What is ultracompress?
ultracompress is a Claude Code mod by michael-berardi that deterministic local compaction for Claude Code: replaces the stock compaction summarizer with the local UltraCompress binary (no model call, no API cost per compaction) and serves a recall. It is listed under Cost & usage and has 3 GitHub stars.
| Type | Claude code mod |
|---|---|
| Author | michael-berardi |
| Repository | michael-berardi/ultracompress |
| Popularity | 3 GitHub stars |
| Category | Cost & usage |
| Security | Review before installing (76/100) |
| Rank | #829 of 5,272 Claude Code mods; #158 in Cost & usage |
| License | MIT |
| Last commit | 2026-10-16 |
| Stars this week | +1 |
| Hooks | 3 events |
| Sees | ? calls, compaction |
| Draws on | nothing |
Is ultracompress safe to install?
ultracompress scores 76/100 on the MCPMods security check: Review before installing. Things to review: starts processes outside the sandbox; reads environment variables. It passed 6 of 8 checks.
Mod footprints come from claude plugin validate, which lists every event a mod hooks and every API call it makes without running it.
| Check | Result |
|---|---|
| No network access | Pass |
| Starts processes outside the sandbox | Review |
| Writes no files or config | Pass |
| Reads environment variables | Review |
| Only sees the events it hooks | Pass |
| Doesn't drive Claude | Pass |
| Passes claude plugin validate | Pass |
| Has an open-source license | Pass |
API calls in its code
| Call | What it means |
|---|---|
$.env.get | reads env vars |
$.fs.stat | reads files |
$.process.run | runs processes |
$.session.cwd | |
$.session.id | |
$.tool.register | drives Claude |
$.ui.log | draws interface |
$.ui.toast | draws interface |
How do I install ultracompress?
- Check your Claude Code version. Mods need Claude Code 2.1.287 or later and are on by default.
claude --version
- Read its footprint. This lists every event it hooks and every API call it makes, without running it.
git clone https://github.com/michael-berardi/ultracompress claude plugin validate ./ultracompress/claude-code
- Install it. Run this in your terminal, then /reload-plugins in an open session.
git clone https://github.com/michael-berardi/ultracompress && claude --plugin-dir ./ultracompress/claude-code
Or ask Claude to set it up
Paste this into Claude Code and it installs ultracompress for you:
Install the "ultracompress" Claude Code mod from https://github.com/michael-berardi/ultracompress/tree/main/claude-code. Run claude plugin validate on it first and show me what it can access before you enable it.