Pay-per-request API collection on Base via x402 — $0.02/call in USDC, no API keys required.
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/12` 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 offers 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 listed at $0.02 per request with no API keys, no rate limits, and no minimum commitments.
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 spec, no request/response schema documentation, and no usage examples available from the crawled content. The endpoint at `/api/v1/collections/12` appears to be a collection-level resource, but its exact input parameters and response format are unknown.
Capabilities
Use cases
- —Accessing a bundled collection of API services with a single per-request USDC micropayment
- —Agent-driven API consumption without pre-registration or API key management
- —Programmatic access to data, AI, finance, or utility endpoints on a pay-as-you-go basis
Fit
Best for
- —Developers wanting zero-signup, pay-per-use API access
- —AI agents that can settle x402 payments on Base in USDC
- —Users who need low-cost micropayment API calls without rate limits
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Anyone without a Base-compatible USDC wallet or x402 client
- —High-volume production workloads requiring well-documented, stable schemas
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/collections/12 \
-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 with clear pricing ($0.02 USDC on Base). However, documentation is essentially nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, no examples, and the purpose of the /collections/12 endpoint specifically is unclear beyond its generic 'Premium API Access' label.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages all render only 'Connect wallet'
- —No OpenAPI or schema definition found for any endpoint
- —The specific purpose and expected input/output of /api/v1/collections/12 is undocumented
- —Cannot verify what data or functionality is actually returned by this endpoint
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/v1/collections/12
- —All endpoints are listed at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC contract address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/collections/12