Summary
Built an app in the new app builder and wants to surface it inside an existing Classic app (under the existing module header) so users don't feel like they're switching apps, but embedding the new app via an iFrame isn't working.
AI Response
Embedding a new app builder app inside a Classic app via the IFrame component is not currently a supported flow. A Retool staff member confirmed this exact scenario is not supported yet, though it is being tracked internally as a high-priority request. The failure is expected: new app builder pages set a restrictive frame-src content security policy, which blocks them from rendering in an iFrame, and the auth callback also breaks in that context. For now, the reliable path is to link out to the new app rather than iFrame it, and to keep classic-app reuse within modules (a Classic app concept). Watching the linked threads is the best way to catch when native support ships.
Sources
Embedding new Retool AI app into Classic app
Same scenario (embedding a new app builder app in a Classic app via iFrame yields an 'Invalid auth callback' error); Retool staff confirm it isn't currently supported but is being tracked as high priority.
Explains that the new React app builder page enforces a restrictive frame-src CSP header, which is why iFrame embedding of these apps fails.
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