diff --git a/crates/ipx/src/daemon.rs b/crates/ipx/src/daemon.rs
index 94e5974..93dc60d 100644
--- a/crates/ipx/src/daemon.rs
+++ b/crates/ipx/src/daemon.rs
@@ -358,6 +358,16 @@ mod tests {
     use super::*;
     use crate::test_util::{feed, test_ctx};
 
+    #[tokio::test]
+    async fn the_daemon_sleeps_at_least_30_s_and_at_most_10_minutes() {
+        let ctx = test_ctx(config::Config::default()).await;
+        assert_eq!(until_next_scan(&ctx).await, Duration::from_secs(600), "nothing to check: the ceiling");
+        let mut cfg = config::Config::default();
+        cfg.feeds.insert("never-checked".into(), feed());
+        let ctx = test_ctx(cfg).await;
+        assert_eq!(until_next_scan(&ctx).await, Duration::from_secs(30), "due now: the floor, not a spin");
+    }
+
     #[tokio::test]
     async fn a_reload_takes_the_catalogue_another_ipx_wrote() {
         let with = |id: &str| {
diff --git a/crates/ipx/tests/daemon.rs b/crates/ipx/tests/daemon.rs
new file mode 100644
index 0000000..a095dca
--- /dev/null
+++ b/crates/ipx/tests/daemon.rs
@@ -0,0 +1,218 @@
+//! The daemon as production runs it: the built binary, a scratch config and SQLite database, a
+//! feed served from this process, and SIGTERM sent as Docker sends it (#400). A process of its
+//! own, because a signal sent to the test binary would reach every test in it.
+
+use std::io::{BufRead, BufReader, Read, Write};
+use std::net::{TcpListener, TcpStream};
+use std::path::{Path, PathBuf};
+use std::process::{Child, Command, Output, Stdio};
+use std::time::{Duration, Instant};
+
+const EPISODE_BYTES: u64 = 50_000_000;
+
+/// A feed of one episode, and the episode, sent 4 KB every 50 ms: a download that takes minutes.
+fn serve_feed() -> u16 {
+    let l = TcpListener::bind("127.0.0.1:0").unwrap();
+    let port = l.local_addr().unwrap().port();
+    std::thread::spawn(move || {
+        for sock in l.incoming().flatten() {
+            std::thread::spawn(move || answer(sock, port));
+        }
+    });
+    port
+}
+
+fn answer(mut sock: TcpStream, port: u16) {
+    let mut line = String::new();
+    if BufReader::new(&sock).read_line(&mut line).is_err() {
+        return;
+    }
+    if line.contains("/ep.mp3") {
+        let head = format!("HTTP/1.1 200 OK\r\nContent-Type: audio/mpeg\r\nContent-Length: {EPISODE_BYTES}\r\n\r\n");
+        // An MP3's frame sync first, so the file is taken for audio.
+        let mut chunk = vec![0u8; 4096];
+        chunk[..2].copy_from_slice(&[0xFF, 0xFB]);
+        if sock.write_all(head.as_bytes()).is_err() {
+            return;
+        }
+        while sock.write_all(&chunk).is_ok() {
+            chunk[..2].fill(0);
+            std::thread::sleep(Duration::from_millis(50));
+        }
+        return;
+    }
+    let body = format!(
+        r#"<?xml version="1.0"?><rss version="2.0"><channel><title>Slow</title><item><title>One</title><guid>g1</guid><enclosure url="http://127.0.0.1:{port}/ep.mp3" type="audio/mpeg" length="{EPISODE_BYTES}"/></item></channel></rss>"#
+    );
+    let _ = sock.write_all(format!("HTTP/1.1 200 OK\r\nContent-Length: {}\r\n\r\n{body}", body.len()).as_bytes());
+}
+
+struct Scratch {
+    root: PathBuf,
+    web: u16,
+}
+
+impl Scratch {
+    fn new(feed_port: u16) -> Self {
+        let root = std::env::temp_dir().join(format!("ipx-daemon-test-{}", std::process::id()));
+        let _ = std::fs::remove_dir_all(&root);
+        std::fs::create_dir_all(root.join("data")).unwrap();
+        let web = TcpListener::bind("127.0.0.1:0").unwrap().local_addr().unwrap().port();
+        std::fs::write(
+            root.join("config.toml"),
+            format!(
+                r#"[general]
+download_dir = "{root}/downloads"
+socket = "{root}/ipx.sock"
+schedule = "every 60m"
+fetch_internal = ["127.0.0.1"]
+
+[torrent]
+enabled = false
+
+[web]
+enabled = true
+bind = "127.0.0.1:{web}"
+token = ""
+
+[feeds.slow]
+url = "http://127.0.0.1:{feed_port}/feed.xml"
+"#,
+                root = root.display()
+            ),
+        )
+        .unwrap();
+        Self { root, web }
+    }
+
+    fn ipx(&self, args: &[&str]) -> Command {
+        let mut c = Command::new(env!("CARGO_BIN_EXE_ipx"));
+        c.args(args)
+            .env("IPX_CONFIG", self.root.join("config.toml"))
+            .env("IPX_DATA_DIR", self.root.join("data"))
+            .env("IPX_ADMIN_PASSWORD", "a test password")
+            .env("IPX_LOG", "ipx=info")
+            .stdin(Stdio::null());
+        // Nothing of the shell's: no Postgres, no traces, no JSON log, no TypeSafe key.
