> ## Documentation Index
> Fetch the complete documentation index at: https://langchain-5e9cc07a-preview-docsfl-1776371397-e812a24.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Sandbox auth proxy

> Inject credentials into outbound API requests from sandboxes without hardcoding secrets.

<Warning>
  Sandboxes are in private preview. APIs and features may change as we iterate. [Sign up for the waitlist](https://www.langchain.com/langsmith-sandboxes-waitlist?ref=docs.langchain.com) to get access.
</Warning>

The auth proxy lets sandbox code call external APIs (OpenAI, Anthropic, GitHub, etc.) without hardcoding credentials. When configured on a sandbox, a proxy sidecar automatically injects authentication headers into matching outbound requests using your workspace secrets.

<Warning>
  You must configure your secrets (e.g., `OPENAI_API_KEY`) in your LangSmith [workspace](/langsmith/administration-overview#workspaces) settings before creating a sandbox that references them.
</Warning>

## Configure auth proxy rules

Add a `proxy_config` when creating a sandbox. Each rule specifies:

| Field         | Description                                                |
| ------------- | ---------------------------------------------------------- |
| `match_hosts` | Hosts to intercept (supports globs like `*.github.com`)    |
| `match_paths` | Paths to match (empty = all paths)                         |
| `headers`     | Headers to inject, each with a `name`, `type`, and `value` |
| `no_proxy`    | Hosts to bypass the proxy entirely (e.g. `localhost`)      |

### Header types

Each header has a `type` that controls how its value is stored and displayed:

| Type               | Description                                                                |
| ------------------ | -------------------------------------------------------------------------- |
| `workspace_secret` | References a workspace secret using `{KEY}` syntax. Resolved at push time. |
| `plaintext`        | Value is stored and returned as-is. Use for non-sensitive headers.         |
| `opaque`           | Write-only. Value is encrypted at rest and never returned via the API.     |

## Single API example

Create a sandbox that automatically injects an OpenAI API key into outbound requests:

```bash theme={null}
curl -X POST "$LANGSMITH_ENDPOINT/api/v2/sandboxes/boxes" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "template_name": "python-sandbox",
    "name": "openai-sandbox",
    "wait_for_ready": true,
    "proxy_config": {
      "rules": [
        {
          "name": "openai-api",
          "match_hosts": ["api.openai.com"],
          "headers": [
            {
              "name": "Authorization",
              "type": "workspace_secret",
              "value": "Bearer {OPENAI_API_KEY}"
            }
          ]
        }
      ]
    }
  }'
```

The sandbox can now call OpenAI with no API key setup—the proxy injects it automatically.

## Multiple API example

Add multiple rules to authenticate with several services at once:

```bash theme={null}
curl -X POST "$LANGSMITH_ENDPOINT/api/v2/sandboxes/boxes" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "template_name": "python-sandbox",
    "name": "multi-api-sandbox",
    "wait_for_ready": true,
    "proxy_config": {
      "rules": [
        {
          "name": "openai-api",
          "match_hosts": ["api.openai.com"],
          "headers": [
            {
              "name": "Authorization",
              "type": "workspace_secret",
              "value": "Bearer {OPENAI_API_KEY}"
            }
          ]
        },
        {
          "name": "anthropic-api",
          "match_hosts": ["api.anthropic.com"],
          "headers": [
            {
              "name": "x-api-key",
              "type": "workspace_secret",
              "value": "{ANTHROPIC_API_KEY}"
            },
            {
              "name": "anthropic-version",
              "type": "plaintext",
              "value": "2023-06-01"
            }
          ]
        },
        {
          "name": "github-api",
          "match_hosts": ["api.github.com"],
          "match_paths": ["/repos/*", "/user"],
          "headers": [
            {
              "name": "Authorization",
              "type": "workspace_secret",
              "value": "Bearer {GITHUB_TOKEN}"
            }
          ]
        }
      ],
      "no_proxy": ["localhost", "127.0.0.1"]
    }
  }'
```

## Configure via SDK

<CodeGroup>
  ```python Python theme={null}
  from langsmith.sandbox import SandboxClient

  client = SandboxClient()

  client.create_sandbox(
      template_name="python-sandbox",
      name="openai-sandbox",
      proxy_config={
          "rules": [
              {
                  "name": "openai-api",
                  "match_hosts": ["api.openai.com"],
                  "headers": [
                      {
                          "name": "Authorization",
                          "type": "workspace_secret",
                          "value": "Bearer {OPENAI_API_KEY}",
                      }
                  ],
              }
          ]
      },
  )
  ```

  ```ts TypeScript theme={null}
  import { SandboxClient } from "langsmith/experimental/sandbox";

  const client = new SandboxClient();

  await client.createSandbox({
    templateName: "python-sandbox",
    name: "openai-sandbox",
    proxyConfig: {
      rules: [
        {
          name: "openai-api",
          matchHosts: ["api.openai.com"],
          headers: [
            {
              name: "Authorization",
              type: "workspace_secret",
              value: "Bearer {OPENAI_API_KEY}",
            },
          ],
        },
      ],
    },
  });
  ```
</CodeGroup>

***

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