diff --git a/README.md b/README.md
index a2cfcf2..1dcd4ad 100644
--- a/README.md
+++ b/README.md
@@ -123,6 +123,9 @@ Press `?` in the app (outside a text input) for the full, always-current list.
 | Attach / recreate a session | click its row |
 | Full session menu (shell, review, rename, editor, PR, lifecycle) | right-click row |
 | New session in a project | `+` on the project |
+| Add-project path: complete to common prefix | `Tab` |
+| Add-project path: pick / drill into a directory | `↑` / `↓`, then `Enter` |
+| Add-project path: native folder picker | `Browse…` |
 | Project shell | `$` on the project |
 | Cycle sidebar view (project / sections / stacks) | `⇄` |
 | Move a session to a section | drag its row onto a section header (drop on *In Progress* to unpin) |
diff --git a/package-lock.json b/package-lock.json
index 3de8d14..435d0c7 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -13,6 +13,7 @@
         "@shikijs/themes": "^4.2.0",
         "@tauri-apps/api": "^2",
         "@tauri-apps/plugin-clipboard-manager": "^2.3.2",
+        "@tauri-apps/plugin-dialog": "^2.7.1",
         "@xterm/addon-clipboard": "^0.2.0",
         "@xterm/addon-fit": "^0.10.0",
         "@xterm/addon-web-links": "^0.11.0",
@@ -1411,6 +1412,15 @@
         "@tauri-apps/api": "^2.8.0"
       }
     },
+    "node_modules/@tauri-apps/plugin-dialog": {
+      "version": "2.7.1",
+      "resolved": "https://registry.npmjs.org/@tauri-apps/plugin-dialog/-/plugin-dialog-2.7.1.tgz",
+      "integrity": "sha512-OK1UBXYt+ojcmxMktzzuyonYIFta8CmAASpX+CA+DTGK24KlHjhYI6x2iOJ/TjZF4N7/ACK1oFmEOjIY9IhzOQ==",
+      "license": "MIT OR Apache-2.0",
+      "dependencies": {
+        "@tauri-apps/api": "^2.11.0"
+      }
+    },
     "node_modules/@types/chai": {
       "version": "5.2.3",
       "resolved": "https://registry.npmjs.org/@types/chai/-/chai-5.2.3.tgz",
diff --git a/package.json b/package.json
index 7d0002e..3a09e30 100644
--- a/package.json
+++ b/package.json
@@ -23,6 +23,7 @@
     "@shikijs/themes": "^4.2.0",
     "@tauri-apps/api": "^2",
     "@tauri-apps/plugin-clipboard-manager": "^2.3.2",
+    "@tauri-apps/plugin-dialog": "^2.7.1",
     "@xterm/addon-clipboard": "^0.2.0",
     "@xterm/addon-fit": "^0.10.0",
     "@xterm/addon-web-links": "^0.11.0",
diff --git a/src-tauri/Cargo.lock b/src-tauri/Cargo.lock
index 28aa281..cd9fd82 100644
--- a/src-tauri/Cargo.lock
+++ b/src-tauri/Cargo.lock
@@ -702,6 +702,8 @@ dependencies = [
  "tauri",
  "tauri-build",
  "tauri-plugin-clipboard-manager",
+ "tauri-plugin-dialog",
+ "tempfile",
  "tokio",
  "tracing",
  "uuid",
@@ -4178,7 +4180,7 @@ version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "680998035259dcfcafe653688bf2aa6d3e2dc05e98be6ab46afb089dc84f1df8"
 dependencies = [
- "proc-macro-crate 1.3.1",
+ "proc-macro-crate 2.0.0",
  "proc-macro2",
  "quote",
  "syn 2.0.117",
@@ -4317,6 +4319,7 @@ checksum = "e3e0adef53c21f888deb4fa59fc59f7eb17404926ee8a6f59f5df0fd7f9f3272"
 dependencies = [
  "bitflags 2.13.0",
  "block2",
+ "libc",
  "objc2",
  "objc2-core-foundation",
 ]
@@ -5531,6 +5534,30 @@ dependencies = [
  "web-sys",
 ]
 
+[[package]]
+name = "rfd"
+version = "0.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a15ad77d9e70a92437d8f74c35d99b4e4691128df018833e99f90bcd36152672"
+dependencies = [
+ "block2",
+ "dispatch2",
+ "glib-sys",
+ "gobject-sys",
+ "gtk-sys",
+ "js-sys",
+ "log",
+ "objc2",
+ "objc2-app-kit",
+ "objc2-core-foundation",
+ "objc2-foundation",
+ "raw-window-handle",
+ "wasm-bindgen",
+ "wasm-bindgen-futures",
+ "web-sys",
+ "windows-sys 0.60.2",
+]
+
 [[package]]
 name = "rgb"
 version = "0.8.53"
@@ -6542,6 +6569,48 @@ dependencies = [
  "thiserror 2.0.18",
 ]
 
