Index onlineMerchant portal
Api Endpoint

CORS Header Checker

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.

Open interactive test console

Offering

Provider
cors-header-checker.underscoredone.com
Method
POST
Offering type
Api Endpoint
Transport type
http
Category
Development
Delivery
Not provided
Pricing model
Not provided
x402 version
2

Endpoint context

URL
https://cors-header-checker.underscoredone.com/check
MIME type
application/json
First seen
2026-10-16T01:50:10.647Z
Last seen
Tags
cors headers, CORS, cross origin, access-control-allow-origin, cors policy

Website

Payment pricing

x402 payment terms are the authoritative price for calling this endpoint.

Payment option 1
0.01 USDC
Atomic price: 10000 · Network: eip155:8453 · Asset: USDC · Scheme: exact
Payment option 2
0.01 USDC
Atomic price: 10000 · Network: solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp · Asset: USDC · Scheme: exact
Raw x402 terms
[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "10000",
    "payTo": "0xE9740820225B3918b4ddd1292C7cA4Ca0e2C2F08"
  },
  {
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "amount": "10000",
    "payTo": "8ugAWAXDB8V18kiUrGZTq1oMvU3C6Fxs8hfC6rvzQT3b"
  }
]

Observed health

Status
Reachable
Latest latency
54 ms
Average latency
98 ms
HTTP status
405
Last checked
Reachability
100% over 8 checks

Latency is measured to the first response headers. A reachable result does not verify response accuracy or merchant identity.

Input schema

{
  "type": "object",
  "properties": {
    "type": {
      "type": "string",
      "const": "http"
    },
    "method": {
      "type": "string",
      "enum": [
        "POST",
        "PUT",
        "PATCH"
      ]
    },
    "bodyType": {
      "type": "string",
      "enum": [
        "json",
        "form-data",
        "text"
      ]
    },
    "body": {
      "type": "object",
      "properties": {
        "url": {
          "type": "string",
          "description": "The full web address of the endpoint you want to check — must start with http:// or https://."
        },
        "origin": {
          "type": "string",
          "description": "The website address you want to test cross-origin access from, for example https://myapp.com. Defaults to https://example.com if you leave it out."
        }
      },
      "required": [
        "url"
      ],
      "additionalProperties": false
    }
  },
  "required": [
    "type",
    "method",
    "bodyType",
    "body"
  ],
  "additionalProperties": false
}

Output schema

{
  "type": "object",
  "properties": {
    "type": {
      "type": "string"
    },
    "example": {
      "type": "object",
      "properties": {
        "api_version": {
          "type": "string"
        },
        "url": {
          "type": "string"
        },
        "origin_tested": {
          "type": "string"
        },
        "status": {
          "type": "integer"
        },
        "cors_enabled": {
          "type": "boolean"
        },
        "origin_allowed": {
          "type": "boolean"
        },
        "headers": {
          "type": "object",
          "additionalProperties": true
        },
        "error": {
          "type": "string"
        }
      },
      "required": [
        "api_version",
        "url",
        "origin_tested",
        "status",
        "cors_enabled",
        "origin_allowed",
        "headers",
        "error"
      ]
    }
  },
  "required": [
    "type"
  ]
}