GitHub - zdk/lowfat: lowfat - slim your command output. strips noise, saves tokens.

lowfat is a lightweight CLI tool that reduces AI token costs by filtering unnecessary CLI output before it reaches your agent.

Core focus

Lightweight — Small single binary, small core; but extensible. Local-first — No telemetry; you own your data. Composable — UNIX-style pipes, mix built-ins and your own filters; not magic. User-owned — lowfat history shows what you run most; allow you to customize for your usecase.

Install cargo install lowfat # or brew install zdk/tools/lowfat Pre-built binaries on GitHub Releases. Setup Pick one of: Claude Code hook — add to .claude/settings.json: { "hooks": { "PreToolUse": [ { "matcher": "Bash", "hooks": [{ "type": "command", "command": "lowfat hook" }] } ] } } Shell integration — auto-activates inside agent environments (CLAUDECODE=1, CODEX_ENV), or set LOWFAT_ENABLE=1 to force it on any shell: echo 'eval "$(lowfat shell-init zsh)"' >> ~/.zshrc # or ~/.bashrc OpenCode plugin — one command, no config editing: lowfat opencode install # writes ~/.config/opencode/plugins/lowfat.ts Restart OpenCode; commands are rewritten transparently before they run. Remove it anytime with lowfat opencode uninstall. Direct usage — prefix any command: lowfat git status lowfat docker ps lowfat ls -la Pi agent — in ~/.pi/agent/settings.json: { "shellCommandPrefix": "eval \"$(lowfat shell-init zsh)\"; " } Usage highlights # See what's configured and how loud each filter is being lowfat info # status badge + active filters lowfat info git # pipeline for `git` lowfat info --config # full resolved config

# See what lowfat has saved you lowfat stats # lifetime token savings lowfat stats --audit # recent plugin executions lowfat history # rank commands by potential savings

# Dial the aggressiveness lowfat level ultra # max compression LOWFAT_LEVEL=lite lowfat git log

# one-off override

# Write a plugin lowfat plugin new terraform # scaffold ~/.lowfat/plugins/terraform/ lowfat plugin doctor # check plugins (and pre-install any Python deps)

# Test a plugin against a sample without installing it cat samples/git-diff-full.txt | lowfat filter --explain ./filter.lf --sub=diff --level=ultra Learn more

docs/ARCHITECTURE.md — high-level diagram: CLI, Runner, Plugins, Builtins docs/CONFIG.md — .lowfat file, env vars, pipeline DSL, built-in processors, the history ranking docs/PLUGINS.md — lf-filter (the .lf plugin DSL), shell escape hatches, PEP 723 + uv, AI agent prompt

Alternatives

rtk context-mode lean-ctx tokf tamp ecotokens token-enhancer

License Apache-2.0 AI notice Multiple AI tools were used for this project