feat: connect standalone host to local TUI

crates/client/src/lib.rs

@@ -37,9 +37,9 @@ pub use backend_workspace::{
 };
 pub use runtime_command::WorkerRuntimeCommand;
 pub use target::{
-    BackendTarget, Dashboard, LocalTarget, ResolvedTarget, Target, TargetError, TargetKind,
-    WorkerByName, WorkerConnection, WorkerConnectionSelector, WorkerList, WorkerListRequest,
-    WorkerResume, WorkerSpawn,
+    BackendTarget, Dashboard, LocalTarget, ResolvedTarget, StandaloneTarget, Target, TargetError,
+    TargetKind, WorkerByName, WorkerConnection, WorkerConnectionSelector, WorkerList,
+    WorkerListRequest, WorkerResume, WorkerSpawn,
 };
 
 pub use spawn::{

crates/client/src/target.rs

@@ -1,16 +1,20 @@
-use std::fmt;
+use std::{fmt, path::PathBuf};
 
 use crate::{BackendRuntimeListTarget, BackendRuntimeTarget, WorkerRuntimeCommand};
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum TargetKind {
+    /// Legacy local Runtime process/socket authority.
     Local,
+    /// One-process Standalone authority with no Runtime or Workspace backend.
+    Standalone,
     Backend,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum ResolvedTarget {
     Local,
+    Standalone,
     Backend {
         base_url: String,
         workspace_id: String,
@@ -21,6 +25,7 @@ impl ResolvedTarget {
     pub fn kind(&self) -> TargetKind {
         match self {
             Self::Local => TargetKind::Local,
+            Self::Standalone => TargetKind::Standalone,
             Self::Backend { .. } => TargetKind::Backend,
         }
     }
@@ -30,6 +35,7 @@ impl fmt::Display for TargetKind {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
             Self::Local => f.write_str("local"),
+            Self::Standalone => f.write_str("Standalone"),
             Self::Backend => f.write_str("Backend"),
         }
     }
@@ -107,8 +113,13 @@ impl WorkerConnectionSelector {
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct WorkerSpawn {
-    pub runtime_command: WorkerRuntimeCommand,
+pub enum WorkerSpawn {
+    LegacyLocal {
+        runtime_command: WorkerRuntimeCommand,
+    },
+    Standalone {
+        state_dir: PathBuf,
+    },
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -213,7 +224,7 @@ impl Target for LocalTarget {
     }
 
     fn spawn_worker(&self) -> Result<WorkerSpawn, TargetError> {
-        Ok(WorkerSpawn {
+        Ok(WorkerSpawn::LegacyLocal {
             runtime_command: self.runtime_command()?,
         })
     }
@@ -261,6 +272,65 @@ impl Target for LocalTarget {
     }
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct StandaloneTarget {
+    state_dir: PathBuf,
+}
+
+impl StandaloneTarget {
+    #[must_use]
+    pub fn new(state_dir: impl Into<PathBuf>) -> Self {
+        Self {
+            state_dir: state_dir.into(),
+        }
+    }
+}
+
+impl Target for StandaloneTarget {
+    fn kind(&self) -> TargetKind {
+        TargetKind::Standalone
+    }
+
+    fn resolve(&self) -> Result<ResolvedTarget, TargetError> {
+        Ok(ResolvedTarget::Standalone)
+    }
+
+    fn spawn_worker(&self) -> Result<WorkerSpawn, TargetError> {
+        Ok(WorkerSpawn::Standalone {
+            state_dir: self.state_dir.clone(),
+        })
+    }
+
+    fn worker_by_name(&self) -> Result<WorkerByName, TargetError> {
+        Err(TargetError::unsupported(
+            "Worker name attachment",
+            self.kind(),
+        ))
+    }
+
+    fn resume_worker(&self) -> Result<WorkerResume, TargetError> {
+        Err(TargetError::unsupported("Worker restore", self.kind()))
+    }
+
+    fn dashboard(&self) -> Result<Dashboard, TargetError> {
+        Err(TargetError::unsupported("Worker dashboard", self.kind()))
+    }
+
+    fn list_workers(&self, _request: WorkerListRequest) -> Result<WorkerList, TargetError> {
+        Err(TargetError::unsupported("Worker listing", self.kind()))
+    }
+
+    fn connect_worker(
+        &self,
+        _selector: WorkerConnectionSelector,
+    ) -> Result<WorkerConnection, TargetError> {
+        Err(TargetError::unsupported(
+            "Backend runtime worker connection",
+            self.kind(),
+        ))
+    }
+}
+
 impl Target for BackendTarget {
     fn kind(&self) -> TargetKind {
         TargetKind::Backend
@@ -303,7 +373,9 @@ impl Target for BackendTarget {
                 base_url,
                 workspace_id,
             }),
-            ResolvedTarget::Local => unreachable!("BackendTarget cannot resolve as Local"),
+            ResolvedTarget::Local | ResolvedTarget::Standalone => {
+                unreachable!("BackendTarget cannot resolve as a local target")
+            }
         }
     }
 
