feat(webdav): follow-up 补齐自动同步与大文件防护 (#1043)

* feat(webdav): add robust auto sync with failure feedback (cherry picked from commit bb6760124a62a964b36902c004e173534910728f) * fix(webdav): enforce bounded download and extraction size (cherry picked from commit 7777d6ec2b9bba07c8bbba9b04fe3ea6b15e0e79) * fix(webdav): only show auto-sync callout for auto-source errors * refactor(webdav): remove services->commands auto-sync dependency
2026-03-20 05:28:44 +08:00 · 2026-02-15 20:58:17 +08:00
parent 508aa6070c
commit 20f62bf4f8
19 changed files with 777 additions and 104 deletions
--- a/src-tauri/Cargo.toml
+++ b/src-tauri/Cargo.toml
@@ -57,7 +57,7 @@ url = "2.5"
 auto-launch = "0.5"
 once_cell = "1.21.3"
 base64 = "0.22"
-rusqlite = { version = "0.31", features = ["bundled", "backup"] }
+rusqlite = { version = "0.31", features = ["bundled", "backup", "hooks"] }
 indexmap = { version = "2", features = ["serde"] }
 rust_decimal = "1.33"
 uuid = { version = "1.11", features = ["v4"] }
--- a/src-tauri/src/commands/webdav_sync.rs
+++ b/src-tauri/src/commands/webdav_sync.rs
@@ -1,8 +1,6 @@
 #![allow(non_snake_case)]

-use serde_json::{Value, json};
-use std::future::Future;
-use std::sync::OnceLock;
+use serde_json::{json, Value};
 use tauri::State;

 use crate::commands::sync_support::{
@@ -13,8 +11,9 @@ use crate::services::webdav_sync as webdav_sync_service;
 use crate::settings::{self, WebDavSyncSettings};
 use crate::store::AppState;

-fn persist_sync_error(settings: &mut WebDavSyncSettings, error: &AppError) {
+fn persist_sync_error(settings: &mut WebDavSyncSettings, error: &AppError, source: &str) {
    settings.status.last_error = Some(error.to_string());
+    settings.status.last_error_source = Some(source.to_string());
    let _ = settings::update_webdav_sync_status(settings.status.clone());
 }

@@ -57,20 +56,16 @@ fn resolve_password_for_request(
    incoming
 }

+#[cfg(test)]
 fn webdav_sync_mutex() -> &'static tokio::sync::Mutex<()> {
-    static LOCK: OnceLock<tokio::sync::Mutex<()>> = OnceLock::new();
-    LOCK.get_or_init(|| tokio::sync::Mutex::new(()))
+    webdav_sync_service::sync_mutex()
 }

 async fn run_with_webdav_lock<T, Fut>(operation: Fut) -> Result<T, AppError>
 where
-    Fut: Future<Output = Result<T, AppError>>,
+    Fut: std::future::Future<Output = Result<T, AppError>>,
 {
-    let result = {
-        let _guard = webdav_sync_mutex().lock().await;
-        operation.await
-    };
-    result
+    webdav_sync_service::run_with_sync_lock(operation).await
 }

 fn map_sync_result<T, F>(result: Result<T, AppError>, on_error: F) -> Result<T, String>
@@ -112,7 +107,9 @@ pub async fn webdav_sync_upload(state: State<'_, AppState>) -> Result<Value, Str
    let mut settings = require_enabled_webdav_settings()?;

    let result = run_with_webdav_lock(webdav_sync_service::upload(&db, &mut settings)).await;
-    map_sync_result(result, |error| persist_sync_error(&mut settings, error))
+    map_sync_result(result, |error| {
+        persist_sync_error(&mut settings, error, "manual")
+    })
 }

 #[tauri::command]
@@ -120,10 +117,11 @@ pub async fn webdav_sync_download(state: State<'_, AppState>) -> Result<Value, S
    let db = state.db.clone();
    let db_for_sync = db.clone();
    let mut settings = require_enabled_webdav_settings()?;
+    let _auto_sync_suppression = crate::services::webdav_auto_sync::AutoSyncSuppressionGuard::new();

    let sync_result = run_with_webdav_lock(webdav_sync_service::download(&db, &mut settings)).await;
    let mut result = map_sync_result(sync_result, |error| {
-        persist_sync_error(&mut settings, error)
+        persist_sync_error(&mut settings, error, "manual")
    })?;

    // Post-download sync is best-effort: snapshot restore has already succeeded.
@@ -179,8 +177,8 @@ mod tests {
    use crate::error::AppError;
    use crate::settings::{AppSettings, WebDavSyncSettings};
    use serial_test::serial;
-    use std::sync::Arc;
    use std::sync::atomic::{AtomicBool, Ordering};
+    use std::sync::Arc;
    use std::time::Duration;

    #[tokio::test]
@@ -287,6 +285,7 @@ mod tests {
        persist_sync_error(
            &mut current,
            &crate::error::AppError::Config("boom".to_string()),
+            "manual",
        );

        let after = crate::settings::get_webdav_sync_settings().expect("read webdav settings");
@@ -304,6 +303,7 @@ mod tests {
                .contains("boom"),
            "status error should be updated"
        );
+        assert_eq!(after.status.last_error_source.as_deref(), Some("manual"));
    }

    #[test]
--- a/src-tauri/src/database/mod.rs
+++ b/src-tauri/src/database/mod.rs
@@ -37,7 +37,7 @@ pub use dao::OmoGlobalConfig;

 use crate::config::get_app_config_dir;
 use crate::error::AppError;
-use rusqlite::Connection;
+use rusqlite::{hooks::Action, Connection};
 use serde::Serialize;
 use std::sync::Mutex;

@@ -76,6 +76,17 @@ pub struct Database {
    pub(crate) conn: Mutex<Connection>,
 }

+fn register_db_change_hook(conn: &Connection) {
+    conn.update_hook(Some(
+        |action: Action, _database: &str, table: &str, _row_id: i64| match action {
+            Action::SQLITE_INSERT | Action::SQLITE_UPDATE | Action::SQLITE_DELETE => {
+                crate::services::webdav_auto_sync::notify_db_changed(table);
+            }
+            _ => {}
+        },
+    ));
+}
+
 impl Database {
    /// 初始化数据库连接并创建表
    ///
@@ -93,6 +104,7 @@ impl Database {
        // 启用外键约束
        conn.execute("PRAGMA foreign_keys = ON;", [])
            .map_err(|e| AppError::Database(e.to_string()))?;
+        register_db_change_hook(&conn);

        let db = Self {
            conn: Mutex::new(conn),
@@ -111,6 +123,7 @@ impl Database {
        // 启用外键约束
        conn.execute("PRAGMA foreign_keys = ON;", [])
            .map_err(|e| AppError::Database(e.to_string()))?;
+        register_db_change_hook(&conn);

        let db = Self {
            conn: Mutex::new(conn),
--- a/src-tauri/src/lib.rs
+++ b/src-tauri/src/lib.rs
@@ -702,6 +702,10 @@ pub fn run() {
            }

            let _tray = tray_builder.build(app)?;
+            crate::services::webdav_auto_sync::start_worker(
+                app_state.db.clone(),
+                app.handle().clone(),
+            );
            // 将同一个实例注入到全局状态，避免重复创建导致的不一致
            app.manage(app_state);

