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/2` is labeled "Premium API Access" and accepts POST requests, settling payments in USDC (contract 0x8335…2913) on Base. The x402 challenge advertises a maxAmountRequired of 20,000 base units, which at 6 decimals for USDC equals $0.02 per request.
The provider's landing page lists 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 $0.02 per request with no API keys, no rate limits, and no minimum commitments required.
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/2` endpoint likely serves as a bundled or collection-level access point, but its exact input parameters and response format are unknown from the available material.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time financial data like token quotes, gas estimates, and exchange rates on a per-call basis
- —Running data analytics queries and exporting data with instant crypto-settled micropayments
- —Using utility services like geocoding, validation, and conversion without subscription commitments
Fit
Best for
- —Agents or developers who want keyless, pay-as-you-go API access settled in USDC on Base
- —Low-volume or bursty workloads where per-request pricing avoids subscription overhead
- —x402-compatible AI agents that can autonomously pay for API calls
Not for
- —High-volume production workloads needing SLAs, rate limit guarantees, or detailed documentation
- —Users who need fiat billing or cannot transact in USDC on the Base network
- —Developers requiring well-documented request/response schemas before integration
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/collections/2 \
-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 all documentation pages are empty beyond a wallet-connect prompt. The exact functionality of the /collections/2 endpoint is undocumented.
Warnings
- —No OpenAPI or schema documentation available — request/response formats are unknown
- —All doc pages (/docs, /api, /pricing, /README) render only 'Connect wallet' with no content
- —The specific purpose and input format of /api/v1/collections/2 is not documented
- —No rate limit or SLA information provided
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/v1/collections/2
- —All endpoints are listed at $0.02 per request with no API keys, no rate limits, and no minimumshttps://lowpaymentfee.com
- —Four categories of APIs are offered: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —Documentation pages render only a Connect wallet prompt with no further contenthttps://lowpaymentfee.com/docs