@@ -375,6 +447,37 @@ mod tests {
         assert_eq!(LocalTarget::new().resolve().unwrap(), ResolvedTarget::Local);
     }
 
+    #[test]
+    fn standalone_target_carries_in_process_state_without_resolving_runtime_command() {
+        let target = StandaloneTarget::new("/tmp/yoi-standalone-state");
+
+        assert_eq!(target.kind(), TargetKind::Standalone);
+        assert_eq!(target.resolve().unwrap(), ResolvedTarget::Standalone);
+        assert_eq!(
+            target.spawn_worker().unwrap(),
+            WorkerSpawn::Standalone {
+                state_dir: PathBuf::from("/tmp/yoi-standalone-state"),
+            }
+        );
+    }
+
+    #[test]
+    fn standalone_target_never_falls_back_to_legacy_local_operations() {
+        let target = StandaloneTarget::new("/tmp/yoi-standalone-state");
+
+        assert_eq!(
+            target.worker_by_name().unwrap_err().to_string(),
+            "Worker name attachment is not supported by Standalone target"
+        );
+        assert_eq!(
+            target
+                .list_workers(WorkerListRequest::new(None))
+                .unwrap_err()
+                .to_string(),
+            "Worker listing is not supported by Standalone target"
+        );
+    }
+
     #[test]
     fn backend_target_builds_workspace_scoped_dashboard() {
         let target = BackendTarget::new("http://127.0.0.1:8787", Some("workspace-a"));

crates/tui/Cargo.toml

@@ -10,6 +10,7 @@ e2e-test = []
 
 [dependencies]
 client = { workspace = true }
+standalone = { workspace = true }
 protocol = { workspace = true }
 ratatui = { version = "0.30.0", features = ["scrolling-regions"] }
 base64 = "0.22.1"

crates/tui/src/console/mod.rs

@@ -22,7 +22,8 @@ use protocol::{Greeting, RewindSummary, RewindTarget, RewindTargetId, Segment};
 use ratatui::Terminal;
 use ratatui::backend::CrosstermBackend;
 use session_store::SegmentId;
-use tokio::sync::mpsc;
+use standalone::{StandaloneHost, StandaloneLaunchConfig};
+use tokio::sync::{broadcast, mpsc};
 
 use base64::{Engine as _, engine::general_purpose::STANDARD as BASE64_STANDARD};
 use client::{BackendRuntimeClient, BackendRuntimeTarget, WorkerClient, WorkerRuntimeCommand};
@@ -174,13 +175,33 @@ pub(crate) async fn run_worker_name(
 enum ConsoleConnection {
     LegacySocket(WorkerClient),
     BackendRuntime(BackendRuntimeClient),
+    Standalone {
+        host: Option<StandaloneHost>,
+        events: broadcast::Receiver<Event>,
+        initial_snapshot: Option<Event>,
+    },
 }
 
 impl ConsoleConnection {
+    fn standalone(host: StandaloneHost) -> Self {
+        let events = host.subscribe();
+        let initial_snapshot = Some(host.snapshot());
+        Self::Standalone {
+            host: Some(host),
+            events,
+            initial_snapshot,
+        }
+    }
+
     fn try_next_event(&mut self) -> Option<Event> {
         match self {
             Self::LegacySocket(client) => client.try_next_event(),
             Self::BackendRuntime(client) => client.try_next_event(),
+            Self::Standalone {
+                events,
+                initial_snapshot,
+                ..
+            } => initial_snapshot.take().or_else(|| events.try_recv().ok()),
         }
     }
 
