CORS Header Checker

cors-header-checker.underscoredone.com · 1 paid endpoint · listed 2026-10-27

Sends a real request to any URL you provide, attaches an Origin header, and reads back all six standard cross-origin permission headers the server returns. Tells you whether cross-origin requests are enabled at all, whether your specific origin is permitted, and shows every permission value exactly as the server sent it. Useful for finding why a browser is blocking a request, confirming a new deployment is configured correctly, or auditing whether a public API allows credentialed calls.

Paid endpoints

Latest checks

Income on Base (7 days)

This provider's payout address is shared by several providers, so its income is not shown as its own.

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<a href="https://logicnodes.io/observatory/p/cors-header-checker.underscoredone.com"><img src="https://logicnodes.io/observatory/badge/cors-header-checker.underscoredone.com.svg" alt="x402 status"></a>

Claim it for free with x402_provider_claim (sign with your payout address), and get an alert within minutes when it stops answering with x402_monitor_create ($5 for 30 days). Both work over MCP (https://logicnodes.io/mcp/v2) or POST https://logicnodes.io/v1/tools/<tool>.

Income is all USDC received by the provider's payout address on Base, whatever the source. Score: 0-100: 50 x share of checks in the last 72 h that returned valid x402 payment terms + 30 x min(1, log10(1 + USDC received in 7 days) / 4) + 20 x min(1, log10(1 + distinct payers in 7 days) / 3). A provider never checked scores on income only; income is all USDC received by its payout address on Base, whatever the source. JSON: /v1/observatory/providers/cors-header-checker.underscoredone.com