+[[package]]
+name = "tauri-plugin-dialog"
+version = "2.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "65981abb771e74e571a38196c3baa11c459379164791eba0e67abc1a5fac9884"
+dependencies = [
+ "log",
+ "raw-window-handle",
+ "rfd",
+ "serde",
+ "serde_json",
+ "tauri",
+ "tauri-plugin",
+ "tauri-plugin-fs",
+ "thiserror 2.0.18",
+ "url",
+]
+
+[[package]]
+name = "tauri-plugin-fs"
+version = "2.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b7ecc274121aca0c036a2b42d1cbe83d368d348f54e0bb8a735c2b1548e8f371"
+dependencies = [
+ "anyhow",
+ "dunce",
+ "glob",
+ "log",
+ "objc2-foundation",
+ "percent-encoding",
+ "schemars 0.8.22",
+ "serde",
+ "serde_json",
+ "serde_repr",
+ "tauri",
+ "tauri-plugin",
+ "tauri-utils",
+ "thiserror 2.0.18",
+ "toml 1.1.2+spec-1.1.0",
+ "url",
+]
+
 [[package]]
 name = "tauri-runtime"
 version = "2.11.2"
@@ -8182,6 +8251,15 @@ dependencies = [
  "windows-targets 0.52.6",
 ]
 
+[[package]]
+name = "windows-sys"
+version = "0.60.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2f500e4d28234f72040990ec9d39e3a6b950f9f22d3dba18416c35882612bcb"
+dependencies = [
+ "windows-targets 0.53.5",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.61.2"
@@ -8230,13 +8308,30 @@ dependencies = [
  "windows_aarch64_gnullvm 0.52.6",
  "windows_aarch64_msvc 0.52.6",
  "windows_i686_gnu 0.52.6",
- "windows_i686_gnullvm",
+ "windows_i686_gnullvm 0.52.6",
  "windows_i686_msvc 0.52.6",
  "windows_x86_64_gnu 0.52.6",
  "windows_x86_64_gnullvm 0.52.6",
  "windows_x86_64_msvc 0.52.6",
 ]
 
+[[package]]
+name = "windows-targets"
+version = "0.53.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4945f9f551b88e0d65f3db0bc25c33b8acea4d9e41163edf90dcd0b19f9069f3"
+dependencies = [
+ "windows-link 0.2.1",
+ "windows_aarch64_gnullvm 0.53.1",
+ "windows_aarch64_msvc 0.53.1",
+ "windows_i686_gnu 0.53.1",
+ "windows_i686_gnullvm 0.53.1",
+ "windows_i686_msvc 0.53.1",
+ "windows_x86_64_gnu 0.53.1",
+ "windows_x86_64_gnullvm 0.53.1",
+ "windows_x86_64_msvc 0.53.1",
+]
+
 [[package]]
 name = "windows-threading"
 version = "0.1.0"
@@ -8273,6 +8368,12 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
 
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a9d8416fa8b42f5c947f8482c43e7d89e73a173cead56d044f6a56104a6d1b53"
+
 [[package]]
 name = "windows_aarch64_msvc"
 version = "0.42.2"
@@ -8291,6 +8392,12 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
 
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9d782e804c2f632e395708e99a94275910eb9100b2114651e04744e9b125006"
+
 [[package]]
 name = "windows_i686_gnu"
 version = "0.42.2"
@@ -8309,12 +8416,24 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
 
+[[package]]
+name = "windows_i686_gnu"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "960e6da069d81e09becb0ca57a65220ddff016ff2d6af6a223cf372a506593a3"
+
 [[package]]
 name = "windows_i686_gnullvm"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
 
+[[package]]
+name = "windows_i686_gnullvm"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fa7359d10048f68ab8b09fa71c3daccfb0e9b559aed648a8f95469c27057180c"
+
 [[package]]
 name = "windows_i686_msvc"
 version = "0.42.2"
@@ -8333,6 +8452,12 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
 
+[[package]]
+name = "windows_i686_msvc"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e7ac75179f18232fe9c285163565a57ef8d3c89254a30685b57d83a38d326c2"
+
 [[package]]
 name = "windows_x86_64_gnu"
 version = "0.42.2"
@@ -8351,6 +8476,12 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
 
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c3842cdd74a865a8066ab39c8a7a473c0778a3f29370b5fd6b4b9aa7df4a499"
+
 [[package]]
 name = "windows_x86_64_gnullvm"
 version = "0.42.2"
@@ -8369,6 +8500,12 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
 
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ffa179e2d07eee8ad8f57493436566c7cc30ac536a3379fdf008f47f6bb7ae1"
+
 [[package]]
 name = "windows_x86_64_msvc"
 version = "0.42.2"
@@ -8387,6 +8524,12 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
 
