diff --git a/crates/ide-host/src/plugins/api.rs b/crates/ide-host/src/plugins/api.rs
index 2a20f9561..434a276be 100644
--- a/crates/ide-host/src/plugins/api.rs
+++ b/crates/ide-host/src/plugins/api.rs
@@ -733,6 +733,14 @@ impl HostApi for PluginApi {
         Ok(())
     }
 
+    fn open_project(&self, client: Option<&str>, path: String, new_window: bool) -> Result<(), HostError> {
+        let client = from_window(client, "open a project")?;
+        self.shared
+            .sink
+            .emit(Some(client), PluginEvent::OpenProject { plugin_id: self.id().to_owned(), path, new_window });
+        Ok(())
+    }
+
     fn ask(
         &self,
         client: Option<&str>,
diff --git a/crates/ide-host/src/plugins/remote_host.rs b/crates/ide-host/src/plugins/remote_host.rs
index b003ab921..ca463134f 100644
--- a/crates/ide-host/src/plugins/remote_host.rs
+++ b/crates/ide-host/src/plugins/remote_host.rs
@@ -119,6 +119,7 @@ pub fn forwarded(event: &PluginEvent) -> bool {
             | PluginEvent::OpenLocation { .. }
             | PluginEvent::CopyToClipboard { .. }
             | PluginEvent::OpenUrl { .. }
+            | PluginEvent::OpenProject { .. }
             | PluginEvent::PromptRequested { .. }
             | PluginEvent::PromptClosed { .. }
             | PluginEvent::RevealView { .. }
diff --git a/crates/ide-host/src/plugins/types.rs b/crates/ide-host/src/plugins/types.rs
index 61b75abb8..0cf9b8b20 100644
--- a/crates/ide-host/src/plugins/types.rs
+++ b/crates/ide-host/src/plugins/types.rs
@@ -222,6 +222,9 @@ pub enum PluginEvent {
     /// Open `url` (`http(s)://`) in the system browser.
     #[serde(rename_all = "camelCase")]
     OpenUrl { plugin_id: String, url: String },
+    /// A window command/event requests the normal File > Open flow.
+    #[serde(rename_all = "camelCase")]
+    OpenProject { plugin_id: String, path: String, new_window: bool },
     /// A command waits for the user's answer: show `prompt`, then report it with
     /// `plugin_answer_prompt(prompt_id, …)`.
     #[serde(rename_all = "camelCase")]
diff --git a/crates/ide-host/tests/plugins.rs b/crates/ide-host/tests/plugins.rs
index 74ed0de20..c84170442 100644
--- a/crates/ide-host/tests/plugins.rs
+++ b/crates/ide-host/tests/plugins.rs
@@ -3352,3 +3352,40 @@ fn invalid_plugin_icons_refuse_the_package() {
         assert!(err.contains(expected), "{id}: {err}");
     }
 }
+
+#[test]
+fn directory_prompts_and_project_requests_use_the_calling_window_without_a_capability() {
+    use ide_plugin::Prompt;
+    let f = fixture(Limits { timeout: Duration::from_millis(500), ..Limits::default() });
+    f.install(&sample("jobs"));
+    f.host.set_capability("jobs", "project.read", false).unwrap();
+    let (result, prompt) =
+        run_and_answer(&f, "pick-directory", Some("C:/work"), Some(&["C:/work/repo"]), Duration::from_millis(700));
+    assert_eq!(result.unwrap().as_deref(), Some("C:/work/repo"));
+    assert_eq!(prompt, Prompt::PickDirectory { title: "Clone target".into(), initial: Some("C:/work".into()) });
+    assert_eq!(run_and_answer(&f, "pick-directory", None, None, Duration::ZERO).0.unwrap().as_deref(), Some("none"));
+    assert!(run_and_answer(&f, "pick-directory", None, Some(&["relative"]), Duration::ZERO).0.is_err());
+    assert!(f.run("jobs", "pick-directory", Some("relative")).is_err());
+    for (cmd, new_window) in [("open-project", false), ("open-project-new", true)] {
+        f.take_events();
+        let inv = Invocation { client: Some("second".into()), ..f.inv() };
+        f.host.run_command("jobs", cmd, Some("C:/work/repo"), inv).unwrap();
+        let requests = f
+            .take_events()
+            .into_iter()
+            .filter_map(|(client, event)| match event {
+                PluginEvent::OpenProject { plugin_id, path, new_window } => Some((client, plugin_id, path, new_window)),
+                _ => None,
+            })
+            .collect::<Vec<_>>();
+        assert_eq!(requests, vec![(Some("second".into()), "jobs".into(), "C:/work/repo".into(), new_window)]);
+        let error = f.host.run_command("jobs", cmd, Some("/work/repo"), Invocation::default()).unwrap_err();
+        assert_eq!(error.kind, ErrorKind::InvalidInput, "{error:?}");
+    }
+    assert!(f.host.run_command("jobs", "pick-directory", None, Invocation::default()).is_err());
+    for path in ["relative", "/bad\npath", ""] {
+        f.take_events();
+        assert!(f.run("jobs", "open-project", Some(path)).is_err());
+        assert!(!f.take_events().iter().any(|(_, event)| matches!(event, PluginEvent::OpenProject { .. })));
+    }
+}
diff --git a/crates/ide-plugin/src/runtime.rs b/crates/ide-plugin/src/runtime.rs
index d27449533..ce2a59298 100644
--- a/crates/ide-plugin/src/runtime.rs
+++ b/crates/ide-plugin/src/runtime.rs
@@ -69,6 +69,10 @@ pub trait HostApi: Send + Sync {
         let _ = (client, url);
         Ok(())
     }
+    fn open_project(&self, client: Option<&str>, path: String, new_window: bool) -> Result<(), HostError> {
+        let _ = (client, path, new_window);
+        Err(HostError::Invalid("opening projects is unavailable".into()))
+    }
     /// Shows `prompt` in `client`'s window and waits for the answer until the
     /// user gives one or `cancel` fires: the chosen keys (`QuickPick`), the
     /// text (`Input`, one element) or any value (`Confirm`: OK); `None` when
diff --git a/crates/ide-plugin/src/types.rs b/crates/ide-plugin/src/types.rs
index d071a247f..02e1b86dd 100644
--- a/crates/ide-plugin/src/types.rs
+++ b/crates/ide-plugin/src/types.rs
@@ -88,6 +88,8 @@ pub enum Prompt {
     Input { prompt: String, value: Option<String>, multiline: bool },
     #[serde(rename_all = "camelCase")]
     Confirm { title: String, message: String },
+    #[serde(rename_all = "camelCase")]
+    PickDirectory { title: String, initial: Option<String> },
 }
 
 /// Kinds of workbench events a plugin can subscribe to (`on-event:<kind>`).
diff --git a/crates/ide-plugin/src/wit_host.rs b/crates/ide-plugin/src/wit_host.rs
index 368510666..acdba792d 100644
--- a/crates/ide-plugin/src/wit_host.rs
+++ b/crates/ide-plugin/src/wit_host.rs
@@ -350,6 +350,22 @@ impl ui::Host for StoreData {
         Ok(answer.map(|keys| keys.and_then(|keys| keys.into_iter().next())))
     }
 
