Atmos is an infrastructure runtime that coordinates tools such as Terraform, OpenTofu, Kubernetes, Helm, Packer, Ansible, and containers through consistent commands and configuration. It is for teams running cloud infrastructure on laptops, in CI, or through AI agents across environments and regions. Its catalogue entries provide skills, agents, commands, and other add-ons for Atmos workflows.
Borrowing it
Nothing to install: this file belongs to cloudposse/atmos. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/cloudposse/atmos/main/CLAUDE.mdgit clone --depth 1 https://github.com/cloudposse/atmosWrote 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/instructions/cloudposse/atmos/claude-md)<a href="https://agentmods.dev/instructions/cloudposse/atmos/claude-md"><img src="https://agentmods.dev/badge/instructions/cloudposse/atmos/claude-md/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/instructions/cloudposse/atmos/claude-md"><img src="https://agentmods.dev/badge/instructions/cloudposse/atmos/claude-md.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 | $0.06165 | $0.06165 |
| Opus 5.5 | $0.02466 | $0.02466 |
| Sonnet 5.5 | $0.01233 | $0.01233 |
| Haiku 4.5 | $0.00617 | $0.00617 |
Grade A, and why
atmos 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 today.
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 — 455 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
Guidance for Claude Code when working with this repository.
Project Overview
Atmos: Go CLI for cloud infrastructure orchestration via Terraform/Helmfile/Packer with stack-based config, templating, policy validation, vendoring, and terminal UI.
Git Worktrees (MANDATORY)
This repository uses git worktrees for parallel development. When working in a worktree:
- ALWAYS stay within the current working directory - Never escape to parent directories
- Use relative paths or paths under the current working directory - Do not hardcode
/Users/*/atmos/paths - The worktree IS the repository - All files, including
pkg/,cmd/,internal/, exist within the worktree - Never assume the parent directory is the repo - Worktrees like
.conductor/branch-name/are complete, independent working copies
Why this matters: Searching outside the worktree will find stale code from the main branch instead of the current branch's code. This leads to incorrect analysis and recommendations.
For Task agents: When searching for files, always use the current working directory (.) or relative paths. Never construct absolute paths that might escape the worktree.
Concurrent Sessions (MANDATORY)
Multiple Claude sessions may be working on the same branch or worktree simultaneously. To avoid destroying other sessions' work:
- NEVER delete, reset, or discard files you didn't create - Other sessions may have created them
- NEVER run
git reset,git checkout --, orgit cleanwithout explicit user approval - NEVER run
go clean. In particular,go clean -cachedeletes the shared Go build cache and breaks concurrent builds; it is not an approved troubleshooting step. - ALWAYS ask the user before removing untracked files - They may be work-in-progress from another session
- When you see unfamiliar files, assume another session created them - ask the user what to do
- If pre-commit hooks fail due to files you didn't touch, ask the user how to proceed rather than trying to fix or remove them
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.
- today Changed · +22 tokens per session c014e05a1729
- 6d ago Changed · +2 lines · +30 tokens per session 36775d21ba42
- 1mo ago Changed · -1 tokens per session 766d300e3ec9
- 1mo ago Changed b104bb71d08b
- 1mo ago Changed · -1 tokens per session 868477c9b272
- 1mo ago First seen · 453 lines · 6,115 tokens per session scan A 54f945dcd765
atmos CLAUDE.md is an instructions file published in the GitHub repository cloudposse/atmos (1,405 stars, last pushed today), licensed Apache-2.0. It adds 6,165 tokens to every session, about $0.0247 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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