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d6bbff5f0aada427a1e5a6da5f1f98158182f26556f345ac9e04d36d0ebed650"
+
 [[package]]
 name = "winnow"
 version = "0.5.40"
diff --git a/src-tauri/Cargo.toml b/src-tauri/Cargo.toml
index 69f3b19..ed5a609 100644
--- a/src-tauri/Cargo.toml
+++ b/src-tauri/Cargo.toml
@@ -10,6 +10,7 @@ tauri-build = { version = "2", features = [] }
 [dependencies]
 tauri = { version = "2", features = [] }
 tauri-plugin-clipboard-manager = "2"
+tauri-plugin-dialog = "2"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 base64 = "0.22"
@@ -24,3 +25,6 @@ claude-commander = { git = "https://github.com/sizeak/claude-commander", tag = "
 futures = "0.3.32"
 tracing = "0.1.44"
 chrono = "0.4.45"
+
+[dev-dependencies]
+tempfile = "3"
diff --git a/src-tauri/capabilities/default.json b/src-tauri/capabilities/default.json
index 428ff22..c81835c 100644
--- a/src-tauri/capabilities/default.json
+++ b/src-tauri/capabilities/default.json
@@ -7,6 +7,7 @@
     "core:default",
     "core:window:allow-close",
     "clipboard-manager:allow-write-text",
-    "clipboard-manager:allow-read-text"
+    "clipboard-manager:allow-read-text",
+    "dialog:allow-open"
   ]
 }
diff --git a/src-tauri/src/main.rs b/src-tauri/src/main.rs
index 82c4862..49a3069 100644
--- a/src-tauri/src/main.rs
+++ b/src-tauri/src/main.rs
@@ -72,6 +72,7 @@ fn main() {
 
     tauri::Builder::default()
         .plugin(tauri_plugin_clipboard_manager::init())
+        .plugin(tauri_plugin_dialog::init())
         .manage(pty::PtyState::default())
         .setup(|app| {
             groups::spawn_sessions_loop(app.handle().clone());
@@ -105,6 +106,7 @@ fn main() {
             cascade::cascade_abandon,
             cascade::push_stack,
             projects::add_project,
+            projects::complete_path,
             projects::scan_directory,
             projects::remove_project,
             projects::prepare_project_shell,
diff --git a/src-tauri/src/projects.rs b/src-tauri/src/projects.rs
index b78e0b6..bdbe1a0 100644
--- a/src-tauri/src/projects.rs
+++ b/src-tauri/src/projects.rs
@@ -1,6 +1,6 @@
 //! Project management, editor/browser opening, and project shells.
 
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 use serde::Serialize;
 
@@ -8,6 +8,7 @@ use crate::service::{parse_project_id, parse_session_id, service, with_service};
 
 #[tauri::command]
 pub async fn add_project(path: String) -> Result<String, String> {
+    let path = expand_tilde(&path);
     with_service(move |svc| async move {
         svc.add_project(PathBuf::from(path))
             .await
@@ -17,6 +18,19 @@ pub async fn add_project(path: String) -> Result<String, String> {
     .await
 }
 
+/// List directories matching `partial` for the add-project / scan path input's
+/// live autocomplete. `partial` is the (possibly tilde-prefixed) path typed so
+/// far; results are returned in the same tilde form the input used, so the
+/// frontend can drop them straight back into the field.
+#[tauri::command]
+pub fn complete_path(partial: String) -> Vec<String> {
+    let expanded = expand_tilde(&partial);
+    list_matching_dirs(&expanded)
+        .into_iter()
+        .map(|p| unexpand_tilde(&partial, &p))
+        .collect()
+}
+
 #[derive(Serialize)]
 pub struct ScanOutcome {
     added: usize,
@@ -26,7 +40,7 @@ pub struct ScanOutcome {
 /// Scan a directory tree for git repos and add them all as projects.
 #[tauri::command]
 pub async fn scan_directory(path: String) -> Result<ScanOutcome, String> {
-    let dir = PathBuf::from(shellexpand_tilde(&path));
+    let dir = PathBuf::from(expand_tilde(&path));
     if !dir.is_dir() {
         return Err(format!("not a directory: {}", dir.display()));
     }
@@ -127,11 +141,143 @@ fn open_with_platform_opener(target: &str) -> Result<(), String> {
         .map_err(|e| format!("failed to open {target}: {e}"))
 }
 
