src/cli.rs

@@ -91,6 +91,20 @@ pub enum Command {
         /// Agent name or alias
         agent: String,
     },
+    /// Supervise an agent and optionally restart it on crash
+    Watch {
+        /// Agent name or alias
+        agent: String,
+        /// Restart the agent automatically when it dies (with backoff)
+        #[arg(long)]
+        restart: bool,
+        /// Desktop notification on every restart
+        #[arg(long)]
+        notify: bool,
+        /// Check interval in seconds (default: 5)
+        #[arg(long, value_name = "SECS", default_value = "5")]
+        interval: u64,
+    },
     /// Manage command aliases (cc -> claude-code)
     #[command(subcommand)]
     Alias(AliasCmd),

src/commands/mod.rs

@@ -25,6 +25,7 @@ pub mod status_cmd;
 pub mod timeline_cmd;
 pub mod uninstall_cmd;
 pub mod update_cmd;
+pub mod watch_cmd;
 pub mod version_cmd;
 
 use crate::app::App;
@@ -57,6 +58,12 @@ pub fn execute_command(app: &App, cmd: &Command) -> Result<i32> {
             follow,
         } => logs_cmd::run(app, agent, *lines, *follow),
         Command::Open { agent } => open_cmd::run(app, agent),
+        Command::Watch {
+            agent,
+            restart,
+            notify,
+            interval,
+        } => watch_cmd::run(app, agent, *restart, *notify, *interval),
         Command::Alias(sub) => alias_cmd::run(app, sub),
         Command::Start(a) => run_cmd::start(app, a),
         Command::Stop {

src/commands/watch_cmd.rs

@@ -0,0 +1,107 @@
+//! watch: supervise one agent and optionally restart it on crash.
+
+use super::*;
+use crate::cli::StartArgs;
+use crate::process;
+use std::time::Duration;
+
+/// One supervision check. Returns whether the agent is running afterwards.
+/// Restarts are background starts (event + session recorded as usual).
+pub fn check_once(app: &App, agent_name: &str, restart: bool, notify: bool) -> bool {
+    let entry = app.state.get(agent_name).ok().flatten();
+    let running = entry
+        .as_ref()
+        .and_then(|e| e.pid)
+        .map(process::is_running)
+        .unwrap_or(false);
+    if running {
+        return true;
+    }
+    if !restart {
+        app.log.warn(&format!("'{agent_name}' is not running"));
+        return false;
+    }
+    let agent = match app.catalog.resolve(agent_name) {
+        Some(a) => a,
+        None => {
+            app.log.error(&format!("unknown agent '{agent_name}'"));
+            return false;
+        }
+    };
+    app.log.warn(&format!("'{agent_name}' is not running — restarting"));
+    let opts = StartArgs {
+        agent: Some(agent_name.to_string()),
+        background: true,
+        ..Default::default()
+    };
+    match run_cmd::start(app, &opts) {
+        Ok(_) => {
+            if notify {
+                process::desktop_notify("agent-manager", &format!("{} restarted", agent.title()));
+            }
+            true
+        }
+        Err(e) => {
+            app.log.error(&format!("restart failed: {e:#}"));
+            false
+        }
+    }
+}
+
+pub fn run(app: &App, agent: &str, restart: bool, notify: bool, interval: u64) -> Result<i32> {
+    require_agent(app, agent)?;
+    let interval = interval.max(1);
+    app.log.info(&format!("watching '{agent}' every {interval}s (Ctrl-C to stop)"));
+    let mut backoff = 1u64;
+    loop {
+        let ok = check_once(app, agent, restart, notify);
+        if ok {
+            backoff = 1;
+            std::thread::sleep(Duration::from_secs(interval));
+        } else if restart {
+            app.log.warn(&format!("retrying in {backoff}s"));
+            std::thread::sleep(Duration::from_secs(backoff));
+            backoff = (backoff * 2).min(60);
+        } else {
+            std::thread::sleep(Duration::from_secs(interval));
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use clap::Parser;
+
+    #[test]
+    fn check_once_reports_dead_agent_without_restart() {
+        let guard = tempfile::tempdir().unwrap();
+        let dir = guard.path().to_path_buf();
+        std::mem::forget(guard);
+        let cfg = dir.join("config.yaml");
+        std::fs::write(
+            &cfg,
+            concat!(
+                "version: \"1.0\"\n",
+                "settings:\n",
+                "  auto_install_deps: false\n",
+                "agents: []\n",
+            ),
+        )
+        .unwrap();
+        let cli = crate::cli::Cli::parse_from(["am", "--config", cfg.to_str().unwrap()]);
+        let mut app = App::from_cli(cli).unwrap();
+        let mut p = app.paths.clone();
+        p.install_dir = dir.join("agents");
+        p.bin_dir = dir.join("agents").join("bin");
+        p.log_dir = dir.join("logs");
+        p.state_file = dir.join("state.json");
+        p.probe_cache_file = dir.join("probe-cache.json");
+        p.config_dir = Some(dir.join("config"));
+        app.paths = p;
+        // Agent absent de l état : pas running, pas de restart -> false.
+        assert!(!check_once(&app, "claude-code", false, false));
+        // Agent inconnu avec restart : erreur loguée, false.
+        assert!(!check_once(&app, "inconnu", true, false));
+    }
+}

