Attaching files for offline mobile apps in constellation

[RadhakrishnaK17685089 (Radha krishna Kota)]

We’re building an offline-enabled mobile app using Pega Constellation and are aware that:

• In a pure offline Constellation app, the Attach content feature is not supported (as per the docs: online interaction is required for file picker & attachment handling) [docs: constellation UI features for offline].
  Supported Constellation UI features for offline-enabled mobile apps
• The recommended workaround is to use a hybrid architecture: keep the Constellation UI for most screens, but use a traditional UI screen for attachment (e.g., a separate attachment-only case type or screen) to leverage offline attach content [docs: attach content support in offline mode].
  Using traditional UI offline mode with a Constellation app with web portals

This hybrid approach works, but it introduces complexity:

• We need to maintain two UI layers (Constellation + traditional) for what should be a single feature.
• For a simple use case (e.g., just one case type where users need to attach files offline), creating a separate “attachment-only” screen feels like over-engineering and adds extra effort (forms, routing, state sync, etc.).

So I’d like to understand:

1. Architectural reason – What is the real constraint that prevents Attach content from working in offline Constellation mobile apps?
   • Is it a limitation of the Constellation client (Pega Mobile Client + DX API) vs. UIKit,
   • Or a constraint in how file pickers, storage, and sync are handled on the device in offline mode?
2. Alternative in pure Constellation – Is there any workaround or pattern that allows us to attach files in offline mode without having to blend with traditional UI?
   • For example:
     • Using a custom React component + file picker in Constellation that queues uploads until online,
     • Or using a custom control + data page to store base64/refs locally and then submit them later as attachments.
3. Roadmap / guidance – Are there any plans to natively support offline attach in Constellation mobile apps in future releases?

• If not, what’s the recommended long-term pattern for apps that need offline attachments ?

[czerl (Lukasz Czernik)]

@RadhakrishnaK17685089

Thank you for reaching out. Let me answer your questions:

“Architectural reason – What is the real constraint that prevents Attach content from working in offline Constellation mobile apps?”

Offline attachment support in Constellation offline mode is limited. Users can view existing attachments while offline, but they cannot add, edit, or delete attachments until they are online. This limitation is built into the current Constellation offline capability and cannot be changed through configuration.

“Alternative in pure Constellation – Is there any workaround or pattern that allows us to attach files in offline mode without having to blend with traditional UI?”

Custom components or custom controls are not supported offline. However, there is one limited option: A Text (paragraph) field configured as Rich text can accept inline photos taken offline. These images are stored as embedded content within the field (not as formal case attachments). This works for simple scenarios where capturing a photo is sufficient, but it does not replace the attachment framework and should not be treated as a general attachment mechanism. Aside from this, there is no supported offline upload pattern in Constellation other than already mentioned.

“Roadmap / guidance – Are there any plans to natively support offline attach in Constellation mobile apps in future releases?”

Native offline attachment support for Constellation mobile apps is targeted for the Pega Platform 26.1 release.