Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. Every endpoint is priced at $0.02 per request, paid in USDC on the Base network with no API keys, no rate limits, and no upfront commitments. The x402 protocol handles payment inline: callers attach a payment header to each HTTP request, and the server fulfills the call once payment is verified.
The specific endpoint at `/api/v1/transfers/115` is listed as "Premium API Access." Its x402 challenge confirms it accepts POST requests, settles in USDC (contract 0x8335…2913) on Base, and requires a maximum of 20,000 base units (i.e., $0.02 given USDC's 6 decimals). The payment timeout is 300 seconds. No detailed documentation for this particular endpoint's request or response schema was found in the crawl — the docs, pricing, and README pages all returned only a "Connect wallet" stub with no further content.
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 price point. However, without accessible documentation or OpenAPI specs, the exact input/output contracts for any of these endpoints remain unknown.
Capabilities
Use cases
- —Programmatic access to utility or data endpoints without managing API keys or subscriptions
- —Agent-driven workflows that need on-demand API calls settled in USDC on Base
- —Exploring x402 protocol integration for pay-per-request architectures
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that need keyless, pay-as-you-go API access on Base
- —Low-volume consumers who want no subscription overhead
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-throughput production workloads requiring well-documented, battle-tested endpoints
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transfers/115 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing. However, there is no OpenAPI spec, no documentation beyond a landing page listing, no request/response schema, and no examples. The docs/pricing/README pages are all empty stubs. The specific purpose of '/api/v1/transfers/115' is unclear beyond the generic label 'Premium API Access.'
Warnings
- —No OpenAPI or schema documentation available — request and response formats are unknown
- —Docs, pricing, and README pages all return only a 'Connect wallet' stub with no content
- —The specific function of /api/v1/transfers/115 is undocumented; 'Premium API Access' is a generic label
- —The platform lists many endpoint categories but none have publicly accessible documentation
Citations
- —Endpoint returns HTTP 402 with x402 challenge requiring 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/transfers/115
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transfers/115