-fn shellexpand_tilde(path: &str) -> String {
-    if let Some(rest) = path.strip_prefix("~/") {
-        if let Some(home) = std::env::var_os("HOME") {
-            return format!("{}/{}", home.to_string_lossy(), rest);
+fn home() -> Option<String> {
+    std::env::var_os("HOME").map(|h| h.to_string_lossy().into_owned())
+}
+
+/// Expand a leading `~` or `~/` to the user's home directory.
+fn expand_tilde(path: &str) -> String {
+    if path == "~" {
+        if let Some(home) = home() {
+            return home;
+        }
+    } else if let Some(rest) = path.strip_prefix("~/") {
+        if let Some(home) = home() {
+            return format!("{home}/{rest}");
         }
     }
     path.to_string()
 }
+
+/// If `original` used a `~` prefix, re-collapse the home prefix in `expanded`
+/// so completions are shown in the same form the user typed.
+fn unexpand_tilde(original: &str, expanded: &str) -> String {
+    if original.starts_with('~') {
+        if let Some(home) = home() {
+            if let Some(rest) = expanded.strip_prefix(&home) {
+                return format!("~{rest}");
+            }
+        }
+    }
+    expanded.to_string()
+}
+
+/// Split a path into `(parent_dir, partial_name)` at the last `/`.
+fn split_path(value: &str) -> (&str, &str) {
+    match value.rfind('/') {
+        Some(pos) => (&value[..=pos], &value[pos + 1..]),
+        None => ("", value),
+    }
+}
+
+/// List directories inside the parent of `value` whose names start with the
+/// trailing partial name. Symlinks are followed only when they resolve to a
+/// directory; unreadable parents yield an empty list.
+fn list_matching_dirs(value: &str) -> Vec<String> {
+    let (parent, partial) = split_path(value);
+
+    let parent_path = if parent.is_empty() {
+        Path::new(".")
+    } else {
+        Path::new(parent)
+    };
+
+    let Ok(entries) = std::fs::read_dir(parent_path) else {
+        return Vec::new();
+    };
+
+    let mut matches: Vec<String> = entries
+        .filter_map(|e| e.ok())
+        .filter(|e| {
+            e.file_type()
+                .map(|ft| ft.is_dir() || ft.is_symlink())
+                .unwrap_or(false)
+        })
+        .filter_map(|e| {
+            let name = e.file_name().to_string_lossy().into_owned();
+            if name.starts_with(partial) {
+                // For symlinks, verify the target is a directory.
+                if e.file_type().map(|ft| ft.is_symlink()).unwrap_or(false) && !e.path().is_dir() {
+                    return None;
+                }
+                let full = if parent.is_empty() {
+                    name
+                } else if parent.ends_with('/') {
+                    format!("{parent}{name}")
+                } else {
+                    format!("{parent}/{name}")
+                };
+                Some(full)
+            } else {
+                None
+            }
+        })
+        .collect();
+
+    matches.sort();
+    matches
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{list_matching_dirs, split_path};
+    use std::fs;
+
+    fn setup_dirs(names: &[&str]) -> tempfile::TempDir {
+        let tmp = tempfile::tempdir().unwrap();
+        for name in names {
+            fs::create_dir_all(tmp.path().join(name)).unwrap();
+        }
+        tmp
+    }
+
+    #[test]
+    fn lists_matching_subdirectories_sorted() {
+        let tmp = setup_dirs(&["project-a", "project-b", "other"]);
+        let got = list_matching_dirs(&format!("{}/project", tmp.path().display()));
+        assert_eq!(
+            got,
+            vec![
+                format!("{}/project-a", tmp.path().display()),
+                format!("{}/project-b", tmp.path().display()),
+            ]
+        );
+    }
+
+    #[test]
+    fn files_are_excluded() {
+        let tmp = setup_dirs(&["dir_a"]);
+        fs::write(tmp.path().join("file_a"), "x").unwrap();
+        let got = list_matching_dirs(&format!("{}/", tmp.path().display()));
+        assert_eq!(got, vec![format!("{}/dir_a", tmp.path().display())]);
+    }
+
+    #[test]
+    fn hidden_dirs_are_included() {
+        let tmp = setup_dirs(&[".hidden", "visible"]);
+        let got = list_matching_dirs(&format!("{}/.h", tmp.path().display()));
+        assert_eq!(got, vec![format!("{}/.hidden", tmp.path().display())]);
+    }
+
+    #[test]
+    fn unreadable_parent_yields_empty() {
+        assert!(list_matching_dirs("/nonexistent_surely_xyz_123/foo").is_empty());
+    }
+
+    #[test]
+    fn split_path_splits_at_last_slash() {
+        assert_eq!(split_path("/home/user/pro"), ("/home/user/", "pro"));
+        assert_eq!(split_path("/home/user/"), ("/home/user/", ""));
+        assert_eq!(split_path("pro"), ("", "pro"));
+    }
+}
diff --git a/src/help.ts b/src/help.ts
index 3d27357..334a7bc 100644
--- a/src/help.ts
+++ b/src/help.ts
@@ -17,6 +17,7 @@ const HELP_SECTIONS: [string, [string, string][]][] = [
     "Sidebar",
     [
       ["⋯ menu", "Add project, scan directory, delete merged-PR sessions"],
+      ["Path input", "Type to autocomplete dirs (Tab completes, ↑/↓ pick, Enter drills in/commits, Browse… opens picker)"],
       ["⇄", "Cycle view: project / sections / section stacks"],
       ["Drag row → section", "Move a session to a section (drop on In Progress to unpin)"],
       ["● (yellow)", "Unread: agent finished while you were away"],
diff --git a/src/main.ts b/src/main.ts
index 00b7aec..d7aa6c4 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -2,6 +2,7 @@ import { invoke, Channel } from "@tauri-apps/api/core";
 import { listen } from "@tauri-apps/api/event";
 import { getCurrentWindow } from "@tauri-apps/api/window";
 import { writeText, readText } from "@tauri-apps/plugin-clipboard-manager";
+import { open as openFolderDialog } from "@tauri-apps/plugin-dialog";
 import { Terminal } from "@xterm/xterm";
 import { FitAddon } from "@xterm/addon-fit";
 import { WebLinksAddon } from "@xterm/addon-web-links";
@@ -1738,35 +1739,152 @@ function projectMenuItems(group: ProjectGroup, createKey: string = group.id): Me
   ];
 }
 