--- a/src-tauri/src/services/mod.rs
+++ b/src-tauri/src/services/mod.rs
@@ -11,6 +11,7 @@ pub mod speedtest;
 pub mod stream_check;
 pub mod usage_stats;
 pub mod webdav;
+pub mod webdav_auto_sync;
 pub mod webdav_sync;

 pub use config::ConfigService;
--- a/src-tauri/src/services/webdav.rs
+++ b/src-tauri/src/services/webdav.rs
@@ -8,6 +8,7 @@ use std::time::Duration;

 use crate::error::AppError;
 use crate::proxy::http_client;
+use futures::StreamExt;

 const DEFAULT_TIMEOUT_SECS: u64 = 30;
 /// Timeout for large file transfers (PUT/GET of db.sql, skills.zip).
@@ -237,15 +238,7 @@ pub async fn put_bytes(
    )
    .send()
    .await
-    .map_err(|e| {
-        webdav_transport_error(
-            "webdav.put_failed",
-            "PUT 请求",
-            "PUT request",
-            url,
-            &e,
-        )
-    })?;
+    .map_err(|e| webdav_transport_error("webdav.put_failed", "PUT 请求", "PUT request", url, &e))?;

    if resp.status().is_success() {
        return Ok(());
@@ -259,6 +252,7 @@ pub async fn put_bytes(
 pub async fn get_bytes(
    url: &str,
    auth: &WebDavAuth,
+    max_bytes: usize,
 ) -> Result<Option<(Vec<u8>, Option<String>)>, AppError> {
    let client = http_client::get();
    let resp = apply_auth(
@@ -269,15 +263,7 @@ pub async fn get_bytes(
    )
    .send()
    .await
-    .map_err(|e| {
-        webdav_transport_error(
-            "webdav.get_failed",
-            "GET 请求",
-            "GET request",
-            url,
-            &e,
-        )
-    })?;
+    .map_err(|e| webdav_transport_error("webdav.get_failed", "GET 请求", "GET request", url, &e))?;

    if resp.status() == StatusCode::NOT_FOUND {
        return Ok(None);
@@ -285,22 +271,29 @@ pub async fn get_bytes(
    if !resp.status().is_success() {
        return Err(webdav_status_error("GET", resp.status(), url));
    }
+    ensure_content_length_within_limit(resp.headers(), max_bytes, url)?;
+
    let etag = resp
        .headers()
        .get("etag")
        .and_then(|v| v.to_str().ok())
        .map(|s| s.to_string());
-    let bytes = resp
-        .bytes()
-        .await
-        .map_err(|e| {
+    let mut bytes = Vec::new();
+    let mut stream = resp.bytes_stream();
+    while let Some(chunk) = stream.next().await {
+        let chunk = chunk.map_err(|e| {
            AppError::localized(
                "webdav.response_read_failed",
                format!("读取 WebDAV 响应失败: {e}"),
                format!("Failed to read WebDAV response: {e}"),
            )
        })?;
-    Ok(Some((bytes.to_vec(), etag)))
+        if bytes.len().saturating_add(chunk.len()) > max_bytes {
+            return Err(response_too_large_error(url, max_bytes));
+        }
+        bytes.extend_from_slice(&chunk);
+    }
+    Ok(Some((bytes, etag)))
 }

 /// HEAD request to retrieve the ETag. Returns `None` on 404.
@@ -315,13 +308,7 @@ pub async fn head_etag(url: &str, auth: &WebDavAuth) -> Result<Option<String>, A
    .send()
    .await
    .map_err(|e| {
-        webdav_transport_error(
-            "webdav.head_failed",
-            "HEAD 请求",
-            "HEAD request",
-            url,
-            &e,
-        )
+        webdav_transport_error("webdav.head_failed", "HEAD 请求", "HEAD request", url, &e)
    })?;

    if resp.status() == StatusCode::NOT_FOUND {
@@ -386,9 +373,7 @@ pub fn webdav_status_error(op: &str, status: StatusCode, url: &str) -> AppError

    if matches!(status, StatusCode::UNAUTHORIZED | StatusCode::FORBIDDEN) {
        if jgy {
-            zh.push_str(
-                "。坚果云请使用「第三方应用密码」，并确认地址指向 /dav/ 下的目录。",
-            );
+            zh.push_str("。坚果云请使用「第三方应用密码」，并确认地址指向 /dav/ 下的目录。");
            en.push_str(
                ". For Jianguoyun, use an app-specific password and ensure the URL points under /dav/.",
            );
@@ -401,9 +386,7 @@ pub fn webdav_status_error(op: &str, status: StatusCode, url: &str) -> AppError
        en.push_str(". Common Jianguoyun cause: URL is outside a writable /dav/ directory.");
    } else if op == "MKCOL" && status == StatusCode::CONFLICT {
        if jgy {
-            zh.push_str(
-                "。坚果云不允许自动创建顶层文件夹，请先在网页端手动创建后重试。",
-            );
+            zh.push_str("。坚果云不允许自动创建顶层文件夹，请先在网页端手动创建后重试。");
            en.push_str(
                ". Jianguoyun does not allow creating top-level folders automatically; create it manually first.",
            );
@@ -446,9 +429,47 @@ fn redact_url(raw: &str) -> String {
    }
 }

+fn response_too_large_error(url: &str, max_bytes: usize) -> AppError {
+    let max_mb = max_bytes / 1024 / 1024;
+    AppError::localized(
+        "webdav.response_too_large",
+        format!(
+            "WebDAV 响应体超过上限（{} MB）: {}",
+            max_mb,
+            redact_url(url)
+        ),
+        format!(
+            "WebDAV response body exceeds limit ({} MB): {}",
+            max_mb,
+            redact_url(url)
+        ),
+    )
+}
+
+fn ensure_content_length_within_limit(
+    headers: &reqwest::header::HeaderMap,
+    max_bytes: usize,
+    url: &str,
+) -> Result<(), AppError> {
+    let Some(content_length) = headers.get(reqwest::header::CONTENT_LENGTH) else {
+        return Ok(());
+    };
+    let Ok(raw) = content_length.to_str() else {
+        return Ok(());
+    };
+    let Ok(value) = raw.parse::<u64>() else {
+        return Ok(());
+    };
+    if value > max_bytes as u64 {
+        return Err(response_too_large_error(url, max_bytes));
+    }
+    Ok(())
+}
+
 #[cfg(test)]
 mod tests {
    use super::*;
+    use reqwest::header::{HeaderMap, HeaderValue, CONTENT_LENGTH};

