feat: -d/--detach flag for non-interactive use

p/src/cli.rs

@@ -14,7 +14,10 @@ Run on a specific worker:
   p <worker> -- <command>
 
 Skip directory sync:
-  p -n -- <command>"
+  p -n -- <command>
+
+Detach immediately and print the job ID (for scripting / AI agents):
+  p -d -- <command>"
 )]
 pub struct Cli {
     #[command(subcommand)]

p/src/commands/run.rs

@@ -1,6 +1,7 @@
 use anyhow::{Context, Result};
 use base64::{engine::general_purpose::STANDARD as B64, Engine};
 use chrono::Utc;
+use std::io::IsTerminal;
 use uuid::Uuid;
 
 use crate::{
@@ -9,10 +10,19 @@ use crate::{
     ssh, sync,
 };
 
-pub fn execute(worker_name: Option<&str>, cmd: Vec<String>, no_sync: bool) -> Result<()> {
+pub fn execute(
+    worker_name: Option<&str>,
+    cmd: Vec<String>,
+    no_sync: bool,
+    detach: bool,
+) -> Result<()> {
     let cfg = config::load()?;
     let worker = cfg.resolve_worker(worker_name)?.clone();
 
+    // Auto-detach when stdout is not a terminal (pipe, script, AI agent, etc.).
+    // Explicit -d also sets detach=true before we get here.
+    let detach = detach || !std::io::stdout().is_terminal();
+
     let id = Uuid::new_v4().to_string();
     let short_id = &id[..8];
     let session = format!("p-{}", short_id);
@@ -41,9 +51,13 @@ pub fn execute(worker_name: Option<&str>, cmd: Vec<String>, no_sync: bool) -> Re
     // ── 2. Sync directory ─────────────────────────────────────────────────────
 
     if no_sync {
-        eprintln!("Skipping sync (--no-sync).");
+        if !detach {
+            eprintln!("Skipping sync (--no-sync).");
+        }
     } else {
-        eprintln!("Syncing to {}...", worker.name);
+        if !detach {
+            eprintln!("Syncing to {}...", worker.name);
+        }
         sync::push_dir(&worker, &std::env::current_dir()?, &work_dir)
             .context("directory sync failed")?;
     }
@@ -84,13 +98,23 @@ pub fn execute(worker_name: Option<&str>, cmd: Vec<String>, no_sync: bool) -> Re
 
     ssh::run_capture(&worker, &setup).context("failed to set up job on worker")?;
 
-    // ── 4. Attach to the tmux session ─────────────────────────────────────────
-    //    run.sh keeps the session alive after the job finishes (via `read`),
-    //    so there is no race between job completion and our attach call.
+    // ── 4. Attach or detach ───────────────────────────────────────────────────────
+
+    if detach {
+        // Non-interactive mode: print only the job UUID to stdout and exit.
+        // stderr is kept clean so the caller can capture just the ID:
+        //   p logs $(p -d -- make)
+        println!("{}", id);
+        return Ok(());
+    }
+
+    // Interactive mode: attach to the tmux session.
+    // run.sh keeps the session alive after the job finishes (via `read`),
+    // so there is no race between job completion and our attach call.
     //
-    //    Ctrl+B D detaches cleanly mid-run; the job keeps going in the background.
-    //    Any other key on the "press any key" screen triggers `tmux detach-client`
-    //    from within run.sh — no [exited] or [detached] flash.
+    // Ctrl+B D detaches cleanly mid-run; the job keeps going in the background.
+    // Any other key on the "press any key" screen triggers `tmux detach-client`
+    // from within run.sh — no [exited] or [detached] flash.
 
     let sid = short_id.to_string();
     ctrlc::set_handler(move || {

p/src/main.rs

@@ -20,19 +20,21 @@ fn main() -> Result<()> {
 
         if cmd.is_empty() {
             eprintln!("error: no command specified after --");
-            eprintln!("usage: p [-n] [<worker>] -- <command>");
+            eprintln!("usage: p [-n] [-d] [<worker>] -- <command>");
             std::process::exit(1);
         }
 
         let mut no_sync = false;
+        let mut detach = false;
         let mut worker: Option<String> = None;
 
         for arg in pre {
             match arg.as_str() {
                 "-n" | "--no-sync" => no_sync = true,
+                "-d" | "--detach" => detach = true,
                 flag if flag.starts_with('-') => {
                     eprintln!(
-                        "error: unknown flag '{}'\nusage: p [-n] [<worker>] -- <command>",
+                        "error: unknown flag '{}'\nusage: p [-n] [-d] [<worker>] -- <command>",
                         flag
                     );
                     std::process::exit(1);
@@ -47,7 +49,7 @@ fn main() -> Result<()> {
             }
         }
 
-        return commands::run::execute(worker.as_deref(), cmd, no_sync);
+        return commands::run::execute(worker.as_deref(), cmd, no_sync, detach);
     }
 
     // All other subcommands go through clap.

p/src/sync.rs

@@ -1,5 +1,6 @@
 // Directory sync via rsync over SSH.
 use anyhow::{Context, Result};
+use std::io::IsTerminal;
 use std::path::Path;
 use std::process::Command;
 
@@ -13,7 +14,12 @@ pub fn push_dir(worker: &WorkerConfig, local_dir: &Path, remote_path: &str) -> R
     let (user_host, port) = parse_connection(&worker.connection);
 
     let mut cmd = Command::new("rsync");
-    cmd.args(["-az", "--info=progress2", "--filter=:- .gitignore"]);
+    // Only show progress when there is a human watching.
+    if std::io::stdout().is_terminal() {
+        cmd.args(["-az", "--info=progress2", "--filter=:- .gitignore"]);
+    } else {
+        cmd.args(["-az", "--filter=:- .gitignore"]);
+    }
 
     if let Some(p) = port {
         cmd.arg(format!("-e=ssh -p {}", p));