context-alarm

A Claude Code mod that warns when the context window fills up and suggests saving the session's decisions with /save-context before automatic compaction summarises them away. Part of claude-plugins.

What it does

• At 80% (the warn_percent setting, 50 to 95): a notice, a status line under the prompt (Context 83% · /save-context suggested) and /save-context suggested in the empty prompt box.
• 10 points higher: one more notice that automatic compaction is close.
• Before an automatic compaction without a save: a last notice. The compaction still runs.
• After /save-context runs: the suggestions stop and the status line says so.
• /context-alarm: shows how full the context is and the thresholds.

It installs project-workflow from the same marketplace as a dependency, which provides /save-context.

What it reads and does

• Reads: how full the context window is, whether /save-context ran, and when an automatic compaction starts.
• Does: notices, a status line under the prompt, and /save-context suggested in the empty prompt box. It never runs save-context itself.
• Hooks: skill.prompt (save-context only) notes that it ran and passes the skill's prompt on unchanged. session.compact only warns; the compaction still runs. command.run answers its own /context-alarm command and no other.
• Privacy: see PRIVACY.md.
• Never: sends anything anywhere (no network calls, no telemetry).

Install

Needs Claude Code 2.1.287 or later (mods). Tested on 2.1.289.

/plugin marketplace add mutlumehmet/claude-plugins
/plugin install context-alarm@mehmetmutlu

A mod runs inside Claude Code with your permissions. Read the code before you install any mod.

Known gaps

• On the turn that crosses the threshold the prompt suggestion can be missed (the new percent arrives after the turn ends); the notice and status line still show.
• If one turn jumps past both thresholds, only the second notice shows.
• Nothing is drawn in the VS Code chat panel.

About

Made by Mehmet Mutlu, part of claude-plugins. More of his work at mehmetmutlu.dev.

License

MIT