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/164` is listed as "Premium API Access" and costs $0.02 per call (20,000 base units of USDC with 6 decimals). No API keys, accounts, or rate limits are required — callers simply attach an x402 payment header with each request.
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. Payments settle in USDC on Base to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3`.
Note that the specific functionality behind the `/api/v1/transfers/164` endpoint is unclear — the description simply says "Premium API Access" with no further documentation on what data or service it returns. The docs, pricing, and README pages on the site all render only a "Connect wallet" prompt with no substantive content. Without documentation or example responses, the actual behavior of this endpoint is unknown.
Capabilities
Use cases
- —Accessing premium API services with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, instant API access
- —Testing x402 protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers or agents wanting no-signup, pay-as-you-go API access
- —x402 protocol experimentation on Base network
- —Low-cost per-call API consumption without subscriptions
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —Use cases requiring known, well-documented response schemas
- —Anyone without USDC on Base network
Quick start
# The endpoint requires an x402 payment header (USDC on Base).
# 1. Probe for the 402 challenge:
curl -X POST https://lowpaymentfee.com/api/v1/transfers/164
# 2. Parse the 402 JSON, construct the X-PAYMENT header per x402 spec,
# then re-send with payment attached:
curl -X POST https://lowpaymentfee.com/api/v1/transfers/164 \
-H "X-PAYMENT: <signed-payment-payload>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (returns a valid 402 challenge) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no example requests or responses, and the actual functionality of this specific endpoint is completely undocumented. The docs/pricing/README pages are all blank beyond a wallet-connect prompt.
Warnings
- —The specific functionality of /api/v1/transfers/164 is undocumented — 'Premium API Access' is the only description available.
- —All documentation pages (docs, pricing, README) render only a 'Connect wallet' prompt with no substantive content.
- —No OpenAPI spec, request schema, or response schema is available.
- —The broader platform lists many API categories (AI, finance, analytics, etc.) but none have documented schemas or example responses.
Citations
- —Endpoint returns 402 with x402 challenge requiring 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/transfers/164
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/transfers/164
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Multiple API categories listed: Data & Analytics, AI & ML, Finance & Web3, Infrastructurehttps://lowpaymentfee.com
- —Docs, pricing, and README pages show only 'Connect wallet' with no documentation contenthttps://lowpaymentfee.com/docs