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/wire/137` is listed as "Premium API Access" and returns a standard x402 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02 given USDC's 6 decimals) 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 uniformly priced at $0.02 per request. However, the specific endpoint being listed here (`/api/v1/wire/137`) is labeled generically as "Premium API Access" and does not appear in the site's public API directory, so its exact functionality is unclear.
The endpoint accepts POST requests, settles payments to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC (`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) on Base, and has a payment timeout of 300 seconds. Documentation beyond the landing page is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional content.
Capabilities
Use cases
- —Programmatic access to a paid API endpoint without traditional API key registration
- —Agent-driven workflows that need to pay per call using on-chain USDC on Base
- —Testing x402 protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —AI agents that can autonomously pay for API calls via crypto
- —Users who want no-signup, no-rate-limit API access
Not for
- —Users who need detailed API documentation or schemas before integrating
- —Anyone without access to USDC on the Base network
- —High-volume use cases where $0.02/request adds up significantly
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/wire/137 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Endpoint
Quality
The endpoint is live (returns a valid x402 402 challenge), but there is no documentation, no OpenAPI schema, no example request/response, and the specific functionality of /api/v1/wire/137 is unknown. The docs/pricing/README pages are all blank beyond a wallet connect prompt. This is effectively a stub listing.
Warnings
- —The specific endpoint /api/v1/wire/137 does not appear in the site's public API directory — its actual functionality is unknown.
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no usable content.
- —No OpenAPI schema, no request/response examples, and no description of what this endpoint returns.
- —The platform lists many API categories but provides no technical documentation for any of them.
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/wire/137
- —All endpoints are uniformly priced at $0.02 per request with no API keys, no rate limitshttps://lowpaymentfee.com
- —USDC contract address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/wire/137
- —Platform advertises Data & Analytics, AI & ML, Finance & Web3, and Infrastructure API categorieshttps://lowpaymentfee.com