Guide · x402

What CORS is and is not, how to read the console error, simple versus preflighted reque…

What CORS is and is not, how to read the console error, simple versus preflighted requests, the headers a server must return (Allow-Origin, Methods, Headers, Credentials), common mistakes with wildcards, redirects and proxies, and when a dev proxy is the righ…

by Saylor Innovations Knowledge Base · verified provider · updated 2026-10-21

30d calls—

30d payers—

MethodGET

Outputjson

What it does

Capabilities

Fix Browser CORS Errors Step by Step - a 6-minute technical guide

Use it when

Use when an agent needs live, structured data or analysis that should be fetched at request time instead of guessed by a model.

Don't use it when

Do not use for investment, medical, legal, or safety-critical decisions without independent verification.

Tags: web & domains · beginner · cors · http · browser · headers · api · x402 · pay-per-request · no-api-key · agent-readable

Call contract

Method: GET
Input: HTTP request
Output: json

No input exampleProvider did not publish one in Bazaar metadata.

Output example

{
  "success": true,
  "data": {},
  "source": "Saylor Innovations"
}

Use with an agent

Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
Inspect. Fetch /resources/cors-error-debugging.json for the price and payment options.
Pay. Call GET https://saylorinnovations.com/api/kb/cors-error-debugging. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC or USDT on Solana, Base, Polygon, Arbitrum One, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price: $0.01 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Solana, Base, Polygon, Arbitrum One

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Solana solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp	USDC	$0.01	7LSjfrJf8fNsB8VA9u7N3WEn25smQLpob3SvyUvXacy7	120s
exact	Solana solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp	USDT	$0.01	7LSjfrJf8fNsB8VA9u7N3WEn25smQLpob3SvyUvXacy7	120s
exact	Base eip155:8453	USDC	$0.01	0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa	120s
exact	Polygon eip155:137	USDC	$0.01	0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa	120s
exact	Arbitrum One eip155:42161	USDC	$0.01	0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa	120s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "payTo": "7LSjfrJf8fNsB8VA9u7N3WEn25smQLpob3SvyUvXacy7",
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "amount": "10000",
    "amountUsd": 0.01,
    "maxTimeoutSeconds": 120
  },
  {
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "payTo": "7LSjfrJf8fNsB8VA9u7N3WEn25smQLpob3SvyUvXacy7",
    "asset": "Es9vMFrzaCERmJfrF4H2FYD4KCoNkY11McCe8BenwNYB",
    "amount": "10000",
    "amountUsd": 0.01,
    "maxTimeoutSeconds": 120
  },
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "10000",
    "amountUsd": 0.01,
    "maxTimeoutSeconds": 120
  },
  {
    "scheme": "exact",
    "network": "eip155:137",
    "payTo": "0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa",
    "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
    "amount": "10000",
    "amountUsd": 0.01,
    "maxTimeoutSeconds": 120
  },
  {
    "scheme": "exact",
    "network": "eip155:42161",
    "payTo": "0xA2A8dF0f7CaaBEa4e120a2568118f141569fc8aa",
    "asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
    "amount": "10000",
    "amountUsd": 0.01,
    "maxTimeoutSeconds": 120
  }
]

Schemas

Output schema (JSON Schema)

{
  "type": "object",
  "additionalProperties": true,
  "properties": {
    "success": {
      "type": "boolean"
    },
    "data": {
      "type": "object",
      "additionalProperties": true,
      "properties": {}
    },
    "source": {
      "type": "string"
    }
  },
  "examples": [
    {
      "success": true,
      "data": {},
      "source": "Saylor Innovations"
    }
  ]
}

Example shape — generated from the schema, not a captured live response

{
  "success": true,
  "data": {},
  "source": "Saylor Innovations"
}

Examples

curl

curl -X GET 'https://saylorinnovations.com/api/kb/cors-error-debugging'
# -> 402 Payment Required; read PAYMENT-REQUIRED
# retry the identical request with PAYMENT-SIGNATURE

JavaScript

const res = await fetch("https://saylorinnovations.com/api/kb/cors-error-debugging", {
  "method": "GET"
});
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

Python

import httpx
res = httpx.request("GET", "https://saylorinnovations.com/api/kb/cors-error-debugging")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Details

Provider: Saylor Innovations Knowledge Base
Endpoint: https://saylorinnovations.com/api/kb/cors-error-debugging
Side effects: none; read-only GET endpoint after x402 payment
License: LicenseRef-Saylor-Agent-Use-1.0
Repository: https://github.com/SaylorInnovations/solana-x402
Machine-readable: /resources/cors-error-debugging.json