diff --git a/CLAUDE.md b/CLAUDE.md
index 5656fb0..5d644b1 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -29,9 +29,9 @@ The Tauri dev server runs on port 1422 (`vite.config.ts` and `tauri.conf.json`).
 
 Two-crate workspace (`resolver = "2"`, edition 2021) plus a Tauri app:
 
-- **onyx-core** — Pure Rust library. Storage trait with `FileSystemStorage` implementation, `TaskRepository` (main API), data models, config, error types. No CLI/UI dependencies.
+- **onyx-core** — Pure Rust library. Storage trait with `FileSystemStorage` implementation, `TaskRepository` (main API), data models, config, error types. No CLI/UI dependencies. `keyring` feature-gated behind `keyring-storage` (default on) for Android compatibility.
 - **onyx-cli** — CLI frontend using clap. Commands are in `src/commands/` (init, workspace, list, task, group). Output formatting in `src/output.rs`.
-- **apps/tauri/** — Tauri v2 GUI. Svelte 5 frontend in `src/`, Rust backend in `src-tauri/` with Tauri commands that call into `onyx-core`.
+- **apps/tauri/** — Tauri v2 GUI. Svelte 5 frontend in `src/`, Rust backend in `src-tauri/` with Tauri commands that call into `onyx-core`. `notify` crate feature-gated for Android.
 - **apps/flutter/** — Flutter GUI. Dart frontend in `lib/src/`, Rust backend in `rust/` via flutter_rust_bridge FFI into `onyx-core`.
 
 ### Key patterns
@@ -61,6 +61,7 @@ The GUI uses Svelte 5 runes mode (`$state`, `$derived`, `$effect`, `$props()`).
 - **Phase 1** (Core + CLI): Complete
 - **Phase 2** (WebDAV sync): Backend done, CLI done, GUI wired (settings auto-populates credentials)
 - **Phase 3** (GUI MVP): Complete — both Tauri and Flutter GUIs at feature parity
+- **Phase 4** (Mobile): Tauri Android cfg-gated, needs `tauri android init` + build
 
 ### GUI features done
 
@@ -85,6 +86,7 @@ The GUI uses Svelte 5 runes mode (`$state`, `$derived`, `$effect`, `$props()`).
 - Push/pull/full sync mode selection (session-only, in settings)
 - Desktop packaging (Linux: AppImage + .deb)
 - Flutter GUI at full parity with Tauri (WebDAV UI, has_time, sync status, sync mode)
+- Tauri desktop-only deps (notify, keyring) feature-gated for Android compilation
 
 ### GUI features NOT yet done
 
diff --git a/apps/tauri/src-tauri/Cargo.toml b/apps/tauri/src-tauri/Cargo.toml
index 3752fda..19b69ec 100644
--- a/apps/tauri/src-tauri/Cargo.toml
+++ b/apps/tauri/src-tauri/Cargo.toml
@@ -19,14 +19,16 @@ tauri-plugin-dialog = "2"
 tauri-plugin-os = "2"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
-onyx-core = { path = "../../../crates/onyx-core" }
+onyx-core = { path = "../../../crates/onyx-core", default-features = false }
 tokio = { version = "1", features = ["full"] }
 uuid = { version = "1", features = ["serde", "v4"] }
 chrono = { version = "0.4", features = ["serde"] }
-notify = "7"
-notify-debouncer-mini = "0.5"
+notify = { version = "7", optional = true }
+notify-debouncer-mini = { version = "0.5", optional = true }
 
 [package.metadata.tauri]
 
 [features]
+default = ["desktop"]
+desktop = ["notify", "notify-debouncer-mini", "onyx-core/keyring-storage"]
 custom-protocol = ["tauri/custom-protocol"]
diff --git a/apps/tauri/src-tauri/src/lib.rs b/apps/tauri/src-tauri/src/lib.rs
index 75bf467..7cbe413 100644
--- a/apps/tauri/src-tauri/src/lib.rs
+++ b/apps/tauri/src-tauri/src/lib.rs
@@ -4,6 +4,7 @@ use std::time::Instant;
 
 use chrono::Utc;
 
+#[cfg(not(target_os = "android"))]
 use notify_debouncer_mini::{new_debouncer, DebouncedEventKind};
 use serde::{Deserialize, Serialize};
 use tauri::{Emitter, Manager, State};
@@ -17,10 +18,12 @@ use onyx_core::{
     webdav,
 };
 
+#[cfg(not(target_os = "android"))]
 /// Active file watcher stored globally so it lives for the app lifetime.
 static WATCHER: Mutex<Option<notify_debouncer_mini::Debouncer<notify::RecommendedWatcher>>> =
     Mutex::new(None);
 
+#[cfg(not(target_os = "android"))]
 /// Shared mute timestamp — set before writes, checked by the watcher.
 static LAST_WRITE: Mutex<Option<Instant>> = Mutex::new(None);
 
@@ -55,10 +58,14 @@ impl From<CoreSyncResult> for SyncResult {
 }
 
 /// Suppress file watcher events for the next second (call before writes).
+#[cfg(not(target_os = "android"))]
 fn mute_watcher(_state: &mut AppState) {
     *LAST_WRITE.lock().unwrap() = Some(Instant::now());
 }
 
