Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. The specific resource `/api/v1/messages/174` accepts POST requests and charges up to 20,000 base units of USDC (0x8335…2913) on the Base network, which equals $0.02 per request (USDC uses 6 decimals). Payment is handled entirely through the x402 header mechanism — no API keys, accounts, or rate limits are required.
The broader lowpaymentfee.com platform advertises a suite of pay-per-call APIs across four categories: 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 listed at $0.02 per request. However, this specific listing is for `/api/v1/messages/174`, whose exact functionality is labeled only as "Premium API Access" — it does not appear in the site's published API catalog, so its precise behavior is unclear.
The endpoint is live and returns a valid x402 challenge with a 300-second payment timeout. No OpenAPI schema, request/response examples, or detailed documentation were found during crawling. The site's docs, pricing, and README pages all resolve to a minimal "Connect wallet" prompt with no additional content.
Capabilities
Use cases
- —Programmatic access to a premium API resource without needing an API key or account
- —Agent-driven workflows that pay per call using USDC on Base
- —Testing x402 payment flows against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment-gated APIs
- —AI agents that need keyless, pay-as-you-go API access
- —Crypto-native applications settling microtransactions on Base
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —Applications requiring free or subscription-based pricing models
- —Use cases needing a well-documented, specific API contract (the exact behavior of this endpoint is undocumented)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/messages/174 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, but there is no OpenAPI schema, no request/response documentation, and the specific resource '/api/v1/messages/174' is not listed in the site's own API catalog. Its actual functionality is unknown beyond the generic label 'Premium API Access'. Docs pages returned only 'Connect wallet' with no content.
Warnings
- —The endpoint /api/v1/messages/174 does not appear in the provider's own published API catalog — its exact functionality is unknown.
- —No OpenAPI spec, request schema, or response schema is available.
- —Documentation pages (/pricing, /README, /api) returned no useful content beyond a 'Connect wallet' prompt.
- —The provider's catalog lists many endpoints but none match this specific path, raising questions about what this resource actually does.
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/messages/174
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/messages/174
- —The site advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The site lists APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com