diff --git a/src/cli.rs b/src/cli.rs
index 7200884..54c4d81 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -169,6 +169,27 @@ pub enum Command {
         #[arg(long, value_name = "CATEGORY")]
         category: Option<String>,
     },
+    /// Search the command history (am and shell commands)
+    History {
+        /// Only commands of this kind (am or shell)
+        #[arg(long, value_name = "KIND")]
+        kind: Option<String>,
+        /// Only commands run in this directory
+        #[arg(long, value_name = "DIR")]
+        cwd: Option<String>,
+        /// Full-text search in the command line
+        #[arg(long, value_name = "TEXT")]
+        search: Option<String>,
+        /// Only failed commands
+        #[arg(long)]
+        failed: bool,
+        /// Only commands of this session
+        #[arg(long, value_name = "ID")]
+        session: Option<String>,
+        /// Maximum number of entries (default: 100)
+        #[arg(long, value_name = "N", default_value = "100")]
+        limit: usize,
+    },
     /// Show detailed information about one agent
     Info {
         /// Agent name or alias
diff --git a/src/commands/history_cmd.rs b/src/commands/history_cmd.rs
new file mode 100644
index 0000000..63df270
--- /dev/null
+++ b/src/commands/history_cmd.rs
@@ -0,0 +1,96 @@
+//! history: search and reuse the structured command history.
+
+use super::*;
+use crate::history::{self, HistoryEntry};
+use crate::output::print_json;
+
+/// Filter history entries; returns them most recent first.
+pub fn filter(
+    app: &App,
+    kind: Option<&str>,
+    cwd: Option<&str>,
+    search: Option<&str>,
+    failed: bool,
+    session: Option<&str>,
+    limit: usize,
+) -> Vec<(String, HistoryEntry)> {
+    let _ = session; // session filtering happens by reading one file directly
+    let mut out: Vec<(String, HistoryEntry)> = Vec::new();
+    let dir = history::dir(app);
+    for f in history::files(&dir).iter().rev() {
+        let sid = history::session_of_file(f).unwrap_or_default();
+        if let Some(s) = session {
+            if sid != s {
+                continue;
+            }
+        }
+        let Ok(text) = std::fs::read_to_string(f) else {
+            continue;
+        };
+        let mut entries: Vec<HistoryEntry> = text
+            .lines()
+            .filter(|l| !l.trim().is_empty())
+            .filter_map(|l| serde_json::from_str::<HistoryEntry>(l).ok())
+            .collect();
+        entries.reverse();
+        for e in entries {
+            if kind.map_or(true, |k| e.kind == k)
+                && cwd.map_or(true, |c| e.cwd.as_deref() == Some(c))
+                && search.map_or(true, |s| e.cmd.to_lowercase().contains(&s.to_lowercase()))
+                && (!failed || e.exit_code.is_some())
+            {
+                out.push((sid.clone(), e));
+                if limit > 0 && out.len() >= limit {
+                    return out;
+                }
+            }
+        }
+    }
+    out
+}
+
+pub fn run(
+    app: &App,
+    kind: Option<&str>,
+    cwd: Option<&str>,
+    search: Option<&str>,
+    failed: bool,
+    session: Option<&str>,
+    limit: usize,
+) -> Result<i32> {
+    history::migrate(app)?;
+    let rows = filter(app, kind, cwd, search, failed, session, limit);
+    if app.json() {
+        let payload: Vec<serde_json::Value> = rows
+            .iter()
+            .enumerate()
+            .map(|(i, (sid, e))| {
+                serde_json::json!({
+                    "n": rows.len() - i,
+                    "ts": e.ts,
+                    "cmd": e.cmd,
+                    "kind": e.kind,
+                    "cwd": e.cwd,
+                    "exit_code": e.exit_code,
+                    "duration_ms": e.duration_ms,
+                    "session": sid,
+                })
+            })
+            .collect();
+        print_json(&payload);
+        return Ok(0);
+    }
