prevent conflic between obsidian sync and headless sync.

server/plugins/headless-sync/plugin/src/core-sync-guard.js

@@ -1,9 +1,14 @@
 const { Notice } = require("obsidian");
-const fs = require("fs"); // Using fs shim
+const fs = require("fs");
 
+const CORE_PLUGINS_PATH = ".obsidian/core-plugins.json";
+
+// Reads core-plugins.json via the fs shim. When headless sync is active,
+// the shim patches sync: false, so this returns false. When the flag is
+// cleared (user action), this returns the real value.
 function isCoreSyncEnabled() {
   try {
-    const data = fs.readFileSync(".obsidian/core-plugins.json", "utf-8");
+    const data = fs.readFileSync(CORE_PLUGINS_PATH, "utf-8");
     const config = JSON.parse(data);
     return config.sync === true;
   } catch {
@@ -27,11 +32,31 @@ function showConflictWarning(title, message) {
   });
 }
 
-function startCoreSyncWatcher(plugin, api, wsListener) {
+function startCoreSyncGuard(plugin, api, wsListener) {
+  const app = plugin.app;
+  const vaultId = app.vault.getName();
+
+  // Monkey-patch syncPlugin.enable() to clear the shim flag before
+  // Obsidian writes core-plugins.json. This ensures the read transform
+  // doesn't block a user-initiated core sync enable.
+  const syncPlugin = app.internalPlugins.getPluginById("sync");
+  let origEnable = null;
+
+  if (syncPlugin) {
+    origEnable = syncPlugin.enable.bind(syncPlugin);
+
+    syncPlugin.enable = function (...args) {
+      window.__ignisHeadlessSyncActive = false;
+      api.stopSync(vaultId).catch(() => {});
+      return origEnable(...args);
+    };
+  }
+
+  // Watch for core-plugins.json changes via WebSocket.
   let wasEnabled = isCoreSyncEnabled();
 
   const rawHandler = (msg) => {
-    if (msg.type === "modified" && msg.path === ".obsidian/core-plugins.json") {
+    if (msg.type === "modified" && msg.path === CORE_PLUGINS_PATH) {
       handleCoreSyncChange();
     }
   };
@@ -42,9 +67,6 @@ function startCoreSyncWatcher(plugin, api, wsListener) {
     const enabled = isCoreSyncEnabled();
 
     if (enabled && !wasEnabled) {
-      const vaultId = plugin.app.vault.getName();
-
-      api.stopSync(vaultId).catch(() => {});
       showConflictWarning(
         "Headless Sync Stopped",
         "Obsidian Sync has been enabled. Headless Sync has been automatically " +
@@ -59,11 +81,15 @@ function startCoreSyncWatcher(plugin, api, wsListener) {
   return {
     cleanup() {
       wsListener.offRaw();
+
+      if (syncPlugin && origEnable) {
+        syncPlugin.enable = origEnable;
+      }
     },
   };
 }
 
 module.exports = {
   isCoreSyncEnabled,
-  startCoreSyncWatcher,
+  startCoreSyncGuard,
 };

server/plugins/headless-sync/plugin/src/main.js

@@ -2,7 +2,7 @@ const { Plugin } = require("obsidian");
 const { HeadlessSyncSettingTab } = require("./settings-tab");
 const { WsListener } = require("./ws-listener");
 const { initSyncStatusBar } = require("./sync-status-bar");
-const { startCoreSyncWatcher } = require("./core-sync-guard");
+const { startCoreSyncGuard } = require("./core-sync-guard");
 const api = require("./api");
 
 class IgnisHeadlessSyncPlugin extends Plugin {
@@ -14,7 +14,7 @@ class IgnisHeadlessSyncPlugin extends Plugin {
 
     this.addSettingTab(new HeadlessSyncSettingTab(this.app, this));
 
-    this._coreSyncWatcher = startCoreSyncWatcher(this, api, this.wsListener);
+    this._coreSyncGuard = startCoreSyncGuard(this, api, this.wsListener);
 
     this.addCommand({
       id: "start-sync",
@@ -53,9 +53,11 @@ class IgnisHeadlessSyncPlugin extends Plugin {
   }
 
   onunload() {
-    if (this._coreSyncWatcher) {
-      this._coreSyncWatcher.cleanup();
-      this._coreSyncWatcher = null;
+    window.__ignisHeadlessSyncActive = false;
+
+    if (this._coreSyncGuard) {
+      this._coreSyncGuard.cleanup();
+      this._coreSyncGuard = null;
     }
 
     if (this._syncStatusBarCleanup) {

server/plugins/headless-sync/sync-manager.js

@@ -124,12 +124,6 @@ class SyncManager {
       throw new Error(`No sync configuration for vault: ${vaultId}`);
     }
 
-    if (this.isCoreSyncEnabled(state.vaultPath)) {
-      const msg = `Cannot start sync for ${vaultId}: Obsidian Sync core plugin is enabled`;
-      this.ctx.log(msg);
-      throw new Error(msg);
-    }
-
     if (state.status === "running") {
       this.ctx.log(`Sync already running for ${vaultId}`);
       return this.getState(vaultId);
@@ -316,31 +310,11 @@ class SyncManager {
     }
   }
 
-  isCoreSyncEnabled(vaultPath) {
-    try {
-      const configPath = path.join(vaultPath, ".obsidian", "core-plugins.json");
-      const data = fs.readFileSync(configPath, "utf-8");
-      const config = JSON.parse(data);
-      return config.sync === true;
-    } catch {
-      return false;
-    }
-  }
-
   autoStartAll() {
     let started = 0;
-    let skipped = 0;
 
     for (const [vaultId, state] of this.states) {
       if (state.autoStart && state.status === "stopped") {
-        if (this.isCoreSyncEnabled(state.vaultPath)) {
-          this.ctx.log(
-            `Skipping auto-start for ${vaultId}: Obsidian Sync core plugin is enabled`,
-          );
-          skipped++;
-          continue;
-        }
-
         try {
           this.startSync(vaultId);
           started++;
@@ -353,12 +327,6 @@ class SyncManager {
     if (started > 0) {
       this.ctx.log(`Auto-started sync for ${started} vault(s)`);
     }
-
-    if (skipped > 0) {
-      this.ctx.log(
-        `Skipped ${skipped} vault(s) due to Obsidian Sync being enabled`,
-      );
-    }
   }
 
   async shutdown() {