@@ -188,6 +209,18 @@ impl ConsoleConnection {
         match self {
             Self::LegacySocket(client) => client.next_event().await,
             Self::BackendRuntime(client) => client.next_event().await,
+            Self::Standalone { host, events, .. } => loop {
+                match events.recv().await {
+                    Ok(event) => break Some(event),
+                    Err(broadcast::error::RecvError::Lagged(_)) => {
+                        let Some(host) = host.as_ref() else {
+                            break None;
+                        };
+                        break Some(host.snapshot());
+                    }
+                    Err(broadcast::error::RecvError::Closed) => break None,
+                }
+            },
         }
     }
 
@@ -195,8 +228,78 @@ impl ConsoleConnection {
         match self {
             Self::LegacySocket(client) => Ok(client.send(method).await?),
             Self::BackendRuntime(client) => Ok(client.send(method).await?),
+            Self::Standalone { host, .. } => {
+                let host = host.as_ref().ok_or_else(|| {
+                    io::Error::new(
+                        io::ErrorKind::BrokenPipe,
+                        "Standalone Worker has already shut down",
+                    )
+                })?;
+                Ok(host.send(method.clone()).await?)
+            }
         }
     }
+
+    async fn shutdown(&mut self) -> Result<(), Box<dyn std::error::Error>> {
+        if let Self::Standalone { host, .. } = self
+            && let Some(host) = host.take()
+        {
+            host.shutdown().await?;
+        }
+        Ok(())
+    }
+}
+
+pub(crate) async fn run_standalone(
+    workspace_root: PathBuf,
+    state_dir: PathBuf,
+    worker_name: Option<String>,
+    profile: Option<String>,
+) -> Result<(), Box<dyn std::error::Error>> {
+    let worker_name = worker_name.unwrap_or_else(|| "local".to_string());
+    let profile = profile.map_or(manifest::ProfileSelector::Default, |profile| {
+        manifest::ProfileSelector::parse_cli(&profile)
+    });
+    let history_root = workspace_root.clone();
+    let launch = StandaloneLaunchConfig {
+        state_dir,
+        cwd: workspace_root,
+        profile,
+        worker_name: worker_name.clone(),
+    }
+    .resolve()
+    .map_err(|error| {
+        io::Error::new(
+            io::ErrorKind::InvalidInput,
+            format!("Standalone launch configuration failed: {error}"),
+        )
+    })?;
+    let host = StandaloneHost::start(launch)
+        .await
+        .map_err(|error| io::Error::other(format!("Standalone Worker startup failed: {error}")))?;
+    let mut connection = ConsoleConnection::standalone(host);
+
+    let mut terminal = match enter_fullscreen() {
+        Ok(terminal) => terminal,
+        Err(error) => {
+            let _ = connection.shutdown().await;
+            return Err(error);
+        }
+    };
+    let mut app = App::new_with_persistent_input_history(worker_name, &history_root);
+    let run_result = run_loop(&mut terminal, &mut app, &mut connection, None).await;
+    let shutdown_result = connection
+        .shutdown()
+        .await
+        .map_err(|error| io::Error::other(format!("Standalone Worker shutdown failed: {error}")));
+    let leave_result = leave_fullscreen(&mut terminal);
+
+    if let Err(error) = run_result {
+        return Err(error);
+    }
+    shutdown_result?;
+    leave_result?;
+    Ok(())
 }
 
 pub(crate) async fn run_backend_runtime(
@@ -208,13 +311,8 @@ pub(crate) async fn run_backend_runtime(
     let workspace_root = std::env::current_dir().unwrap_or_else(|_| std::path::PathBuf::from("."));
     let mut app = App::new_with_persistent_input_history(worker_label, &workspace_root);
     app.connected = true;
-    let result = run_loop(
-        &mut terminal,
-        &mut app,
-        ConsoleConnection::BackendRuntime(client),
-        None,
-    )
-    .await;
+    let mut connection = ConsoleConnection::BackendRuntime(client);
+    let result = run_loop(&mut terminal, &mut app, &mut connection, None).await;
     let _ = leave_fullscreen(&mut terminal);
     result
 }
@@ -228,13 +326,8 @@ async fn run_connected_pod(
     let workspace_root = std::env::current_dir().unwrap_or_else(|_| std::path::PathBuf::from("."));
     let mut app = App::new_with_persistent_input_history(worker_name, &workspace_root);
     app.connected = true;
-    run_loop(
-        terminal,
-        &mut app,
-        ConsoleConnection::LegacySocket(client),
-        Some(runtime_command),
-    )
-    .await
+    let mut connection = ConsoleConnection::LegacySocket(client);
+    run_loop(terminal, &mut app, &mut connection, Some(runtime_command)).await
 }
 
 pub(crate) async fn open_from_dashboard(
@@ -460,13 +553,8 @@ async fn run(
             app.connected = true;
             // The Worker sends `Event::Snapshot` automatically on connect;
             // no explicit method call is required to fetch history.
-            run_loop(
-                terminal,
-                &mut app,
-                ConsoleConnection::LegacySocket(client),
-                Some(runtime_command),
-            )
-            .await?;
+            let mut connection = ConsoleConnection::LegacySocket(client);
+            run_loop(terminal, &mut app, &mut connection, Some(runtime_command)).await?;
         }
         Err(e) => {
             app.push_error(format!(
@@ -791,7 +879,7 @@ async fn drain_worker_events(
 async fn run_loop(
     terminal: &mut Terminal<CrosstermBackend<io::Stdout>>,
     app: &mut App,
-    mut client: ConsoleConnection,
+    client: &mut ConsoleConnection,
     runtime_command: Option<WorkerRuntimeCommand>,
 ) -> Result<(), Box<dyn std::error::Error>> {
     let (_terminal_reader, mut term_rx) = TerminalEventReader::spawn()?;
@@ -804,11 +892,11 @@ async fn run_loop(
         }
 
         let handled_term_event =
-            drain_terminal_events(app, &mut client, &mut term_rx, runtime_command.as_ref()).await?;
+            drain_terminal_events(app, client, &mut term_rx, runtime_command.as_ref()).await?;
         if app.quit {
             break;
         }
-        let handled_worker_event = drain_worker_events(app, &mut client).await?;
+        let handled_worker_event = drain_worker_events(app, client).await?;
         if handled_term_event || handled_worker_event {
             terminal.draw(|f| ui::draw(f, app))?;
             continue;
@@ -816,8 +904,7 @@ async fn run_loop(
 
         match next_loop_input(&mut term_rx, app.connected, client.next_event()).await {
             LoopInput::Terminal(term_event) => {
-                handle_terminal_event(app, &mut client, term_event?, runtime_command.as_ref())
-                    .await?;
+                handle_terminal_event(app, client, term_event?, runtime_command.as_ref()).await?;
             }
             LoopInput::Worker(event) => match event {
                 Some(ev) => {

crates/tui/src/lib.rs

@@ -36,7 +36,7 @@ use crossterm::execute;
 use crossterm::terminal::{LeaveAlternateScreen, disable_raw_mode, enable_raw_mode};
 use session_store::SegmentId;
 
-use client::{Target, WorkerConnectionSelector, WorkerListRequest};
+use client::{Target, WorkerConnectionSelector, WorkerListRequest, WorkerSpawn};
 
 #[derive(Debug)]
 pub struct LaunchOptions {
@@ -85,6 +85,49 @@ pub enum LaunchMode {
     Panel { include_stopped: bool },
 }
 
