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rynfar rynfar

Meridian Plugin Pi Scrub

Development community

Description

Meridian plugin: strip pi-coding-agent identity fingerprints from the system prompt before it reaches Claude

Installation

This entry records only its repository, not the path inside it, so there is no exact command to give. Open the source below and copy the folder into ~/.claude/skills/, or the file into ~/.claude/agents/.

README

@rynfar/meridian-plugin-pi-scrub

A [Meridian](https://github.com/rynfar/meridian) plugin that strips pi-coding-agent's identifying fingerprints from the system prompt before it reaches Claude.

Why

Pi's built-in default prompt opens with `"You are an expert coding assistant operating inside pi, a coding agent harness..."` and includes a multi-line "Pi documentation" block that references pi's SDK, extensions, themes, etc.

When Meridian routes pi → Claude Max with `codeSystemPrompt: true`, those pi-identity sections are:

  1. Redundant — Claude Code's preset already owns identity, tone, safety, and general tool-use guidance.
  2. A detection fingerprint — they give Anthropic's detection a clear "this isn't Claude Code" signal that can trigger Extra-Usage billing or rate-limit flags.

This plugin surgically removes those two blocks and replaces the identity paragraph with a neutral, generic coding-assistant framing. Everything else in pi's prompt (tools list, guidelines, date, cwd, any user- or harness-appended content, subagent-specific prompt body, project context, skills block) is preserved verbatim.

The scrub is **idempotent** — running it twice on the same string is a no-op.

Install

Option 1: Local clone (recommended for dev)

git clone https://github.com/rynfar/meridian-plugin-pi-scrub.git ~/repos/meridian-plugin-pi-scrub
cd ~/repos/meridian-plugin-pi-scrub
npm install
npm run build

Then point Meridian's plugin config at the built file:

mkdir -p ~/.config/meridian
cat > ~/.config/meridian/plugins.json <<'JSON'
{
  "plugins": [
    { "path": "/Users/YOU/repos/meridian-plugin-pi-scrub/dist/index.js", "enabled": true }
  ]
}
JSON

Restart Meridian (or `curl -X POST http://localhost:3456/plugins/reload`).

Verify at `http://localhost:3456/plugins` — you should see `pi-scrub` listed as **active**.

Option 2: Drop-in file

If you prefer auto-discovery, symlink or copy `dist/index.js` into `~/.config/meridian/plugins