canopus

canopus is a skill for Claude Code from mishahanin/heading-os. It costs 111 tokens per session (3,682 once invoked), scanned A, original, Apache-2.0.

A seven-step engineering process for building non-trivial work in a shared workspace. It includes steps for defining value, planning, checking the work, and recording decisions, with two points where the operator must take action.

In plain words
What is it for?
Use it to organize substantial engineering tasks, create and check a work contract, coordinate GitHub and pytest work, and keep a committed record of key decisions.
Why use it?
It gives complex work a fixed structure and helps expose weak requirements before implementation begins.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: mentions subagents.

Good fit Use it to organize substantial engineering tasks, create and check a work contract, coordinate GitHub and pytest work, and keep a committed record of key decisions.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/mishahanin/heading-os/canopus
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.

Any agent
npx skills add mishahanin/heading-os --skill canopus
Clone the repo
git clone --depth 1 https://github.com/mishahanin/heading-os

Made for: Claude Code.

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 canopus

README.md
[![agentmods](https://agentmods.dev/badge/skills/mishahanin/heading-os/canopus/github.svg)](https://agentmods.dev/skills/mishahanin/heading-os/canopus)
Your own site
<a href="https://agentmods.dev/skills/mishahanin/heading-os/canopus"><img src="https://agentmods.dev/badge/skills/mishahanin/heading-os/canopus/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for canopus

Your own site · 80×15
<a href="https://agentmods.dev/skills/mishahanin/heading-os/canopus"><img src="https://agentmods.dev/badge/skills/mishahanin/heading-os/canopus.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 111 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,682 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Prompt Injection · line 249
    Hidden instructions were detected in comments or invisible text. These could contain malicious directives. Manual review is recommended.
    Fix: Audit all comments and invisible characters. Remove any instructions that direct the agent to perform unauthorized actions. Use plain, reviewable content.
How audits are shown
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 $0.00111 $0.03682
Opus 5 $0.00056 $0.01841
Sonnet 5 $0.00022 $0.00736
Haiku 4.5 $0.00011 $0.00368

Measured 9d ago against content hash 24357685a500, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

canopus 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 9d 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/skills/canopus/SKILL.md · 293 lines

How it starts

The opening of the file, as written. The whole thing — 293 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Canopus

The standard for building anything non-trivial here. Seven steps, two of them the operator's own. Every mechanical part is built out of git, GitHub and pytest rather than re-implemented in Python. One shell command defeated 93 percent of the retired version's hand-built prevention surface.

The one thing this exists to prevent: a contract too weak to decide anything, passing as one that decided. Across all 62 prior records a contract was never once weakened after the fact, and was born too weak thirty times. The green to distrust is the one no wrong implementation was ever made to fail.

Bare /canopus — the seven steps

Nothing is run. Show the agenda below and name the step the work in hand is at. Read that position from the conversation, never from the disk. Only steps 4 and 7 leave a trace in this repository, so a position read off it is a guess dressed as a measurement.

The seven steps

The agenda has exactly one definition, scripts/utils/canopus_steps.py. This file may summarise it and may never renumber it.

1. Define the Value
2. superpowers:brainstorming                 -> scope document
3. superpowers:writing-plans                 -> plan
4. /scrutinize the plan, apply every finding -> the operator's commit
5. superpowers:subagent-driven-development   -> implementation
6. /scrutinize --relentless, apply every finding
7. Production

Steps 4 and 7 are the operator's. The seven steps fall into four acts:

  • Act 1, steps 1 to 4. Nothing is built yet.
  • Act 2, step 5. The implementer is not the planner.
  • Act 3, step 6. Green is not the same as right.
  • Act 4, step 7. The undo is named before anyone needs it.

Step 3 — what makes a plan worth committing

Four properties, and a plan missing any of them buys nothing at step 4. The authoring detail behind properties 1 and 4 is references/planning-gate.md. It carries the five contract-writing rules, each earned by a measured failure, and how to read probe's table. Read it before writing a contract.

Read the full file on GitHub · 293 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 9d ago First seen · 293 lines · 111 tokens per session scan A 24357685a500

Subscribe to this mod's changes

canopus is a skill published in the GitHub repository mishahanin/heading-os (11 stars, last pushed today), licensed Apache-2.0. It adds 111 tokens to every session and 3,682 once invoked, about $0.0006 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.

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