Observe compaction window
Hooks that fire before and after context window compaction — preserve critical state, log what gets summarized, or block compaction
Observation Hooks Hooks & Lifecycle
Supported
Partial
No
Unknown
Codex CLI Current · Apr 2026 
Copilot Current · Apr 2026 
Windsurf Current · Apr 2026 2.1.10 - 2.1.143
3.82.0 - 3.83.0
0.88.0 - 0.128.0
2025.10 - 2026.05
2.4 - 3.2
1.13.3 - 2.1.29
2.0.0 - 2.1.10
3.82.0
0.36.0 - 0.88.0
2025.07 - 2025.10
1.7 - 2.0
1.2.1 - 1.13.3
1.0.48 - 1.0.85
3.82.0
0.2.0 - 0.36.0
2025.07
1.2
1.2.1
0.2.54 - 1.0.41
3.36.0 - 3.82.0
0.2.0
2025.06 - 2025.07
0.45 - 1.2
1.2.1
0.2.31 - 0.2.54
1.5.0 - 3.33.0
—
—
0.45
1.0.2 - 1.2.1
Supported by 3 of 6 agents.
HoverTap any cell for version details.
Sub-capabilities
- PreCompact: save state or block compaction if in a critical section
- PostCompact: reinject lost context or verify information survived
- Claude Code: PreCompact can block via exit code 2; PostCompact fires after completion
- Cursor: preCompact is observational (non-blocking)