How do I install the Cmux Diagnostics skill?

Run npx skillmds add om-scogo/cmux-diagnostics in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Cmux Diagnostics safe to use?

This skill has not completed SkillMD's automated safety review yet. Capability flags: docs only. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Cmux Diagnostics?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Cmux Diagnostics free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Cmux Diagnostics?

om-scogo (@om-scogo) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Cmux Diagnostics by om-scogo — Agent Skill

Name: Cmux Diagnostics
Rating: 4.666666666666667 (3 reviews)
Author: om-scogo

Cmux Diagnostics

Run end-user cmux diagnostics. Use when cmux hooks, notifications, session restore, settings, browser automation, socket access, CLI control, or agent resume behavior is not working, or when the user asks for a cmux health check, doctor report, or support-safe debug summary.

om-scogo 1d892ea 4 files · 11.3 KB Updated Sep 9, 2026 0 repo stars

File contents

cmux Diagnostics

Use this skill to collect and interpret support-safe cmux diagnostics for end users. Default to read-only checks. Do not dump hook config files, session stores, prompt logs, tokens, or environment secrets.

Quick Report

Run the bundled read-only diagnostic script first:

# From a cmux checkout
skills/cmux-diagnostics/scripts/cmux-diagnostics

# From an installed skill
~/.agents/skills/cmux-diagnostics/scripts/cmux-diagnostics

# From a Codex-only skills.sh install
~/.codex/skills/cmux-diagnostics/scripts/cmux-diagnostics

Use --include-context only when workspace names, cwd paths, and current cmux identifiers are relevant to the user-reported issue:

skills/cmux-diagnostics/scripts/cmux-diagnostics --include-context

What to Check

CLI and socket health:
```
command -v cmux
cmux ping
cmux capabilities --json
```
If socket commands fail, check whether the agent is running inside a cmux terminal and whether socket automation is enabled.
Settings health:
```
~/.agents/skills/cmux-settings/scripts/cmux-settings validate
~/.agents/skills/cmux-settings/scripts/cmux-settings get terminal.autoResumeAgentSessions
```
If the user installed with skills.sh, use ~/.codex/skills/cmux-settings/scripts/cmux-settings instead. If terminal.autoResumeAgentSessions is false, cmux restores panes but will not automatically resume saved agent sessions.
Hook installation:
```
cmux hooks setup --agent codex
cmux hooks setup --agent opencode
cmux hooks setup
```
Only run install or uninstall commands after the user agrees. cmux hooks setup installs supported agents found on PATH and skips missing agents.
Session restore evidence:
```
ls -lh ~/.cmuxterm/*-hook-sessions.json 2>/dev/null
```
Missing session stores usually means the agent has not run inside cmux since hooks were installed, hooks are disabled, or the agent integration does not support resume capture.
Notification path:
```
cmux notify "cmux diagnostic test"
```
Use this only when the user is ready for a visible test notification.

Interpretation

cmux not found: the CLI is not installed or not on PATH for this shell.
cmux ping fails: app is not reachable through the current socket path, the app is closed, or automation access is disabled.
No CMUX_WORKSPACE_ID or CMUX_SURFACE_ID: the command is probably running outside a cmux terminal. Some hooks intentionally no-op outside cmux.
Hook config exists but no session store: run one supported agent inside cmux after installing hooks, then re-check.
Session store exists but restore does not launch agents: check terminal.autoResumeAgentSessions and whether the saved executable still exists on PATH.
Settings validation fails: fix the config first. Invalid config can make later symptoms misleading.

Rules

Stay read-only until the user asks to fix something.
Never print raw hook files, session JSON, prompt logs, shell history, tokens, or API keys.
Summarize file presence, size, modified time, and marker presence instead of contents.
Prefer narrow fixes such as cmux hooks setup --agent codex over reinstalling every integration.
After a fix, rerun the diagnostic script and report the changed lines.

---name: cmux-diagnosticsdescription: Run end-user cmux diagnostics. Use when cmux hooks, notifications, session restore, settings, browser automation, socket access, CLI control, or agent resume behavior is not working, or when the user asks for a cmux health check, doctor report, or support-safe debug summary.--- # cmux Diagnostics Use this skill to collect and interpret support-safe cmux diagnostics for end users. Default to read-only checks. Do not dump hook config files, session stores, prompt logs, tokens, or environment secrets. ## Quick Report Run the bundled read-only diagnostic script first: ```bash # From a cmux checkout skills/cmux-diagnostics/scripts/cmux-diagnostics # From an installed skill ~/.agents/skills/cmux-diagnostics/scripts/cmux-diagnostics # From a Codex-only skills.sh install ~/.codex/skills/cmux-diagnostics/scripts/cmux-diagnostics ``` Use `--include-context` only when workspace names, cwd paths, and current cmux identifiers are relevant to the user-reported issue: ```bash skills/cmux-diagnostics/scripts/cmux-diagnostics --include-context ``` ## What to Check 1. CLI and socket health: ```bash command -v cmux cmux ping cmux capabilities --json ``` If socket commands fail, check whether the agent is running inside a cmux terminal and whether socket automation is enabled. 2. Settings health: ```bash ~/.agents/skills/cmux-settings/scripts/cmux-settings validate ~/.agents/skills/cmux-settings/scripts/cmux-settings get terminal.autoResumeAgentSessions ``` If the user installed with `skills.sh`, use `~/.codex/skills/cmux-settings/scripts/cmux-settings` instead. If `terminal.autoResumeAgentSessions` is false, cmux restores panes but will not automatically resume saved agent sessions. 3. Hook installation: ```bash cmux hooks setup --agent codex cmux hooks setup --agent opencode cmux hooks setup ``` Only run install or uninstall commands after the user agrees. `cmux hooks setup` installs supported agents found on PATH and skips missing agents. 4. Session restore evidence: ```bash ls -lh ~/.cmuxterm/*-hook-sessions.json 2>/dev/null ``` Missing session stores usually means the agent has not run inside cmux since hooks were installed, hooks are disabled, or the agent integration does not support resume capture. 5. Notification path: ```bash cmux notify "cmux diagnostic test" ``` Use this only when the user is ready for a visible test notification. ## Interpretation - `cmux` not found: the CLI is not installed or not on PATH for this shell. - `cmux ping` fails: app is not reachable through the current socket path, the app is closed, or automation access is disabled. - No `CMUX_WORKSPACE_ID` or `CMUX_SURFACE_ID`: the command is probably running outside a cmux terminal. Some hooks intentionally no-op outside cmux. - Hook config exists but no session store: run one supported agent inside cmux after installing hooks, then re-check. - Session store exists but restore does not launch agents: check `terminal.autoResumeAgentSessions` and whether the saved executable still exists on PATH. - Settings validation fails: fix the config first. Invalid config can make later symptoms misleading. ## Rules - Stay read-only until the user asks to fix something. - Never print raw hook files, session JSON, prompt logs, shell history, tokens, or API keys. - Summarize file presence, size, modified time, and marker presence instead of contents. - Prefer narrow fixes such as `cmux hooks setup --agent codex` over reinstalling every integration. - After a fix, rerun the diagnostic script and report the changed lines.

Frequently asked questions