Context bloats up after a conversation fork
Open 💬 3 comments Opened Jun 1, 2026 by KernelBypass
💡 Likely answer: A maintainer (etraut-openai, contributor)
responded on this thread — see the highlighted reply below.
What version of the IDE extension are you using?
26.527.31454
What subscription do you have?
Pro
Which IDE are you using?
VS Code Version: 1.122.1
What platform is your computer?
Linux (Debian dev container on Mac host)
What issue are you seeing?
Before the fork 38% left:
<img width="1185" height="649" alt="Image" src="https://github.com/user-attachments/assets/a2607eca-d2fa-4746-9914-aeac2082bbe2" />
---
After the fork 29% left:
<img width="1172" height="574" alt="Image" src="https://github.com/user-attachments/assets/65055478-9f47-493d-ad19-eee448daed9a" />
---
So, significant bloat up.
If anything, the post-fork should be smaller.
The fork eliminated only 2 small follow-up messages.
There was no compaction in-between.
What steps can reproduce the bug?
- for the conversation
- the fork has more bloated context
What is the expected behavior?
- the fork should be smaller context
Additional information
_No response_
3 Comments
A fork copies all of the history of the original session, including any subagent threads.
If you want to compact the forked thread, you can manually invoke
/compactafter the fork.Hi @etraut-openai, thanks for your reply.
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Right, so isn't the fork supposed to be 1 to 1 of the original then, at worst?
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I absolutely do not. The whole reason I forked was to preserve context without compacting by releasing several messages from the thread.
Ah, I misunderstood what you were saying. I thought you were saying that you expected the context window usage to shrink after a fork. You're saying that you expect it _not to grow_ after a fork. That's a reasonable assumption. Reopening.