copperhead CLAUDE.md

copperhead CLAUDE.md is an instructions file for coding agents from copperheadhq/copperhead. It costs 1,242 tokens per session, scanned A, original, Apache-2.0.

Project instructions for Copperhead, a TypeScript command-line agent that designs and edits KiCad circuit-board projects. KiCad is electronic-design software; the instructions cover its specifications, architecture, commands, testing, and verification workflow.

In plain words
What is it for?
Use them when implementing or verifying Copperhead commands, agent behavior, KiCad file changes, or ERC/DRC checks, which detect electrical and layout-rule problems.
Why use it?
They give agents the project's authoritative rules and safety checks for editing circuit schematics and printed-circuit-board files.

Instructions file

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add instructions/copperheadhq/copperhead/claude-md
Clone the repo
git clone --depth 1 https://github.com/copperheadhq/copperhead

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for copperhead CLAUDE.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/copperheadhq/copperhead/claude-md.svg)](https://agentmods.dev/instructions/copperheadhq/copperhead/claude-md)
Your own site
<a href="https://agentmods.dev/instructions/copperheadhq/copperhead/claude-md"><img src="https://agentmods.dev/badge/instructions/copperheadhq/copperhead/claude-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 1,242 This file is loaded in full into every session.
When invoked 1,242 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
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 $0.01242 $0.01242
Opus 5 $0.00621 $0.00621
Sonnet 5 $0.00248 $0.00248
Haiku 4.5 $0.00124 $0.00124

Measured 4d ago against content hash a533dcd6c3fa, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

copperhead 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 4d 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 · 56 lines

How it starts

The opening of the file, as written. The whole thing — 56 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

What this repo is

copperhead — "Cursor for circuit boards": a TypeScript CLI agent that designs and edits real KiCad projects (.kicad_sch/.kicad_pcb s-expression files), keeps markdown design docs as memory, and verifies its own work with kicad-cli ERC/DRC. Apache-2.0, Node ≥ 20.

Current state: Phase 1 implemented, pending full live verification. The CLI builds and runs (init, check/verify, do, sync, create), and the offline test suite is green. Live AC-3.x integration tests run only for explicitly configured providers: API keys enable the direct OpenAI/Anthropic paths, and COPPERHEAD_TEST_CODEX=1 enables the local saved-login Codex path. See the status note at the top of openspec/changes/build-copperhead-phase-1/tasks.md for the exact split.

Sources of truth

  • openspec/specs/SPEC.md — the complete technical specification: product definition, architecture, CLI surface, agent loop, tool schemas, config, safety rails, and binary acceptance criteria (AC-1 … AC-7). Read this before any design or implementation work.
  • openspec/changes/build-copperhead-phase-1/ — the active change: proposal.md (what/why), design.md (decisions D1–D14 with rationale), specs/*/spec.md (seven capability delta specs with WHEN/THEN scenarios), tasks.md (implementation checklist in dependency order).

When spec-level behavior changes, update SPEC.md and the change artifacts together — the delta specs' scenarios are meant to map 1:1 onto SPEC.md's acceptance criteria.

Workflow (OpenSpec)

This repo uses OpenSpec spec-driven development. Planning artifacts are managed with the openspec CLI and the /opsx:* skills:

  • /opsx:apply — implement tasks from the change (check off tasks.md as you go)
  • /opsx:update — revise planning artifacts coherently (never edits code)
  • /opsx:archive — archive the change when implemented; merges delta specs into openspec/specs/

Read the full file on GitHub · 56 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. 4d ago First seen · 56 lines · 1,242 tokens per session scan A a533dcd6c3fa

Subscribe to this mod's changes

copperhead CLAUDE.md is an instructions file published in the GitHub repository copperheadhq/copperhead (56 stars, last pushed 4d ago), licensed Apache-2.0. It adds 1,242 tokens to every session, about $0.0062 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 2026-08-30.

Related

Other instructions, from other repositories