    #[test]
    fn build_remote_url_encodes_path_segments() {
@@ -498,10 +519,34 @@ mod tests {
    #[test]
    fn redact_url_hides_credentials_and_query_values() {
        let redacted = redact_url("https://alice:secret@example.com:8443/dav?token=abc&foo=1");
-        assert_eq!(
-            redacted,
-            "https://example.com:8443/dav?[keys:foo,token]"
-        );
+        assert_eq!(redacted, "https://example.com:8443/dav?[keys:foo,token]");
        assert!(!redacted.contains("secret"));
    }
+
+    #[test]
+    fn ensure_content_length_within_limit_accepts_missing_or_small_values() {
+        let empty = HeaderMap::new();
+        assert!(
+            ensure_content_length_within_limit(&empty, 1024, "https://dav.example.com").is_ok()
+        );
+
+        let mut small = HeaderMap::new();
+        small.insert(CONTENT_LENGTH, HeaderValue::from_static("1024"));
+        assert!(
+            ensure_content_length_within_limit(&small, 1024, "https://dav.example.com").is_ok()
+        );
+    }
+
+    #[test]
+    fn ensure_content_length_within_limit_rejects_oversized_values() {
+        let mut large = HeaderMap::new();
+        large.insert(CONTENT_LENGTH, HeaderValue::from_static("2048"));
+
+        let err = ensure_content_length_within_limit(&large, 1024, "https://dav.example.com")
+            .expect_err("oversized response should be rejected");
+        assert!(
+            err.to_string().contains("too large") || err.to_string().contains("超过"),
+            "unexpected error: {err}"
+        );
+    }
 }
--- a/src-tauri/src/services/webdav_auto_sync.rs
+++ b/src-tauri/src/services/webdav_auto_sync.rs
@@ -0,0 +1,277 @@
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Arc;
+use std::sync::OnceLock;
+use std::time::{Duration, Instant};
+
+use serde_json::json;
+use tauri::{AppHandle, Emitter};
+use tokio::sync::mpsc::error::TrySendError;
+use tokio::sync::mpsc::{channel, Receiver, Sender};
+
+use crate::error::AppError;
+use crate::services::webdav_sync as webdav_sync_service;
+use crate::settings::{self, WebDavSyncSettings};
+
+const AUTO_SYNC_DEBOUNCE_MS: u64 = 1000;
+pub(crate) const MAX_AUTO_SYNC_WAIT_MS: u64 = 10_000;
+
+static DB_CHANGE_TX: OnceLock<Sender<String>> = OnceLock::new();
+static AUTO_SYNC_SUPPRESS_DEPTH: AtomicUsize = AtomicUsize::new(0);
+
+pub(crate) struct AutoSyncSuppressionGuard;
+
+impl AutoSyncSuppressionGuard {
+    pub fn new() -> Self {
+        AUTO_SYNC_SUPPRESS_DEPTH.fetch_add(1, Ordering::SeqCst);
+        Self
+    }
+}
+
+impl Drop for AutoSyncSuppressionGuard {
+    fn drop(&mut self) {
+        let _ =
+            AUTO_SYNC_SUPPRESS_DEPTH.fetch_update(Ordering::SeqCst, Ordering::SeqCst, |value| {
+                Some(value.saturating_sub(1))
+            });
+    }
+}
+
+pub(crate) fn is_auto_sync_suppressed() -> bool {
+    AUTO_SYNC_SUPPRESS_DEPTH.load(Ordering::SeqCst) > 0
+}
+
+pub fn should_trigger_for_table(table: &str) -> bool {
+    let normalized = table.trim().to_ascii_lowercase();
+    matches!(
+        normalized.as_str(),
+        "providers"
+            | "provider_endpoints"
+            | "mcp_servers"
+            | "prompts"
+            | "skills"
+            | "skill_repos"
+            | "settings"
+            | "proxy_config"
+    )
+}
+
+pub(crate) fn enqueue_change_signal(tx: &Sender<String>, table: &str) -> bool {
+    match tx.try_send(table.to_string()) {
+        Ok(()) => true,
+        Err(TrySendError::Full(_)) | Err(TrySendError::Closed(_)) => false,
+    }
+}
+
+pub(crate) fn auto_sync_wait_duration(started_at: Instant, now: Instant) -> Option<Duration> {
+    let max_wait = Duration::from_millis(MAX_AUTO_SYNC_WAIT_MS);
+    let debounce = Duration::from_millis(AUTO_SYNC_DEBOUNCE_MS);
+    let elapsed = now.saturating_duration_since(started_at);
+    if elapsed >= max_wait {
+        return None;
+    }
+    Some(debounce.min(max_wait - elapsed))
+}
+
+fn should_run_auto_sync(settings: Option<&WebDavSyncSettings>) -> bool {
+    let Some(sync) = settings else {
+        return false;
+    };
+    sync.enabled && sync.auto_sync
+}
+
+fn persist_auto_sync_error(settings: &mut WebDavSyncSettings, error: &AppError) {
+    settings.status.last_error = Some(error.to_string());
+    settings.status.last_error_source = Some("auto".to_string());
+    let _ = settings::update_webdav_sync_status(settings.status.clone());
+}
+
+fn emit_auto_sync_status_updated(app: &AppHandle, status: &str, error: Option<&str>) {
+    let payload = match error {
+        Some(message) => json!({
+            "source": "auto",
+            "status": status,
+            "error": message,
+        }),
+        None => json!({
+            "source": "auto",
+            "status": status,
+        }),
+    };
+
+    if let Err(err) = app.emit("webdav-sync-status-updated", payload) {
+        log::debug!("[WebDAV] failed to emit sync status update event: {err}");
+    }
+}
+
+async fn run_auto_sync_upload(
+    db: &crate::database::Database,
+    app: &AppHandle,
+) -> Result<(), AppError> {
+    let mut settings = settings::get_webdav_sync_settings();
+    if !should_run_auto_sync(settings.as_ref()) {
+        return Ok(());
+    }
+
+    let mut sync_settings = match settings.take() {
+        Some(value) => value,
+        None => return Ok(()),
+    };
+
+    let result = webdav_sync_service::run_with_sync_lock(webdav_sync_service::upload(
+        db,
+        &mut sync_settings,
+    ))
+    .await;
+    match result {
+        Ok(_) => {
+            emit_auto_sync_status_updated(app, "success", None);
+            Ok(())
+        }
+        Err(err) => {
+            persist_auto_sync_error(&mut sync_settings, &err);
+            emit_auto_sync_status_updated(app, "error", Some(&err.to_string()));
+            Err(err)
+        }
+    }
+}
+
+pub fn notify_db_changed(table: &str) {
+    if is_auto_sync_suppressed() {
+        return;
+    }
+    if !should_trigger_for_table(table) {
+        return;
+    }
+    let Some(tx) = DB_CHANGE_TX.get() else {
+        return;
+    };
+    let _ = enqueue_change_signal(tx, table);
+}
+
+pub fn start_worker(db: Arc<crate::database::Database>, app: tauri::AppHandle) {
+    if DB_CHANGE_TX.get().is_some() {
+        return;
+    }
+
+    // Buffer size 1 is enough: we only need "dirty" signals, not every event.
+    let (tx, rx) = channel::<String>(1);
+    if DB_CHANGE_TX.set(tx).is_err() {
+        return;
+    }
+
+    tauri::async_runtime::spawn(async move {
+        run_worker_loop(db, rx, app).await;
+    });
+}
+
+async fn run_worker_loop(
+    db: Arc<crate::database::Database>,
+    mut rx: Receiver<String>,
+    app: tauri::AppHandle,
+) {
+    while let Some(first_table) = rx.recv().await {
+        let started_at = Instant::now();
+        let mut merged_count = 1usize;
+
+        loop {
+            let Some(wait_for) = auto_sync_wait_duration(started_at, Instant::now()) else {
+                break;
+            };
+            let timeout = tokio::time::timeout(wait_for, rx.recv()).await;
+
+            match timeout {
+                Ok(Some(_)) => merged_count += 1,
+                Ok(None) => return,
+                Err(_) => break,
+            }
+        }
+
+        log::debug!(
+            "[WebDAV][AutoSync] Triggered by table={first_table}, merged_changes={merged_count}"
+        );
+
+        if let Err(err) = run_auto_sync_upload(&db, &app).await {
+            log::warn!("[WebDAV][AutoSync] Upload failed: {err}");
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{
+        auto_sync_wait_duration, enqueue_change_signal, is_auto_sync_suppressed,
+        should_run_auto_sync, should_trigger_for_table, AutoSyncSuppressionGuard,
+        MAX_AUTO_SYNC_WAIT_MS,
+    };
+    use crate::settings::WebDavSyncSettings;
+    use std::time::{Duration, Instant};
+    use tokio::sync::mpsc::channel;
+
+    #[test]
+    fn should_trigger_sync_for_config_tables_only() {
+        assert!(should_trigger_for_table("providers"));
+        assert!(should_trigger_for_table("settings"));
+        assert!(!should_trigger_for_table("proxy_request_logs"));
+        assert!(!should_trigger_for_table("provider_health"));
+    }
+
+    #[test]
+    fn suppression_guard_enables_and_restores_state() {
+        assert!(!is_auto_sync_suppressed());
+        {
+            let _guard = AutoSyncSuppressionGuard::new();
+            assert!(is_auto_sync_suppressed());
+        }
+        assert!(!is_auto_sync_suppressed());
+    }
+
+    #[test]
+    fn max_wait_caps_flush_latency_for_continuous_events() {
+        let started = Instant::now();
+        let later = started + Duration::from_millis(MAX_AUTO_SYNC_WAIT_MS + 1);
+        assert!(auto_sync_wait_duration(started, later).is_none());
+    }
+
+    #[tokio::test]
+    async fn enqueue_change_signal_drops_when_channel_is_full() {
+        let (tx, _rx) = channel::<String>(1);
+        assert!(enqueue_change_signal(&tx, "providers"));
+        assert!(!enqueue_change_signal(&tx, "providers"));
+    }
+
+    #[test]
+    fn should_run_auto_sync_requires_enabled_and_auto_sync_flag() {
+        assert!(!should_run_auto_sync(None));
+
+        let disabled = WebDavSyncSettings {
+            enabled: false,
+            auto_sync: true,
+            ..WebDavSyncSettings::default()
+        };
+        assert!(!should_run_auto_sync(Some(&disabled)));
+
+        let auto_sync_off = WebDavSyncSettings {
+            enabled: true,
+            auto_sync: false,
+            ..WebDavSyncSettings::default()
+        };
+        assert!(!should_run_auto_sync(Some(&auto_sync_off)));
+
+        let enabled = WebDavSyncSettings {
+            enabled: true,
+            auto_sync: true,
+            ..WebDavSyncSettings::default()
+        };
+        assert!(should_run_auto_sync(Some(&enabled)));
+    }
+
+    #[test]
+    fn service_layer_does_not_depend_on_commands_layer() {
+        let source = include_str!("webdav_auto_sync.rs");
+        let needle = ["crate", "commands", ""].join("::");
+        assert!(
+            !source.contains(&needle),
+            "services layer should not depend on commands layer"
+        );
+    }
+}
--- a/src-tauri/src/services/webdav_sync.rs
+++ b/src-tauri/src/services/webdav_sync.rs
@@ -5,7 +5,9 @@