+    fn pick_directory(&mut self, title: String, initial: Option<String>) -> Fallible<Option<String>> {
+        if let Some(path) = &initial
+            && let Err(error) = validate_ui_path(path)
+        {
+            return Ok(Err(error));
+        }
+        let answer = self.ask(Prompt::PickDirectory { title: clip(title, MAX_TITLE), initial });
+        Ok(answer.and_then(|answer| {
+            let path = answer.and_then(|items| items.into_iter().next());
+            if let Some(path) = &path {
+                validate_ui_path(path)?;
+            }
+            Ok(path)
+        }))
+    }
+
     fn pick_many(&mut self, title: String, items: Vec<ui::PickItem>) -> Fallible<Option<Vec<String>>> {
         Ok(self.pick_prompt(title, items, true))
     }
@@ -407,6 +423,14 @@ impl storage::Host for StoreData {
 }
 
 impl workspace::Host for StoreData {
+    fn open_project(&mut self, path: String, new_window: bool) -> Fallible<()> {
+        if let Err(error) = self.require_interactive().and_then(|_| validate_ui_path(&path)) {
+            return Ok(Err(error));
+        }
+        let client = self.invocation.client.clone();
+        Ok(self.host.open_project(client.as_deref(), path, new_window).map_err(to_wit))
+    }
+
     fn projects(&mut self) -> Fallible<Vec<Resource<ProjectRes>>> {
         if let Err(e) = self.require(Capability::ProjectRead) {
             return Ok(Err(e));
@@ -994,3 +1018,32 @@ pub(crate) mod file_actions_bindings {
         with: { "openidea:plugin/types": super::bindings::openidea::plugin::types },
     });
 }
+
+/// Paths belong to the UI machine, which can have a different OS than the plugin host.
+fn validate_ui_path(path: &str) -> Result<(), wit::Error> {
+    let b = path.as_bytes();
+    let absolute = path.starts_with('/')
+        || path.starts_with("\\\\")
+        || (b.first().is_some_and(u8::is_ascii_alphabetic)
+            && b.get(1) == Some(&b':')
+            && matches!(b.get(2), Some(b'/' | b'\\')));
+    if !absolute || path.len() > 8192 || path.chars().any(char::is_control) {
+        return Err(wit::Error::Invalid("expected an absolute UI directory path of at most 8192 bytes".into()));
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod project_ui_tests {
+    use super::validate_ui_path;
+    #[test]
+    fn validates_ui_paths_without_using_the_plugin_hosts_os() {
+        for path in ["/work/repo", "C:/work/repo", r"C:\work\repo", r"\\server\share\repo"] {
+            assert!(validate_ui_path(path).is_ok(), "{path:?}");
+        }
+        for path in ["repo", "C:repo", "/bad\npath", ""] {
+            assert!(validate_ui_path(path).is_err(), "{path:?}");
+        }
+        assert!(validate_ui_path(&format!("/{}", "x".repeat(8192))).is_err());
+    }
+}
diff --git a/crates/ide-plugin/tests/fixtures/commit/dist/plugin.wasm.sources b/crates/ide-plugin/tests/fixtures/commit/dist/plugin.wasm.sources
index afeba1992..fe3499425 100644
--- a/crates/ide-plugin/tests/fixtures/commit/dist/plugin.wasm.sources
+++ b/crates/ide-plugin/tests/fixtures/commit/dist/plugin.wasm.sources
@@ -1 +1 @@
-5752ebfddd9d2f2aef2ed7dfea7f39b3439f28b7f9bd09e2f32e40a65fc65f07
+2ddbea56d198b52839c6506c9d03a87ea1c0cd8b518c0f3ee58f4eecf9d320e2
diff --git a/crates/ide-plugin/tests/fixtures/hello/dist/plugin.wasm.sources b/crates/ide-plugin/tests/fixtures/hello/dist/plugin.wasm.sources
index 1c16ed578..b42bca3d3 100644
--- a/crates/ide-plugin/tests/fixtures/hello/dist/plugin.wasm.sources
+++ b/crates/ide-plugin/tests/fixtures/hello/dist/plugin.wasm.sources
@@ -1 +1 @@
-5f0ec195975e34065350eddabc252b830d2d7e8c87842be2d6310bff5a22eb67
+6709ed49ec442d7deca083534c13c35a1ca0355de8d073c55609ce784fe65db7
diff --git a/crates/ide-plugin/tests/fixtures/hover/dist/plugin.wasm.sources b/crates/ide-plugin/tests/fixtures/hover/dist/plugin.wasm.sources
index 75d41c99a..b42508379 100644
--- a/crates/ide-plugin/tests/fixtures/hover/dist/plugin.wasm.sources
+++ b/crates/ide-plugin/tests/fixtures/hover/dist/plugin.wasm.sources
@@ -1 +1 @@
-9551f337f0949c7249b022b8663333a66ae3534a7e0e112b37ed93d431960a54
+1915812d45316cf499611f471cf7abfdad47aa158295493bf81362f690ace866
diff --git a/crates/ide-plugin/tests/fixtures/indexer/dist/plugin.wasm.sources b/crates/ide-plugin/tests/fixtures/indexer/dist/plugin.wasm.sources
index d4079b4f3..1f0182d59 100644
--- a/crates/ide-plugin/tests/fixtures/indexer/dist/plugin.wasm.sources
+++ b/crates/ide-plugin/tests/fixtures/indexer/dist/plugin.wasm.sources
@@ -1 +1 @@
-600ef2642cfb359fea47e10a6a056e3e34f230681152aaff5077127da4325f10
+b55985f72b2636a84441f8effef10f8c4f638bd65be3f2f247d9a636c20e767b
diff --git a/crates/ide-plugin/tests/fixtures/inlay-hints/dist/plugin.wasm.sources b/crates/ide-plugin/tests/fixtures/inlay-hints/dist/plugin.wasm.sources
index fc837c71a..c39baa1ef 100644
--- a/crates/ide-plugin/tests/fixtures/inlay-hints/dist/plugin.wasm.sources
+++ b/crates/ide-plugin/tests/fixtures/inlay-hints/dist/plugin.wasm.sources
@@ -1 +1 @@
-c766b42405732d8d0dfec0955c6592e937928c96f2aedcbf317cddb55fccbdcb
+62888af0c9fb057ec4a696f0bfd5fd6fd07495a16a3021b4143de74b5cd30e26
diff --git a/crates/ide-plugin/tests/fixtures/jobs/dist/plugin.wasm b/crates/ide-plugin/tests/fixtures/jobs/dist/plugin.wasm
index f6d907d3d..1becbb272 100644
Binary files a/crates/ide-plugin/tests/fixtures/jobs/dist/plugin.wasm and b/crates/ide-plugin/tests/fixtures/jobs/dist/plugin.wasm differ
diff --git a/crates/ide-plugin/tests/fixtures/jobs/dist/plugin.wasm.sources b/crates/ide-plugin/tests/fixtures/jobs/dist/plugin.wasm.sources
index 278f01c95..850d179fd 100644
--- a/crates/ide-plugin/tests/fixtures/jobs/dist/plugin.wasm.sources
+++ b/crates/ide-plugin/tests/fixtures/jobs/dist/plugin.wasm.sources
@@ -1 +1 @@
-de40d28209203e58809622204dc17818a1c110f66515d3bb2dbca100861f544d
+79a67b0af9e0118961a83eecd644c2e1b87a98043d34b96bc49d4042af5d895f
diff --git a/crates/ide-plugin/tests/fixtures/jobs/plugin.toml b/crates/ide-plugin/tests/fixtures/jobs/plugin.toml
index 6da670a06..9f5e3ee51 100644
--- a/crates/ide-plugin/tests/fixtures/jobs/plugin.toml
+++ b/crates/ide-plugin/tests/fixtures/jobs/plugin.toml
@@ -38,3 +38,13 @@ category = "Jobs"
 [contributes.settings]
 title = "Jobs"
 schema = "settings.schema.json"
+
+[[contributes.commands]]
+id = "pick-directory"
+title = "Pick directory"
+[[contributes.commands]]
+id = "open-project"
+title = "Open project"
+[[contributes.commands]]
+id = "open-project-new"
+title = "Open project in new window"
diff --git a/crates/ide-plugin/tests/fixtures/jobs/src/lib.rs b/crates/ide-plugin/tests/fixtures/jobs/src/lib.rs
index 9ec2d17bb..9d03b33a2 100644
--- a/crates/ide-plugin/tests/fixtures/jobs/src/lib.rs
+++ b/crates/ide-plugin/tests/fixtures/jobs/src/lib.rs
@@ -61,6 +61,11 @@ impl Plugin for Jobs {
                 host::open_url(arg.unwrap_or_default())?;
                 Ok(None)
             }
+            "pick-directory" => Ok(Some(host::pick_directory("Clone target", arg)?.unwrap_or_else(|| "none".into()))),
+            "open-project" | "open-project-new" => {
+                host::open_project(arg.unwrap_or_default(), id == "open-project-new")?;
+                Ok(None)
+            }
             "pick" | "pick-many" => {
                 let long_key = "k".repeat(300);
                 let items = [
diff --git a/crates/ide-plugin/tests/fixtures/misbehave/dist/plugin.wasm.sources b/crates/ide-plugin/tests/fixtures/misbehave/dist/plugin.wasm.sources
index 9b46a386e..78e0147a0 100644
--- a/crates/ide-plugin/tests/fixtures/misbehave/dist/plugin.wasm.sources
+++ b/crates/ide-plugin/tests/fixtures/misbehave/dist/plugin.wasm.sources
@@ -1 +1 @@
-1cde3e85cce52c303c9629dade79a4349e0963fb868947a8e53f74ae248efd24
+6c12157f6d1040ce3f9495aaef0e0ea89818ab8af1ded6e2655e3d9304131255
diff --git a/crates/ide-plugin/tests/fixtures/semantic-tokens/dist/plugin.wasm.sources b/crates/ide-plugin/tests/fixtures/semantic-tokens/dist/plugin.wasm.sources
index fecbd15f9..c1d39c41d 100644
--- a/crates/ide-plugin/tests/fixtures/semantic-tokens/dist/plugin.wasm.sources
+++ b/crates/ide-plugin/tests/fixtures/semantic-tokens/dist/plugin.wasm.sources
@@ -1 +1 @@
-8c7e44efd87d5463fc2333adffe051c9937e80e06869c2f5ffe8b49daa49ec0d
+9db9019b6322a9f007ca49b6e3bf918f33df02407827ba797854e2486301733a
diff --git a/crates/ide-plugin/tests/fixtures/storage/dist/plugin.wasm.sources b/crates/ide-plugin/tests/fixtures/storage/dist/plugin.wasm.sources
index ed6a8ea46..6337c0927 100644
--- a/crates/ide-plugin/tests/fixtures/storage/dist/plugin.wasm.sources
+++ b/crates/ide-plugin/tests/fixtures/storage/dist/plugin.wasm.sources
@@ -1 +1 @@
-295f568f9bc12eb0f005771c611c85d1e3622a32548ceb04e10fd395cc61fa82
+fea7a5340fed353c8d09d7b7caba0c5ca23763fe9c6ece930c61d84e5b7dc0d5
diff --git a/crates/ide-plugin/tests/fixtures/tables/dist/plugin.wasm.sources b/crates/ide-plugin/tests/fixtures/tables/dist/plugin.wasm.sources
index 87140907b..f58a78ab7 100644
--- a/crates/ide-plugin/tests/fixtures/tables/dist/plugin.wasm.sources
+++ b/crates/ide-plugin/tests/fixtures/tables/dist/plugin.wasm.sources
@@ -1 +1 @@
-5d510fc9bdfe868bd392a8a0a46739f23db3db38bd9adb43d6b3c05d0c125c1d
+5bf76257aac231326bdcb618b511d4f94ed711f217a15ecad10e4dd15525d840
diff --git a/crates/ide-workspace/src/window_groups.rs b/crates/ide-workspace/src/window_groups.rs
index da095146b..53b61d1ae 100644
--- a/crates/ide-workspace/src/window_groups.rs
+++ b/crates/ide-workspace/src/window_groups.rs
@@ -84,16 +84,24 @@ impl WindowGroups {
         Ok(before)
     }
 