+    for (i, (_sid, e)) in rows.iter().enumerate() {
+        let n = rows.len() - i;
+        let ts = e.ts.get(0..16).unwrap_or(&e.ts);
+        let flag = match e.exit_code {
+            Some(_) => "✗".to_string(),
+            None => " ".to_string(),
+        };
+        println!("{n:>4} {flag} {ts}  {}", e.cmd);
+    }
+    if rows.is_empty() {
+        app.log.info("no matching history — run 'am' and type some commands");
+    }
+    Ok(0)
+}
diff --git a/src/commands/mod.rs b/src/commands/mod.rs
index f31fbfd..dcbbce7 100644
--- a/src/commands/mod.rs
+++ b/src/commands/mod.rs
@@ -5,6 +5,7 @@ pub mod config_cmd;
 pub mod doctor_cmd;
 pub mod export_import;
 pub mod help_cmd;
+pub mod history_cmd;
 pub mod info_cmd;
 pub mod install_cmd;
 pub mod list_cmd;
@@ -78,6 +79,22 @@ pub fn execute_command(app: &App, cmd: &Command) -> Result<i32> {
         Command::Uninstall { agent, purge } => uninstall_cmd::run(app, agent, *purge),
         Command::Update { agent, all } => update_cmd::run(app, agent.as_deref(), *all),
         Command::Search { keyword, category } => search_cmd::run(app, keyword, category.as_deref()),
+        Command::History {
+            kind,
+            cwd,
+            search,
+            failed,
+            session,
+            limit,
+        } => history_cmd::run(
+            app,
+            kind.as_deref(),
+            cwd.as_deref(),
+            search.as_deref(),
+            *failed,
+            session.as_deref(),
+            *limit,
+        ),
         Command::Info { agent } => info_cmd::run(app, agent),
         Command::Help { command, find } => help_cmd::run(app, command.as_deref(), find.as_deref()),
         Command::Version => version_cmd::run(app),
diff --git a/src/help.rs b/src/help.rs
index 857aeca..714dc33 100644
--- a/src/help.rs
+++ b/src/help.rs
@@ -238,6 +238,28 @@ pub static HELP_SPECS: &[HelpSpec] = &[
             HelpExample { desc: "Starts of one agent since a date.", code: "log claude-code --kind start --since 2026-08-01" },
         ],
     },
+    HelpSpec {
+        name: "history",
+        category: "Commands",
+        usage: "history {flags}",
+        about: "Search the command history (am and shell commands).",
+        search_terms: &["past", "commands", "rerun"],
+        flags: &[
+            HelpFlag { short: "", long: "--kind", value: "KIND", desc: "Only commands of this kind (am or shell)" },
+            HelpFlag { short: "", long: "--cwd", value: "DIR", desc: "Only commands run in this directory" },
+            HelpFlag { short: "", long: "--search", value: "TEXT", desc: "Full-text search in the command line" },
+            HelpFlag { short: "", long: "--failed", value: "", desc: "Only failed commands" },
+            HelpFlag { short: "", long: "--session", value: "ID", desc: "Only commands of this session" },
+        ],
+        subcommands: &[],
+        parameters: &[],
+        io: None,
+        examples: &[
+            HelpExample { desc: "The last 100 commands.", code: "history" },
+            HelpExample { desc: "Find past installs.", code: "history --search install" },
+            HelpExample { desc: "Failed commands only.", code: "history --failed" },
+        ],
+    },
     HelpSpec {
         name: "search",
         category: "Commands",
diff --git a/src/history.rs b/src/history.rs
new file mode 100644
index 0000000..b93d83f
--- /dev/null
+++ b/src/history.rs
@@ -0,0 +1,274 @@
+//! Structured command history: one JSONL file per REPL session under
+//! history/<session>.jsonl. Replaces the flat history.txt (imported once).
+
+use crate::app::App;
+use anyhow::{anyhow, Context, Result};
+use serde::{Deserialize, Serialize};
+use std::path::{Path, PathBuf};
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct HistoryEntry {
+    /// RFC 3339 timestamp.
+    pub ts: String,
+    pub cmd: String,
+    /// "am" (agent-manager command) or "shell" (system gateway command).
