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ArcticFoxz
ArcticFoxz

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Built a local pre-processing plugin for Claude Code after research & measuring real metrics (3,500+ tests, v1.22.1) — Looking for feedback & ideas

#security #python #ai #showdev

Hi everyone,

I wanted to share a project I’ve been developing for my own workflow with Claude Code, and hopefully get some feedback and ideas from the community on where to take it next.

How it started

Working on large-scale, complex projects, I needed better control over context, token consumption, and security. Before building my own tool, I tested various plugins in the market. As someone who likes to measure and verify metrics independently, I ran tests on actual context usage and noticed that under large, messy repository conditions, results often varied from what was expected.

Since my projects involve sensitive codebases, I wanted a deterministic local pre-processing layer that sanitizes, budgets, and organizes data before anything is passed to Claude Code—ensuring zero unexpected data leaks and absolute predictability.

The struggle & research

What started as a simple helper script turned into a serious engineering effort. I went through over 1,000 research papers and technical docs to refine context retention, token budgeting, and local redaction.

Building reliability tooling is a constant battle against edge cases: silent context loss, false successes, cross-platform path quirks (like Windows process locks), and state drift.

My rule became: Never believe a bug is fixed until a test proves it.

Today, the plugin (chamnan) is at v1.22.1. It's built in pure Python (standard library only, zero external packages) and backed by 3,500+ automated tests.

What it actually does (It's NOT an AI, it's a pre-processing / reliability layer)

  • Deterministic Context Budgeting: Pre-indexes and trims repository context before passing it to Claude Code (slashed Quick Index overhead dramatically in real-world tests).
  • Local Security & Redaction: Runs local choke-point scrubbing so secrets and internal strings never leave your machine.
  • Agent Continuity / Memory: Keeps track of session decisions, lessons, and project history locally inside .chamnan/ so Claude Code doesn't waste tokens re-discovering architecture across sessions.
  • Monorepo & Multi-adapter support: Designed to handle nested checkouts, messy directory trees, and OS-specific edge cases cleanly.

Looking for community feedback

I dogfood this daily, but since I built it to share with other developers working on large or privacy-conscious projects, I'd love to hear your thoughts:

  1. What edge cases or repository structures have broken your Claude Code workflows in the past?
  2. What safety verifications or context features would you like to see in a local helper plugin?

If you're interested in the architecture or test setup, you can check out the repository here: https://github.com/ArcticFox2029/chamnan

Appreciate any feedback!

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