+struct TerminalModeGuard {
+    active: bool,
+}
+
+impl TerminalModeGuard {
+    fn new() -> Self {
+        Self { active: true }
+    }
+
+    fn restore(&mut self) -> io::Result<()> {
+        if !self.active {
+            return Ok(());
+        }
+        self.active = false;
+        let mut stdout = io::stdout();
+        execute!(
+            stdout,
+            DisableMouseCapture,
+            LeaveAlternateScreen,
+            DisableBracketedPaste,
+            crossterm::cursor::Show
+        )?;
+        disable_raw_mode()
+    }
+}
+
+impl Drop for TerminalModeGuard {
+    fn drop(&mut self) {
+        if self.active {
+            let mut stdout = io::stdout();
+            let _ = execute!(
+                stdout,
+                DisableMouseCapture,
+                LeaveAlternateScreen,
+                DisableBracketedPaste,
+                crossterm::cursor::Show
+            );
+            let _ = disable_raw_mode();
+            self.active = false;
+        }
+    }
+}
+
 pub async fn launch(options: LaunchOptions) -> ExitCode {
     let LaunchOptions {
         target,
@@ -109,14 +152,19 @@ pub async fn launch(options: LaunchOptions) -> ExitCode {
         eprintln!("yoi: {e}");
         return ExitCode::FAILURE;
     }
+    let mut terminal_mode = TerminalModeGuard::new();
 
     let result = match mode {
         LaunchMode::Spawn {
             worker_name,
             profile,
         } => match target.spawn_worker() {
-            Ok(spawn) => {
-                console::run_spawn(None, worker_name, profile, spawn.runtime_command).await
+            Ok(WorkerSpawn::LegacyLocal { runtime_command }) => {
+                console::run_spawn(None, worker_name, profile, runtime_command).await
+            }
+            Ok(WorkerSpawn::Standalone { state_dir }) => {
+                console::run_standalone(workspace_root.clone(), state_dir, worker_name, profile)
+                    .await
             }
             Err(e) => Err(Box::new(e) as Box<dyn std::error::Error>),
         },
@@ -176,9 +224,13 @@ pub async fn launch(options: LaunchOptions) -> ExitCode {
             Err(e) => Err(Box::new(e) as Box<dyn std::error::Error>),
         },
         LaunchMode::ResumeWithSession { id, worker_name } => match target.spawn_worker() {
-            Ok(spawn) => {
-                console::run_spawn(Some(id), worker_name, None, spawn.runtime_command).await
+            Ok(WorkerSpawn::LegacyLocal { runtime_command }) => {
+                console::run_spawn(Some(id), worker_name, None, runtime_command).await
             }
+            Ok(WorkerSpawn::Standalone { .. }) => Err(Box::new(io::Error::new(
+                io::ErrorKind::Unsupported,
+                "Standalone session restore is not implemented",
+            )) as Box<dyn std::error::Error>),
             Err(e) => Err(Box::new(e) as Box<dyn std::error::Error>),
         },
         LaunchMode::Panel { include_stopped } => match target.dashboard() {
@@ -198,15 +250,7 @@ pub async fn launch(options: LaunchOptions) -> ExitCode {
     // alternate-screen buffer.
     #[cfg(feature = "e2e-test")]
     e2e_observer::emit("tui", "terminal_cleanup_started", serde_json::json!({}));
-    let mut stdout = io::stdout();
-    let _ = execute!(
-        stdout,
-        DisableMouseCapture,
-        LeaveAlternateScreen,
-        DisableBracketedPaste
-    );
-    let _ = disable_raw_mode();
-    let _ = execute!(stdout, crossterm::cursor::Show);
+    let _ = terminal_mode.restore();
     #[cfg(feature = "e2e-test")]
     e2e_observer::emit("tui", "terminal_cleanup_finished", serde_json::json!({}));
 

crates/yoi/src/cli_connection.rs

@@ -1,4 +1,4 @@
-use client::{BackendTarget, LocalTarget, Target, TargetKind};
+use client::{BackendTarget, LocalTarget, StandaloneTarget, Target, TargetKind};
 use serde::Deserialize;
 
 use super::{ParseError, read_client_default_connection, resolve_backend_url};
@@ -107,6 +107,18 @@ pub(crate) trait CliConnectionResolver {
 #[derive(Debug, Default, Clone, Copy)]
 pub(crate) struct ClientConfigCliConnectionResolver;
 
