---
name: multi-agent-mux-create
description: "Create a new agent session (claude, antigravity/agy) in a dedicated tmux session for context-preserving long-running work. Always creates a tmux session — never backgrounds with nohup/disown. Writes the new session to .mam/agent-sessions.yaml. Use when you want to start a fresh agent (no prior UUID) for a new project workspace."
version: 1.0.0
author: godopu
license: MIT
platforms: [linux, macos]
environments: [terminal, tmux]
metadata:
  hermes:
    tags: [agent, tmux, claude, antigravity, agy, multi-agent, context, session]
    related_skills: [multi-agent-mux-resume, multi-agent-mux-stop, multi-agent-mux-monitor, claude-code]
    prereq_skills: [claude-code]
---

# Multi-Agent Create — Start a Fresh Agent in a tmux Session

> **Companion skills**: `multi-agent-mux-resume` (resume an existing UUID), `multi-agent-mux-stop` (terminate), `multi-agent-mux-monitor` (live status).
> **Single source of truth**: `./.mam/agent-sessions.yaml` (this skill writes to it; never read it ad-hoc — go through this skill).

## What this skill does

Spawn a new agent (`claude` or `agy`/antigravity-cli) in a **dedicated tmux session** for context-preserving long-running work. The tmux session is the *container*; the agent's session ID is *data* inside the container. **This skill creates the container + starts the agent — but does not resume an old conversation** (use `multi-agent-mux-resume` for that).

For all agents: the tmux session name is produced by **`lib.sh::derive_session_name`** — the single source of truth shared by create/resume/stop/status/monitor (P0-A). The rule (verbatim from the function):

> slug = the **two trailing path components** of the absolute workspace, `_`→`-`, lowercased, joined with `-`; name = `<slug>-creator-<agent>`.

So `$WORKSPACE_ROOT/landing_page/refer_landing_page` + `claude` → `landing-page-refer-landing-page-creator-claude`. The workspace basename (`refer_landing_page`) **is** included; the hand-written historical entry that dropped it (`lab-landing-page-creator-claude`) was the bug, not the convention.

## Pre-flight checks

Before doing anything, verify the environment:

```bash
# 1) tmux available and isolated server status
command -v tmux || { echo "ERROR: tmux not installed"; exit 1; }
echo "Tmux server name: ${TMUX_SERVER_NAME:-default}"

# 2) claude / agy available
command -v claude  # required for --agent claude
command -v agy     # required for --agent agy

# 3) claude auth (if --agent claude)
claude auth status 2>&1 | python3 -c "import json,sys; d=json.load(sys.stdin); assert d.get('loggedIn'), 'claude not logged in'"

# 4) target workspace exists
test -d "$WORKSPACE" || { echo "ERROR: workspace $WORKSPACE not a directory"; exit 1; }
```

If any check fails → `kanban_block(reason="...")` (worker path) or report to user (interactive path). Do not proceed with a half-broken setup.

## Standard names

- **tmux session name**: `derive_session_name <workspace> <agent>` (lib.sh)
  - `<workspace-slug>` = `basename $(dirname $WORKSPACE)` `-` `basename $WORKSPACE` (lowercase, `_`→`-`)
  - examples: `landing-page-refer-landing-page-creator-claude`, `paper-pdf2md-creator-agy`
  - never re-derive this by hand — source lib.sh and call the function
- **wrapper script** (claude only): `~/.local/bin/<workspace-slug>-creator-claude`
  - contents: tmux new-session with `claude` inside, auto-handles trust/bypass dialogs
  - see `<workdir>/agent_sessions.md` for the canonical wrapper template

## Tmux Server Isolation (격리 서버)

When running multiple agent sessions alongside other workflows (e.g., cmux, Kanban workers, manual tmux sessions), sharing the default tmux server can lead to session name conflicts, monitoring clutter, and accidental destruction of user sessions via global commands.

To prevent this, you can run this skill inside an **isolated tmux server** using the `TMUX_SERVER_NAME` environment variable or the `--tmux-server <name>` flag (opt-in).

### How to use
1. **Via Environment Variable**:
   ```bash
   export TMUX_SERVER_NAME=multi-agent-canary
   # All subsequent commands (create, status, stop, etc.) will run in the isolated 'multi-agent-canary' tmux server.
   ```
2. **Via Option Flag**:
   ```bash
   bash scripts/create_session.sh --workspace /path/to/project --agent claude --role developer --tmux-server multi-agent-canary
   ```
3. **Submit Job Integration**:
   You can automatically register a delegated job with a prompt when creating a session:
   ```bash
   bash scripts/create_session.sh --workspace /path/to/project --agent claude --role developer --submit-job "Task prompt here"
   ```
4. **Onboard Integration**:
   You can automatically submit a project alignment/orientation job to the new agent when creating a session:
   ```bash
   bash scripts/create_session.sh --workspace /path/to/project --agent claude --role developer --onboard
   ```

### Recommended Alias
You can set an alias in your shell to easily query sessions on the isolated server:
```bash
alias tmc='tmux -L multi-agent-canary'
tmc ls  # Lists only your multi-agent sessions
```

### Safety Rules (Pitfall 29 Summary)
- Never use global server termination commands like `tmux kill-server` or `tmux kill-session -a` as they will destroy all sessions on that server (including your own workspace sessions if they share the server).
- By using an isolated server via `TMUX_SERVER_NAME`, your agent sessions are completely separated from your default user workspace, ensuring 0% interference.

