nix/hosts/netty/pi-agent.nix
2026-04-03 01:36:25 +00:00

76 lines
2.3 KiB
Nix

{
pkgs,
username,
...
}:
let
piAgentEnvFile = "/var/lib/pi-agent/pi-agent.env";
piAgentEnvCheck = pkgs.writeShellScript "pi-agent-env-check" ''
[ -f "${piAgentEnvFile}" ]
'';
# Wrapper that exec's pi inside tmux's foreground process so systemd
# tracks the actual PID. When pi dies, tmux exits, systemd sees it
# and triggers Restart=on-failure.
piAgentStart = pkgs.writeShellScript "start-pi-agent" ''
export PATH="${pkgs.nodejs_22}/bin:$PATH"
npm_prefix="$(npm prefix -g 2>/dev/null)"
pi_bin="$npm_prefix/bin/pi"
if [ ! -x "$pi_bin" ]; then
echo "pi binary not found at $pi_bin" >&2
exit 1
fi
# tmux runs in the foreground (-D) so systemd tracks this process.
# The inner shell exec's pi so the tmux pane PID *is* the pi PID.
exec ${pkgs.tmux}/bin/tmux new-session -D -s pi-agent \
"exec $pi_bin --chat-bridge"
'';
in
{
# Ensure state directory and env file have correct permissions.
systemd.tmpfiles.rules = [
"d /var/lib/pi-agent 0750 ${username} users -"
"z ${piAgentEnvFile} 0600 ${username} users -"
];
# Pi agent running 24/7 in a foreground tmux session.
# Extensions (pi-channels, pi-schedule-prompt, pi-subagents) load
# inside Pi's process and handle Telegram bridging, scheduled tasks,
# and background subagent delegation.
#
# The --chat-bridge flag auto-enables the Telegram bridge on startup.
# Telegram bot token lives in ~/.pi/agent/settings.json (see pi-channels docs).
# ANTHROPIC_API_KEY comes from the env file.
#
# tmux session name: pi-agent
# Attach for debugging: tmux attach -t pi-agent
systemd.services.pi-agent = {
description = "Pi Coding Agent (24/7)";
after = [ "network-online.target" ];
wants = [ "network-online.target" ];
wantedBy = [ "multi-user.target" ];
path = [
pkgs.nodejs_22
pkgs.git
pkgs.tmux
pkgs.coreutils
];
environment = {
HOME = "/home/${username}";
NODE_NO_WARNINGS = "1";
};
serviceConfig = {
Type = "simple";
User = username;
Group = "users";
WorkingDirectory = "/home/${username}";
ExecCondition = piAgentEnvCheck;
EnvironmentFile = piAgentEnvFile;
ExecStart = piAgentStart;
Restart = "on-failure";
RestartSec = 10;
};
};
}