+    #[serde(default = "kind_am")]
+    pub kind: String,
+    #[serde(default)]
+    pub cwd: Option<String>,
+    #[serde(default)]
+    pub exit_code: Option<i32>,
+    #[serde(default)]
+    pub duration_ms: Option<u64>,
+    #[serde(default)]
+    pub agent: Option<String>,
+}
+
+fn kind_am() -> String {
+    "am".to_string()
+}
+
+impl HistoryEntry {
+    pub fn now(cmd: impl Into<String>) -> Self {
+        HistoryEntry {
+            ts: crate::installers::now_rfc3339(),
+            cmd: cmd.into(),
+            kind: "am".to_string(),
+            cwd: None,
+            exit_code: None,
+            duration_ms: None,
+            agent: None,
+        }
+    }
+
+    pub fn with_kind(mut self, kind: impl Into<String>) -> Self {
+        self.kind = kind.into();
+        self
+    }
+
+    pub fn with_cwd(mut self, cwd: Option<String>) -> Self {
+        self.cwd = cwd;
+        self
+    }
+
+    pub fn with_exit_code(mut self, code: Option<i32>) -> Self {
+        self.exit_code = code;
+        self
+    }
+
+    pub fn with_duration_ms(mut self, ms: u64) -> Self {
+        self.duration_ms = Some(ms);
+        self
+    }
+
+    pub fn with_agent(mut self, agent: Option<String>) -> Self {
+        self.agent = agent;
+        self
+    }
+}
+
+/// Directory holding the per-session history files.
+pub fn dir(app: &App) -> PathBuf {
+    app.events_dir().join("history")
+}
+
+/// Append one entry to the session file of a REPL session.
+pub fn record(app: &App, session: &str, entry: &HistoryEntry) -> Result<()> {
+    let d = dir(app);
+    std::fs::create_dir_all(&d).ok();
+    let path = d.join(format!("{session}.jsonl"));
+    let line = serde_json::to_string(entry)?;
+    let mut f = std::fs::OpenOptions::new()
+        .create(true)
+        .append(true)
+        .open(&path)
+        .with_context(|| format!("cannot open history file {}", path.display()))?;
+    use std::io::Write;
+    f.write_all(line.as_bytes())?;
+    f.write_all(b"\n")?;
+    Ok(())
+}
+
+/// One-shot migration: import the flat history.txt into the structured
+/// directory. Returns the number of imported entries.
+pub fn migrate(app: &App) -> Result<usize> {
+    let txt = app.paths.state_file.with_file_name("history.txt");
+    if !txt.exists() {
+        return Ok(0);
+    }
+    let d = dir(app);
+    let already = d.join("migrated.jsonl").exists();
+    if already {
+        return Ok(0);
+    }
+    let text = std::fs::read_to_string(&txt)
+        .with_context(|| format!("cannot read {}", txt.display()))?;
+    let mut count = 0;
+    for line in text.lines() {
+        let trimmed = line.trim();
+        if trimmed.is_empty() || trimmed.starts_with('#') {
+            continue;
+        }
+        let entry = HistoryEntry::now(trimmed.to_string())
+            .with_kind("am".to_string())
+            .with_cwd(None);
+        record(app, "migrated", &entry)?;
+        count += 1;
+    }
+    Ok(count)
+}
+
+/// History files of a directory, oldest first.
+pub fn files(dir: &Path) -> Vec<PathBuf> {
+    let mut out: Vec<PathBuf> = std::fs::read_dir(dir)
+        .map(|rd| {
+            rd.flatten()
+                .map(|e| e.path())
+                .filter(|p| p.is_file())
+                .filter(|p| p.extension().and_then(|e| e.to_str()) == Some("jsonl"))
+                .collect()
+        })
+        .unwrap_or_default();
+    out.sort();
+    out
+}
+
+/// Read all entries across sessions, most recent first. Corrupt lines are
+/// skipped silently.
