PostCompact Hook — LSP Cache Flush

After Claude Code compacts the context window, cached LSP symbol positions can become stale: the LSP server still holds the old line numbers from before compaction, and the next navigation call may resolve to the wrong location.

This feature adds a two-part fix:

Server side: workspace(action: status, post_compact: true)

workspace(action: status) accepts a new boolean parameter post_compact. When true, all active LSP clients are shut down immediately and the call returns early:

{ "flushed": true, "hint": "LSP position caches cleared. Clients restart automatically on the next navigation call..." }

LSP clients restart lazily on the next symbol_at or references call — there is no manual restart step and no disruption to the session. The normal status fields (project_root, languages, etc.) are not included in the flush response.

Plugin side: PostCompact hook

The companion plugin (codescout-companion) adds a PostCompact hook that fires automatically after every context compaction. Because hooks run outside the MCP transport and cannot call tools directly, the hook injects an additionalContext directive:

codescout PostCompact: context was compacted.
→ Call workspace(action: status, post_compact: true) as your FIRST action to flush stale LSP position caches.
   LSP clients restart lazily — no disruption to the session.

The agent sees this as the first message of the new turn and calls workspace(action: status, post_compact: true) before any navigation work.

When is this useful?

Long coding sessions where the context is compacted mid-task — especially when there are open LSP-backed files (Rust, TypeScript, Kotlin) and the agent immediately needs accurate symbol_at results after compaction.

Upgrade path

Requires:

• codescout ≥ 0.4.1 (server-side post_compact parameter)
• codescout-companion plugin with the PostCompact hook registered in hooks/hooks.json