+    /// The member `detach(member)` will make active: the selection, or the selected member's neighbour.
+    pub fn successor(&self, member: &str) -> Option<String> {
+        let group = self.group(member)?;
+        if group.selected != member {
+            return Some(group.selected.clone());
+        }
+        let index = group.members.iter().position(|m| m == member)?;
+        let next = if index + 1 < group.members.len() { index + 1 } else { index.checked_sub(1)? };
+        Some(group.members[next].clone())
+    }
+
     /// Returns the remaining active member, including when the last pair dissolves.
     pub fn detach(&mut self, member: &str) -> Option<String> {
+        let selected = self.successor(member)?;
         let i = self.groups.iter().position(|g| g.members.iter().any(|m| m == member))?;
         let group = &mut self.groups[i];
-        let index = group.members.iter().position(|m| m == member).unwrap();
-        group.members.remove(index);
-        if group.selected == member {
-            group.selected = group.members[index.min(group.members.len() - 1)].clone();
-        }
-        let selected = group.selected.clone();
+        group.members.retain(|m| m != member);
+        group.selected = selected.clone();
         if group.members.len() < 2 {
             self.groups.remove(i);
         }
@@ -213,6 +221,19 @@ mod tests {
         assert!(groups.group("a").is_none());
     }
 
+    #[test]
+    fn the_successor_is_the_member_detach_selects() {
+        let mut groups = WindowGroups::default();
+        groups.merge(members(&["a", "b", "c"]), "b").unwrap();
+        assert_eq!(groups.successor("a"), Some("b".into()));
+        assert_eq!(groups.successor("b"), Some("c".into()));
+        groups.select("a", "c").unwrap();
+        assert_eq!(groups.successor("c"), Some("b".into()));
+        assert_eq!(groups.successor("unrelated"), None);
+        assert_eq!(groups.detach("c"), Some("b".into()));
+        assert_eq!(groups.group("a").unwrap().selected, "b");
+    }
+
     #[test]
     fn merging_groups_and_reordering_keep_unique_members() {
         let mut groups = WindowGroups::default();
diff --git a/plugins/README.md b/plugins/README.md
index 9bada5b16..b87015afb 100644
--- a/plugins/README.md
+++ b/plugins/README.md
@@ -1254,3 +1254,17 @@ A new host function touches:
 Then run `plugins/build.sh`; CI's `plugins` job runs `plugins/build.sh --check`
 plus fmt, clippy (host and wasm) and the tests of the SDK, the official
 plugins and the fixtures.
+
+### Directory selection and opening projects (API 1.3)
+
+`host::pick_directory(title, initial)` opens the window's native folder chooser
+and returns an absolute path, or `None` when dismissed. Like `pick`, it is only
+available during a command or event from a window; waiting for the user does not
+consume the plugin's call budget. `initial` is an optional absolute directory.
+
+`host::open_project(path, new_window)` requests the normal File › Open flow in
+that window (`false`) or a new window (`true`). Existing project windows are
+reused as usual, and the normal trust prompt and unsaved-change guard apply.
+The call acknowledges the request; cancellation or opening errors are handled by
+the window. Neither API needs a capability. Paths belong to the UI machine,
+including when plugin code runs on a remote host.
diff --git a/plugins/official/ai-completion/dist/plugin.wasm.sources b/plugins/official/ai-completion/dist/plugin.wasm.sources
index 07b79acd0..e57057dab 100644
--- a/plugins/official/ai-completion/dist/plugin.wasm.sources
+++ b/plugins/official/ai-completion/dist/plugin.wasm.sources
@@ -1 +1 @@
-df2aad3aa261a7cc4059c92666d221d1599306d47049b7b97a7bba263c6f51e5
+2d93f4f7eb0529528591ac1b7057a02cae7ed978eb21fe2be2f188529560b972
diff --git a/plugins/official/checkstyle/dist/plugin.wasm.sources b/plugins/official/checkstyle/dist/plugin.wasm.sources
index ab7fc8de2..e79f0de1f 100644
--- a/plugins/official/checkstyle/dist/plugin.wasm.sources
+++ b/plugins/official/checkstyle/dist/plugin.wasm.sources
@@ -1 +1 @@
-ef4128ec97e203c3dd0c49f3bcdbfaa5eb2be59123dc4628fc31d52dc61b3186
+af52d666db0224b43e19193d90331d54c9645ebd63c183ede65abc5666c15fd7
diff --git a/plugins/official/csv-editor/dist/plugin.wasm.sources b/plugins/official/csv-editor/dist/plugin.wasm.sources
index 1e822e99b..e2b69d6f9 100644
--- a/plugins/official/csv-editor/dist/plugin.wasm.sources
+++ b/plugins/official/csv-editor/dist/plugin.wasm.sources
@@ -1 +1 @@
-14dc3f5a5356ed82a84e7802c822545cba412d3e4a3b614aab6f4f7d3686584c
+a5bcffff3f4bb1c01840bd7b16d5e90908b293ef7676ffd81264a2fa850f91c7
diff --git a/plugins/official/git-toolbox/dist/plugin.wasm.sources b/plugins/official/git-toolbox/dist/plugin.wasm.sources
index 1b79b8a4e..f7fe17cce 100644
--- a/plugins/official/git-toolbox/dist/plugin.wasm.sources
+++ b/plugins/official/git-toolbox/dist/plugin.wasm.sources
@@ -1 +1 @@
-936d9fdad9752fa34a4a7ac18014c7bfc7cbd1b22f71b1501c667f4b83faad0b
+d20a458237ecdd0d34de2be8e4df527f2ed647627b784bf5df1206e18beba2b1
diff --git a/plugins/official/graphviz/dist/plugin.wasm.sources b/plugins/official/graphviz/dist/plugin.wasm.sources
index 678c34a17..e930ae3a1 100644
--- a/plugins/official/graphviz/dist/plugin.wasm.sources
+++ b/plugins/official/graphviz/dist/plugin.wasm.sources
@@ -1 +1 @@
-7b559f3febbd3acd56f08d530209212ab2d7da1c794346e2beaf0f19d0a3227f
+d9b33e747442c539541778b2a907fc02226e9af120962d4f384820b76674d40a
diff --git a/plugins/official/key-promoter/dist/plugin.wasm.sources b/plugins/official/key-promoter/dist/plugin.wasm.sources
index fc8a91825..9d3a94175 100644
--- a/plugins/official/key-promoter/dist/plugin.wasm.sources
+++ b/plugins/official/key-promoter/dist/plugin.wasm.sources
@@ -1 +1 @@
-b2e111085be32495ac82055e8258f8841a4a44979b4052ef102bb5726efc90e5
+b8c276a0d40a1615a658dc643f81e67683cfea57eb47282ff155c8df148fd771
diff --git a/plugins/official/license-header/dist/plugin.wasm.sources b/plugins/official/license-header/dist/plugin.wasm.sources
index 12094f2f7..1ef873589 100644
--- a/plugins/official/license-header/dist/plugin.wasm.sources
+++ b/plugins/official/license-header/dist/plugin.wasm.sources
@@ -1 +1 @@
-522aa68db4454f9c5511a90c74c6c26a8b95922e6725d9e411ddde7db998fa71
+c12eaf6b64a2482c83dab1958a195c939c38574d0bc15af1afcdaf811cf311d5
diff --git a/plugins/official/mybatis/dist/plugin.wasm.sources b/plugins/official/mybatis/dist/plugin.wasm.sources
index a97db01e5..6dd517787 100644
--- a/plugins/official/mybatis/dist/plugin.wasm.sources
+++ b/plugins/official/mybatis/dist/plugin.wasm.sources
@@ -1 +1 @@
-2f23364367583f9101cea4fc8f4ff190038a8b04c0f3b07a0f145c917807c237
+fa12ebc743e31fa57b31c0a623708133a232754d110bd687ef16d1037be62b19
diff --git a/plugins/official/regex-tester/dist/plugin.wasm.sources b/plugins/official/regex-tester/dist/plugin.wasm.sources
index f6ed5943c..e48b05177 100644
--- a/plugins/official/regex-tester/dist/plugin.wasm.sources
+++ b/plugins/official/regex-tester/dist/plugin.wasm.sources
@@ -1 +1 @@
-028e26a83c42ee3e01781e0006e857b1234c8dd655c1619de79aaee116998e9f
+53271d32104c682e510b4b5a8edb3467c77b39ee58d9b14c891513a494526180
diff --git a/plugins/official/solidity/dist/plugin.wasm.sources b/plugins/official/solidity/dist/plugin.wasm.sources
index 4f4a414a0..609942a06 100644
--- a/plugins/official/solidity/dist/plugin.wasm.sources
+++ b/plugins/official/solidity/dist/plugin.wasm.sources
@@ -1 +1 @@
-9a19f399c1aa5fbc4d80aa7d11c5b73d968d0664bbc12dea8488d5fcab846075
+2eb51fed9362021834f237f80553979a56ed1d8301d78b551e5911768b6e443c
diff --git a/plugins/official/string-tools/dist/plugin.wasm.sources b/plugins/official/string-tools/dist/plugin.wasm.sources
index 2b16319be..1d1abe1b9 100644
--- a/plugins/official/string-tools/dist/plugin.wasm.sources
+++ b/plugins/official/string-tools/dist/plugin.wasm.sources
@@ -1 +1 @@
-73b65742330387b7dbf498c6ec275ab41a55475243d771c1274de70b939c327f
+82547cce827ac884aafed961134e5d54be3dcd937990a3c372dfcdd8102aea23
diff --git a/sdk/rust/openidea-plugin/src/host.rs b/sdk/rust/openidea-plugin/src/host.rs
index 393858ff8..dce8a446b 100644
--- a/sdk/rust/openidea-plugin/src/host.rs
+++ b/sdk/rust/openidea-plugin/src/host.rs
@@ -109,6 +109,13 @@ mod imp {
         wit::ui::pick(title, &pick_items(items)).map_err(error)
     }
 
+    pub fn pick_directory(title: &str, initial: Option<&str>) -> Result<Option<String>, Error> {
+        wit::ui::pick_directory(title, initial).map_err(error)
+    }
+    pub fn open_project(path: &str, new_window: bool) -> Result<(), Error> {
+        wit::workspace::open_project(path, new_window).map_err(error)
+    }
+
     pub fn pick_many(title: &str, items: &[PickItem]) -> Result<Option<Vec<String>>, Error> {
         wit::ui::pick_many(title, &pick_items(items)).map_err(error)
     }
@@ -799,3 +806,17 @@ pub mod storage {
 #[cfg(target_arch = "wasm32")]
 #[doc(hidden)]
 pub use imp::{event as __event, range_from as __range_from, range_to as __range_to};
+
+/// Chooses a directory on the UI machine. `None` when dismissed; no capability.
+/// Same window/command/event rules as [`pick`].
+pub fn pick_directory(title: &str, initial: Option<&str>) -> Result<Option<String>, Error> {
+    imp::pick_directory(title, initial)
+}
+
+/// Requests the normal File > Open flow, including project trust, in the
+/// invoking window (`false`) or a new window (`true`). No capability.
+/// Only commands/events of a window can request this; errors opening the
+/// project are shown by that window. `path` belongs to the UI machine.
+pub fn open_project(path: &str, new_window: bool) -> Result<(), Error> {
+    imp::open_project(path, new_window)
+}
diff --git a/sdk/rust/openidea-plugin/src/mock.rs b/sdk/rust/openidea-plugin/src/mock.rs
index 618779787..4466a43e0 100644
--- a/sdk/rust/openidea-plugin/src/mock.rs
+++ b/sdk/rust/openidea-plugin/src/mock.rs
@@ -72,6 +72,7 @@ struct State {
     fetch_error: Option<Error>,
     clipboard: Option<String>,
     opened_urls: Vec<String>,
+    opened_projects: Vec<(String, bool)>,
     answers: VecDeque<Option<Vec<String>>>,
     revealed_views: Vec<String>,
     diagnostics: BTreeMap<String, Vec<Diagnostic>>,
@@ -130,6 +131,11 @@ impl MockHost {
         Self { state }
     }
 
+    /// Project-open requests, in order: (UI path, new window).
+    pub fn opened_projects(&self) -> Vec<(String, bool)> {
+        self.state.borrow().opened_projects.clone()
+    }
+
     /// Grants exactly these capabilities.
     pub fn with_capabilities(self, caps: &[&str]) -> Self {
         self.state.borrow_mut().capabilities = caps.iter().map(|s| (*s).to_owned()).collect();
@@ -470,6 +476,33 @@ pub mod current {
         })
     }
 
+    pub fn pick_directory(_title: &str, initial: Option<&str>) -> Result<Option<String>, Error> {
+        if let Some(path) = initial {
+            ui_path(path)?;
+        }
+        Ok(with(|s| s.answers.pop_front().flatten()).and_then(|a| a.into_iter().next()))
+    }
+
+    pub fn open_project(path: &str, new_window: bool) -> Result<(), Error> {
+        ui_path(path)?;
+        with(|s| s.opened_projects.push((path.to_owned(), new_window)));
+        Ok(())
+    }
+
+    /// The host's check: an absolute path on the UI machine, whatever its OS.
+    fn ui_path(path: &str) -> Result<(), Error> {
+        let b = path.as_bytes();
+        let absolute = path.starts_with('/')
+            || path.starts_with("\\\\")
+            || (b.first().is_some_and(u8::is_ascii_alphabetic)
+                && b.get(1) == Some(&b':')
+                && matches!(b.get(2), Some(b'/' | b'\\')));
+        if !absolute || path.len() > 8192 || path.chars().any(char::is_control) {
+            return Err(Error::Invalid("expected an absolute UI directory path of at most 8192 bytes".into()));
+        }
+        Ok(())
+    }
+
     pub fn pick(title: &str, items: &[PickItem]) -> Result<Option<String>, Error> {
         let keys = pick_many(title, items)?;
         match keys {
@@ -1045,3 +1078,22 @@ mod tests {
         assert_eq!(mock.diagnostics()["/project/a.java"].len(), 1);
     }
 }
+
+#[cfg(test)]
+mod project_ui_tests {
+    use super::MockHost;
+    use crate::host;
+    #[test]
+    fn folder_choices_and_project_requests_need_no_capability() {
+        let mock = MockHost::install().with_capabilities(&[]);
+        mock.answer_next_prompt(Some(&["C:/work/repo"]));
+        assert_eq!(host::pick_directory("Target", Some("C:/work")).unwrap().as_deref(), Some("C:/work/repo"));
+        assert_eq!(host::pick_directory("Target", None).unwrap(), None);
+        host::open_project("C:/work/repo", true).unwrap();
+        host::open_project("/home/user/repo", false).unwrap();
+        assert_eq!(mock.opened_projects(), vec![("C:/work/repo".into(), true), ("/home/user/repo".into(), false)]);
+        for path in ["relative", "C:relative", "/bad\npath", ""] {
+            assert!(host::open_project(path, false).is_err());
+        }
+    }
+}
diff --git a/sdk/rust/openidea-plugin/wit/host.wit b/sdk/rust/openidea-plugin/wit/host.wit
index 3b74fc92f..06a8885c5 100644
--- a/sdk/rust/openidea-plugin/wit/host.wit
+++ b/sdk/rust/openidea-plugin/wit/host.wit
@@ -57,6 +57,9 @@ interface ui {
     /// a window (including in editor providers). Waiting doesn't count against
     /// the call's budget.
     pick: func(title: string, items: list<pick-item>) -> result<option<string>, error>;
+    /// Native folder chooser; an absolute path, or `none` when dismissed.
+    /// Same window, command/event and budget rules as `pick`; no capability.
+    pick-directory: func(title: string, initial: option<string>) -> result<option<string>, error>;
     /// Like `pick`, with any number of items chosen.
     pick-many: func(title: string, items: list<pick-item>) -> result<option<list<string>>, error>;
     /// Asks for a line of text, pre-filled with `value`; `none` when dismissed.
diff --git a/sdk/rust/openidea-plugin/wit/workspace.wit b/sdk/rust/openidea-plugin/wit/workspace.wit
index bcf84e32e..b31964e8b 100644
--- a/sdk/rust/openidea-plugin/wit/workspace.wit
+++ b/sdk/rust/openidea-plugin/wit/workspace.wit
@@ -3,6 +3,11 @@ package openidea:plugin@1.3.0;
 interface workspace {
     use types.{error};
 
+    /// Requests File > Open in this command/event's window (or a new window),
+    /// including the usual project trust prompt. Needs no capability.
+    /// `path` is an absolute directory path on the UI machine.
+    open-project: func(path: string, new-window: bool) -> result<_, error>;
+
     /// What a path inside a project is.
     enum file-kind {
         file,
diff --git a/src-tauri/src/commands/mod.rs b/src-tauri/src/commands/mod.rs
index d49fbf723..f4a7f1d93 100644
--- a/src-tauri/src/commands/mod.rs
+++ b/src-tauri/src/commands/mod.rs
@@ -87,6 +87,7 @@ pub fn builder() -> tauri_specta::Builder<tauri::Wry> {
         window_group::window_group_close,
         window_group::window_group_close_tabs,
         window_group::window_group_cancel_close,
+        window_group::window_group_before_close,
         window_group::window_group_reorder,
         window_group::window_group_restore,
         app::light_edit_open,
diff --git a/src-tauri/src/commands/window_group.rs b/src-tauri/src/commands/window_group.rs
index f6d4d29ae..f016e9519 100644
--- a/src-tauri/src/commands/window_group.rs
+++ b/src-tauri/src/commands/window_group.rs
@@ -55,6 +55,20 @@ pub fn window_group_cancel_close(window: WebviewWindow) {
     groups::cancel_close(window.app_handle(), window.label());
 }
 