 use std::collections::BTreeMap;
 use std::fs;
+use std::future::Future;
 use std::process::Command;
+use std::sync::OnceLock;

 use chrono::Utc;
 use serde::{Deserialize, Serialize};
@@ -33,6 +35,21 @@ const REMOTE_DB_SQL: &str = "db.sql";
 const REMOTE_SKILLS_ZIP: &str = "skills.zip";
 const REMOTE_MANIFEST: &str = "manifest.json";
 const MAX_DEVICE_NAME_LEN: usize = 64;
+const MAX_MANIFEST_BYTES: usize = 1024 * 1024;
+pub(super) const MAX_SYNC_ARTIFACT_BYTES: u64 = 512 * 1024 * 1024;
+
+pub fn sync_mutex() -> &'static tokio::sync::Mutex<()> {
+    static LOCK: OnceLock<tokio::sync::Mutex<()>> = OnceLock::new();
+    LOCK.get_or_init(|| tokio::sync::Mutex::new(()))
+}
+
+pub async fn run_with_sync_lock<T, Fut>(operation: Fut) -> Result<T, AppError>
+where
+    Fut: Future<Output = Result<T, AppError>>,
+{
+    let _guard = sync_mutex().lock().await;
+    operation.await
+}

 fn localized(key: &'static str, zh: impl Into<String>, en: impl Into<String>) -> AppError {
    AppError::localized(key, zh, en)
@@ -145,13 +162,15 @@ pub async fn download(
    let auth = auth_for(settings);

    let manifest_url = remote_file_url(settings, REMOTE_MANIFEST)?;
-    let (manifest_bytes, etag) = get_bytes(&manifest_url, &auth).await?.ok_or_else(|| {
-        localized(
-            "webdav.sync.remote_empty",
-            "远端没有可下载的同步数据",
-            "No downloadable sync data found on the remote.",
-        )
-    })?;
+    let (manifest_bytes, etag) = get_bytes(&manifest_url, &auth, MAX_MANIFEST_BYTES)
+        .await?
+        .ok_or_else(|| {
+            localized(
+                "webdav.sync.remote_empty",
+                "远端没有可下载的同步数据",
+                "No downloadable sync data found on the remote.",
+            )
+        })?;

    let manifest: SyncManifest =
        serde_json::from_slice(&manifest_bytes).map_err(|e| AppError::Json {
@@ -181,7 +200,7 @@ pub async fn fetch_remote_info(settings: &WebDavSyncSettings) -> Result<Option<V
    let auth = auth_for(settings);
    let manifest_url = remote_file_url(settings, REMOTE_MANIFEST)?;