-/** Path input at the top of the sidebar for add-project / scan-directory. */
+/** Longest common prefix of a list of strings (drives Tab completion). */
+function longestCommonPrefix(strings: string[]): string {
+  if (!strings.length) return "";
+  let prefix = strings[0];
+  for (const s of strings.slice(1)) {
+    while (prefix && !s.startsWith(prefix)) prefix = prefix.slice(0, -1);
+    if (!prefix) break;
+  }
+  return prefix;
+}
+
+/** Path input at the top of the sidebar for add-project / scan-directory, with
+ *  a live directory-completion dropdown (Tab → common prefix, ↑/↓ to pick,
+ *  Enter on a match drills in, Enter on free text commits) and a native folder
+ *  picker via "Browse…". Seeded with `~/` so the first listing shows $HOME. */
 function renderTopInput(mode: "add" | "scan"): HTMLDivElement {
   const wrap = document.createElement("div");
-  wrap.className = "create-input";
+  wrap.className = "create-input path-input";
+  const row = document.createElement("div");
+  row.className = "path-input-row";
   const input = noTextAssist(document.createElement("input"));
   input.placeholder = mode === "add" ? "path to git repo…" : "directory to scan for repos…";
+  input.value = "~/";
+  const browse = document.createElement("button");
+  browse.className = "path-browse";
+  browse.textContent = "Browse…";
+  const listEl = document.createElement("div");
+  listEl.className = "path-completions";
+  row.append(input, browse);
+  wrap.append(row, listEl);
+
+  let completions: string[] = [];
+  let selected = -1; // -1 = nothing highlighted (Enter commits the typed value)
+  let debounce: number | undefined;
+
+  function renderCompletions(): void {
+    listEl.innerHTML = "";
+    completions.forEach((c, i) => {
+      const r = document.createElement("div");
+      r.className = "path-completion";
+      r.classList.toggle("selected", i === selected);
+      r.textContent = c;
+      // mousedown (not click) so the pick lands before the input's blur.
+      r.addEventListener("mousedown", (e) => {
+        e.preventDefault();
+        input.value = `${c}/`;
+        selected = -1;
+        void refresh();
+        input.focus();
+      });
+      listEl.appendChild(r);
+    });
+  }
+
+  async function refresh(): Promise<void> {
+    let next: string[];
+    try {
+      next = await invoke<string[]>("complete_path", { partial: input.value });
+    } catch {
+      next = [];
+    }
+    completions = next;
+    selected = completions.length ? Math.min(selected, completions.length - 1) : -1;
+    renderCompletions();
+  }
+
+  function commit(path: string): void {
+    topInput = null;
+    input.disabled = true;
+    const call =
+      mode === "add"
+        ? invoke("add_project", { path })
+        : invoke<{ added: number; skipped: number }>("scan_directory", { path }).then((r) =>
+            toast(`Scan complete: ${r.added} added, ${r.skipped} already present`),
+          );
+    call
+      .catch((err) => toast(`${mode === "add" ? "add project" : "scan"} failed: ${err}`, "error"))
+      .finally(() => void refreshNow());
+    renderSidebar();
+  }
+
+  input.addEventListener("input", () => {
+    selected = -1;
+    clearTimeout(debounce);
+    debounce = window.setTimeout(() => void refresh(), 100);
+  });
+
   input.addEventListener("keydown", (e) => {
+    e.stopPropagation();
     if (e.key === "Escape") {
       topInput = null;
       renderSidebar();
+      return;
     }
-    if (e.key === "Enter" && input.value.trim()) {
-      const path = input.value.trim();
-      topInput = null;
-      input.disabled = true;
-      const call =
-        mode === "add"
-          ? invoke("add_project", { path })
-          : invoke<{ added: number; skipped: number }>("scan_directory", { path }).then((r) =>
-              toast(`Scan complete: ${r.added} added, ${r.skipped} already present`),
-            );
-      call
-        .catch((err) => toast(`${mode === "add" ? "add project" : "scan"} failed: ${err}`, "error"))
-        .finally(() => void refreshNow());
-      renderSidebar();
+    if (e.key === "ArrowDown") {
+      e.preventDefault();
+      if (completions.length) {
+        selected = (selected + 1) % completions.length;
+        renderCompletions();
+      }
+      return;
+    }
+    if (e.key === "ArrowUp") {
+      e.preventDefault();
+      if (completions.length) {
+        selected = selected <= 0 ? completions.length - 1 : selected - 1;
+        renderCompletions();
+      }
+      return;
+    }
+    if (e.key === "Tab") {
+      e.preventDefault();
+      const lcp = longestCommonPrefix(completions);
+      if (lcp && lcp.length > input.value.length) {
+        input.value = lcp;
+        void refresh();
+      }
+      return;
+    }
+    if (e.key === "Enter") {
+      // A highlighted row drills into that directory; otherwise commit the
+      // typed path (the "I typed the full path, just add it" case).
+      if (selected >= 0 && completions[selected]) {
+        input.value = `${completions[selected]}/`;
+        selected = -1;
+        void refresh();
+      } else if (input.value.trim()) {
+        commit(input.value.trim());
+      }
     }
   });
-  wrap.appendChild(input);
-  setTimeout(() => input.focus(), 0);
+
+  browse.addEventListener("click", () => {
+    void openFolderDialog({ directory: true }).then((picked) => {
+      if (typeof picked === "string") {
+        input.value = picked;
+        input.focus();
+        void refresh();
+      }
+    });
+  });
+
+  setTimeout(() => {
+    input.focus();
+    void refresh();
+  }, 0);
   return wrap;
 }
 
