Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. It is one of many endpoints offered by the lowpaymentfee.com platform, which hosts a collection of pay-per-request APIs spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. All endpoints are priced at $0.02 per request, settled in USDC on the Base network, with no API keys, rate limits, or commitments required.
The specific endpoint `/api/v1/payments/91` is labeled "Premium API Access" in the x402 challenge but lacks further documentation about what data or functionality it returns. The x402 challenge confirms it is live, accepts POST requests, and charges a maximum of 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) per call. Payment is made to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` on Base.
The platform's documentation pages (docs, pricing, README) all resolve but contain only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema documentation, and no examples of what this particular endpoint returns. The broader site lists 16 endpoints across four categories, but the `/api/v1/payments/91` path does not correspond to any of the publicly listed endpoints, making its actual functionality unclear.
Capabilities
Use cases
- —Accessing a premium API endpoint with per-request USDC micropayments on Base
- —Integrating x402 payment-gated API calls into agent workflows
- —Testing x402 protocol integrations with low-cost endpoints
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing pay-per-call API access without API keys
- —Low-cost per-request API consumption on Base
Not for
- —Users needing detailed API documentation or schemas before integrating
- —High-volume use cases where per-request pricing may add up
- —Anyone who needs to know exactly what the endpoint returns before paying
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/91 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI spec, no request/response schema, and no explanation of what this specific endpoint actually does. The path '/api/v1/payments/91' does not match any of the publicly listed endpoints on the site. All doc pages are empty beyond a wallet connect prompt.
Warnings
- —No documentation available — all doc/pricing/README pages show only 'Connect wallet'
- —The endpoint path /api/v1/payments/91 does not match any of the 16 publicly listed API endpoints on the site
- —No request or response schema is documented; actual functionality of this endpoint is unknown
- —No OpenAPI spec or ai-plugin manifest found
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/payments/91
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform lists 16 endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Documentation, pricing, and README pages contain only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs