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/46` 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 broader platform organizes its APIs into 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 listed endpoints are priced 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 technical detail. There is no OpenAPI schema, no request/response examples, and no description of what the `/collections/46` endpoint specifically returns. The endpoint is live (returns a proper 402 x402 challenge), but without documentation it is unclear what data or functionality this particular collection endpoint provides versus the individually named endpoints listed on the homepage.
Capabilities
Use cases
- —Accessing data analytics or AI inference endpoints without subscription commitments
- —Making one-off API calls with crypto micropayments on Base
- —Integrating pay-per-use utility services (geocoding, validation, conversion) into agent workflows
Fit
Best for
- —Developers wanting no-signup, no-API-key access to common utility endpoints
- —AI agents that can settle x402 payments in USDC on Base
- —Users who prefer pay-per-call pricing over monthly subscriptions
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume use cases where per-call pricing may not be cost-effective
- —Developers who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/collections/46 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and no documentation beyond a wallet-connect prompt. The purpose of /collections/46 specifically is undocumented, making this effectively a stub listing.
Warnings
- —No API documentation available — docs, pricing, and README pages only show 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format for /collections/46
- —Purpose of the /collections/46 endpoint is unclear — it may be a bundle or a specific resource but this is not documented
- —No request or response examples available anywhere in the crawled material
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/v1/collections/46
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and no minimumshttps://lowpaymentfee.com
- —The platform offers APIs in four categories: Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/collections/46
- —Docs, pricing, API, and README pages render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs