F5 Workforce AI Security provides proxy auto-config (PAC) files that route generative AI (GenAI) traffic through Workforce AI Security for governance and monitoring. A PAC file is a JavaScript function that runs in web browsers and applications. The function determines the proxy server for each network request. Only GenAI traffic goes to Workforce AI Security. All other traffic keeps its typical route.

You can distribute the PAC file URL through a platform for mobile device management (MDM). Examples are Google Workspace, Microsoft Intune, Jamf Pro, and Rippling. The approach needs no agent. It needs no other endpoint software either. Standard browser and operating system support for proxy auto-configuration is enough.

When a PAC file routes GenAI traffic through Workforce AI Security, the platform applies the policies that you set up. These include service access controls, Content Controls, and detection of personally identifiable information (PII). Workforce AI Security records all governed sessions in User Activity for visibility, auditing, and compliance reporting.

A PAC file contains a JavaScript function called FindProxyForURL(url, host). The function evaluates each network request and returns a proxy directive. Workforce AI Security PAC files include a list of GenAI service domains. When a browser or application requests a URL, the function checks the destination against known GenAI services. If the destination matches, the request goes through the proxy infrastructure of Workforce AI Security, where policies apply. If not, the request goes directly to its destination without interception.

Because only GenAI traffic uses the proxy, any effect on performance is limited to that traffic. You don't need proxy infrastructure for all web traffic.

To use PAC files, you first create a Proxy connector. The connector generates a unique PAC file URL for your organization. The URL includes authentication and routing information.

The generated URL follows this format, where {connector-id} is a unique identifier for your connector:

Use the URL exactly as the admin interface shows it. When you set up endpoints or an MDM platform, don't change or rebuild the URL by hand.

Copy the PAC file URL. Then send the URL to endpoints with the tool you prefer. You can set the URL in the operating system, the browser, or both.

Common deployment methods:

Ready-made scripts and profiles already contain the PAC file URL of your connector. See Use the Proxy connector deployment files.

The PAC file includes a default list of public GenAI service domains that Workforce AI Security routes through its proxy. You can add domains to this list or remove domains from it.

To add domains, append the addService query parameter to the PAC file URL. Use this parameter to intercept traffic to GenAI services in preview features. Use it also for services that the default service list doesn't yet include.

The addService parameter accepts a comma-separated list of domain patterns. You can use the asterisk (*) wildcard to match subdomains.

This example PAC file URL adds two services:

In this example, Workforce AI Security routes all subdomains of example.com and the domain api.example.net, in addition to the default service list.

To remove domains, append the removeService query parameter to the PAC file URL. When you don't want Workforce AI Security to intercept traffic to specific GenAI services, use this parameter. Examples are services that another governance mechanism controls, or services that must stay unrestricted.

The removeService parameter accepts a comma-separated list of domain patterns. The parameter uses the same wildcard syntax as addService.

This example PAC file URL removes one service:

In this example, Workforce AI Security doesn't route subdomains of example.org, including subdomains in the default service list.

You can use addService and removeService together to set the exact list of intercepted domains. Each time an endpoint requests the PAC file, Workforce AI Security applies the changes to the default service list.

This example PAC file URL uses both parameters:

Notes about service list customization:

When you change a query parameter, update the PAC file URL on your endpoints. Use your MDM platform or change each endpoint by hand.

If you already have a PAC file, you can chain it to add Workforce AI Security and keep your current proxy configuration. With chaining on, the Workforce AI Security PAC file first checks whether a request matches a GenAI service. If the request matches, it goes through Workforce AI Security. If the request doesn't match, your existing PAC file sets the route.

Your existing PAC file can route traffic through corporate proxies. It can also handle split-tunnel VPN scenarios or apply other network routing policies. Workforce AI Security handles only GenAI traffic, and your existing PAC file sets the route for everything else.

To turn on chaining, append the chain query parameter to the PAC file URL. Set its value to the absolute URL of your existing PAC file. URL-encode the value. Unencoded special characters can break the query string.

For example, if your existing PAC file is at this address:

The PAC file URL with chaining is:

The encoding replaces the colon (:) with %3A and each forward slash (/) with %2F. Most tools and browsers encode values for you. If you build a URL by hand, apply the encoding yourself.

When a browser or application retrieves this PAC file, the combined logic works in this order:

You can combine chaining with service list customization by using more than one query parameter. Encode each parameter value:

Requirements for chaining:

Workforce AI Security PAC files include a services endpoint. The endpoint returns the list of GenAI service domains for a connector in JavaScript Object Notation (JSON). This feature is in preview. It might change in future releases.

To view the service list for a connector, use the services.json path under the connector path:

The response is a JSON object that contains an array of domain patterns. This example shows only the first entries of the array:

The endpoint accepts the addService and removeService query parameters. Use them to preview the effective service list with your changes applied:

Use the services endpoint in these ways:

The structure and availability of the services endpoint might change based on customer feedback. Don't build critical dependencies on the endpoint in its current form.

Some clients don't fully support proxying over Transport Layer Security (TLS) or PAC semantics. For these unsupported user agents, the PAC output returns DIRECT; for matched GenAI service domains on purpose. The traffic bypasses Workforce AI Security. The failopen parameter can't override this behavior.

Current unsupported user agents:

When a request comes from an unsupported user agent:

Windows components that use WinHTTP networking get no interception. To get governance for this traffic:

Workforce AI Security builds the PAC content for the user agent that retrieves the PAC file. If an unsupported component downloads the PAC file, the returned PAC file embeds DIRECT; for matched domains. An example is a system auto-proxy service. Any client that later uses that PAC file follows the embedded DIRECT; logic, including clients that support HTTPS proxying. The component that fetches the PAC file must represent the clients that use the file. If the fetching component doesn't represent those clients, change your configuration.

By default, requests from unsupported user agents use DIRECT mode for matched GenAI service domains. To override this behavior, append the ignoreUnsupported query parameter to the PAC file URL.

To bypass the check for unsupported user agents, use a URL like this one:

When you set ignoreUnsupported=true:

Test a user agent from the unsupported list. If the user agent completes TLS proxying in your environment, use this parameter. You can also use this parameter to try proxy routing for all traffic, regardless of the user agent.

When a client can't complete proxy authentication or TLS proxying, fail open controls what happens for matched GenAI service domains. When fail open is active, the PAC output adds a DIRECT; fallback after the proxy directive. The request then proceeds without interception.

Behavior, where <PROXY_ADDRESS> stands for the proxy address in the PAC output:

Control fail open with a query parameter:

When an endpoint requests the PAC file, Workforce AI Security sets the fail-open behavior in the generated PAC content. For example, the content gets a DIRECT; fallback. If a system component retrieves the PAC file and triggers fail open, all later clients get the DIRECT; fallback. The fallback applies regardless of the capabilities of each client. To avoid unintended fail open, force typical behavior with ?failopen=false. Or make sure a representative client retrieves the PAC file.

Notes:

Workforce AI Security keeps the PAC file content current with the latest public service catalog entries. When Workforce AI Security adds a GenAI service to the catalog or updates one, the PAC file changes to match. Endpoints receive current routing logic without manual work.

After you set the PAC file URL on endpoints, you don't need to update the URL itself. The URL stays the same for the life of the Proxy connector. Workforce AI Security changes the service list and routing logic behind the same URL.