The lifecycle model follows the organization-neutral AI Guide playbook mosaicstack/aiguide:playbooks/tmux-fleet.md (commit 2a0b0b5): a dedicated holder owns the tmux server/socket; agent units join it and stop only their own exact-match session.

Layout

mosaic-tmux-holder.service — user-mode holder that owns the named tmux server.
mosaic-agent@.service — user-mode template for one reusable agent session.
test-fleet-units.sh — validates unit syntax and required relationships.

The agent template calls:

~/.config/mosaic/tools/fleet/start-agent-session.sh <agent-name>

which starts or reuses a tmux session on MOSAIC_TMUX_SOCKET.

Local customization

Per-agent overrides live outside the package in:

~/.config/mosaic/fleet/agents/<agent>.env

Example:

MOSAIC_TMUX_SOCKET=mosaic-factory
MOSAIC_AGENT_RUNTIME=claude
MOSAIC_AGENT_WORKDIR=/home/jarvis/src/mosaic-stack
# Optional escape hatch for PoC/canary agents:
# MOSAIC_AGENT_COMMAND=mosaic yolo claude

Manual canary sequence

mkdir -p ~/.config/systemd/user ~/.config/mosaic/tools/fleet ~/.config/mosaic/fleet/agents
cp packages/mosaic/framework/systemd/user/mosaic-*.service ~/.config/systemd/user/
cp packages/mosaic/framework/tools/fleet/start-agent-session.sh ~/.config/mosaic/tools/fleet/
chmod +x ~/.config/mosaic/tools/fleet/start-agent-session.sh
systemctl --user daemon-reload
systemctl --user start mosaic-tmux-holder.service
systemctl --user start mosaic-agent@canary.service
tmux -L mosaic-factory ls

Do not use tmux kill-server without -L mosaic-factory; this pattern is meant to avoid disturbing the user's default tmux server.