+pub fn read_all(app: &App, limit: usize) -> Vec<HistoryEntry> {
+    let d = dir(app);
+    let mut out: Vec<HistoryEntry> = Vec::new();
+    for f in files(&d).iter().rev() {
+        if let Ok(text) = std::fs::read_to_string(f) {
+            let mut entries: Vec<HistoryEntry> = text
+                .lines()
+                .filter(|l| !l.trim().is_empty())
+                .filter_map(|l| serde_json::from_str::<HistoryEntry>(l).ok())
+                .collect();
+            entries.reverse(); // newest first within one file
+            out.extend(entries);
+            if limit > 0 && out.len() >= limit {
+                break;
+            }
+        }
+    }
+    if limit > 0 {
+        out.truncate(limit);
+    }
+    out
+}
+
+/// Parse the session id from a history file name ("20260815_143926.jsonl").
+pub fn session_of_file(path: &Path) -> Option<String> {
+    path.file_name()
+        .and_then(|n| n.to_str())
+        .map(|n| n.trim_end_matches(".jsonl").to_string())
+}
+
+/// Corrupt-history guard: a session file that cannot be parsed is reported,
+/// never fatal.
+pub fn validate_file(path: &Path) -> Result<()> {
+    let text = std::fs::read_to_string(path)
+        .with_context(|| format!("cannot read history file {}", path.display()))?;
+    for (i, line) in text.lines().enumerate() {
+        if line.trim().is_empty() {
+            continue;
+        }
+        serde_json::from_str::<HistoryEntry>(line).map_err(|e| {
+            anyhow!("history file {} line {} is corrupt: {e}", path.display(), i + 1)
+        })?;
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use clap::Parser;
+
+    fn test_app(tag: &str) -> App {
+        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;
+        let _ = tag;
+        app
+    }
+
+    #[test]
+    fn record_and_read_back() {
+        let app = test_app("hist");
+        record(&app, "s1", &HistoryEntry::now("install jcode")).unwrap();
+        record(
+            &app,
+            "s1",
+            &HistoryEntry::now("ls").with_kind("shell".to_string()).with_duration_ms(12),
+        )
+        .unwrap();
+        let all = read_all(&app, 0);
+        assert_eq!(all.len(), 2);
+        assert_eq!(all[0].cmd, "ls", "most recent first");
+        assert_eq!(all[0].kind, "shell");
+        assert_eq!(all[0].duration_ms, Some(12));
+        assert_eq!(all[1].cmd, "install jcode");
+    }
+
+    #[test]
+    fn migration_imports_flat_file_once() {
+        let app = test_app("mig");
+        let txt = app.paths.state_file.with_file_name("history.txt");
+        std::fs::write(&txt, "install jcode
+start group:dev
+
+").unwrap();
+        assert_eq!(migrate(&app).unwrap(), 2);
+        assert_eq!(migrate(&app).unwrap(), 0, "second run is a no-op");
+        let all = read_all(&app, 0);
+        assert_eq!(all.len(), 2);
+        assert_eq!(all[0].cmd, "start group:dev");
+    }
+
+    #[test]
+    fn corrupt_lines_are_skipped() {
+        let app = test_app("corrupt");
+        record(&app, "s1", &HistoryEntry::now("list")).unwrap();
+        // Append garbage to the session file.
+        let d = dir(&app);
+        let f = d.join("s1.jsonl");
+        let mut text = std::fs::read_to_string(&f).unwrap();
+        text.push_str("not json at all
+");
+        std::fs::write(&f, text).unwrap();
+        let all = read_all(&app, 0);
+        assert_eq!(all.len(), 1);
+        assert!(validate_file(&f).is_err());
+    }
+
+    #[test]
+    fn session_of_file_extracts_id() {
+        assert_eq!(
+            session_of_file(Path::new("20260815_143926.jsonl")),
+            Some("20260815_143926".to_string())
+        );
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index b581d10..85b1a62 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -21,6 +21,7 @@ pub mod doctor;
 pub mod download;
 pub mod events;
 pub mod help;
+pub mod history;
 pub mod installers;
 pub mod nav;
 pub mod output;
diff --git a/src/repl.rs b/src/repl.rs
index f26dacc..679318f 100644
--- a/src/repl.rs
+++ b/src/repl.rs
@@ -63,6 +63,7 @@ const COMMAND_DESCRIPTIONS: &[(&str, &str)] = &[
     ("sessions", "list agent sessions"),
     ("stats", "usage statistics"),
     ("log", "read the event journal"),
+    ("history", "search command history"),
     ("search", "search the catalog"),
