Pay-per-call API suite on Base (USDC) covering data, AI, finance, and utilities at $0.02/request.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad collection of endpoints spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. Every endpoint is priced at $0.02 per request, paid in USDC on the Base network via the x402 protocol. There are no API keys, no rate limits, and no minimum commitments — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/messages/167` is listed as "Premium API Access" but its exact functionality is not documented beyond that label. The wider platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation. All endpoints accept HTTP POST and return `application/json`.
The probed endpoint returned a valid 402 challenge requesting a maximum of 20,000 base units of USDC (0x8335…) on Base, which equals $0.02 (USDC uses 6 decimals). Settlement goes to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` with a 300-second timeout. The x402 version is 1, scheme is "exact". No OpenAPI spec, robots.txt, or agents.txt were found, and the /api, /pricing, and /README pages all returned only a "Connect wallet" prompt with no additional documentation.
Capabilities
Use cases
- —Accessing premium API content with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Testing x402 protocol integrations against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —AI agents that need frictionless, keyless API access
- —Users who want to avoid subscriptions and pay only per call
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/messages/167 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Example
Request
{
"url": "https://lowpaymentfee.com/api/v1/messages/167",
"body": {},
"method": "POST",
"headers": {
"X-PAYMENT": "<x402-payment-token>",
"Content-Type": "application/json"
}
}Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and network. However, there is no OpenAPI spec, no documentation for this specific endpoint's input/output, and the /api, /pricing, and /README pages are empty beyond a wallet-connect prompt. The exact purpose of /api/v1/messages/167 is unknown beyond the generic 'Premium API Access' label.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The specific function of /api/v1/messages/167 is undocumented — 'Premium API Access' is the only description
- —The /pricing, /api, and /README pages returned no useful content (only 'Connect wallet')
- —No example responses are available; output format is unknown
Citations
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The 402 challenge for /api/v1/messages/167 requests maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/messages/167
- —Available API categories include Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com