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/5` is labeled "Premium API Access" and accepts payment in USDC (contract 0x8335…2913 on Base). The maximum amount required per call is 20,000 base units of USDC, which at 6 decimals equals $0.02 per request.
The broader platform advertises four categories of APIs: 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. The platform emphasizes no API keys, no rate limits, no minimums, and instant access.
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/5` endpoint returned a valid 402 challenge confirming it is live, but what data it actually returns upon successful payment is unknown from the available material.
Capabilities
Use cases
- —Accessing data analytics and reports on a per-request payment basis without API keys
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) with micropayments
- —Fetching crypto price feeds, exchange rates, gas estimates via pay-per-use
- —Geocoding and data conversion utilities without subscription commitments
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —Agents that can settle x402 payments in USDC on Base
- —Use cases requiring occasional API calls without subscription overhead
Not for
- —High-volume production workloads where per-request pricing adds up quickly
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/collections/5 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (valid 402 challenge captured) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and all documentation pages are empty beyond a wallet-connect prompt. The actual functionality behind '/api/v1/collections/5' is undocumented, making this effectively a stub listing.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema definition for any endpoint
- —The actual data returned by /api/v1/collections/5 upon successful payment is completely unknown
- —No request body schema or response examples available anywhere in crawled material
- —Platform lists many endpoints but none have documented input/output contracts
Citations
- —The endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/collections/5
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/collections/5
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com