     ("info", "agent details"),
     ("install", "install an agent"),
@@ -139,7 +140,7 @@ impl AmCompleter {
         Self {
             theme: std::cell::Cell::new(crate::theme::default_theme()),
             commands: vec![
-                "list", "status", "sessions", "stats", "log", "search", "info", "install", "uninstall", "update",
+                "list", "status", "sessions", "stats", "log", "history", "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",
@@ -894,21 +895,24 @@ pub fn run(app: &App) -> Result<i32> {
             .with_cwd(Some(current_dir_string())),
     );
     let _ = crate::sessions::start_repl(app, &sid, Some(current_dir_string()));
+    if let Err(e) = crate::history::migrate(app) {
+        app.log.verbose(&format!("history migration skipped: {e:#}"));
+    }
     print!("{}", banner(app, &session, &sid));
-    let result = match run_with_editor(app, &mut session) {
+    let result = match run_with_editor(app, &mut session, &sid) {
         Ok(code) => Ok(code),
         Err(e) => {
             app.log.verbose(&format!(
                 "line editor unavailable ({e:#}); falling back to plain input"
             ));
-            run_plain(app, &mut session)
+            run_plain(app, &mut session, &sid)
         }
     };
     let _ = crate::sessions::finish_repl(app, &sid);
     result
 }
 
-fn run_with_editor(app: &App, session: &mut ShellSession) -> Result<i32> {
+fn run_with_editor(app: &App, session: &mut ShellSession, sid: &str) -> Result<i32> {
     let mut rl: rustyline::Editor<AmCompleter, rustyline::history::FileHistory> =
         rustyline::Editor::new()?;
     rl.set_helper(Some(AmCompleter::new(app)));
@@ -936,6 +940,7 @@ fn run_with_editor(app: &App, session: &mut ShellSession) -> Result<i32> {
                 let t = Instant::now();
                 let result = handle_input(app, session, &mut last, &trimmed);
                 last_duration = Some(t.elapsed());
+                record_history(app, sid, &trimmed, &result, t.elapsed());
                 // 'theme <name>' may have switched the app theme: repoint the
                 // completion menu at the new palette.
                 if let Some(h) = rl.helper_mut() {
@@ -959,8 +964,33 @@ fn run_with_editor(app: &App, session: &mut ShellSession) -> Result<i32> {
     Ok(0)
 }
 
+/// Append one structured history entry for a REPL command.
+fn record_history(
+    app: &App,
+    sid: &str,
+    line: &str,
+    result: &Result<bool>,
+    elapsed: std::time::Duration,
+) {
+    let kind = if is_am_command(line.split_whitespace().next().unwrap_or("")) {
+        "am"
+    } else {
+        "shell"
+    };
+    let exit_code = if result.is_err() { Some(1) } else { None };
+    let _ = crate::history::record(
+        app,
+        sid,
+        &crate::history::HistoryEntry::now(line.to_string())
+            .with_kind(kind.to_string())
+            .with_cwd(Some(current_dir_string()))
+            .with_exit_code(exit_code)
+            .with_duration_ms(elapsed.as_millis() as u64),
+    );
+}
+
 /// Plain fallback when no terminal/line editor is available.
-fn run_plain(app: &App, session: &mut ShellSession) -> Result<i32> {
+fn run_plain(app: &App, session: &mut ShellSession, sid: &str) -> Result<i32> {
     let started = Instant::now();
     let mut last: Option<DataTable> = None;
     let mut last_duration: Option<Duration> = None;
@@ -979,6 +1009,7 @@ fn run_plain(app: &App, session: &mut ShellSession) -> Result<i32> {
         let t = Instant::now();
         let result = handle_input(app, session, &mut last, &line);
         last_duration = Some(t.elapsed());
+        record_history(app, sid, &line, &result, t.elapsed());
         match result {
             Ok(true) => break,
             Ok(false) => {}
@@ -1273,6 +1304,10 @@ fn is_am_command(word: &str) -> bool {
         word,
         "list"
             | "status"
+            | "sessions"
+            | "stats"
+            | "log"
+            | "history"
             | "search"
             | "info"
             | "install"
diff --git a/tests/history_test.rs b/tests/history_test.rs
new file mode 100644
index 0000000..c1fbc20
--- /dev/null
+++ b/tests/history_test.rs
@@ -0,0 +1,105 @@
+//! Structured history: record, read, filter, migration, command.
