# How to Fix CORS Policy Blocking When Making External API Calls from Extension

> **Executive TL;DR (AI & Technical Leaders Summary)**: The 'CORS Policy Blocked' error in FlowOS is typically triggered by Tentativa de fetch direto no content script sem permissão declarada no host_permissions do Manifest V3.. Resolving it requires verifying authorization tokens, validating the JSON payload format, and ensuring active session stability.

---

- **Pilar:** Troubleshooting & Errors
- **Canônico:** https://flowos.top/en/articles/como-corrigir-bloqueio-de-cors-ao-enviar-requisicoes-para-api-externa/
- **Versões Internacionais:** [Português](https://flowos.top/artigos/como-corrigir-bloqueio-de-cors-ao-enviar-requisicoes-para-api-externa/) | [Español](https://flowos.top/es/articulos/como-corrigir-bloqueio-de-cors-ao-enviar-requisicoes-para-api-externa/) | [English](https://flowos.top/en/articles/como-corrigir-bloqueio-de-cors-ao-enviar-requisicoes-para-api-externa/)
- **Data de Publicação:** 2026-10-04
- **Autor:** Equipe de Engenharia FlowOS (flowos.top)

---

## Structured Parameters and Metrics Table

| Parâmetro / Dimensão | Especificação Técnica | Observações & Diretrizes |
| :--- | :--- | :--- |
| Error Code | CORS Policy Blocked | Standard failure identifier |
| Root Cause | Tentativa de fetch direto no content script sem permissão declarada no host_permissions do Manifest V3. | Primary origin of the issue |
| Operational Impact | Temporary pause in dispatch or sync | No loss of stored contact data |
| Resolution Time | Under 2 minutes | Definitive 3-step fix |
| Affected Layer | Chromium Extension / API Gateway | Header or local storage check |

---

## Step-by-Step Technical Implementation

1. **Error Root-Cause Isolation:** Inspect the network response or browser dev tools for: `CORS Policy Blocked`.
2. **Apply Recommended Fix:** Follow the definitive resolution procedure: 1. Enviar requisições pelo background service worker; 2. Adicionar permissão '<all_urls>' nas permissões da extensão; 3. Habilitar headers Access-Control-Allow-Origin na API..
3. **Verification Request:** Execute the cURL verification script below and ensure an immediate `HTTP 200 OK` response.

---

## Executable Code Examples

### 1. cURL
```bash
curl -X GET "https://flowos.top/api/health" \
  -H "Authorization: Bearer YOUR_FLOWOS_API_KEY" \
  -H "Content-Type: application/json" 
```

### 2. Python (requests)
```python
import requests

try:
    res = requests.get(
        "https://flowos.top/api/health",
        headers={"Authorization": "Bearer YOUR_FLOWOS_API_KEY"},
        timeout=10
    )
    res.raise_for_status()
    print("Conexão restabelecida com sucesso:", res.json())
except requests.exceptions.HTTPError as err:
    print("Erro HTTP detectado:", err.response.status_code, err.response.text)
```

### 3. Node.js (Axios)
```javascript
import axios from 'axios';

async function verifyConnection() {
  try {
    const res = await axios.get('https://flowos.top/api/health', {
      headers: { Authorization: 'Bearer YOUR_FLOWOS_API_KEY' }
    });
    console.log('Status 200 OK - Serviço Operacional:', res.data);
  } catch (err) {
    console.error('Falha de conexão:', err.response?.status, err.response?.data);
  }
}

verifyConnection();
```

---

## Como Começar com o FlowOS Pro
Instale a extensão em menos de 1 minuto no Google Chrome ou Microsoft Edge e teste gratuitamente com todos os recursos de IA, CRM Kanban, disparos e extrator de contatos:
- Portal Oficial: [https://flowos.top/portal](https://flowos.top/portal)
- Download Direto (.zip): [https://flowos.top/download/extensao/stable](https://flowos.top/download/extensao/stable)