Detect missing project paths and allow remapping

main.js

@@ -341,6 +341,47 @@ ipcMain.handle('remove-project', (_event, projectPath) => {
   }
 });
 
+// --- IPC: remap-project ---
+ipcMain.handle('remap-project', (_event, oldPath, newPath) => {
+  try {
+    const stat = fs.statSync(newPath);
+    if (!stat.isDirectory()) return { error: 'Path is not a directory' };
+
+    // Find the folder key for the old project path
+    const folder = oldPath.replace(/[/_]/g, '-').replace(/^-/, '-');
+    const folderPath = path.join(PROJECTS_DIR, folder);
+    if (!fs.existsSync(folderPath)) return { error: 'No session data found for this project' };
+
+    // Rewrite cwd in all session JSONL files so CLI --resume also works
+    const jsonlFiles = fs.readdirSync(folderPath).filter(f => f.endsWith('.jsonl'));
+    for (const file of jsonlFiles) {
+      const filePath = path.join(folderPath, file);
+      const content = fs.readFileSync(filePath, 'utf8');
+      const updated = content.split('\n').map(line => {
+        if (!line) return line;
+        try {
+          const parsed = JSON.parse(line);
+          if (parsed.cwd === oldPath) {
+            parsed.cwd = newPath;
+            return JSON.stringify(parsed);
+          }
+        } catch {}
+        return line;
+      }).join('\n');
+      const tmp = filePath + '.tmp';
+      fs.writeFileSync(tmp, updated);
+      fs.renameSync(tmp, filePath);
+    }
+
+    // Refresh the folder cache so the new path takes effect
+    refreshFolder(folder);
+    notifyRendererProjectsChanged();
+    return { ok: true };
+  } catch (err) {
+    return { error: err.message };
+  }
+});
+
 // --- IPC: get-projects ---
 ipcMain.handle('open-external', (_event, url) => {
   log.info('[open-external IPC]', url);

preload.js

@@ -35,6 +35,7 @@ contextBridge.exposeInMainWorld('api', {
   browseFolder: () => ipcRenderer.invoke('browse-folder'),
   addProject: (projectPath) => ipcRenderer.invoke('add-project', projectPath),
   removeProject: (projectPath) => ipcRenderer.invoke('remove-project', projectPath),
+  remapProject: (oldPath, newPath) => ipcRenderer.invoke('remap-project', oldPath, newPath),
   openExternal: (url) => ipcRenderer.invoke('open-external', url),
 
   // Send (fire-and-forget)

public/app.js

@@ -731,6 +731,7 @@ async function launchNewSession(project, sessionOptions) {
   if (!result.ok) {
     entry.terminal.write(`\r\nError: ${result.error}\r\n`);
     entry.closed = true;
+    showSession(sessionId);
     return;
   }
   if (typeof setSessionMcpActive === 'function') setSessionMcpActive(sessionId, !!result.mcpActive);
@@ -797,6 +798,7 @@ async function openSession(session, customOptions) {
   if (!result.ok) {
     entry.terminal.write(`\r\nError: ${result.error}\r\n`);
     entry.closed = true;
+    showSession(sessionId);
     return;
   }
   if (typeof setSessionMcpActive === 'function') setSessionMcpActive(sessionId, !!result.mcpActive);

public/sidebar.js

@@ -278,14 +278,15 @@ function renderProjects(projects, resort) {
 
     // Build DOM
     const group = document.createElement('div');
-    group.className = 'project-group';
+    group.className = 'project-group' + (project.missing ? ' missing' : '');
     group.id = fId;
 
     const header = document.createElement('div');
     header.className = 'project-header';
     header.id = 'ph-' + fId;
     const shortName = project.projectPath.split('/').filter(Boolean).slice(-2).join('/');
-    header.innerHTML = `<span class="arrow">&#9660;</span> <span class="project-name">${shortName}</span>`;
+    const missingIcon = project.missing ? '<svg class="project-missing-icon" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M10.29 3.86L1.82 18a2 2 0 0 0 1.71 3h16.94a2 2 0 0 0 1.71-3L13.71 3.86a2 2 0 0 0-3.42 0z"/><line x1="12" y1="9" x2="12" y2="13"/><line x1="12" y1="17" x2="12.01" y2="17"/></svg> ' : '';
+    header.innerHTML = `<span class="arrow">&#9660;</span> ${missingIcon}<span class="project-name">${escapeHtml(shortName)}</span>`;
 
     const scheduleBtn = document.createElement('button');
     scheduleBtn.className = 'project-schedule-btn';
@@ -305,6 +306,14 @@ function renderProjects(projects, resort) {
     archiveGroupBtn.innerHTML = ICONS.archive(18);
     header.appendChild(archiveGroupBtn);
 
+    if (project.missing) {
+      const remapBtn = document.createElement('button');
+      remapBtn.className = 'project-remap-btn';
+      remapBtn.title = 'Change project path';
+      remapBtn.innerHTML = '<svg width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"/><polyline points="17 8 12 3 7 8"/><line x1="12" y1="3" x2="12" y2="15"/></svg>';
+      header.appendChild(remapBtn);
+    }
+
     const newBtn = document.createElement('button');
     newBtn.className = 'project-new-btn';
     newBtn.innerHTML = '<svg width="12" height="12" viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5"><line x1="6" y1="2" x2="6" y2="10"/><line x1="2" y1="6" x2="10" y2="6"/></svg>';
@@ -313,8 +322,10 @@ function renderProjects(projects, resort) {
 
     const sessionsList = buildSessionsList(fId, visible, older);
 