diff --git a/src/playwright/iwft/network/TauriSimulator.testHelper.ts b/src/playwright/iwft/network/TauriSimulator.testHelper.ts
index 2519e98..b5ce45e 100644
--- a/src/playwright/iwft/network/TauriSimulator.testHelper.ts
+++ b/src/playwright/iwft/network/TauriSimulator.testHelper.ts
@@ -32,6 +32,9 @@ class TauriSimulator {
   private ptyChannels: Record<string, { channel: { id: number }; index: number }> = {};
   private nextComment = 1;
   private nextSession = 1;
+  private nextProject = 1;
+  private dirs: string[];
+  private browsePath: string | null;
   private openedUrls: string[] = [];
   // Section moves the frontend actually dispatched (a no-op drop short-circuits
   // before invoke, so this stays empty — how a negative test tells them apart).
@@ -43,6 +46,8 @@ class TauriSimulator {
     this.config = seed.config ?? {};
     this.keybindings = seed.keybindings ?? {};
     this.customThemes = seed.customThemes ?? [];
+    this.dirs = seed.dirs ?? [];
+    this.browsePath = seed.browsePath ?? null;
     this.comments = {};
     this.reviewed = {};
     for (const [id, review] of Object.entries(seed.reviews)) {
@@ -73,6 +78,12 @@ class TauriSimulator {
     return this.snapshot.groups.flatMap((g) => g.sessions);
   }
 
+  /** Projects the fake now holds (name + repo_path) — what an add-project test
+   *  asserts against. */
+  getProjects(): { id: string; name: string; repo_path: string }[] {
+    return this.snapshot.groups.map((g) => ({ id: g.id, name: g.name, repo_path: g.repo_path }));
+  }
+
   /** Current section buckets (null in project view) — what a move-to-section
    *  test asserts placement against. */
   getSectionBuckets(): { name: string; session_ids: string[] }[] | null {
@@ -136,6 +147,16 @@ class TauriSimulator {
         return this.moveToSection(args.id as string, (args.section as string | null) ?? null);
       case "merged_pr_sessions":
         return this.mergedPrSessions();
+      // ----- add project / scan / path autocomplete -----
+      case "complete_path":
+        return this.completePath(args.partial as string);
+      case "add_project":
+        return this.addProject(args.path as string);
+      case "scan_directory":
+        return this.scanDirectory(args.path as string);
+      // ----- dialog plugin (native folder picker behind "Browse…") -----
+      case "plugin:dialog|open":
+        return this.browsePath;
       // ----- PTY lifecycle (terminal tabs) -----
       case "prepare_attach":
         return null;
@@ -278,6 +299,39 @@ class TauriSimulator {
     this.snapshot.sections = buckets;
   }
 
