Pay-per-call API platform on Base via x402 — $0.02/request, no API keys required.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to gate access to a variety of endpoints across data analytics, AI/ML inference, finance/Web3, and utility services. Each call costs $0.02 in USDC on the Base network, with no API keys, rate limits, or subscription commitments required.
The specific endpoint at `/api/v1/payments/152` is listed as "Premium API Access" and accepts POST requests. The x402 challenge confirms it is live, requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02 per request price point. However, documentation pages (docs, pricing, README) returned only a "Connect wallet" prompt with no further technical detail, so the actual request/response schemas for this specific endpoint and the others are unknown.
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 protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that need frictionless, keyless API access on Base
- —Low-volume or sporadic API consumers who prefer pay-per-use over subscriptions
Not for
- —Users who need detailed API documentation or OpenAPI schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Developers without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/152 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, confirming pricing and payment details. However, there is no OpenAPI schema, no documentation beyond a wallet-connect prompt, and no information about what this specific endpoint actually does or what request/response bodies look like. The listing is essentially a stub with confirmed liveness.
Warnings
- —No API documentation available — docs, pricing, and README pages all return only 'Connect wallet' with no technical content.
- —The purpose and input/output schema of /api/v1/payments/152 ('Premium API Access') is completely undocumented; it is unclear what this endpoint actually returns.
- —No OpenAPI spec or request/response examples are provided by the platform.
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC on Base (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913), equaling $0.02.https://lowpaymentfee.com/api/v1/payments/152
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure.https://lowpaymentfee.com