Developers prototyping with low-cost, no-commitment endpoints
- —Web3-native applications that can settle payments in USDC on Base
Not for
- —High-volume production workloads that need SLAs, rate guarantees, or dedicated support
- —Users who cannot transact in USDC on the Base network
- —Applications requiring detailed API documentation or guaranteed response schemas
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/inbox/77 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no OpenAPI schema, no request/response examples, and the specific functionality of /api/v1/inbox/77 is undocumented. The crawled docs pages are effectively empty. This is a stub-level listing.
Warnings
- —The specific purpose of /api/v1/inbox/77 ('Premium API Access') is not documented — it is unclear what data or service it returns.
- —No OpenAPI or JSON schema is available for any endpoint on the platform.
- —Documentation pages (/api, /pricing, /README) all resolve to a minimal 'Connect wallet' page with no useful content.
- —The broad catalog of endpoints (AI, finance, data, utils) is advertised on the landing page but none have been individually verified beyond this one inbox endpoint.
Citations
- —The endpoint returns a 402 challenge requesting USDC payment on Base network with maxAmountRequired of 20000 base unitshttps://lowpaymentfee.com/api/v1/inbox/77
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/inbox/77
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Four endpoint categories listed: Data & Analytics, AI & Machine Learning, Finance & Web3, Infrastructurehttps://lowpaymentfee.com