## Workflow

```bash
WORKSPACE=/path/to/project
AGENT=claude  # or agy
source .agents/skills/lib.sh
SESSION_NAME="$(derive_session_name "$WORKSPACE" "$AGENT")"

# 1. If session already alive, fail fast
tmux has-session -t "$SESSION_NAME" 2>/dev/null && {
  echo "ERROR: tmux session '$SESSION_NAME' already exists. Use multi-agent-mux-resume to attach or multi-agent-mux-stop first."
  exit 1
}

# 2. Spawn the tmux session with the agent inside
case "$AGENT" in
  claude)
    # Use the wrapper if it exists, else inline tmux new-session
    # Use the wrapper if it exists (LOCAL_BIN env var overrides default $HOME/.local/bin)
    local_bin="${LOCAL_BIN:-$HOME/.local/bin}"
    if [ -x "$local_bin/$SESSION_NAME" ]; then
      nohup "$local_bin/$SESSION_NAME" >/dev/null 2>&1 &
    else
      tmux new-session -d -s "$SESSION_NAME" -x 140 -y 40 -c "$WORKSPACE" "claude"
    fi
    ;;
  agy)
    tmux new-session -d -s "$SESSION_NAME" -x 140 -y 40 -c "$WORKSPACE" "agy --dangerously-skip-permissions"
    ;;
  *) echo "ERROR: --agent must be claude or agy, got: $AGENT"; exit 2 ;;
esac

# 3. Wait for agent TUI to be ready (varies: claude ~5s, agy ~3s)
sleep 6

# 4. Capture pane metadata
PANE_PID=$(tmux list-panes -t "$SESSION_NAME" -F '#{pane_pid}')
PANE_CWD=$(tmux list-panes -t "$SESSION_NAME" -F '#{pane_current_path}')
PANE_CMD=$(tmux list-panes -t "$SESSION_NAME" -F '#{pane_current_command}')
TMUX_EPOCH=$(tmux list-sessions -F '#{session_created}' -t "$SESSION_NAME" 2>/dev/null | head -1)
```

## Registering the session in agent-sessions.yaml

After spawn, append a new `tmux_sessions[]` entry to `.mam/agent-sessions.yaml`:

```yaml
- name: <SESSION_NAME>
  status: running
  tmux_session_created_at: 2026-06-17T...Z   # ISO 8601 UTC
  tmux_session_epoch: <TMUX_EPOCH>
  tmux_server: <TMUX_SERVER_NAME>           # Isolated server name (default: 'default')
  pane:
    index: 0
    pid: <PANE_PID>
    cmd: <AGENT>            # 'claude' or 'agy'
    cmd_full: <full command line, see table below>
    cwd: <PANE_CWD>
  tui:                     # only for claude
    model: <from TUI status>
    provider: <from TUI status>
    plan: <from TUI status>
    account: <from TUI status>
    version: <from TUI status>
  start_command: <the exact tmux new-session command used>
  attach_command: "tmux attach -t <SESSION_NAME>"
  kill_command: "tmux kill-session -t <SESSION_NAME>"
```

`cmd_full` per agent (this is the actual command line in the pane, not the resume command):

| agent | cmd_full |
|---|---|
| claude (interactive) | `claude` |
| agy (interactive) | `agy --dangerously-skip-permissions` |

Use the `agent-sessions-yaml-edit` script in `scripts/` to safely append (preserves comments + format):

```bash
bash .agents/skills/multi-agent-mux-create/scripts/create_session.sh \
  --workspace "$WORKSPACE" --agent "$AGENT" --role "$ROLE" --session "$SESSION_NAME"
```

The script handles the YAML append, pane capture, and the `last_visible_status` placeholder.

## Pitfalls

- **Don't use `nohup`/`disown`/`setsid` for the agent itself** — those background the agent outside tmux. The whole point of this skill is *the tmux session is the supervisor*. `nohup` is OK only for *launching the wrapper* (which itself creates the tmux session via `tmux new-session -d`).
- **Don't trust `--session-id <uuid>` flags blindly** — claude/agy may not accept a fixed session id on first spawn. The session id is *assigned* on first user message; you can read it back from `~/.claude/projects/.../session.jsonl` headers or `~/.gemini/.../cache/last_conversations.json` AFTER the first message.
- **Wrapper script MUST NOT be created via `hermes profile alias`** — that command writes a `hermes -p <profile>` wrapper that destroys the tmux behavior. Create wrappers manually (see `lab-landing-page-creator-claude` template).
- **Always use the workspace-relative path** in tmux `cwd` — relative paths break when tmux respawns in a different shell context.
- **The first `claude` message generates the session id** — `multi-agent-mux-create` only sets up the *container*. If you need a known session id for later resume, send a placeholder message (e.g. "init") and read it back, then call `multi-agent-mux-resume` later.

## Verification

After spawn + YAML append:

```bash
# 1. tmux session is alive
tmux has-session -t "$SESSION_NAME" && echo OK || echo MISSING

# 2. pane has the expected cmd + cwd
tmux list-panes -t "$SESSION_NAME" -F 'cmd=#{pane_current_command} cwd=#{pane_current_path}'

# 3. agent-sessions.yaml has the new entry
python3 -c "
import yaml
d = yaml.safe_load(open('.mam/agent-sessions.yaml'))
names = [s['name'] for s in d['tmux_sessions']]
assert '$SESSION_NAME' in names, 'session not registered'
print('OK:', names)
"

# 4. Optional: check the TUI status via capture-pane
tmux capture-pane -t "$SESSION_NAME" -p -S -20   # TUI ready = agent banner visible, no dialog text
```

## When NOT to use this skill

- **Resuming an old conversation** → `multi-agent-mux-resume`
- **Killing an existing session** → `multi-agent-mux-stop`
- **Just attaching to an existing session** → `tmux attach -t <name>` (no skill needed)
- **One-shot print mode (claude -p "...")** → no tmux needed; use `claude-code` skill's print mode