+        for v in
+            ["IPX_DATABASE_URL", "OTEL_EXPORTER_OTLP_ENDPOINT", "IPX_LOG_FORMAT", "TYPESAFE_KEY", "IPX_TYPESAFE_URL"]
+        {
+            c.env_remove(v);
+        }
+        c
+    }
+
+    fn run(&self, args: &[&str]) -> Output {
+        self.ipx(args).output().unwrap()
+    }
+
+    /// A daemon, its log going to `log`.
+    fn daemon(&self, log: &str) -> Child {
+        let log = std::fs::File::create(self.root.join(log)).unwrap();
+        self.ipx(&["daemon"]).stdout(Stdio::null()).stderr(log).spawn().unwrap()
+    }
+
+    fn log(&self, name: &str) -> String {
+        std::fs::read_to_string(self.root.join(name)).unwrap_or_default()
+    }
+
+    fn socket(&self) -> PathBuf {
+        self.root.join("ipx.sock")
+    }
+
+    /// Bytes of the download under way, in the downloads folder's incomplete files.
+    fn downloading(&self) -> u64 {
+        let dir = self.root.join("downloads/.ipx-incomplete");
+        std::fs::read_dir(dir).map_or(0, |d| d.flatten().filter_map(|e| e.metadata().ok()).map(|m| m.len()).sum())
+    }
+}
+
+fn until(what: &str, limit: Duration, mut ok: impl FnMut() -> bool) {
+    let started = Instant::now();
+    while !ok() {
+        assert!(started.elapsed() < limit, "{what}: not after {limit:?}");
+        std::thread::sleep(Duration::from_millis(100));
+    }
+}
+
+fn text(o: &Output) -> String {
+    format!("{}{}", String::from_utf8_lossy(&o.stdout), String::from_utf8_lossy(&o.stderr))
+}
+
+/// SIGTERM, as `docker stop` sends; how long it took to exit.
+fn terminate(child: &mut Child) -> Duration {
+    let started = Instant::now();
+    assert!(Command::new("kill").args(["-TERM", &child.id().to_string()]).status().unwrap().success());
+    loop {
+        if let Some(status) = child.try_wait().unwrap() {
+            assert!(status.success(), "the daemon exited {status}");
+            return started.elapsed();
+        }
+        if started.elapsed() > Duration::from_secs(10) {
+            let _ = child.kill();
+            panic!("the daemon ignored SIGTERM for 10 s");
+        }
+        std::thread::sleep(Duration::from_millis(50));
+    }
+}
+
+fn get(port: u16, path: &str) -> String {
+    let mut s = TcpStream::connect(("127.0.0.1", port)).unwrap();
+    write!(s, "GET {path} HTTP/1.1\r\nHost: 127.0.0.1\r\nConnection: close\r\n\r\n").unwrap();
+    let mut out = String::new();
+    let _ = s.read_to_string(&mut out);
+    out
+}
+
+fn token_in(config: &Path) -> String {
+    let text = std::fs::read_to_string(config).unwrap();
+    let line = text.lines().find(|l| l.trim_start().starts_with("token")).expect("a token line");
+    line.split('"').nth(1).unwrap_or("").to_owned()
+}
+
+#[test]
+fn the_daemon_starts_answers_refuses_a_second_and_stops_on_sigterm_mid_download() {
+    let s = Scratch::new(serve_feed());
+    let mut first = s.daemon("first.log");
+    until("the control socket", Duration::from_secs(60), || s.socket().exists() && s.run(&["status"]).status.success());
+
+    // Through the socket: the daemon's own answer, in words.
+    let status = s.run(&["status"]);
+    assert!(text(&status).contains("1 feeds,"), "{}", text(&status));
+    let local = s.run(&["--local", "status"]);
+    assert!(local.status.success() && text(&local).contains("1 feeds,"), "{}", text(&local));
+
+    // A first start with no token writes one, and it signs in.
+    let token = token_in(&s.root.join("config.toml"));
+    assert_eq!(token.len(), 64, "a session-strength token");
+    assert!(!s.log("first.log").contains(&token), "the log says where the token is, never what it is");
+    let me = get(s.web, &format!("/api/me?token={token}"));
+    assert!(me.starts_with("HTTP/1.1 200"), "{me}");
+    assert!(get(s.web, "/api/me").starts_with("HTTP/1.1 401"));
+
+    // Two daemons on one socket would fight over the database.
+    let second = s.ipx(&["daemon"]).output().unwrap();
+    assert!(!second.status.success());
+    assert!(text(&second).contains("a daemon is already listening"), "{}", text(&second));
+    assert!(s.run(&["status"]).status.success(), "the first is still serving");
+
+    // The first pass starts at once and takes the episode, which takes minutes. SIGTERM stops it.
+    until("the download to start", Duration::from_secs(60), || s.downloading() > 0);
+    let took = terminate(&mut first);
+    assert!(took < Duration::from_secs(5), "stopped in {took:?}");
+    assert!(!s.socket().exists(), "the socket is removed");
+    assert!(s.log("first.log").contains("abandoning the job in progress"), "{}", s.log("first.log"));
+
+    // Never recorded, the abandoned file is still queued, not lost or marked failed. The next start
+    // takes it at its feed's next check, not at once (#410).
+    let queued = s.run(&["--local", "status"]);
+    assert!(text(&queued).contains("1 queued to download, 0 downloaded"), "{}", text(&queued));
+    let mut again = s.daemon("again.log");
+    until("the restarted daemon", Duration::from_secs(60), || s.log("again.log").contains("daemon started"));
+    terminate(&mut again);
+
+    // No daemon: the command does the work itself.
+    let alone = s.run(&["status"]);
+    assert!(alone.status.success() && text(&alone).contains("1 feeds,"), "{}", text(&alone));
+    let _ = std::fs::remove_dir_all(&s.root);
+}