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

# Policy and proxy

> Use browser policy for scope and proxy configuration for egress without confusing the two controls.

Production browser jobs need two separate boundaries:

* Policy controls what the browser is allowed to do.
* Proxy controls the network path used by browser traffic.

Use both when the job has a known target and a required egress route. Do not treat either one as permission to access a site, bypass a blocker, or ignore site rules.

## Support matrix

| Need                         | Supported surfaces                                                                                                                                      | Notes                                                                                                                  |
| ---------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------- |
| Full browser policy          | SDK browser creation, SDK agent browser creation, SDK quick actions, REST browser creation, REST quick actions, MCP `manage_browsers` create            | Use `BrowserNavigationPolicy` fields such as `allowedDomains`, `authDomains`, `downloads`, `uploads`, and `approvals`. |
| CLI agent domain boundary    | `web agent --allow-domain <domain>`                                                                                                                     | The CLI agent exposes domain allow-listing, not the full policy object.                                                |
| MCP server startup policy    | `web mcp run --allow-domain`, `--allow-origin`, `--private-access localhost`                                                                            | Applies to browsers the MCP runtime creates.                                                                           |
| Custom proxy                 | SDK browser creation, SDK agent browser creation, SDK quick actions, CLI browser creation, CLI quick actions, REST browser creation, REST quick actions | Keep proxy URLs in environment variables.                                                                              |
| MCP custom proxy             | Not exposed                                                                                                                                             | MCP tool schemas do not include a browser-create proxy field.                                                          |
| CLI `web agent` custom proxy | Not exposed                                                                                                                                             | Use SDK `web.agent({ browser: { create: { proxy } } })` when browser-agent work needs a custom proxy.                  |

## SDK browser job

```ts theme={null}
import { Web } from "@webcompute/sdk";

const web = new Web();

const browser = await web.browser.create({
  proxy: process.env.RESIDENTIAL_PROXY_URL,
  recording: true,
  policy: {
    mode: "strict",
    allowedDomains: ["vendor.example"],
    authDomains: ["login.vendor.example"],
    downloads: { mode: "requireApproval", maxBytes: 25_000_000 },
    uploads: { mode: "deny" },
    approvals: { destructiveActions: "requireApproval" },
  },
});

try {
  const result = await browser.playwright.execute({
    code: `
      await page.goto("https://vendor.example/account");
      return { title: await page.title(), url: page.url() };
    `,
    capture: { status: true, observation: { kind: "aria", includeOn: "always" } },
  });

  console.log(result.result);
} finally {
  await browser.close();
}
```

In deterministic browser control, the application owns the target, extraction, validation, and cleanup.

## SDK agent job

```ts theme={null}
const agent = web.agent({
  model,
  browser: {
    create: {
      proxy: process.env.RESIDENTIAL_PROXY_URL,
      recording: true,
      policy: { allowedDomains: ["vendor.example"] },
    },
  },
  approval: "ask",
});

const result = await agent.run({
  startUrl: "https://vendor.example",
  goal: "Review the visible account status and return the account name, plan, and renewal date.",
});
```

In browser-agent work, the model chooses browser steps inside the browser boundary you configured.

## MCP policy

```bash theme={null}
web mcp run \
  --allow-domain sec.gov \
  --private-access localhost
```

MCP policy is useful when a coding agent creates browsers through `manage_browsers`. It is not a proxy setting. If an MCP workflow needs a proxied browser, create that browser through SDK, CLI, or REST first, then reuse the browser ID where the workflow supports it.

## Failure handling

| Signal                             | Response                                                                                         |
| ---------------------------------- | ------------------------------------------------------------------------------------------------ |
| Policy denial                      | Stop or refine the policy deliberately. Do not retry with a wider policy automatically.          |
| Proxy authentication failure       | Rotate or correct the proxy credential outside prompts and logs.                                 |
| Proxy connection failure           | Retry with backoff only if the job is safe to repeat.                                            |
| Unexpected auth or redirect domain | Add `authDomains` or `redirectDomains` only after confirming the domain belongs to the workflow. |
| Upload/download policy decision    | Ask for human review when the action can expose data or change state.                            |

Reference: [policy reference](/reference/policy-reference), [proxy reference](/reference/proxy-reference), [security and secrets](/production/security-and-secrets), and [errors and retries](/production/errors-and-retries).