+/// This window closes next (its prompts passed): a fullscreen group's host first hands its Space
+/// to the tab that takes over.
+#[tauri::command]
+#[specta::specta]
+pub async fn window_group_before_close(window: WebviewWindow) -> IdeResult<()> {
+    #[cfg(target_os = "macos")]
+    return groups::before_close(window.app_handle(), window.label()).await;
+    #[cfg(not(target_os = "macos"))]
+    {
+        let _ = window;
+        Ok(())
+    }
+}
+
 #[tauri::command]
 #[specta::specta]
 pub async fn window_group_reorder(window: WebviewWindow, labels: Vec<String>) -> IdeResult<()> {
diff --git a/src-tauri/src/macos.rs b/src-tauri/src/macos.rs
index 3d32a8de1..7b6a63add 100644
--- a/src-tauri/src/macos.rs
+++ b/src-tauri/src/macos.rs
@@ -173,6 +173,44 @@ pub fn watch_fullscreen_host(host: &WebviewWindow, left: impl Fn() + Send + 'sta
     })
 }
 
+thread_local! {
+    /// Windows being waited on to finish entering fullscreen.
+    static ENTERING_FULLSCREEN: std::cell::RefCell<std::collections::HashMap<String, FullscreenObserver>> = std::cell::RefCell::default();
+}
+
+/// Toggles `window` into native fullscreen and resolves once it is there, or after `timeout`.
+pub async fn enter_fullscreen_and_wait(window: &WebviewWindow, timeout: std::time::Duration) -> tauri::Result<()> {
+    let (tx, rx) = tokio::sync::oneshot::channel();
+    let label = window.label().to_owned();
+    let target = window.clone();
+    on_main(window, move || unsafe {
+        let Ok(pointer) = target.ns_window() else { return };
+        let native = &*pointer.cast::<NSWindow>();
+        let tx = std::cell::Cell::new(Some(tx));
+        let block = block2::RcBlock::new(move |_| {
+            if let Some(tx) = tx.take() {
+                let _ = tx.send(());
+            }
+        });
+        let observer = NSNotificationCenter::defaultCenter().addObserverForName_object_queue_usingBlock(
+            Some(objc2_app_kit::NSWindowDidEnterFullScreenNotification),
+            Some(native),
+            None,
+            &block,
+        );
+        ENTERING_FULLSCREEN.with_borrow_mut(|waits| waits.insert(label, FullscreenObserver(observer)));
+    })?;
+    let toggled = native_toggle_fullscreen(window);
+    if toggled.is_ok() {
+        let _ = tokio::time::timeout(timeout, rx).await;
+    }
+    let label = window.label().to_owned();
+    on_main(window, move || {
+        ENTERING_FULLSCREEN.with_borrow_mut(|waits| waits.remove(&label));
+    })?;
+    toggled
+}
+
 /// An observer on the workspace's notification center, removed when dropped.
 struct WorkspaceObserver(Retained<NSNotificationCenter>, Retained<ProtocolObject<dyn NSObjectProtocol>>);
 
diff --git a/src-tauri/src/window_groups.rs b/src-tauri/src/window_groups.rs
index 0601fb32f..70ea2dd37 100644
--- a/src-tauri/src/window_groups.rs
+++ b/src-tauri/src/window_groups.rs
@@ -19,6 +19,9 @@ const FRAME_SETTLE_AFTER_MOVE: Duration = Duration::from_millis(100);
 /// Longest wait for a closed host's fullscreen Space to go before the next tab takes the screen.
 #[cfg(target_os = "macos")]
 const SPACE_TEARDOWN: Duration = Duration::from_millis(1500);
+/// Longest wait for the tab taking over from a closing host to enter its own fullscreen Space.
+#[cfg(target_os = "macos")]
+const SPACE_HANDOVER: Duration = Duration::from_millis(2000);
 /// Coalesces the move/resize events a drag emits.
 static FRAME_SYNC_GENERATION: AtomicU64 = AtomicU64::new(0);
 
@@ -327,6 +330,13 @@ pub fn toggle_fullscreen(window: &WebviewWindow) -> IdeResult<bool> {
 /// Makes `host` the fullscreen window of its group, or of its own Space when ungrouped.
 #[cfg(target_os = "macos")]
 fn host_fullscreen(app: &AppHandle, host: &WebviewWindow) -> IdeResult<()> {
+    prepare_host(app, host)?;
+    crate::macos::native_toggle_fullscreen(host).map_err(|e| IdeError::internal(e.to_string()))
+}
+
+/// `host` and the other members of its group, ready for `host` to enter fullscreen.
+#[cfg(target_os = "macos")]
+fn prepare_host(app: &AppHandle, host: &WebviewWindow) -> IdeResult<()> {
     let err = |e: tauri::Error| IdeError::internal(e.to_string());
     let members = app.state::<WindowsState>().groups.lock().group(host.label()).map(|g| g.members.clone());
     crate::macos::set_fullscreen_auxiliary(host, None).map_err(err)?;
@@ -338,8 +348,29 @@ fn host_fullscreen(app: &AppHandle, host: &WebviewWindow) -> IdeResult<()> {
     if members.is_some() {
         watch_host(app, host)?;
     }
-    host.show().map_err(err)?;
-    crate::macos::native_toggle_fullscreen(host).map_err(err)
+    host.show().map_err(err)
+}
+
+/// A fullscreen group's host is about to close, past its prompts. The tab that takes over leaves
+/// for a Space of its own first, so the screen moves straight to it; were the host closed first,
+/// its Space would end and show the desktop until the next one opened.
+#[cfg(target_os = "macos")]
+pub async fn before_close(app: &AppHandle, caller: &str) -> IdeResult<()> {
+    let state = app.state::<WindowsState>();
+    let Some(members) = state.groups.lock().group(caller).map(|g| g.members.clone()) else { return Ok(()) };
+    if state.quitting() || fullscreen_host(app, &members).is_none_or(|host| host.label() != caller) {
+        return Ok(());
+    }
+    // Detached now, the closing host leaves nothing for `destroyed` to hand over.
+    let next = state.groups.lock().detach(caller);
+    changed(app);
+    let Some(next) = next.and_then(|label| app.get_webview_window(&label)) else { return Ok(()) };
+    prepare_host(app, &next)?;
+    crate::macos::enter_fullscreen_and_wait(&next, SPACE_HANDOVER)
+        .await
+        .map_err(|e| IdeError::internal(e.to_string()))?;
+    windows::focus(&next);
+    Ok(())
 }
 
