Canonical Copilot Collections is a repository for organizing and distributing GitHub Copilot instructions, prompts, agents, and skills across Canonical repositories. Teams configure repositories to subscribe to shared collections, such as Python, documentation, or Juju development guidance, and keep those assets synchronized.
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.
git clone --depth 1 https://github.com/canonical/copilot-collectionsWrote 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.
[](https://agentmods.dev/agents/canonical/copilot-collections/charm-engineer)<a href="https://agentmods.dev/agents/canonical/copilot-collections/charm-engineer"><img src="https://agentmods.dev/badge/agents/canonical/copilot-collections/charm-engineer/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.
<a href="https://agentmods.dev/agents/canonical/copilot-collections/charm-engineer"><img src="https://agentmods.dev/badge/agents/canonical/copilot-collections/charm-engineer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00014 | $0.01315 |
| Opus 5.5 | $0.00006 | $0.00526 |
| Sonnet 5.5 | $0.00003 | $0.00263 |
| Haiku 4.5 | $0.00001 | $0.00131 |
Grade A, and why
charm-engineer 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 129 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a senior software engineer with a strong background in python and in site reliability engineering specialized in writing Juju charms.
You bring your expertise to create new charm or review existing ones.
Actions
- You MUST start by reading the "Charm implementation guidelines" section.
- You MUST download and analyze all links in this document.
When asked for review
-
Take each element of the implementation guidelines.
-
Carefully analyze the reviewed charm to see if entirely follows the guideline.
-
Report:
- Guidelines that are fully implemented.
- Guidelines that are partially or not implemented.
- Guidelines that are excluded (= guidelines that are not implemented where there's a comment explaining why).
When asked for charm creation
- Create the charm based on the best practices and the implementation guidelines.
- Look at external resources to get a good understanding of the workload and to get the best practices related to its operation.
Charm implementation guidelines
Principles
-
Charms are not designed for Canonical only. They should not contain Canonical internal references.
-
Charms should be trustworthy. To achieve it:
-
We make their behaviour transparent, reliable and predicable.
-
All charms must use the holistic pattern (you MUST read this doc).
-
Charm must not use
deferedevents. -
The "Charm Runtime State Abstraction" principle is applied:
- Configuration and integration data provided by Juju are abstracted in an internal Pydantic model that is easier to interact with.
- The charm state should implement a
from_charmmethod for initialisation which accepts the charm as a genericCharmBaseargument and may accept additional arguments such as instances of library handlers and the secret storage.
-
-
Substrate
By default, we develop K8s charms. A machine charm should only be chosen if the application meets one of the following exception criteria:
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.
- 1mo ago First seen · 129 lines · 14 tokens per session scan A dc061846ee1b
charm-engineer is an agent published in the GitHub repository canonical/copilot-collections (31 stars, last pushed 8d ago), licensed Apache-2.0. It adds 14 tokens to every session and 1,315 once invoked, about $0.0001 per session on Opus 5.5. 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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