src/help.rs

@@ -312,6 +312,26 @@ pub static HELP_SPECS: &[HelpSpec] = &[
             HelpExample { desc: "Open the install directory.", code: "open claude-code" },
         ],
     },
+    HelpSpec {
+        name: "watch",
+        category: "Commands",
+        usage: "watch {flags} <agent>",
+        about: "Supervise an agent and optionally restart it on crash.",
+        search_terms: &["monitor", "supervise", "restart"],
+        flags: &[
+            HelpFlag { short: "", long: "--restart", value: "", desc: "Restart the agent automatically when it dies (with backoff)" },
+            HelpFlag { short: "", long: "--notify", value: "", desc: "Desktop notification on every restart" },
+            HelpFlag { short: "", long: "--interval", value: "SECS", desc: "Check interval in seconds (default: 5)" },
+        ],
+        subcommands: &[],
+        parameters: &[
+            HelpParam { name: "agent", typ: "string", desc: "Agent name or alias" },
+        ],
+        io: None,
+        examples: &[
+            HelpExample { desc: "Supervise with auto-restart.", code: "watch claude-code --restart --notify" },
+        ],
+    },
     HelpSpec {
         name: "alias",
         category: "Commands",

src/repl.rs

@@ -70,6 +70,7 @@ const COMMAND_DESCRIPTIONS: &[(&str, &str)] = &[
     ("init", "generate a project config"),
     ("alias", "manage aliases"),
     ("open", "open the install dir"),
+    ("watch", "supervise an agent"),
     ("search", "search the catalog"),
     ("info", "agent details"),
     ("install", "install an agent"),
@@ -146,7 +147,7 @@ impl AmCompleter {
         Self {
             theme: std::cell::Cell::new(crate::theme::default_theme()),
             commands: vec![
-                "list", "status", "sessions", "stats", "projects", "timeline", "log", "logs", "history", "init", "alias", "open", "search", "info", "install", "uninstall", "update",
+                "list", "status", "sessions", "stats", "projects", "timeline", "log", "logs", "history", "init", "alias", "open", "watch", "search", "info", "install", "uninstall", "update",
                 "start", "stop", "restart", "run", "doctor", "config", "completion",
                 "self-update", "self-uninstall", "export", "import", "shell", "theme",
                 "ls", "dir", "cd", "ps", "where", "get", "help", "version", "exit",
@@ -1230,6 +1231,12 @@ fn handle_line(
         "open" => Command::Open {
             agent: need("agent name")?,
         },
+        "watch" => Command::Watch {
+            agent: need("agent name")?,
+            restart: flag("--restart"),
+            notify: flag("--notify"),
+            interval: opt_value("--interval").and_then(|v| v.parse().ok()).unwrap_or(5),
+        },
         "alias" => match rest.first().map(|s| s.as_str()) {
             Some("add") if rest.len() >= 3 => Command::Alias(crate::cli::AliasCmd::Add {
                 name: rest[1].clone(),
@@ -1398,6 +1405,7 @@ fn is_am_command(word: &str) -> bool {
             | "init"
             | "alias"
             | "open"
+            | "watch"
             | "search"
             | "info"
             | "install"