 #[cfg(target_os = "macos")]
diff --git a/src/bindings.ts b/src/bindings.ts
index f2e8f829d..f4431c017 100644
--- a/src/bindings.ts
+++ b/src/bindings.ts
@@ -42,6 +42,11 @@ export const commands = {
 	windowGroupCloseTabs: (keep: string, labels: string[]) => typedError<null, IdeError>(__TAURI_INVOKE("window_group_close_tabs", { keep, labels })),
 	/**  This window kept its project open (unsaved-changes prompt cancelled); stops a batch close. */
 	windowGroupCancelClose: () => __TAURI_INVOKE<void>("window_group_cancel_close"),
+	/**
+	 *  This window closes next (its prompts passed): a fullscreen group's host first hands its Space
+	 *  to the tab that takes over.
+	 */
+	windowGroupBeforeClose: () => typedError<null, IdeError>(__TAURI_INVOKE("window_group_before_close")),
 	windowGroupReorder: (labels: string[]) => typedError<null, IdeError>(__TAURI_INVOKE("window_group_reorder", { labels })),
 	windowGroupRestore: () => typedError<null, IdeError>(__TAURI_INVOKE("window_group_restore")),
 	/**
@@ -5983,6 +5988,8 @@ export type PluginEvent =
 { type: "copyToClipboard"; pluginId: string; text: string } | 
 /**  Open `url` (`http(s)://`) in the system browser. */
 { type: "openUrl"; pluginId: string; url: string } | 
+/**  A window command/event requests the normal File > Open flow. */
+{ type: "openProject"; pluginId: string; path: string; newWindow: boolean } | 
 /**
  *  A command waits for the user's answer: show `prompt`, then report it with
  *  `plugin_answer_prompt(prompt_id, …)`.
@@ -6388,7 +6395,7 @@ export type ProjectStructureSettings = {
  *  What a plugin asks the user (`ui.pick`, `ui.pick-many`, `ui.input`,
  *  `ui.input-multiline`, `ui.confirm`).
  */
-export type Prompt = { kind: "quickPick"; title: string; items: PickItem[]; multiple: boolean } | { kind: "input"; prompt: string; value: string | null; multiline: boolean } | { kind: "confirm"; title: string; message: string };
+export type Prompt = { kind: "quickPick"; title: string; items: PickItem[]; multiple: boolean } | { kind: "input"; prompt: string; value: string | null; multiline: boolean } | { kind: "confirm"; title: string; message: string } | { kind: "pickDirectory"; title: string; initial: string | null };
 
 export type ProxyKind = "http" | "socks";
 
