Pay-per-call API platform on Base (USDC) offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that provides a broad collection of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and general utility services. All endpoints are paid per-request using USDC on the Base network via the x402 protocol — no API keys, no rate limits, and no subscriptions required.
The specific endpoint at `/api/v1/keys/91` is listed as "Premium API Access" and accepts POST requests. Its x402 challenge advertises a maximum cost of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per request (USDC uses 6 decimals). The platform's landing page confirms a flat $0.02/request pricing model across all listed endpoints.
The broader platform advertises endpoints for metrics, reports, data export, insights, sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation. However, no OpenAPI schema, detailed documentation, or example request/response payloads were found during the crawl — the /api, /pricing, and /README pages all returned only a "Connect wallet" prompt with no substantive content. The actual behavior and input/output formats of this specific endpoint remain unclear.
Capabilities
Use cases
- —Agents needing on-demand API access without managing API keys or subscriptions
- —Programmatic access to data, AI, or utility endpoints with crypto micropayments
- —Testing x402 payment flows on Base with low-cost endpoints
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents with USDC on Base that need diverse utility endpoints
- —Prototyping x402-based payment integrations
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume production workloads where $0.02/request adds up significantly
- —Users without USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/keys/91 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"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, no example requests or responses, and the purpose of this specific endpoint (/api/v1/keys/91 — 'Premium API Access') is ambiguous. The crawled pages beyond the landing page returned no useful content.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The /api, /pricing, and /README pages returned no content beyond 'Connect wallet'
- —The specific purpose and input/output format of /api/v1/keys/91 is unclear — 'Premium API Access' is vague
- —No example requests or responses are available to verify actual functionality
Citations
- —The platform advertises $0.02/request flat pricing with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —The x402 challenge for /api/v1/keys/91 specifies maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/keys/91
- —The platform lists endpoints across data/analytics, AI/ML, finance/Web3, and infrastructure categorieshttps://lowpaymentfee.com