Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to accept USDC payments on the Base network. The specific endpoint `/api/v1/transfers/137` is listed as "Premium API Access" and returns a 402 challenge requiring payment of up to 20,000 base units of USDC (i.e., $0.02) per call. No API keys or rate limits are required; callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader platform advertises multiple API categories including Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are priced at $0.02 per request.
However, the specific functionality of the `/api/v1/transfers/137` endpoint is unclear. The path suggests a transfer or transaction-related operation, but no documentation, request schema, or response schema is available beyond the generic "Premium API Access" label. The docs, pricing, and API pages all returned only a "Connect wallet" prompt with no further content. Without concrete documentation on what this endpoint accepts or returns, callers should treat this as an exploratory integration.
Capabilities
Use cases
- —Programmatic access to premium API services paid per-call with USDC 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
- —AI agents that need frictionless pay-per-use API access without signup
- —Applications already operating on the Base L2 network with USDC
Not for
- —Users who need detailed API documentation and guaranteed SLAs before integrating
- —High-volume use cases where per-request pricing at $0.02 may add up significantly
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transfers/137 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Endpoint
Quality
The endpoint is live (returns a valid 402 x402 challenge), but there is no documentation, no request/response schema, and no explanation of what /api/v1/transfers/137 actually does. The docs pages are empty beyond a wallet-connect prompt. This is effectively a stub listing.
Warnings
- —No documentation available — docs, pricing, API, and README pages all return only 'Connect wallet' with no content.
- —The specific functionality of /api/v1/transfers/137 is unknown; the path implies a transfer operation but no schema or description is provided.
- —No OpenAPI spec, no request body schema, and no response schema are available.
- —No examples of successful responses exist in the crawl material.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/transfers/137
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transfers/137
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com