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 on the Base network. The site hosts a collection of pay-per-request APIs spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities, all priced at $0.02 per request paid in USDC (USD Coin) on Base.
The specific endpoint `/api/v1/transactions/289` is listed under the "Premium API Access" description in the x402 challenge. The maxAmountRequired is 20000 base units of USDC (which uses 6 decimals), equating to $0.02 per call. Payment is made via the x402 protocol's X-PAYMENT header — no API keys, no rate limits, and no subscriptions required. The endpoint accepts POST requests and returns application/json responses.
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 — all at the same $0.02/request price point. However, documentation beyond the landing page is essentially empty (pages show only "Connect wallet"), so the actual functionality behind this specific transaction endpoint is unclear.
Capabilities
Use cases
- —Accessing premium data or services with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Testing x402 payment protocol integrations
Fit
Best for
- —Developers experimenting with x402 pay-per-call protocols
- —Agents needing keyless, on-demand API access settled in USDC on Base
- —Low-commitment API usage without subscriptions
Not for
- —Users needing detailed API documentation or guaranteed SLAs
- —High-volume use cases where per-request pricing becomes expensive
- —Users without Base network USDC wallets
Quick start
# POST with x402 payment header (USDC on Base, $0.02/call)
curl -X POST https://lowpaymentfee.com/api/v1/transactions/289 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>"Endpoint
Quality
The x402 challenge is live and confirms pricing and network details, but there is no documentation, no OpenAPI schema, no example requests/responses, and the actual functionality of this specific endpoint (/api/v1/transactions/289) is entirely unclear. The docs, API, pricing, and README pages all render only 'Connect wallet' with no useful content.
Warnings
- —No documentation available — all doc pages show only 'Connect wallet'
- —Actual functionality of /api/v1/transactions/289 is unknown; 'Premium API Access' is the only description
- —No OpenAPI schema or example payloads available
- —Cannot verify what data or service is returned after payment
Citations
- —Endpoint returns 402 with x402 challenge requiring 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/transactions/289
- —Site advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transactions/289