+  /** Directories that are direct children of `partial`'s parent and whose
+   *  basename starts with its trailing segment — mirrors the backend's
+   *  list_matching_dirs over the seeded `dirs` (no real filesystem). */
+  private completePath(partial: string): string[] {
+    const slash = partial.lastIndexOf("/");
+    const parent = slash >= 0 ? partial.slice(0, slash + 1) : "";
+    const name = slash >= 0 ? partial.slice(slash + 1) : partial;
+    const results = new Set<string>();
+    for (const d of this.dirs) {
+      if (parent && !d.startsWith(parent)) continue;
+      const rest = parent ? d.slice(parent.length) : d;
+      const seg = rest.split("/")[0];
+      if (seg && seg.startsWith(name)) results.add(`${parent}${seg}`);
+    }
+    return [...results].sort();
+  }
+
+  /** Add a project group (no sessions) keyed off the path's basename, mirroring
+   *  the backend add_project; returns the new id like the real command. */
+  private addProject(path: string): string {
+    const id = `proj-add-${this.nextProject++}`;
+    const name = path.replace(/\/+$/, "").split("/").pop() || path;
+    this.snapshot.groups.push({ id, name, repo_path: path, pull_blocked: null, sessions: [] });
+    return id;
+  }
+
+  /** Count seeded dirs nested under `path` as the "added" repos. */
+  private scanDirectory(path: string): { added: number; skipped: number } {
+    const prefix = path.endsWith("/") ? path : `${path}/`;
+    const added = this.dirs.filter((d) => d.startsWith(prefix)).length;
+    return { added, skipped: 0 };
+  }
+
   /** [id, label] pairs for sessions whose PR has merged — the merged-PR sweep source. */
   private mergedPrSessions(): [string, string][] {
     return this.getSessions()
diff --git a/src/playwright/iwft/network/types.testHelper.ts b/src/playwright/iwft/network/types.testHelper.ts
index 8950381..b162465 100644
--- a/src/playwright/iwft/network/types.testHelper.ts
+++ b/src/playwright/iwft/network/types.testHelper.ts
@@ -52,4 +52,9 @@ export type Seed = {
   config?: Record<string, unknown>;
   /** Raw custom themes answered to list_custom_themes (validated by theme.ts). */
   customThemes?: unknown[];
+  /** Absolute directory paths the fake filesystem "contains" — the source for
+   *  complete_path autocomplete. */
+  dirs?: string[];
+  /** Path the native folder picker (Browse…) returns; null models a cancel. */
+  browsePath?: string | null;
 };
diff --git a/src/playwright/iwft/scenarios/sidebar/addProject.iwft.ts b/src/playwright/iwft/scenarios/sidebar/addProject.iwft.ts
new file mode 100644
index 0000000..bd0597f
--- /dev/null
+++ b/src/playwright/iwft/scenarios/sidebar/addProject.iwft.ts
@@ -0,0 +1,62 @@
+import { test, expect } from "../../support/fixture.testHelper";
+import { makeSnapshot } from "../../network/seed.testHelper";
+
+// The add-project path input lives behind the sidebar ⋯ menu. These exercise the
+// autocomplete dropdown (type → filter, Tab → common prefix, ↑/↓ → drill in),
+// the free-text commit, and the native Browse… picker. The fake answers
+// complete_path from a seeded directory list (no real filesystem).
+test.use({
+  seed: {
+    snapshot: makeSnapshot(),
+    reviews: {},
+    dirs: ["/repos/acme", "/repos/beta", "/repos/beta-two", "/work/proj"],
+    browsePath: "/picked/repo",
+  },
+});
+
+test("autocomplete lists directories matching what you type", async ({ sidebar }) => {
+  await sidebar.openAddProject();
+  await sidebar.typePath("/repos/");
+  await expect(sidebar.pathCompletions()).toHaveText(["/repos/acme", "/repos/beta", "/repos/beta-two"]);
+
+  await sidebar.typePath("/repos/be");
+  await expect(sidebar.pathCompletions()).toHaveText(["/repos/beta", "/repos/beta-two"]);
+});
+
+test("Tab completes to the longest common prefix", async ({ sidebar }) => {
+  await sidebar.openAddProject();
+  await sidebar.typePath("/repos/be");
+  await sidebar.pressInPath("Tab");
+  expect(await sidebar.pathValue()).toBe("/repos/beta");
+});
+
+test("arrow-select then Enter drills into the directory", async ({ sidebar }) => {
+  await sidebar.openAddProject();
+  await sidebar.typePath("/repos/");
+  await sidebar.pressInPath("ArrowDown"); // highlight /repos/acme
+  await sidebar.pressInPath("Enter"); // drill in, not commit
+  expect(await sidebar.pathValue()).toBe("/repos/acme/");
+  // Still in the input — no project added yet.
+  expect((await sidebar.storedProjects()).map((p) => p.repo_path)).not.toContain("/repos/acme/");
+});
+
+test("Enter on free text commits the project", async ({ sidebar }) => {
+  await sidebar.openAddProject();
+  await sidebar.typePath("/repos/beta-two");
+  await sidebar.pressInPath("Enter"); // nothing highlighted → commit
+
+  await expect(async () => {
+    const repos = (await sidebar.storedProjects()).map((p) => p.repo_path);
+    expect(repos).toContain("/repos/beta-two");
+  }).toPass();
+  // The new project header renders in the sidebar.
+  await expect(sidebar.sectionHeader("beta-two")).toBeVisible();
+});
+
+test("Browse… fills the input from the native picker", async ({ sidebar }) => {
+  await sidebar.openAddProject();
+  await sidebar.clickBrowse();
+  await expect(async () => {
+    expect(await sidebar.pathValue()).toBe("/picked/repo");
+  }).toPass();
+});
diff --git a/src/playwright/pageObjects/SidebarPageObject.testHelper.ts b/src/playwright/pageObjects/SidebarPageObject.testHelper.ts
index a7fb780..5411bcf 100644
--- a/src/playwright/pageObjects/SidebarPageObject.testHelper.ts
+++ b/src/playwright/pageObjects/SidebarPageObject.testHelper.ts
@@ -138,6 +138,60 @@ export class SidebarPageObject extends AppPageObject {
     });
   }
 
