Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of pay-per-request endpoints across data analytics, AI/ML inference, finance/Web3, and utility services. All endpoints are priced at $0.02 per request, payable in USDC on the Base network with no API keys, rate limits, or subscriptions required.
The specific endpoint at `/api/v1/payments/115` is listed as "Premium API Access" and returns a valid x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0.02 USDC, i.e., $0.02). Payment is settled on-chain to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using the exact payment scheme. The endpoint accepts POST requests and returns `application/json`.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 price point. However, documentation pages (docs, pricing, README) returned only a "Connect wallet" prompt with no substantive technical documentation, so the actual behavior and response schemas of these endpoints remain unverified.
Capabilities
Use cases
- —Accessing premium API functionality with per-call USDC micropayments on Base
- —Agent-driven workflows that need keyless, on-demand API access
- —Testing x402 payment flows against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —AI agents needing keyless pay-per-use API access
- —Users who want to avoid subscriptions and pay only per request
Not for
- —Users who need detailed API documentation or response schemas before integrating
- —High-volume use cases where per-call pricing may add up compared to subscription plans
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/115 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no OpenAPI schema, no documentation of request/response formats, and the docs/pricing/README pages are all empty beyond a wallet connect prompt. The actual functionality behind 'Premium API Access' is unspecified.
Warnings
- —No documentation available — docs, pricing, and README pages all return only 'Connect wallet' with no content.
- —The purpose and response schema of /api/v1/payments/115 ('Premium API Access') is not described anywhere.
- —No OpenAPI spec or input/output schema provided beyond the x402 challenge metadata.
- —The broad catalog of endpoints listed on the homepage is unverified — none were individually probed.
Citations
- —Endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/payments/115
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/payments/115
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com