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/11` 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 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/11` endpoint specifically returns. The endpoint is live (returns a valid 402 challenge), but without documentation it is unclear what data or functionality this particular collection endpoint provides.
Capabilities
Use cases
- —Accessing premium data or analytics without subscription commitments
- —Making one-off API calls settled instantly in USDC on Base
- —Agent-driven workflows that need keyless, pay-per-request API access
Fit
Best for
- —Developers who want zero-commitment, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously on Base
- —Users who prefer crypto-native billing without API key management
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/collections/11 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, documentation is effectively nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI schema, no request/response examples, and no description of what /collections/11 actually returns. The listing is essentially a stub with confirmed liveness.
Warnings
- —No documentation available — all doc/pricing/README pages render only 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format for /collections/11
- —Unknown what data or functionality the /collections/11 endpoint actually provides
- —The broader platform lists many endpoints but none have documented schemas or examples
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 in USDC on Base networkhttps://lowpaymentfee.com/api/v1/collections/11
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints in Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/collections/11