-    let Some((bytes, _)) = get_bytes(&manifest_url, &auth).await? else {
+    let Some((bytes, _)) = get_bytes(&manifest_url, &auth, MAX_MANIFEST_BYTES).await? else {
        return Ok(None);
    };

@@ -214,6 +233,7 @@ fn persist_sync_success(
    let status = WebDavSyncStatus {
        last_sync_at: Some(Utc::now().timestamp()),
        last_error: None,
+        last_error_source: None,
        last_local_manifest_hash: Some(manifest_hash.clone()),
        last_remote_manifest_hash: Some(manifest_hash),
        last_remote_etag: etag,
@@ -319,14 +339,10 @@ fn sha256_hex(bytes: &[u8]) -> String {
 }

 fn detect_system_device_name() -> Option<String> {
-    let env_name = [
-        "CC_SWITCH_DEVICE_NAME",
-        "COMPUTERNAME",
-        "HOSTNAME",
-    ]
-    .iter()
-    .filter_map(|key| std::env::var(key).ok())
-    .find_map(|value| normalize_device_name(&value));
+    let env_name = ["CC_SWITCH_DEVICE_NAME", "COMPUTERNAME", "HOSTNAME"]
+        .iter()
+        .filter_map(|key| std::env::var(key).ok())
+        .find_map(|value| normalize_device_name(&value));

    if env_name.is_some() {
        return env_name;
@@ -341,21 +357,26 @@ fn detect_system_device_name() -> Option<String> {
 }

 fn normalize_device_name(raw: &str) -> Option<String> {
-    let compact = raw.chars().fold(String::with_capacity(raw.len()), |mut acc, ch| {
-        if ch.is_whitespace() {
-            acc.push(' ');
-        } else if !ch.is_control() {
-            acc.push(ch);
-        }
-        acc
-    });
+    let compact = raw
+        .chars()
+        .fold(String::with_capacity(raw.len()), |mut acc, ch| {
+            if ch.is_whitespace() {
+                acc.push(' ');
+            } else if !ch.is_control() {
+                acc.push(ch);
+            }
+            acc
+        });
    let normalized = compact.split_whitespace().collect::<Vec<_>>().join(" ");
    let trimmed = normalized.trim();
    if trimmed.is_empty() {
        return None;
    }

-    let limited = trimmed.chars().take(MAX_DEVICE_NAME_LEN).collect::<String>();
+    let limited = trimmed
+        .chars()
+        .take(MAX_DEVICE_NAME_LEN)
+        .collect::<String>();
    if limited.is_empty() {
        None
    } else {
@@ -405,14 +426,18 @@ async fn download_and_verify(
            format!("Manifest missing artifact: {artifact_name}"),
        )
    })?;
+    validate_artifact_size_limit(artifact_name, meta.size)?;
+
    let url = remote_file_url(settings, artifact_name)?;
-    let (bytes, _) = get_bytes(&url, auth).await?.ok_or_else(|| {
-        localized(
-            "webdav.sync.remote_missing_artifact",
-            format!("远端缺少 artifact 文件: {artifact_name}"),
-            format!("Remote artifact file missing: {artifact_name}"),
-        )
-    })?;
+    let (bytes, _) = get_bytes(&url, auth, MAX_SYNC_ARTIFACT_BYTES as usize)
+        .await?
+        .ok_or_else(|| {
+            localized(
+                "webdav.sync.remote_missing_artifact",
+                format!("远端缺少 artifact 文件: {artifact_name}"),
+                format!("Remote artifact file missing: {artifact_name}"),
+            )
+        })?;

    // Quick size check before expensive hash
    if bytes.len() as u64 != meta.size {
@@ -503,6 +528,21 @@ fn auth_for(settings: &WebDavSyncSettings) -> WebDavAuth {
    auth_from_credentials(&settings.username, &settings.password)
 }

+fn validate_artifact_size_limit(artifact_name: &str, size: u64) -> Result<(), AppError> {
+    if size > MAX_SYNC_ARTIFACT_BYTES {
+        let max_mb = MAX_SYNC_ARTIFACT_BYTES / 1024 / 1024;
+        return Err(localized(
+            "webdav.sync.artifact_too_large",
+            format!("artifact {artifact_name} 超过下载上限（{} MB）", max_mb),
+            format!(
+                "Artifact {artifact_name} exceeds download limit ({} MB)",
+                max_mb
+            ),
+        ));
+    }
+    Ok(())
+}
+
 // ─── Tests ───────────────────────────────────────────────────

 #[cfg(test)]
@@ -646,4 +686,19 @@ mod tests {
            "manifest should not contain deviceId"
        );
    }
+
+    #[test]
+    fn validate_artifact_size_limit_rejects_oversized_artifacts() {
+        let err = validate_artifact_size_limit("skills.zip", MAX_SYNC_ARTIFACT_BYTES + 1)
+            .expect_err("artifact larger than limit should be rejected");
+        assert!(
+            err.to_string().contains("too large") || err.to_string().contains("超过"),
+            "unexpected error: {err}"
+        );
+    }
+
+    #[test]
+    fn validate_artifact_size_limit_accepts_limit_boundary() {
+        assert!(validate_artifact_size_limit("skills.zip", MAX_SYNC_ARTIFACT_BYTES).is_ok());
+    }
 }
--- a/src-tauri/src/services/webdav_sync/archive.rs
+++ b/src-tauri/src/services/webdav_sync/archive.rs
@@ -10,10 +10,8 @@ use zip::DateTime;
 use crate::error::AppError;
 use crate::services::skill::SkillService;

-use super::{io_context_localized, localized, REMOTE_SKILLS_ZIP};
+use super::{io_context_localized, localized, MAX_SYNC_ARTIFACT_BYTES, REMOTE_SKILLS_ZIP};

-/// Maximum total bytes allowed during zip extraction (512 MB).
-const MAX_EXTRACT_BYTES: u64 = 512 * 1024 * 1024;
 /// Maximum number of entries allowed in a zip archive.
 const MAX_EXTRACT_ENTRIES: usize = 10_000;

@@ -92,8 +90,14 @@ pub(super) fn restore_skills_zip(raw: &[u8]) -> Result<(), AppError> {
    if archive.len() > MAX_EXTRACT_ENTRIES {
        return Err(localized(
            "webdav.sync.skills_zip_too_many_entries",
-            format!("skills.zip 条目数过多（{}），上限 {MAX_EXTRACT_ENTRIES}", archive.len()),
-            format!("skills.zip has too many entries ({}), limit is {MAX_EXTRACT_ENTRIES}", archive.len()),
+            format!(
+                "skills.zip 条目数过多（{}），上限 {MAX_EXTRACT_ENTRIES}",
+                archive.len()
+            ),
+            format!(
+                "skills.zip has too many entries ({}), limit is {MAX_EXTRACT_ENTRIES}",
+                archive.len()
+            ),
        ));
    }