+fn standalone_target() -> Result<Box<dyn Target>, ParseError> {
+    let state_dir = manifest::paths::data_dir()
+        .ok_or_else(|| {
+            ParseError(
+                "Standalone state directory is unavailable; set YOI_DATA_DIR, YOI_HOME, XDG_DATA_HOME, or HOME"
+                    .to_string(),
+            )
+        })?
+        .join("standalone");
+    Ok(Box::new(StandaloneTarget::new(state_dir)))
+}
+
 impl CliConnectionResolver for ClientConfigCliConnectionResolver {
     fn resolve_connection(
         &self,
@@ -147,6 +159,11 @@ impl CliConnectionResolver for ClientConfigCliConnectionResolver {
                 resolve_backend_url(explicit_backend_url, workspace_id)?,
                 workspace_id.map(str::to_string),
             ))),
+            (CliConnectionRequirement::ConnectionAware, CliConnectionInput::LocalTarget)
+                if command == CliCommand::DefaultTui =>
+            {
+                standalone_target()
+            }
             (CliConnectionRequirement::ConnectionAware, CliConnectionInput::LocalTarget) => {
                 Ok(Box::new(LocalTarget::new()))
             }
@@ -171,6 +188,10 @@ pub(crate) fn resolve_local_cli_connection<R: CliConnectionResolver + ?Sized>(
     let target = resolver.resolve_connection(command, CliConnectionInput::LocalTarget)?;
     match target.kind() {
         TargetKind::Local => Ok(target),
+        TargetKind::Standalone => Err(ParseError(format!(
+            "{} resolved Standalone where a legacy local target was required",
+            command.display_name()
+        ))),
         TargetKind::Backend => Err(ParseError(format!(
             "{} resolved a Backend target where a local target was required",
             command.display_name()
@@ -193,8 +214,8 @@ pub(crate) fn resolve_backend_cli_connection<R: CliConnectionResolver + ?Sized>(
     )?;
     match target.kind() {
         TargetKind::Backend => Ok(target),
-        TargetKind::Local => Err(ParseError(format!(
-            "{} resolved a local target where a Backend target was required",
+        TargetKind::Local | TargetKind::Standalone => Err(ParseError(format!(
+            "{} resolved a non-Backend target where a Backend target was required",
             command.display_name()
         ))),
     }

crates/yoi/src/main.rs

@@ -687,6 +687,21 @@ fn parse_console_options<R: CliConnectionResolver + ?Sized>(
         &workspace_root,
     )?;
 
+    if target.kind() == TargetKind::Standalone {
+        if session.is_some() {
+            return Err(ParseError(
+                "--local starts a fresh Standalone Worker; --session restore requires the legacy local Runtime"
+                    .to_string(),
+            ));
+        }
+        if socket_override.is_some() {
+            return Err(ParseError(
+                "--local uses an in-process Standalone connection and does not accept --socket"
+                    .to_string(),
+            ));
+        }
+    }
+
     if let (Some(runtime_id), Some(worker_id)) = (runtime_id.clone(), worker_id) {
         return Ok(Mode::Tui {
             target,
@@ -715,6 +730,11 @@ fn parse_console_options<R: CliConnectionResolver + ?Sized>(
             worker_name,
             profile: Some(profile),
         }
+    } else if target.kind() == TargetKind::Standalone {
+        LaunchMode::Spawn {
+            worker_name,
+            profile: None,
+        }
     } else if let Some(session) = session {
         LaunchMode::ResumeWithSession {
             id: parse_session_id(&session.to_string_lossy())?,
@@ -1650,7 +1670,7 @@ Usage:
 Target selection:
   Target options are top-level options and must appear before the command.
 
-      --local              Use the local Worker runtime explicitly
+      --local              Start a one-process Standalone Worker (no Server or Runtime)
       --backend <URL>      Use a Workspace Backend explicitly
       --workspace-id <ID>  Scope Backend routes to a Workspace id
 