+
+mod common;
+
+use agent_manager::commands::history_cmd;
+use agent_manager::history::{self, HistoryEntry};
+use std::path::PathBuf;
+
+#[test]
+fn cli_parses_history() {
+    use agent_manager::cli::{Cli, Command};
+    use clap::Parser;
+    let cli = Cli::parse_from(["am", "history", "--failed", "--search", "install"]);
+    match &cli.command {
+        Some(Command::History {
+            failed, search, ..
+        }) => {
+            assert!(*failed);
+            assert_eq!(search.as_deref(), Some("install"));
+        }
+        other => panic!("unexpected command: {other:?}"),
+    }
+}
+
+#[test]
+fn record_and_read_most_recent_first() {
+    let app = common::test_app("hist", &["history"]);
+    history::record(&app, "s1", &HistoryEntry::now("install jcode")).unwrap();
+    history::record(
+        &app,
+        "s1",
+        &HistoryEntry::now("ls")
+            .with_kind("shell".to_string())
+            .with_duration_ms(12),
+    )
+    .unwrap();
+    let all = history::read_all(&app, 0);
+    assert_eq!(all.len(), 2);
+    assert_eq!(all[0].cmd, "ls");
+    assert_eq!(all[0].kind, "shell");
+    assert_eq!(all[0].duration_ms, Some(12));
+    assert_eq!(all[1].cmd, "install jcode");
+}
+
+#[test]
+fn migration_imports_flat_history_once() {
+    let app = common::test_app("mig", &["history"]);
+    let txt = app.paths.state_file.with_file_name("history.txt");
+    std::fs::write(&txt, "install jcode
+start group:dev
+
+").unwrap();
+    assert_eq!(history::migrate(&app).unwrap(), 2);
+    assert_eq!(history::migrate(&app).unwrap(), 0, "no-op on second run");
+    let all = history::read_all(&app, 0);
+    assert_eq!(all.len(), 2);
+    assert_eq!(all[0].cmd, "start group:dev");
+}
+
+#[test]
+fn filters_by_kind_search_and_failed() {
+    let app = common::test_app("filt", &["history"]);
+    history::record(
+        &app,
+        "s1",
+        &HistoryEntry::now("install jcode")
+            .with_kind("am".to_string())
+            .with_exit_code(Some(1)),
+    )
+    .unwrap();
+    history::record(
+        &app,
+        "s1",
+        &HistoryEntry::now("ls -la")
+            .with_kind("shell".to_string())
+            .with_cwd(Some("/tmp".to_string())),
+    )
+    .unwrap();
+    assert_eq!(history_cmd::filter(&app, Some("shell"), None, None, false, None, 10).len(), 1);
+    assert_eq!(history_cmd::filter(&app, None, None, Some("install"), false, None, 10).len(), 1);
+    assert_eq!(history_cmd::filter(&app, None, None, None, true, None, 10).len(), 1);
+    assert_eq!(history_cmd::filter(&app, None, Some("/tmp"), None, false, None, 10).len(), 1);
+    assert_eq!(history_cmd::filter(&app, None, None, Some("zzz"), false, None, 10).len(), 0);
+}
+
+#[test]
+fn command_runs_and_migrates() {
+    let app = common::test_app("cmd", &["history"]);
+    let txt = app.paths.state_file.with_file_name("history.txt");
+    std::fs::write(&txt, "install jcode
+").unwrap();
+    let code = history_cmd::run(&app, None, None, None, false, None, 100).unwrap();
+    assert_eq!(code, 0);
+    // Migration created the structured file.
+    assert!(history::dir(&app).join("migrated.jsonl").exists());
+}
+
+#[test]
+fn fixture_session_file_parses() {
+    // Guard for session_of_file used by the display layer.
+    assert_eq!(
+        history::session_of_file(&PathBuf::from("20260815_143926.jsonl")),
+        Some("20260815_143926".to_string())
+    );
+}