@@ -118,15 +122,13 @@ pub(super) fn restore_skills_zip(raw: &[u8]) -> Result<(), AppError> {
            fs::create_dir_all(parent).map_err(|e| AppError::io(parent, e))?;
        }
        let mut out = fs::File::create(&out_path).map_err(|e| AppError::io(&out_path, e))?;
-        let written = std::io::copy(&mut entry, &mut out).map_err(|e| AppError::io(&out_path, e))?;
-        total_bytes += written;
-        if total_bytes > MAX_EXTRACT_BYTES {
-            return Err(localized(
-                "webdav.sync.skills_zip_too_large",
-                format!("skills.zip 解压后体积超过上限（{} MB）", MAX_EXTRACT_BYTES / 1024 / 1024),
-                format!("skills.zip extracted size exceeds limit ({} MB)", MAX_EXTRACT_BYTES / 1024 / 1024),
-            ));
-        }
+        let _written = copy_entry_with_total_limit(
+            &mut entry,
+            &mut out,
+            &mut total_bytes,
+            MAX_SYNC_ARTIFACT_BYTES,
+            &out_path,
+        )?;
    }

    let ssot = SkillService::get_ssot_dir().map_err(|e| {
@@ -327,10 +329,47 @@ fn mark_visited_dir(path: &Path, visited: &mut HashSet<PathBuf>) -> Result<bool,
    Ok(visited.insert(canonical))
 }

+fn copy_entry_with_total_limit<R: Read, W: Write>(
+    reader: &mut R,
+    writer: &mut W,
+    total_bytes: &mut u64,
+    max_total_bytes: u64,
+    out_path: &Path,
+) -> Result<u64, AppError> {
+    let mut buffer = [0u8; 16 * 1024];
+    let mut written = 0u64;
+    loop {
+        let n = reader
+            .read(&mut buffer)
+            .map_err(|e| AppError::io(out_path, e))?;
+        if n == 0 {
+            break;
+        }
+
+        if total_bytes.saturating_add(n as u64) > max_total_bytes {
+            let max_mb = max_total_bytes / 1024 / 1024;
+            return Err(localized(
+                "webdav.sync.skills_zip_too_large",
+                format!("skills.zip 解压后体积超过上限（{} MB）", max_mb),
+                format!("skills.zip extracted size exceeds limit ({} MB)", max_mb),
+            ));
+        }
+
+        writer
+            .write_all(&buffer[..n])
+            .map_err(|e| AppError::io(out_path, e))?;
+        *total_bytes += n as u64;
+        written += n as u64;
+    }
+    Ok(written)
+}
+
 #[cfg(test)]
 mod tests {
-    use super::mark_visited_dir;
+    use super::{copy_entry_with_total_limit, mark_visited_dir};
    use std::collections::HashSet;
+    use std::io::Cursor;
+    use std::path::Path;
    use tempfile::tempdir;

    #[test]
@@ -343,4 +382,29 @@ mod tests {
        assert!(mark_visited_dir(&dir, &mut visited).expect("first visit"));
        assert!(!mark_visited_dir(&dir, &mut visited).expect("second visit"));
    }
+
+    #[test]
+    fn copy_entry_with_total_limit_rejects_oversized_stream_before_write() {
+        let mut reader = Cursor::new(vec![1u8; 16]);
+        let mut writer = Vec::new();
+        let mut total_bytes = 0u64;
+
+        let err = copy_entry_with_total_limit(
+            &mut reader,
+            &mut writer,
+            &mut total_bytes,
+            8,
+            Path::new("skills-extracted/file.bin"),
+        )
+        .expect_err("stream larger than limit should be rejected");
+        assert!(
+            err.to_string().contains("too large") || err.to_string().contains("超过"),
+            "unexpected error: {err}"
+        );
+        assert_eq!(
+            writer.len(),
+            0,
+            "should not write when the first chunk exceeds limit"
+        );
+    }
 }
--- a/src-tauri/src/settings.rs
+++ b/src-tauri/src/settings.rs
@@ -72,6 +72,8 @@ pub struct WebDavSyncStatus {
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub last_error: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub last_error_source: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub last_remote_etag: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub last_local_manifest_hash: Option<String>,
@@ -93,6 +95,8 @@ pub struct WebDavSyncSettings {
    #[serde(default)]
    pub enabled: bool,
    #[serde(default)]
+    pub auto_sync: bool,
+    #[serde(default)]
    pub base_url: String,
    #[serde(default)]
    pub username: String,
@@ -110,6 +114,7 @@ impl Default for WebDavSyncSettings {
    fn default() -> Self {
        Self {
            enabled: false,
+            auto_sync: false,
            base_url: String::new(),
            username: String::new(),
            password: String::new(),
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -3,6 +3,7 @@ import { useTranslation } from "react-i18next";
 import { motion, AnimatePresence } from "framer-motion";
 import { toast } from "sonner";
 import { invoke } from "@tauri-apps/api/core";
+import { listen } from "@tauri-apps/api/event";
 import { useQueryClient } from "@tanstack/react-query";
 import {
  Plus,
@@ -81,6 +82,12 @@ type View =
  | "openclawTools"
  | "openclawAgents";

+interface WebDavSyncStatusUpdatedPayload {
+  source?: string;
+  status?: string;
+  error?: string;
+}
+
 const DRAG_BAR_HEIGHT = isWindows() || isLinux() ? 0 : 28; // px
 const HEADER_HEIGHT = 64; // px
 const CONTENT_TOP_OFFSET = DRAG_BAR_HEIGHT + HEADER_HEIGHT;
@@ -292,6 +299,49 @@ function App() {
    };
  }, [queryClient]);

+  useEffect(() => {
+    let unsubscribe: (() => void) | undefined;
+    let active = true;
+
+    const setupListener = async () => {
+      try {
+        const off = await listen(
+          "webdav-sync-status-updated",
+          async (event) => {
+            const payload = (event.payload ?? {}) as WebDavSyncStatusUpdatedPayload;
+            await queryClient.invalidateQueries({ queryKey: ["settings"] });
+
+            if (payload.source !== "auto" || payload.status !== "error") {
+              return;
+            }
+
+            toast.error(
+              t("settings.webdavSync.autoSyncFailedToast", {
+                error: payload.error || t("common.unknown"),
+              }),
+            );
+          },
+        );
+        if (!active) {
+          off();
+          return;
+        }
+        unsubscribe = off;
+      } catch (error) {
+        console.error(
+          "[App] Failed to subscribe webdav-sync-status-updated event",
+          error,
+        );
+      }
+    };
+
+    void setupListener();
+    return () => {
+      active = false;
+      unsubscribe?.();
+    };
+  }, [queryClient, t]);
+
  useEffect(() => {
    const checkEnvOnStartup = async () => {
      try {
--- a/src/components/settings/WebdavSyncSection.tsx
+++ b/src/components/settings/WebdavSyncSection.tsx
@@ -16,6 +16,7 @@ import { useQueryClient } from "@tanstack/react-query";
 import { toast } from "sonner";
 import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
+import { Switch } from "@/components/ui/switch";
 import {
  Select,
  SelectContent,
@@ -162,6 +163,7 @@ export function WebdavSyncSection({ config }: WebdavSyncSectionProps) {
    password: config?.password ?? "",
    remoteRoot: config?.remoteRoot ?? "cc-switch-sync",
    profile: config?.profile ?? "default",
+    autoSync: config?.autoSync ?? false,
  }));