diff --git a/src/features/app/__tests__/windows.test.ts b/src/features/app/__tests__/windows.test.ts
index b2bed6627..fe15480d7 100644
--- a/src/features/app/__tests__/windows.test.ts
+++ b/src/features/app/__tests__/windows.test.ts
@@ -388,3 +388,36 @@ it("removes the first workspace member while retaining the workspace state root"
   expect(useProject.getState().project?.root).toBe("/workspace");
   expect(useProject.getState().project?.workspace?.projects).toEqual(["/b"]);
 });
+
+describe("explicit project-window requests", () => {
+  it("honours current-window requests even when a project is already open", async () => {
+    useProject.setState(projectState("/p/old") as never);
+    windowOpenProject.mockResolvedValue(ok({ kind: "current" }));
+    const action = windowActions().find((a) => a.id === "file.openProjectPath")!;
+    await action.run({ arg: { path: "/p/new", newWindow: false } } as never);
+    expect(windowOpenProject).toHaveBeenCalledWith("/p/new", false, []);
+    expect(openProject).toHaveBeenCalledWith("/p/new");
+  });
+  it("opens a new window without replacing the current project", async () => {
+    useProject.setState(projectState("/p/old") as never);
+    windowOpenProject.mockResolvedValue(ok({ kind: "opened", label: "project-1" }));
+    const action = windowActions().find((a) => a.id === "file.openProjectPath")!;
+    await action.run({ arg: { path: "/p/new", newWindow: true } } as never);
+    expect(windowOpenProject).toHaveBeenCalledWith("/p/new", true, []);
+    expect(openProject).not.toHaveBeenCalled();
+    expect(useProject.getState().project?.root).toBe("/p/old");
+  });
+  it("keeps the ordinary unsaved-change guard for current-window opens", async () => {
+    const { provideLeaveProjectGuard } = await import("@/platform/project");
+    const dispose = provideLeaveProjectGuard(async () => false);
+    useProject.setState(projectState("/p/old") as never);
+    windowOpenProject.mockResolvedValue(ok({ kind: "current" }));
+    try {
+      const action = windowActions().find((a) => a.id === "file.openProjectPath")!;
+      await action.run({ arg: { path: "/p/new", newWindow: false } } as never);
+      expect(openProject).not.toHaveBeenCalled();
+    } finally {
+      dispose();
+    }
+  });
+});
diff --git a/src/features/app/closeGuard.ts b/src/features/app/closeGuard.ts
index 084fb5244..448435502 100644
--- a/src/features/app/closeGuard.ts
+++ b/src/features/app/closeGuard.ts
@@ -205,6 +205,7 @@ async function onCloseRequested(deps: CloseDeps): Promise<boolean> {
       deps,
     );
     if (!ok) await (ctx.quitting ? commands.appCancelQuit() : commands.windowGroupCancelClose());
+    else if (!ctx.quitting) await commands.windowGroupBeforeClose();
     return ok;
   } catch (e) {
     maybeEditorService()?.cancelClose?.();
diff --git a/src/features/app/windows.ts b/src/features/app/windows.ts
index 4433deb48..4afd1feb5 100644
--- a/src/features/app/windows.ts
+++ b/src/features/app/windows.ts
@@ -445,7 +445,15 @@ export function windowActions(): Action[] {
       category: t("app.category.file"),
       hidden: true,
       run: async (c) => {
-        if (typeof c.arg === "string") await openProjectWithPolicy(c.arg);
+        if (typeof c.arg === "string") return openProjectWithPolicy(c.arg);
+        const arg = c.arg as { path?: unknown; newWindow?: unknown } | null;
+        if (!arg || typeof arg.path !== "string" || typeof arg.newWindow !== "boolean") return;
+        try {
+          const outcome = await call(commands.windowOpenProject(arg.path, arg.newWindow, []));
+          if (outcome.kind === "current") await openHere(arg.path);
+        } catch (error) {
+          openFailed(arg.path, error);
+        }
       },
     },
     {
diff --git a/src/features/plugins/__tests__/projectUi.test.tsx b/src/features/plugins/__tests__/projectUi.test.tsx
new file mode 100644
index 000000000..4edb884a5
--- /dev/null
+++ b/src/features/plugins/__tests__/projectUi.test.tsx
@@ -0,0 +1,76 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { waitFor } from "@testing-library/react";
+import { registerAction } from "@/platform/actions";
+import { provideNotificationService, type NotificationService } from "@/workbench/contributions";
+import { createMemoryPluginsBackend, setPluginsBackend } from "../backend";
+import { handleRuntimeEvent } from "../runtimeUi";
+
+const nativeOpen = vi.hoisted(() => vi.fn());
+vi.mock("@tauri-apps/plugin-dialog", () => ({ open: nativeOpen }));
+const answerPrompt = vi.fn().mockResolvedValue(undefined);
+let notes: Parameters<NotificationService["notify"]>[0][];
+let dispose: (() => void) | undefined;
+beforeEach(() => {
+  vi.clearAllMocks();
+  dispose = undefined;
+  notes = [];
+  provideNotificationService({ notify: (note) => void notes.push(note) });
+  setPluginsBackend({ ...createMemoryPluginsBackend(), answerPrompt });
+});
+afterEach(() => dispose?.());
+const ask = (id: string) =>
+  handleRuntimeEvent({
+    type: "promptRequested",
+    pluginId: "p",
+    promptId: id,
+    prompt: { kind: "pickDirectory", title: "Clone target", initial: "C:/work" },
+  });
+
+describe("project UI requests", () => {
+  it("returns an absolute directory as an IPC path using the supplied title and initial path", async () => {
+    nativeOpen.mockResolvedValue("C:\\work\\repo");
+    ask("directory");
+    await waitFor(() => expect(answerPrompt).toHaveBeenCalledWith("directory", ["C:/work/repo"]));
+    expect(nativeOpen).toHaveBeenCalledWith({
+      directory: true,
+      multiple: false,
+      title: "Clone target",
+      defaultPath: "C:/work",
+    });
+  });
+  it("reports cancellation and picker errors without leaving the plugin waiting", async () => {
+    nativeOpen.mockResolvedValueOnce(null).mockRejectedValueOnce(new Error("picker unavailable"));
+    ask("cancel");
+    await waitFor(() => expect(answerPrompt).toHaveBeenCalledWith("cancel", null));
+    ask("failed");
+    await waitFor(() => expect(answerPrompt).toHaveBeenCalledWith("failed", null));
+    expect(notes).toMatchObject([
+      { level: "error", title: "Cannot choose a directory", body: "Error: picker unavailable" },
+    ]);
+  });
+  it("ignores a native result after the host closes its prompt", async () => {