@@ -1725,7 +1745,9 @@ fn print_memory_lint_help() {
 mod tests {
     use super::*;
     use crate::cli_connection::CliConnectionInput;
-    use client::{BackendTarget, LocalTarget, TargetKind, WorkerListRequest};
+    use client::{
+        BackendTarget, LocalTarget, StandaloneTarget, Target, TargetKind, WorkerListRequest,
+    };
 
     struct FixedCliConnectionResolver {
         backend_url: &'static str,
@@ -1761,7 +1783,11 @@ mod tests {
             let workspace_id = match input {
                 CliConnectionInput::DefaultTarget { workspace_id }
                 | CliConnectionInput::BackendTarget { workspace_id, .. } => workspace_id,
-                CliConnectionInput::LocalTarget => return Ok(Box::new(LocalTarget::new())),
+                CliConnectionInput::LocalTarget => {
+                    return Ok(Box::new(StandaloneTarget::new(
+                        "/tmp/yoi-test-standalone-state",
+                    )));
+                }
             };
             Ok(Box::new(BackendTarget::new(
                 self.backend_url,
@@ -2026,6 +2052,75 @@ backend = "shared"
         }
     }
 
+    #[test]
+    fn parser_explicit_local_overrides_default_backend_with_standalone_target() {
+        let resolver = DefaultBackendCliConnectionResolver {
+            backend_url: "http://default-backend.example",
+        };
+        let args = ["--local", "--worker", "my-local-worker"]
+            .into_iter()
+            .map(String::from)
+            .collect::<Vec<_>>();
+        let mode = parse_args_slice_with_connection_resolver(&args, &resolver).unwrap();
+        let Mode::Tui { target, mode, .. } = mode else {
+            panic!("expected TUI mode")
+        };
+
+        assert_eq!(target.kind(), TargetKind::Standalone);
+        assert!(matches!(
+            mode,
+            LaunchMode::Spawn {
+                worker_name: Some(ref name),
+                profile: None,
+            } if name == "my-local-worker"
+        ));
+        assert!(matches!(
+            target.spawn_worker().unwrap(),
+            client::WorkerSpawn::Standalone { .. }
+        ));
+    }
+
+    #[test]
+    fn parser_rejects_standalone_and_backend_target_together() {
+        let err = parse_args_from(["--local", "--backend", "http://backend.example"]).unwrap_err();
+        assert_eq!(
+            err.to_string(),
+            "--local and --backend are mutually exclusive"
+        );
+    }
+
+    #[test]
+    fn parser_standalone_rejects_legacy_session_and_socket_inputs() {
+        let resolver = DefaultBackendCliConnectionResolver {
+            backend_url: "http://default-backend.example",
+        };
+        let session_args = ["--local", "--session", "session-1"]
+            .into_iter()
+            .map(String::from)
+            .collect::<Vec<_>>();
+        let err = parse_args_slice_with_connection_resolver(&session_args, &resolver).unwrap_err();
+        assert_eq!(
+            err.0,
+            "--local starts a fresh Standalone Worker; --session restore requires the legacy local Runtime"
+        );
+
+        let socket_args = [
+            "--local",
+            "--worker",
+            "worker-a",
+            "--socket",
+            "/tmp/worker.sock",
+        ]
+        .into_iter()
+        .map(String::from)
+        .collect::<Vec<_>>();
+        let err = parse_args_slice_with_connection_resolver(&socket_args, &resolver).unwrap_err();
+        assert_eq!(
+            err.0,
+            "--local uses an in-process Standalone connection and does not accept --socket"
+        );
+    }
+
     #[test]
     fn parse_backend_runtime_target_rejects_legacy_socket_mix() {
         let err = parse_args_from([

crates/yoi/src/objective_cli.rs

@@ -179,6 +179,9 @@ pub fn run(
             })?;
             run_in_workspace(cli, &workspace)
         }
+        ResolvedTarget::Standalone => Err(ObjectiveCliError::new(
+            "Standalone is a one-shot Worker host, not Objective storage authority",
+        )),
         ResolvedTarget::Backend {
             base_url,
             workspace_id,

crates/yoi/src/ticket_cli.rs

@@ -214,6 +214,9 @@ pub fn run(cli: TicketCli, target: ResolvedTarget) -> Result<TicketCliOutput, Ti
             })?;
             run_in_workspace(cli, &workspace)
         }
+        ResolvedTarget::Standalone => Err(TicketCliError::new(
+            "Standalone is a one-shot Worker host, not Ticket storage authority",
+        )),
         ResolvedTarget::Backend {
             base_url,
             workspace_id,