Chat compaction in Lumo

Every conversation with Lumo has a limit on how much it can take in at once. As a chat grows long, with many messages, file uploads, and tool results building up, it can get close to that limit. Compaction automatically frees up space in older parts of a long conversation so you can keep going, without losing track of what you’ve been working on.

Compaction runs automatically. There’s nothing to turn on, and most of the time you won’t notice it.

In this article, you’ll learn:

• How chat compaction works
• How to review a compacted chat
• How to manage files after a chat is shortened
• When compaction can’t help

How chat compaction works

Lumo keeps track of how large a conversation is getting. If a conversation approaches its limit, Lumo shortens the older parts so your request goes through without interruption.

If a message still doesn’t fit, Lumo shortens the chat and resends it automatically.

When Lumo shortens a chat, it’s always your older messages that are affected, never your recent ones.

• Your most recent messages, including the question you just asked, are always kept exactly as written.
• When space needs to be freed, Lumo works through a few steps. First it trims down older file and tool results to shorter placeholders. If that’s not enough, it removes older tool activity entirely while keeping the surrounding conversation. Only if those steps don’t free up enough space does Lumo summarize that part of the conversation in writing.
• Tool calls and their results are never split apart. They’re kept together or removed together.

How to review a compacted chat

If a conversation gets compacted, you’ll see a marker that says something like “Chat shortened to keep going.”

1. Go to lumo.proton.me(nuova finestra) or open the Lumo mobile app, and sign in to your Proton Account.

2. Find the Chat shortened marker in your conversation.

3. Click or tap the marker to expand it. You’ll see what was freed up, including any files or tool results that are no longer being sent to Lumo, and a summary of what Lumo still remembers from that part of the conversation.

Your full conversation history stays visible above the marker. Only what gets sent to Lumo for new replies has changed.

How to manage files after a chat is shortened

Files you’ve shared in a chat are grouped so you can always see what Lumo is currently working with.

1. Go to lumo.proton.me(nuova finestra) or open the Lumo mobile app, and sign in to your Proton Account.

2. Open the Knowledge base panel for your chat.

3. Review files under each heading:

• Attached files: Files that are currently included in your conversation.

• Removed when chat was shortened: These files are still visible in your chat history, but no longer sent to Lumo.
• Excluded: These are files you manually removed yourself.

When compaction can’t help

Compaction works well for long chats with several messages and responses — particularly those with lots of file or tool activity along the way. It can’t shrink a single file or attachment that’s too large to fit on its own. If you upload a file that alone exceeds what Lumo can process in one piece, Lumo will let you know the file is too large rather than trying to compact around it.