-    // Auto-collapse if most recent session is older than threshold, or project matched with no sessions
-    if (project._projectMatchedOnly) {
+    // Auto-collapse if project path is missing, most recent session is older than threshold, or project matched with no sessions
+    if (project.missing) {
+      header.classList.add('collapsed');
+    } else if (project._projectMatchedOnly) {
       header.classList.add('collapsed');
     } else if (searchMatchIds === null && !showStarredOnly && !showRunningOnly) {
       const mostRecent = filtered[0]?.modified;
@@ -454,6 +465,22 @@ function rebindSidebarEvents(projects) {
     if (settingsBtn) {
       settingsBtn.onclick = (e) => { e.stopPropagation(); openSettingsViewer('project', project.projectPath); };
     }
+    const remapBtn = header.querySelector('.project-remap-btn');
+    if (remapBtn) {
+      remapBtn.onclick = async (e) => {
+        e.stopPropagation();
+        const newPath = await window.api.browseFolder();
+        if (!newPath) return;
+        const shortName = project.projectPath.split('/').filter(Boolean).slice(-2).join('/');
+        if (!confirm(`Remap ${shortName} to:\n${newPath}?`)) return;
+        const result = await window.api.remapProject(project.projectPath, newPath);
+        if (result.error) {
+          alert('Failed to remap: ' + result.error);
+        } else {
+          loadProjects();
+        }
+      };
+    }
     const archiveGroupBtn = header.querySelector('.project-archive-btn');
     if (archiveGroupBtn) {
       archiveGroupBtn.onclick = async (e) => {
@@ -474,7 +501,7 @@ function rebindSidebarEvents(projects) {
       };
     }
     header.onclick = (e) => {
-      if (e.target.closest('.project-new-btn') || e.target.closest('.project-archive-btn') || e.target.closest('.project-settings-btn') || e.target.closest('.project-schedule-btn')) return;
+      if (e.target.closest('.project-new-btn') || e.target.closest('.project-archive-btn') || e.target.closest('.project-settings-btn') || e.target.closest('.project-schedule-btn') || e.target.closest('.project-remap-btn')) return;
       header.classList.toggle('collapsed');
     };
   }
@@ -558,6 +585,14 @@ function rebindSidebarEvents(projects) {
     const session = sessionMap.get(sessionId);
     if (!session) return;
 
+    // Sessions under missing projects can't be opened — the path no longer exists
+    if (item.closest('.project-group.missing')) {
+      item.classList.add('disabled');
+      item.title = 'Project path no longer exists — use "Change path" to fix';
+      item.onclick = () => {};
+      return;
+    }
+
     item.onclick = () => openSession(session);
 
     const pin = item.querySelector('.session-pin');

public/style.css

@@ -470,6 +470,40 @@ body { display: flex; flex-direction: column; }
   display: none;
 }
 
+/* Missing project path */
+.project-group.missing {
+  opacity: 0.55;
+}
+.project-group.missing:hover {
+  opacity: 0.8;
+}
+.project-missing-icon {
+  color: #e8a838;
+  vertical-align: middle;
+  margin-right: 2px;
+  flex-shrink: 0;
+}
+.project-remap-btn {
+  background: none;
+  border: none;
+  color: #e8a838;
+  cursor: pointer;
+  padding: 2px 4px;
+  border-radius: 4px;
+  display: none;
+  align-items: center;
+}
+.project-group.missing .project-remap-btn {
+  display: inline-flex;
+}
+.project-remap-btn:hover {
+  background: rgba(232, 168, 56, 0.15);
+}
+.session-item.disabled {
+  opacity: 0.4;
+  cursor: not-allowed;
+}
+
 /* Worktree nested groups */
 .worktree-group {
   margin-left: 12px;

session-cache.js

@@ -175,7 +175,7 @@ function buildProjectsFromCache(showArchived) {
   for (const row of cachedRows) {
     if (hiddenProjects.has(row.projectPath)) continue;
     if (!projectMap.has(row.folder)) {
-      projectMap.set(row.folder, { folder: row.folder, projectPath: row.projectPath, sessions: [] });
+      projectMap.set(row.folder, { folder: row.folder, projectPath: row.projectPath, sessions: [], missing: !fs.existsSync(row.projectPath) });
     }
     const meta = metaMap.get(row.sessionId);
     const s = {
@@ -203,7 +203,7 @@ function buildProjectsFromCache(showArchived) {
       if (!projectMap.has(d.name)) {
         const projectPath = deriveProjectPath(path.join(PROJECTS_DIR, d.name), d.name);
         if (projectPath && !hiddenProjects.has(projectPath)) {
-          projectMap.set(d.name, { folder: d.name, projectPath, sessions: [] });
+          projectMap.set(d.name, { folder: d.name, projectPath, sessions: [], missing: !fs.existsSync(projectPath) });
         }
       }
     }
@@ -236,6 +236,9 @@ function buildProjectsFromCache(showArchived) {
   }
 
   projects.sort((a, b) => {
+    // Missing projects go to the bottom
+    if (a.missing && !b.missing) return 1;
+    if (!a.missing && b.missing) return -1;
     // Empty projects go to the bottom
     if (a.sessions.length === 0 && b.sessions.length > 0) return 1;
     if (b.sessions.length === 0 && a.sessions.length > 0) return -1;