herdr-extensions: Instructions file for Claude Code

CLAUDE.md

herdr-extensions CLAUDE.md is an instructions file for Claude Code from vonzelle-vzt/herdr-extensions. It costs 2,330 tokens per session, scanned A, original, MIT.

Repository instructions for Herdr Extensions, an installer that makes Herdr act like a small version of Visual Studio Code by adding a plugin manifest, scripts, and keyboard shortcuts.

In plain words
What is it for?
Working on the Herdr Extensions command-line installer, plugin templates, shell scripts, configuration edits, panel controls, and diagnostics.
Why use it?
They document design decisions and quiet failure points, helping agents preserve user settings and avoid breaking installation, removal, diagnostics, or keyboard controls.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md. Also seen: mentions CLAUDE.md; mentions Claude Code.

This is vonzelle-vzt/herdr-extensions's own configuration. It tells Claude Code how to work on herdr-extensions itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything herdr-extensions configures →

Reuse

Borrowing it

Nothing to install: this file belongs to vonzelle-vzt/herdr-extensions. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/vonzelle-vzt/herdr-extensions/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/vonzelle-vzt/herdr-extensions

Made for: Claude Code.

Wrote this? Show the measurements

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Per session 2,330 This file is loaded in full into every session.
When invoked 2,330 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.02330 $0.02330
Opus 5 $0.01165 $0.01165
Sonnet 5 $0.00466 $0.00466
Haiku 4.5 $0.00233 $0.00233

Measured 10d ago against content hash 95962efeb1cc, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

herdr-extensions CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

CLAUDE.md · 149 lines

How it starts

The opening of the file, as written. The whole thing — 149 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md — herdr-extensions

Project guidance for Claude Code. Read this before changing anything here; it records the failure modes that are invisible from the code alone.

What this is

An installer, not a framework. It makes herdr behave like a tiny VS Code by writing a plugin manifest, some scripts, and a marker-delimited block of keybindings. There is no plugin manager and no config DSL, deliberately. Read README.md for the product and SPEC.md for every design decision and the reason behind it — SPEC.md is the authority, and each numbered decision is a bug this package prevents.

bin/herdr-extensions is stdlib-only Python targeting 3.9 (what macOS ships), so there is no tomllib. Config edits are marker-delimited text splices, never TOML round-trips — that is also why your comments and settings survive.

Repository map

bin/herdr-extensions      the whole CLI: install / uninstall / doctor / skin
plugin/herdr-plugin.toml  herdr plugin manifest — a TEMPLATE, rendered at install time
plugin/open-panel.sh      launcher: decides open/focus/close, project scope, and panel geometry
plugin/resize-pane.sh     one-keypress divider nudge
plugin/image-paste.sh     stage a clipboard image and type its path to the agent
libexec/<panel>           one script per panel: problems search todo blame markdown tests debug preview
libexec/herdr-fmt         formatter resolver used for format-on-save
skins/*.toml              VS Code colour schemes for herdr itself
tests/                    the oracles; see "Verification" below

🔴 The five things that fail silently

Every one of these has actually shipped broken. None produces an error message.

1. Pane commands run under launchd's PATH. The herdr server is started by launchd, so it execs plugin panes and actions with PATH=/usr/bin:/bin:/usr/sbin:/sbin. Neither /opt/homebrew/bin nor /usr/local/bin nor ~/.local/bin is on it. A bare spiceedit, lazygit, chafa or rg never resolves and the action does nothing at all. Every external binary is therefore an @@TEMPLATE@@ rendered to an absolute path by render_plugin(). Worth knowing: on many machines rg is a shell function, so anything that execves it fails even though it works when you type it.

Read the full file on GitHub · 149 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 10d ago First seen · 149 lines · 2,330 tokens per session scan A 95962efeb1cc

Subscribe to this mod's changes

herdr-extensions CLAUDE.md is an instructions file published in the GitHub repository vonzelle-vzt/herdr-extensions (6 stars, last pushed 1mo ago), licensed MIT. It adds 2,330 tokens to every session, about $0.0117 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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