+#[cfg(target_os = "android")]
+fn mute_watcher(_state: &mut AppState) {}
+
 /// Helper: get or open a TaskRepository for the current workspace.
 fn ensure_repo(state: &mut AppState) -> Result<(), String> {
     if state.repo.is_some() {
@@ -463,6 +470,7 @@ async fn sync_workspace(
 
 // ── File watcher ────────────────────────────────────────────────────
 
+#[cfg(not(target_os = "android"))]
 fn start_watcher(handle: tauri::AppHandle, path: PathBuf) {
     let handle = handle.clone();
     let debouncer = new_debouncer(
@@ -492,12 +500,19 @@ fn start_watcher(handle: tauri::AppHandle, path: PathBuf) {
     }
 }
 
+#[cfg(not(target_os = "android"))]
 #[tauri::command]
 fn watch_workspace(path: String, app_handle: tauri::AppHandle) -> Result<(), String> {
     start_watcher(app_handle, PathBuf::from(path));
     Ok(())
 }
 
+#[cfg(target_os = "android")]
+#[tauri::command]
+fn watch_workspace(_path: String, _app_handle: tauri::AppHandle) -> Result<(), String> {
+    Ok(())
+}
+
 // ── App entry ────────────────────────────────────────────────────────
 
 #[cfg_attr(mobile, tauri::mobile_entry_point)]
@@ -517,6 +532,7 @@ pub fn run() {
                 let s = state.lock().unwrap();
                 s.config.get_current_workspace().ok().map(|(_, ws)| ws.path.clone())
             };
+            #[cfg(not(target_os = "android"))]
             if let Some(path) = workspace_path {
                 start_watcher(handle, path);
             }
diff --git a/crates/onyx-core/Cargo.toml b/crates/onyx-core/Cargo.toml
index 0100d0a..4949aec 100644
--- a/crates/onyx-core/Cargo.toml
+++ b/crates/onyx-core/Cargo.toml
@@ -6,6 +6,10 @@ description = "Core library for local-first task management with markdown storag
 license = "GPL-3.0-or-later"
 repository = "https://github.com/SteelDynamite/onyx"
 
+[features]
+default = ["keyring-storage"]
+keyring-storage = ["keyring"]
+
 [dependencies]
 serde = { workspace = true }
 serde_json = "1.0"
@@ -17,7 +21,7 @@ reqwest = { workspace = true }
 sha2 = { workspace = true }
 quick-xml = { workspace = true }
 tokio = { workspace = true }
-keyring = { version = "3", features = ["apple-native", "windows-native", "sync-secret-service"] }
+keyring = { version = "3", features = ["apple-native", "windows-native", "sync-secret-service"], optional = true }
 
 [dev-dependencies]
 tempfile = "3.0"
diff --git a/crates/onyx-core/src/webdav.rs b/crates/onyx-core/src/webdav.rs
index fc852e5..3a3d532 100644
--- a/crates/onyx-core/src/webdav.rs
+++ b/crates/onyx-core/src/webdav.rs
@@ -379,6 +379,7 @@ fn extract_relative_path(href: &str, base_url: &str, request_path: &str) -> Stri
 
 // --- Credential Storage ---
 
+#[cfg(feature = "keyring-storage")]
 /// Store WebDAV credentials in the platform keychain.
 pub fn store_credentials(domain: &str, username: &str, password: &str) -> Result<()> {
     let service = format!("com.onyx.webdav.{}", domain);
@@ -396,6 +397,13 @@ pub fn store_credentials(domain: &str, username: &str, password: &str) -> Result
     Ok(())
 }
 
+#[cfg(not(feature = "keyring-storage"))]
+/// Store WebDAV credentials (not available without keyring-storage feature).
+pub fn store_credentials(_domain: &str, _username: &str, _password: &str) -> Result<()> {
+    Err(Error::Credential("Credential storage not available on this platform".into()))
+}
+
+#[cfg(feature = "keyring-storage")]
 /// Load WebDAV credentials from the platform keychain, falling back to env vars.
 pub fn load_credentials(domain: &str) -> Result<(String, String)> {
     let service = format!("com.onyx.webdav.{}", domain);
@@ -423,6 +431,23 @@ pub fn load_credentials(domain: &str) -> Result<(String, String)> {
     )))
 }
 
+#[cfg(not(feature = "keyring-storage"))]
+/// Load WebDAV credentials from env vars only (keyring not available).
+pub fn load_credentials(domain: &str) -> Result<(String, String)> {
+    if let (Ok(user), Ok(pass)) = (
+        std::env::var("ONYX_WEBDAV_USER"),
+        std::env::var("ONYX_WEBDAV_PASS"),
+    ) {
+        return Ok((user, pass));
+    }
+
+    Err(Error::Credential(format!(
+        "No credentials found for '{}'. Set ONYX_WEBDAV_USER and ONYX_WEBDAV_PASS.",
+        domain
+    )))
+}
+
+#[cfg(feature = "keyring-storage")]
 /// Delete WebDAV credentials from the platform keychain.
 pub fn delete_credentials(domain: &str) -> Result<()> {
     let service = format!("com.onyx.webdav.{}", domain);
@@ -437,6 +462,12 @@ pub fn delete_credentials(domain: &str) -> Result<()> {
     Ok(())
 }
 
+#[cfg(not(feature = "keyring-storage"))]
+/// Delete WebDAV credentials (no-op without keyring-storage feature).
+pub fn delete_credentials(_domain: &str) -> Result<()> {
+    Ok(())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;