vac

🧹 Vacuum up cruft from your AI coding-agent sessions. A small, standalone Python CLI that cleans, prunes, analyzes, archives, and repairs local session logs for Kiro CLI and Claude Code.

Long agent sessions rot over time — embedded screenshots, giant tool outputs, and ever-growing history. Because these agents replay the whole conversation every turn, that bloat causes real failures:

• Oversized images (>2000px) wedge a session: image dimensions exceed max allowed size for many-image requests: 2000 pixels
• Huge embedded payloads crash the load: Agent connection closed / the selected model cannot continue this conversation
• Runaway context triggers premature, quality-killing auto-compaction
• Hundreds of stale sessions quietly eat disk

vac fixes wedged sessions and keeps them lean:

• clean — strip embedded images (both Kiro forms + Claude), fixing the 2000px / payload-size crashes
• prune — free a chosen % of context tokens from the oldest turns (the "compact the first N%" Kiro's /compact and /rewind can't do)
• analyze / doctor — see what's eating a session and triage the ones about to break
• list / archive — inventory by age and archive old sessions (reversible)

Everything backs up before writing, refuses to touch live sessions, and JSON-validates the result (and offers --dry-run to preview) — so it never corrupts a session.

Install

Pick whichever you have — the installed command is always vac.

pip (universal — works anywhere Python + pip exist):

pip install vac-cli

pipx / uv (isolated global tool):

pipx install vac-cli
uv tool install vac-cli

Homebrew (macOS/Linux):

brew tap homeo26/vac
brew install vac          # short form after tapping
# or one-shot without tapping first:
brew install homeo26/vac/vac

From source, no pipx/uv needed (one-liner):

curl -fsSL https://raw.githubusercontent.com/homeo26/vac/main/install.sh | bash

This creates an isolated venv under ~/.vac and links vac into ~/.local/bin (uses uv automatically if present). Make sure ~/.local/bin is on your PATH.

From a git checkout (for development):

git clone https://github.com/homeo26/vac.git && cd vac
pip install -e ".[test]"        # or:  uv tool install .

Requires Python 3.9+.

Commands

<id> = a session id or a path to a .jsonl. <dur> = 60d 2w 12h 30m. Commands that write (clean, prune, name, archive) apply by default — add --dry-run (-n) to preview. They create a .bak, refuse to edit active/locked sessions (--force overrides), and JSON-validate before writing. Works on both Kiro CLI and Claude Code.

vac doctor                                  # triage everything
vac clean <id> --keep 1                     # drop old images (add --dry-run to preview)
vac prune <id> --oldest 20 --mode hard      # free ~20% of context tokens
vac prune <v3-id> --cap                     # Kiro v3: trim used tool output, run to 100%
vac archive --older-than 60d                # reclaim disk (reversible)

Key concepts

Tokens vs. bytes — which command to use. Kiro's context % counts tokens, not file size. An embedded image is megabytes on disk but only ~1–2K tokens.

• Fixing a file-size problem (2000px image error, "connection closed", disk)? → vac clean (removes image bytes).
• Lowering the context % / delaying auto-compaction? → vac prune (removes text tokens). --mode hard guarantees the target; --mode outputs is non-lossy for the dialogue but frees less.

Age is real last-used time. --older-than and the age column use each session's updated_at metadata, not the file mtime — so sessions that vac itself rewrote aren't misflagged as recently used. Durations: 60d, 2w, 12h, 30m.

Archiving is reversible. vac archive tar.gz's each session (log + metadata + history) to ~/.kiro/sessions/vac-archive-<timestamp>.tar.gz; restore with tar -xzf <archive> -C <dir>.

Images are "lazy", not lost. After the first read, an image's content is already captured in the model's text reply, so keeping it re-sent every turn mostly just burns tokens and hits the image caps. vac clean strips them aggressively (keeps the newest 3 by default) and, for images read from a file, leaves a placeholder with the source path (re-read /tmp/shot.png …) so the model can pull the image back on demand if it ever needs the pixels again.

Safety

• Preview with --dry-run — commands apply by default; -n/--dry-run shows what would change without writing.
• Automatic backup — writes a .bak beside the log (disable with --no-backup).
• Won't touch live sessions — refuses to edit a locked/recently-active session unless --force.
• Keeps source paths — cleared images become a text placeholder, and file-based images can simply be re-read.
• Local only — never makes network calls.

Supported tools

Adapters are pluggable — more tools can be added.

doctor checks

vac doctor flags sessions likely to be wedged:

• Many-image risk — more than ~20 images (Anthropic's stricter 2000px cap).
• Context-bomb entry — any single log entry over ~1 MB (a runaway tool output or embedded image re-sent every turn).
• Oversized session — total size likely to exceed the model's context window.

Each finding prints the exact vac clean … command to fix it.

Development

git clone https://github.com/homeo26/vac.git && cd vac
pip install -e ".[test]"
pytest -q                 # run the test suite

CI runs the tests on every push/PR (Python 3.9 and 3.12). Releases publish to PyPI automatically via OIDC Trusted Publishing when a v* tag is pushed — no tokens stored (see .github/workflows/publish.yml).

License

MIT