+    let finish!: (path: string) => void;
+    nativeOpen.mockImplementationOnce(
+      () =>
+        new Promise<string>((resolve) => {
+          finish = resolve;
+        }),
+    );
+    ask("late");
+    await waitFor(() => expect(nativeOpen).toHaveBeenCalled());
+    handleRuntimeEvent({ type: "promptClosed", promptId: "late" });
+    finish("C:/work/late");
+    await new Promise((resolve) => setTimeout(resolve, 0));
+    expect(answerPrompt).not.toHaveBeenCalled();
+  });
+  it("routes project opens through the normal window action", async () => {
+    const run = vi.fn();
+    dispose = registerAction({ id: "file.openProjectPath", title: "Open Project Path", run });
+    for (const newWindow of [false, true]) {
+      handleRuntimeEvent({ type: "openProject", pluginId: "p", path: "/work/repo", newWindow });
+      await waitFor(() =>
+        expect(run).toHaveBeenCalledWith(expect.objectContaining({ arg: { path: "/work/repo", newWindow } })),
+      );
+    }
+  });
+});
diff --git a/src/features/plugins/runtimeUi.tsx b/src/features/plugins/runtimeUi.tsx
index 6e6c75f65..21cd570cc 100644
--- a/src/features/plugins/runtimeUi.tsx
+++ b/src/features/plugins/runtimeUi.tsx
@@ -22,9 +22,11 @@ import { onIdeEvent } from "@/platform/ipc";
 import { openExternalUrl } from "@/platform/openUrl";
 import { tx, VerbatimTextContext } from "@/platform/i18n";
 import { useProject } from "@/platform/project";
+import { ipcPath } from "@/platform/paths";
 import { shortcutLabel } from "@/platform/keymap";
 import { BarButton } from "@/ui/BarButton";
 import {
+  notifications,
   maybeCommitService,
   maybeEditorService,
   registerStatusItem,
@@ -322,6 +324,26 @@ const openPrompts = new Map<string, AbortController>();
 /** The user's answer in the shape `plugin_answer_prompt` takes: `null` when dismissed. */
 async function askUser(prompt: Prompt, signal: AbortSignal): Promise<string[] | null> {
   switch (prompt.kind) {
+    case "pickDirectory": {
+      if (signal.aborted) return null;
+      try {
+        const { open } = await import("@tauri-apps/plugin-dialog");
+        if (signal.aborted) return null;
+        const selected = await open({
+          directory: true,
+          multiple: false,
+          title: prompt.title,
+          defaultPath: prompt.initial ?? undefined,
+        });
+        if (signal.aborted) return null;
+        const path = Array.isArray(selected) ? selected[0] : selected;
+        return path ? [ipcPath(path)] : null;
+      } catch (error) {
+        if (!signal.aborted)
+          notifications().notify({ level: "error", title: tx("Cannot choose a directory"), body: String(error) });
+        return null;
+      }
+    }
     case "quickPick":
       return pickItems({ title: prompt.title, items: prompt.items, multiple: prompt.multiple, signal, verbatim: true });
     case "input": {
@@ -409,6 +431,9 @@ export function handleRuntimeEvent(e: PluginEvent): boolean {
     case "copyToClipboard":
       void navigator.clipboard?.writeText(e.text);
       return true;
+    case "openProject":
+      void executeAction("file.openProjectPath", { path: e.path, newWindow: e.newWindow });
+      return true;
     case "openUrl":
       void openExternalUrl(e.url);
       return true;
diff --git a/src/platform/locales/text/en.json b/src/platform/locales/text/en.json
index a1893b35c..8c0e04aff 100644
--- a/src/platform/locales/text/en.json
+++ b/src/platform/locales/text/en.json
@@ -192,5 +192,6 @@
   "Cannot install the openidea command": "Cannot install the openidea command",
   "Cannot uninstall the openidea command": "Cannot uninstall the openidea command",
   "Open a new terminal to use the openidea command.": "Open a new terminal to use the openidea command.",
-  "Add {path} to the beginning of PATH, then open a new terminal.": "Add {path} to the beginning of PATH, then open a new terminal."
+  "Add {path} to the beginning of PATH, then open a new terminal.": "Add {path} to the beginning of PATH, then open a new terminal.",
+  "Cannot choose a directory": "Cannot choose a directory"
 }
diff --git a/src/platform/locales/text/zh.json b/src/platform/locales/text/zh.json
index 018a20027..aa54d4672 100644
--- a/src/platform/locales/text/zh.json
+++ b/src/platform/locales/text/zh.json
@@ -6571,5 +6571,6 @@
   "Cannot install the openidea command": "无法安装 openidea 命令",
   "Cannot uninstall the openidea command": "无法卸载 openidea 命令",
   "Open a new terminal to use the openidea command.": "请打开新终端以使用 openidea 命令。",
-  "Add {path} to the beginning of PATH, then open a new terminal.": "请将 {path} 添加到 PATH 开头，然后打开新终端。"
+  "Add {path} to the beginning of PATH, then open a new terminal.": "请将 {path} 添加到 PATH 开头，然后打开新终端。",
+  "Cannot choose a directory": "无法选择目录"
 }
diff --git a/wit/host.wit b/wit/host.wit
index 3b74fc92f..06a8885c5 100644
--- a/wit/host.wit
+++ b/wit/host.wit
@@ -57,6 +57,9 @@ interface ui {
     /// a window (including in editor providers). Waiting doesn't count against
     /// the call's budget.
     pick: func(title: string, items: list<pick-item>) -> result<option<string>, error>;
+    /// Native folder chooser; an absolute path, or `none` when dismissed.
+    /// Same window, command/event and budget rules as `pick`; no capability.
+    pick-directory: func(title: string, initial: option<string>) -> result<option<string>, error>;
     /// Like `pick`, with any number of items chosen.
     pick-many: func(title: string, items: list<pick-item>) -> result<option<list<string>>, error>;
     /// Asks for a line of text, pre-filled with `value`; `none` when dismissed.
diff --git a/wit/workspace.wit b/wit/workspace.wit
index bcf84e32e..b31964e8b 100644
--- a/wit/workspace.wit
+++ b/wit/workspace.wit
@@ -3,6 +3,11 @@ package openidea:plugin@1.3.0;
 interface workspace {
     use types.{error};
 
+    /// Requests File > Open in this command/event's window (or a new window),
+    /// including the usual project trust prompt. Needs no capability.
+    /// `path` is an absolute directory path on the UI machine.
+    open-project: func(path: string, new-window: bool) -> result<_, error>;
+
     /// What a path inside a project is.
     enum file-kind {
         file,