Pay-per-request API collection on Base via x402 — data, AI, finance, and utility endpoints at $0.02/call.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints accessible via the x402 payment protocol on the Base network. The specific endpoint at `/api/v1/collections/20` is labeled "Premium API Access" and charges up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per request. Payment is settled on-chain with no API keys, no rate limits, and no subscriptions required.
The broader platform advertises four categories of endpoints: 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 listed at the same $0.02/request price point.
Documentation is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no detailed documentation for any endpoint. The `/api/v1/collections/20` endpoint itself is live and returns a valid x402 402 challenge, confirming it accepts POST requests and pays out to address 0x1A2B…85F3. Without documentation, the actual request format and response structure for this or any other endpoint remain unknown.
Capabilities
Use cases
- —Accessing data analytics and reports without subscription commitments
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) on a per-call basis
- —Fetching real-time crypto prices, gas estimates, and exchange rates
- —Performing utility operations like geocoding, validation, and data conversion
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go API access
- —Agents that can settle x402 payments in USDC on Base
- —Use cases requiring low-cost, no-commitment API calls
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume workloads where per-request pricing may add up compared to subscription plans
- —Users without a Base-compatible wallet or USDC holdings
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/collections/20 \
-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, documentation is effectively nonexistent — all doc pages show only 'Connect wallet' with no schema, examples, or endpoint descriptions. The purpose of the specific /collections/20 path is unclear beyond the generic 'Premium API Access' label.
Warnings
- —No API documentation available — docs, pricing, API, and README pages all render only 'Connect wallet'
- —No OpenAPI schema or request/response examples provided for any endpoint
- —The specific purpose and expected input/output of /api/v1/collections/20 is undocumented
- —The broad list of advertised endpoints (AI, finance, data, utils) cannot be verified for functionality
Citations
- —The endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 USDC base units on Basehttps://lowpaymentfee.com/api/v1/collections/20
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform advertises endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC contract address on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 with 6 decimalshttps://lowpaymentfee.com/api/v1/collections/20