Older chat history widgets fail to render (404 “Failed to fetch template”), while fresh widgets work

ChatGPT Apps SDK
,
1

Hi Apps SDK community — looking for guidance on a widget rendering issue that only affects older chat history messages.

Issue

  • Widgets render correctly for fresh responses.

  • If a user scrolls up to an older message in the same conversation that previously displayed the widget, the widget area now shows:

    • “Error loading app – Failed to fetch template”

  • This is reproducible across multiple older messages; only history rehydration fails.

Observations

In DevTools, when the old message is in view, ChatGPT triggers a request similar to:

GET https://chatgpt.com/backend-api/ecosystem/widget?...

This request returns:

  • 404 Not Found

The failing URL includes a parameter like:

  • template_pointer=sid:file_...

Fresh widget renders produce a different pointer and load successfully.

Questions

  1. Is template_pointer=sid:file_... expected to be durable for re-rendering widgets in chat history, or can it become invalid (e.g., after updates/republish or due to retention/GC)?

  2. If it can become invalid, what’s the recommended approach to ensure widgets remain renderable in older messages?

    • Keep versioned templates available indefinitely?

    • Use a stable template identifier/URI across releases?

    • Any documented retention expectations?

  3. Any known workarounds or best practices to avoid “Failed to fetch template” for historical messages?

I can share example failing vs working request URLs (with sensitive bits redacted) if needed.

Thanks!

Production update workflow, widget URIs, cache keys - best practices