  // Preset selector — derived from initial URL, updated on user selection
@@ -196,6 +198,7 @@ export function WebdavSyncSection({ config }: WebdavSyncSectionProps) {
      password: config.password ?? "",
      remoteRoot: config.remoteRoot ?? "cc-switch-sync",
      profile: config.profile ?? "default",
+      autoSync: config.autoSync ?? false,
    });
    setPasswordTouched(false);
    setPresetId(detectPreset(config.baseUrl ?? ""));
@@ -237,6 +240,16 @@ export function WebdavSyncSection({ config }: WebdavSyncSectionProps) {
    }
  }, [form.baseUrl, presetId]);

+  const handleAutoSyncChange = useCallback((checked: boolean) => {
+    setForm((prev) => ({ ...prev, autoSync: checked }));
+    setDirty(true);
+    setJustSaved(false);
+    if (justSavedTimerRef.current) {
+      clearTimeout(justSavedTimerRef.current);
+      justSavedTimerRef.current = null;
+    }
+  }, []);
+
  const buildSettings = useCallback((): WebDavSyncSettings | null => {
    const baseUrl = form.baseUrl.trim();
    if (!baseUrl) return null;
@@ -247,6 +260,7 @@ export function WebdavSyncSection({ config }: WebdavSyncSectionProps) {
      password: form.password,
      remoteRoot: form.remoteRoot.trim() || "cc-switch-sync",
      profile: form.profile.trim() || "default",
+      autoSync: form.autoSync,
    };
  }, [form]);

@@ -433,6 +447,9 @@ export function WebdavSyncSection({ config }: WebdavSyncSectionProps) {
  const lastSyncDisplay = lastSyncAt
    ? new Date(lastSyncAt * 1000).toLocaleString()
    : null;
+  const lastError = config?.status?.lastError?.trim();
+  const showAutoSyncError =
+    !!lastError && config?.status?.lastErrorSource === "auto";

  // ─── Render ─────────────────────────────────────────────

@@ -559,6 +576,23 @@ export function WebdavSyncSection({ config }: WebdavSyncSectionProps) {
              disabled={isLoading}
            />
          </div>
+
+          <div className="flex items-start gap-4">
+            <label className="w-40 text-xs font-medium text-foreground shrink-0">
+              {t("settings.webdavSync.autoSync")}
+              <span className="block text-[10px] font-normal text-muted-foreground">
+                {t("settings.webdavSync.autoSyncHint")}
+              </span>
+            </label>
+            <div className="pt-1">
+              <Switch
+                checked={form.autoSync}
+                onCheckedChange={handleAutoSyncChange}
+                aria-label={t("settings.webdavSync.autoSync")}
+                disabled={isLoading}
+              />
+            </div>
+          </div>
        </div>

        {/* Last sync time */}
@@ -567,6 +601,17 @@ export function WebdavSyncSection({ config }: WebdavSyncSectionProps) {
            {t("settings.webdavSync.lastSync", { time: lastSyncDisplay })}
          </p>
        )}
+        {showAutoSyncError && (
+          <div className="rounded-lg border border-red-300/70 bg-red-50/80 px-3 py-2 text-xs text-red-900 dark:border-red-500/50 dark:bg-red-950/30 dark:text-red-200">
+            <p className="font-medium">
+              {t("settings.webdavSync.autoSyncLastErrorTitle")}
+            </p>
+            <p className="mt-1 break-all whitespace-pre-wrap">{lastError}</p>
+            <p className="mt-1 text-[11px] text-red-700/90 dark:text-red-300/80">
+              {t("settings.webdavSync.autoSyncLastErrorHint")}
+            </p>
+          </div>
+        )}

