Lowfat – pluggable CLI filter that saved 91.8% of my LLM tokens

Hi HN, not sure if anyone would be interested, but just wanted to share that I've been maintaining my small tool called 'lowfat' that helps me filters some of my verbose CLI output. It's a single binary, works as an agent hook or a shell wrapper. It has a plugin system to customize filters per command.The idea is pretty simple: agents don't need the full kubectl get -o yaml or any 10k-line dump to make decisions. So that lowfat sits in between, strips the noise, and passes through what matters. Here's my real report after 2 months of personal use: lowfat history --all lowfat plugin candidates ───────────────────────────────────────────────────────── # command runs avg raw cost savings source status 1 kubectl get 101x 14.4K 1.5M 93.9% plugin good 2 grep 103x 13.5K 1.4M 96.2% plugin good 3 git diff 81x 995 80.6K 57.9% built-in good 4 kubectl 90x 485 43.6K 33.6% plugin good 5 docker 127x 5.5K 693.6K 96.1% built-in good 6 ls 489x 117 57.3K 56.2% built-in good 7 find 30x 16.5K 495.0K 95.5% plugin good 8 git show 63x 490 30.9K 38.0% built-in good 9 git 177x 368 65.2K 76.1% built-in good 10 git log 86x 556 47.8K 78.5% built-in good 11 kubectl logs 5x 3.6K 17.8K 43.0% plugin good 12 git status 86x 152 13.1K 58.0% built-in good 13 docker ps 20x 467 9.3K 52.8% plugin good 14 kubectl describe 6x 656 3.9K

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FL score

42

out of 100

Verdict

SKIP

medium confidence

Competition

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Trend

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A CLI filter that reduces LLM token consumption by stripping verbose command output, solving a real but narrow problem for developers using AI agents.

The pain

Developers running AI agents that execute CLI commands waste money and latency sending 10K-line outputs to LLMs when only 100 lines matter. The kubectl get -o yaml dump is 95% noise. This directly hits the wallet of anyone running autonomous agents at scale.

The gap

No existing tool sits between CLI commands and LLM consumption. Developers either accept the waste, manually craft prompts to ignore output, or build one-off solutions. The plugin system lets teams customize filters per their stack (kubectl, docker, git).

Build angle

Start by targeting the highest-ROI use case: teams running agentic workflows with expensive LLM calls. Position as infrastructure for AI agent efficiency, not a general CLI tool. Measure success in dollars saved per deployment, not feature count. Build integrations with popular agent frameworks (LangChain, AutoGPT, etc.) rather than trying to be a universal CLI wrapper.

Strengths

  • Solves a quantifiable, real problem with hard data (91.8% savings on actual usage)
  • Single binary distribution removes friction
  • Plugin system shows the creator understands extensibility
  • Timing aligns with explosion of agentic AI workflows where token costs matter
  • Low complexity means fast iteration and high reliability

Risks

  • Market size unclear, only relevant to developers running AI agents, not general CLI users
  • Adoption requires integration into agent frameworks; standalone tool has limited pull
  • Token savings may shrink as LLM context windows grow and pricing drops
  • Competitive threat from LLM providers building native output filtering
  • Creator has shown no commercial intent; may remain a personal tool indefinitely
  • Requires developers to trust a filter won't strip critical information, high liability
  • Network effects are weak; each team builds custom filters anyway

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