Context management
How Mind automatically summarises conversation history to keep sessions productive within model context limits
Compaction keeps long sessions productive by automatically summarising older conversation history as your session grows. Your goals, decisions, and technical progress are preserved — only the verbose middle gets compressed.
| Capability | IDE | CLI | Web |
|---|---|---|---|
| Automatic compaction | ✓ | ✓ | ✓ |
Manual trigger (/compact) | — | ✓ | — |
| Context usage meter | ✓ | ✓ | ✓ |
How it works
When your conversation approaches the model's context limit, compaction triggers automatically:
- Summary generation — Mind creates a structured summary capturing your goals, decisions, progress, and next steps
- Context reduction — Older conversation history is replaced by the summary, while your most recent messages are kept verbatim
- Continuation — The session continues from where you left off with no interruption
Your goals, decisions, file modifications, and stated constraints survive compaction. What gets compressed is intermediate output — tool call details, exploratory discussion, and resolved error messages.
Example
You've been working on a refactoring task for 45 minutes — the agent has modified 12 files, run tests, and fixed three build errors. Context usage is at 80%.
Compaction fires. The summary captures: which files were modified, what tests pass, the remaining 2 files to refactor, and your constraint that "all changes must be backward-compatible." The last two exchanges (your most recent instruction and the agent's response) stay verbatim.
The agent continues immediately. It knows what's done, what's next, and what your rules are — without carrying 45 minutes of intermediate tool output.
What's preserved vs. summarised
| Always preserved | May be summarised |
|---|---|
| Task status (done / in-progress / pending) | Individual tool call details |
| File paths modified | Intermediate reasoning steps |
| Key decisions and constraints | Code snippets in earlier messages |
| Next steps | Error details from resolved issues |
| Your stated intent and requirements | Exploratory discussion |
Triggering compaction
Compaction is automatic in the IDE. There is no manual trigger.
The context usage meter in the chat panel shows how close you are to the model's limit. When compaction fires, the meter resets to reflect the freed space and the session continues.
Configuration
The CLI exposes two settings that control how much context is retained during compaction:
| Setting | Default | Description |
|---|---|---|
| compaction.excludeMessages | 2 | Minimum number of recent message pairs to retain verbatim |
| compaction.excludeContextWindowPercent | 2 | Minimum percentage of the context window to keep as recent messages |
Both settings are evaluated, and the more conservative (larger) value wins, so enough recent context is always available for the agent to maintain continuity.
Limitations
Compaction is one-way. The full conversation history before the compaction point is not recoverable within the session. If you need to preserve the complete history, export your session before compaction occurs.