> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bundleup.io/llms.txt
> Use this file to discover all available pages before exploring further.

# API Authorization

All requests to the BundleUp Proxy, MCP, Unfied API must be explicitly authorized. Authorization is **connection-scoped** and enforced on every request before it reaches the upstream API.

### **1. API key (Bearer token)**

Used to authenticate the workspace making the request.

```
Authorization: Bearer <YOUR_API_KEY>
```

* Identifies your workspace
* Used for billing, rate limiting, and access control
* Must be kept secret

### **2. Connection identifier**

Used to select **which external account** the request is executed against.

```
BU-Connection-Id: <CONNECTION_ID>
```

* Scopes the request to a single connection
* Determines which OAuth tokens / credentials are used
* Enforces per-connection rate limits
* Required for all proxy requests

### **How authorization works**

When a request hits the proxy, BundleUp:

1. Validates the **API key**
2. Verifies the key has access to the specified connection
3. Loads credentials associated with the connection
4. Enforces rate limits and retries
5. Proxies the request to the upstream API

If any step fails, the request is rejected before contacting the upstream.

<RequestExample>
  ```shellscript cURL theme={null}
  curl https://proxy.bundleup.io/conversations.list \
    -H "Authorization: Bearer sk_live_123" \
    -H "BU-Connection-Id: conn_abc123"
  ```

  ```typescript JavaScript theme={null}
  const client = new BundleUp('sk_live_123');
  const proxy = client.proxy('conn_abc123');
  const response = await proxy.get('/conversations.list');
  ```

  ```python Python theme={null}
  client = BundleUp('sk_live_123')
  proxy = client.proxy('conn_abc123')
  response = proxy.get('/conversations.list')
  ```

  ```ruby Ruby theme={null}
  client = BundleUp::Client.new('sk_live_123')
  proxy = client.proxy('conn_abc123')
  response = proxy.get('/conversations.list')
  ```
</RequestExample>