        {/* Config buttons + save status */}
        <div className="flex flex-wrap items-center gap-3 pt-2">
--- a/src/i18n/locales/en.json
+++ b/src/i18n/locales/en.json
@@ -283,6 +283,8 @@
      "passwordPlaceholder": "App password",
      "remoteRoot": "Remote Root Directory",
      "profile": "Sync Profile Name",
+      "autoSync": "Auto Sync",
+      "autoSyncHint": "When enabled, each database change triggers an automatic WebDAV upload.",
      "test": "Test Connection",
      "testing": "Testing...",
      "testSuccess": "Connection successful",
@@ -294,11 +296,14 @@
      "uploading": "Uploading...",
      "uploadSuccess": "Uploaded to WebDAV",
      "uploadFailed": "Upload failed: {{error}}",
+      "autoSyncFailedToast": "Auto sync failed: {{error}}",
      "download": "Download from Cloud",
      "downloading": "Downloading...",
      "downloadSuccess": "Downloaded and restored from WebDAV",
      "downloadFailed": "Download failed: {{error}}",
      "lastSync": "Last sync: {{time}}",
+      "autoSyncLastErrorTitle": "Last auto sync failed",
+      "autoSyncLastErrorHint": "Please check network or WebDAV settings. Auto sync will retry on future changes.",
      "missingUrl": "Please enter the WebDAV server URL",
      "presets": {
        "label": "Provider",
--- a/src/i18n/locales/ja.json
+++ b/src/i18n/locales/ja.json
@@ -283,6 +283,8 @@
      "passwordPlaceholder": "アプリパスワード",
      "remoteRoot": "リモートルートディレクトリ",
      "profile": "同期プロファイル名",
+      "autoSync": "自動同期",
+      "autoSyncHint": "有効にすると、データベース変更のたびに WebDAV へ自動アップロードします。",
      "test": "接続テスト",
      "testing": "テスト中...",
      "testSuccess": "接続成功",
@@ -294,11 +296,14 @@
      "uploading": "アップロード中...",
      "uploadSuccess": "WebDAV にアップロードしました",
      "uploadFailed": "アップロードに失敗しました：{{error}}",
+      "autoSyncFailedToast": "自動同期に失敗しました：{{error}}",
      "download": "クラウドからダウンロード",
      "downloading": "ダウンロード中...",
      "downloadSuccess": "WebDAV からダウンロード・復元しました",
      "downloadFailed": "ダウンロードに失敗しました：{{error}}",
      "lastSync": "前回の同期：{{time}}",
+      "autoSyncLastErrorTitle": "前回の自動同期に失敗しました",
+      "autoSyncLastErrorHint": "ネットワークまたは WebDAV 設定を確認してください。次回の変更時に自動再試行されます。",
      "missingUrl": "WebDAV サーバー URL を入力してください",
      "presets": {
        "label": "サービス",
--- a/src/i18n/locales/zh.json
+++ b/src/i18n/locales/zh.json
@@ -283,6 +283,8 @@
      "passwordPlaceholder": "应用密码（坚果云请使用「第三方应用密码」）",
      "remoteRoot": "远程根目录",
      "profile": "同步配置名",
+      "autoSync": "自动同步",
+      "autoSyncHint": "开启后每次数据库变更都会自动上传到 WebDAV。",
      "test": "测试连接",
      "testing": "测试中...",
      "testSuccess": "连接成功",
@@ -294,11 +296,14 @@
      "uploading": "上传中...",
      "uploadSuccess": "已上传到 WebDAV",
      "uploadFailed": "上传失败：{{error}}",
+      "autoSyncFailedToast": "自动同步失败：{{error}}",
      "download": "从云端下载",
      "downloading": "下载中...",
      "downloadSuccess": "已从 WebDAV 下载并恢复",
      "downloadFailed": "下载失败：{{error}}",
      "lastSync": "上次同步：{{time}}",
+      "autoSyncLastErrorTitle": "上次自动同步失败",
+      "autoSyncLastErrorHint": "请检查网络或 WebDAV 配置，系统会在后续变更时继续自动重试。",
      "missingUrl": "请填写 WebDAV 服务器地址",
      "presets": {
        "label": "服务商",
--- a/src/lib/schemas/settings.ts
+++ b/src/lib/schemas/settings.ts
@@ -33,6 +33,7 @@ export const settingsSchema = z.object({
  webdavSync: z
    .object({
      enabled: z.boolean().optional(),
+      autoSync: z.boolean().optional(),
      baseUrl: z.string().trim().optional().or(z.literal("")),
      username: z.string().trim().optional().or(z.literal("")),
      password: z.string().optional(),
@@ -42,6 +43,7 @@ export const settingsSchema = z.object({
        .object({
          lastSyncAt: z.number().nullable().optional(),
          lastError: z.string().nullable().optional(),
+          lastErrorSource: z.string().nullable().optional(),
          lastRemoteEtag: z.string().nullable().optional(),
          lastLocalManifestHash: z.string().nullable().optional(),
          lastRemoteManifestHash: z.string().nullable().optional(),
--- a/src/types.ts
+++ b/src/types.ts
@@ -167,6 +167,7 @@ export interface VisibleApps {
 export interface WebDavSyncStatus {
  lastSyncAt?: number | null;
  lastError?: string | null;
+  lastErrorSource?: string | null;
  lastRemoteEtag?: string | null;
  lastLocalManifestHash?: string | null;
  lastRemoteManifestHash?: string | null;
@@ -175,6 +176,7 @@ export interface WebDavSyncStatus {
 // WebDAV v2 同步配置
 export interface WebDavSyncSettings {
  enabled?: boolean;
+  autoSync?: boolean;
  baseUrl?: string;
  username?: string;
  password?: string;
--- a/tests/components/WebdavSyncSection.test.tsx
+++ b/tests/components/WebdavSyncSection.test.tsx
@@ -34,6 +34,17 @@ vi.mock("@/components/ui/input", () => ({
  Input: (props: any) => <input {...props} />,
 }));

+vi.mock("@/components/ui/switch", () => ({
+  Switch: ({ checked, onCheckedChange, ...props }: any) => (
+    <button
+      role="switch"
+      aria-checked={checked}
+      onClick={() => onCheckedChange?.(!checked)}
+      {...props}
+    />
+  ),
+}));
+
 vi.mock("@/components/ui/select", () => ({
  Select: ({ value, onValueChange, children }: any) => (
    <select
@@ -82,6 +93,7 @@ const baseConfig: WebDavSyncSettings = {
  password: "secret",
  remoteRoot: "cc-switch-sync",
  profile: "default",
+  autoSync: false,
  status: {},
 };

@@ -128,6 +140,49 @@ describe("WebdavSyncSection", () => {
    settingsApiMock.webdavSyncDownload.mockResolvedValue({ status: "downloaded" });
  });

+  it("shows auto sync error callout when last auto sync failed", () => {
+    renderSection({
+      ...baseConfig,
+      status: {
+        lastError: "network timeout",
+        lastErrorSource: "auto",
+      },
+    });
+
+    expect(
+      screen.getByText("settings.webdavSync.autoSyncLastErrorTitle"),
+    ).toBeInTheDocument();
+    expect(screen.getByText("network timeout")).toBeInTheDocument();
+  });
+
+  it("does not show auto sync error callout for manual sync errors", () => {
+    renderSection({
+      ...baseConfig,
+      status: {
+        lastError: "manual upload failed",
+        lastErrorSource: "manual",
+      },
+    });
+
+    expect(
+      screen.queryByText("settings.webdavSync.autoSyncLastErrorTitle"),
+    ).not.toBeInTheDocument();
+  });
+
+  it("does not show auto sync error callout when source is missing", () => {
+    renderSection({
+      ...baseConfig,
+      autoSync: true,
+      status: {
+        lastError: "legacy error without source",
+      },
+    });
+
+    expect(
+      screen.queryByText("settings.webdavSync.autoSyncLastErrorTitle"),
+    ).not.toBeInTheDocument();
+  });
+
  it("shows validation error when saving without base url", async () => {
    renderSection({ ...baseConfig, baseUrl: "" });

@@ -150,6 +205,7 @@ describe("WebdavSyncSection", () => {
        baseUrl: "https://dav.example.com/dav/",
        username: "alice",
        password: "secret",
+        autoSync: false,
      }),
      false,
    );
@@ -166,6 +222,24 @@ describe("WebdavSyncSection", () => {
    );
  });

+  it("saves auto sync as true after toggle", async () => {
+    renderSection(baseConfig);
+
+    fireEvent.click(
+      screen.getByRole("switch", { name: "settings.webdavSync.autoSync" }),
+    );
+    fireEvent.click(screen.getByRole("button", { name: "settings.webdavSync.save" }));
+
+    await waitFor(() => {
+      expect(settingsApiMock.webdavSyncSaveSettings).toHaveBeenCalledWith(
+        expect.objectContaining({
+          autoSync: true,
+        }),
+        false,
+      );
+    });
+  });
+
  it("blocks upload when there are unsaved changes", async () => {
    renderSection(baseConfig);

--- a/tests/integration/App.test.tsx
+++ b/tests/integration/App.test.tsx
@@ -209,4 +209,25 @@ describe("App integration with MSW", () => {
    expect(toastErrorMock).not.toHaveBeenCalled();
    expect(toastSuccessMock).toHaveBeenCalled();
  });
+
+  it("shows toast when auto sync fails in background", async () => {
+    const { default: App } = await import("@/App");
+    renderApp(App);
+
+    await waitFor(() =>
+      expect(screen.getByTestId("provider-list").textContent).toContain(
+        "claude-1",
+      ),
+    );
+
+    emitTauriEvent("webdav-sync-status-updated", {
+      source: "auto",
+      status: "error",
+      error: "network timeout",
+    });
+
+    await waitFor(() => {
+      expect(toastErrorMock).toHaveBeenCalled();
+    });
+  });
 });