+  // ----- add project (sidebar menu → path input with autocomplete) -----
+  private readonly pathInput = this.sessions.locator(".path-input input");
+
+  /** Open the sidebar menu and choose "Add project…" — leaves the path input
+   *  focused and pre-seeded with `~/`. */
+  openAddProject(): Promise<void> {
+    return this.step("openAddProject", async () => {
+      await this.page.locator("#sidebar-menu").click();
+      await this.menuItem("Add project…").click();
+      await expect(this.pathInput).toBeVisible();
+    });
+  }
+
+  /** Replace the path input's value and let the debounced completion settle. */
+  typePath(value: string): Promise<void> {
+    return this.step(`typePath: ${value}`, async () => {
+      await this.pathInput.fill(value);
+      // Debounce is 100ms; press a no-op key so `fill` still triggers `input`.
+      await this.page.waitForTimeout(150);
+    });
+  }
+
+  /** The visible autocomplete completion rows, top to bottom. */
+  pathCompletions(): Locator {
+    return this.sessions.locator(".path-completion");
+  }
+
+  /** Press a key in the focused path input (e.g. "Tab", "ArrowDown", "Enter"). */
+  pressInPath(key: string): Promise<void> {
+    return this.step(`pressInPath: ${key}`, () => this.pathInput.press(key));
+  }
+
+  /** The current text in the path input. */
+  pathValue(): Promise<string> {
+    return this.pathInput.inputValue();
+  }
+
+  /** Click the native folder-picker button. */
+  clickBrowse(): Promise<void> {
+    return this.step("clickBrowse", () => this.sessions.locator(".path-browse").click());
+  }
+
+  /** Projects the fake holds (name + repo_path) — assert an add landed. */
+  storedProjects(): Promise<{ id: string; name: string; repo_path: string }[]> {
+    return this.page.evaluate(
+      () =>
+        (
+          window as unknown as {
+            __CC_SIM__: { getProjects(): { id: string; name: string; repo_path: string }[] };
+          }
+        ).__CC_SIM__.getProjects(),
+    );
+  }
+
   // ----- rename (via row context menu → inline input) -----
   rename(title: string, newTitle: string): Promise<void> {
     return this.step(`rename: ${title} → ${newTitle}`, async () => {
diff --git a/src/style.css b/src/style.css
index 6cdd6c7..136b6b4 100644
--- a/src/style.css
+++ b/src/style.css
@@ -1123,6 +1123,48 @@ body {
   outline: none;
 }
 
+.path-input-row {
+  display: flex;
+  gap: 4px;
+}
+
+.path-browse {
+  flex: none;
+  background: var(--bg-inset);
+  border: 1px solid var(--border-strong);
+  border-radius: 4px;
+  color: var(--text);
+  font-size: 11px;
+  padding: 0 8px;
+  cursor: pointer;
+}
+
+.path-browse:hover {
+  border-color: var(--accent);
+}
+
+.path-completions {
+  margin-top: 4px;
+  max-height: 180px;
+  overflow-y: auto;
+}
+
+.path-completion {
+  padding: 4px 8px;
+  font-size: 12px;
+  color: var(--text);
+  border-radius: 4px;
+  cursor: pointer;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.path-completion.selected,
+.path-completion:hover {
+  background: var(--border);
+}
+
 .error {
   padding: 12px;
   color: var(--danger);