The app builder now supports multiple chat conversations (threads) working on the same branch rather than a single thread per branch.

A thread is a single chat conversation with the agent in the Chat tab. Threads are intended to help you keep your work organized by task or theme. For example, use one thread for updating your app theme, and another thread for editing a chart on that page. Manage threads from the Chat tab.

A branch is a set of changes to your app, associated with an app preview, and with its own version history. A branch is the unit of work that you publish, and you create a new branch to begin a distinct line of work. For example, create a new branch when you want to change the resources that your app uses, or when you want to overhaul a page. Manage branches from the Version history tab in the navbar.

When using Source Control, branches in the protected app builder map to branches in your external git repository.

For Enterprise organizations that use Source Control to protect apps, you can now use the app builder to check out a branch that you created outside of Retool. This enables you to transition your changes from a local development environment to the app builder. This can be useful for visually validating your changes in the preview canvas.

You can now build apps with more AI models: Claude Sonnet 5, the GPT-5.6 models (Sol, Terra, and Luna), and Claude Fable 5. Choose a model for each thread in the app builder's Chat tab. Admins can set the organization's default app building provider and model in the AI settings.

Claude Sonnet 5 can be used on paid plans with a Retool-managed key or your own key. The GPT-5.6 models and Claude Fable 5 require you to bring your own key, which is available on the Enterprise plan.

You can now upload files to be used as assets in your app through the Chat tab in the app builder. Previously, uploaded files could only be used as context for the agent.

Common use cases for uploaded files as assets include:

• Embedding PDFs.
• Adding a company logo to the app header.
• Presenting images within the app.

You can now trigger workflows from functions in the new app builder. Converting classic apps that trigger workflows is now supported as a result.

To trigger a workflow from your app, open the Chat tab and prompt your agent with the workflow's name.

The triggered workflow is run on behalf of the app's authenticated user.

Classic apps that include custom components and organization-level themes can now be converted to the new app building experience.

To support custom components, the agent investigates the custom component and recreates it in the converted app with as few changes as possible.

To support classic organization-level themes, the agent applies the same style, color, and typography to the app as were represented in the organization-level theme. The agent does not create a new organization-level theme that applies to apps created with the new app builder.

Retool now supports publishing apps on custom domains. If you self-host Retool (which inherently uses a custom domain) or use a custom domain on a cloud instance, your apps are published to the domain you define in the following format: https://example.retool.com/rr/app/<appName>.

If your organization uses custom domains, previously-published apps should be republished in order to serve them from the appropriate domain.

Apps published on custom domains are subject to an additional set of limitations that are applied because Retool runs your app inside a sandboxed iframe with allow-same-origin disabled.

Admins can now customize the Content Security Policy (CSP) that Retool enforces on apps. Retool applies a strict default policy that restricts which origins an app can load scripts, fonts, images, and other resources from. You can now extend that policy org-wide to allow the additional origins your apps need, or tighten the defaults further.

For example, if custom JavaScript in an app loads a charting library from a CDN such as https://cdn.example.com, the default script-src 'self' policy blocks the script and the app fails to render it. You can now add that origin to script-src so the app can load it without loosening the policy for any other resource.

Configure rules in Settings > App security > Content Security Policy. Changes apply to every app in your organization and are recorded in your audit logs.

For more information, refer to Customize the Content Security Policy for apps.

While prompting from the Chat tab in the new app builder, you can now restore the app to a previous state. Each time the agent finishes making changes, it presents a summary of the changes and a Restore button. Click this button to return your app to the state it was in when the agent finished those changes.

Retool now supports audio and visual browser notifications for app building. If you prompt Retool to build an app and navigate away from the tab, a ping sounds and a red dot appears on the favicon of the tab when you need to return to it. Now, you can multitask and return to the app builder only when your input is required.

This notification occurs at the following key points in the building process:

• The agent needs you to provide input or make a choice (such as selecting a resource).
• The agent needs your approval to run a function.
• The agent is finished building.

To turn off the notification sound, click the Model options selector in the prompting box and toggle off the Sound notifications setting.