Pay-per-call API platform on Base offering data, AI, finance, and utility endpoints at $0.02 each via x402.
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, paid in USDC on the Base network with no API keys, no rate limits, and no minimum commitments.
The specific endpoint listed here (`/api/internal/users`) is described in the x402 challenge as "Premium API Access" and accepts POST requests. 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 via the x402 exact scheme, settling to the provider's wallet on Base. The challenge specifies a 300-second timeout and returns application/json.
Note that while the landing page documents 16 public-facing API endpoints across the four categories above, this particular `/api/internal/users` path is not listed among them. It may be an internal or administrative endpoint. Documentation beyond the landing page is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available.
Capabilities
Use cases
- —Agent-driven data retrieval with per-call USDC micropayments
- —On-demand AI inference (sentiment, summarization, classification) without API key management
- —Fetching real-time crypto gas estimates and token quotes programmatically
- —Geocoding and data validation as utility microservices
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go API access
- —AI agents that can settle x402 payments on Base
- —Projects needing low-cost micropayment-gated endpoints
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-throughput production workloads requiring SLA guarantees
- —Users without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/internal/users \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02/request in USDC on Base). However, this specific endpoint (/api/internal/users) is not documented on the landing page, there is no OpenAPI spec, no request/response schema, and all documentation pages render only 'Connect wallet' with no content. The endpoint's actual functionality is unknown.
Warnings
- —The endpoint /api/internal/users is not listed among the provider's publicly documented APIs — it may be internal or undocumented.
- —All documentation pages (docs, API, pricing, README) return only a 'Connect wallet' prompt with no substantive content.
- —No OpenAPI spec, request schema, or response schema is available for this endpoint.
- —No examples of request or response payloads could be found.
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —16 endpoints listed across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/internal/users
- —Payment settles to wallet 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with 300-second timeouthttps://lowpaymentfee.com/api/internal/users