Borrowing it
Nothing to install: this file belongs to EtanHey/cmuxlayer. 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/EtanHey/cmuxlayer/main/AGENTS.mdgit clone --depth 1 https://github.com/EtanHey/cmuxlayerWrote 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/etanhey/cmuxlayer/agents-md)<a href="https://agentmods.dev/instructions/etanhey/cmuxlayer/agents-md"><img src="https://agentmods.dev/badge/instructions/etanhey/cmuxlayer/agents-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/etanhey/cmuxlayer/agents-md"><img src="https://agentmods.dev/badge/instructions/etanhey/cmuxlayer/agents-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 | $0.01041 | $0.01041 |
| Opus 5.5 | $0.00416 | $0.00416 |
| Sonnet 5.5 | $0.00208 | $0.00208 |
| Haiku 4.5 | $0.00104 | $0.00104 |
Grade A, and why
cmuxlayer AGENTS.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 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 — 80 lines — stays where its author put it; the contents beside it link to each section on GitHub.
cmuxlayer
What this repo is for
cmuxlayer should be a harness for harnesses — one thing that can control every other harness with a single truth.
Codex, Kiro, Cursor CLI, whatever's next. I'm not locked into one and I don't want to be. And they don't die when they're done: formal agents that persist, controlled by one agent.
The panes are already visible — I can go look myself. The point is that orc, the leads, and the other workers know what each other are doing, which model they're on, how many tokens they've burned and how much of their context window is left, without anyone opening a pane. And when a pane dies and something reboots it to resume, it's the same agent, on the right model, and cmuxlayer knows how to change that model on whichever harness it happens to be.
That's the single truth. Everything else here is downstream of it.
The one principle
Where a pane lands is not something an agent should have to remember. It should be deterministic enough that they can't really get it wrong — that's the point of this repo.
A workspace is my mental model of what's scoped. Leads left, workers right, same workspace. Ninety-nine percent of the time I won't ask for anything else, so anything that can quietly put it somewhere else is broken.
Resumable, automatically
Any lead or orchestrator should be able to resume an agent by its ID from the registry — I shouldn't have to go find the session and run resume myself. Mostly that's one of two cases: a worker got killed because its pane broke, or a lead thought it was done and wants it back.
If the session is old and lives in the Drive-mounted folder, cmuxlayer should pull it by agent ID on its own. It should be automatic and work right.
The tools are the product
cmux owns the terminal socket — don't rebuild it. But cmuxlayer must always be able to replace or fix its own backend without killing the MCP connection.
And keep what the tools hand back concise and to the point. They give us way too many rows of data — it eats tokens for no reason.
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 Changed · +27 tokens per session d0f31a107151
- 1mo ago Changed · +29 lines · +455 tokens per session 997758ade16d
- 1mo ago First seen · 51 lines · 559 tokens per session scan A a7d5f714a13a
cmuxlayer AGENTS.md is an instructions file published in the GitHub repository EtanHey/cmuxlayer (30 stars, last pushed yesterday), licensed Apache-2.0. It adds 1,041 tokens to every session, about $0.0042 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.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
vscode model-prompts.instructions.md
Model-specific prompt authoring and registry guidelines.