feat: release channels (alpha/beta/stable) via PostHog feature flags

- Add `release_channel` to Settings (Rust + TypeScript)
- Add channel selector in Settings panel (alpha/beta/stable)
- Pass `release_channel` as PostHog person property on identify
- Add `isFeatureEnabled()` helper: alpha always true, beta/stable
  use PostHog flags with hardcoded fallback defaults
- Update `useFeatureFlag` to delegate to PostHog-backed evaluation
  (localStorage overrides still work for dev/QA)
- Create ADR-0042 (supersedes ADR-0017)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/ARCHITECTURE.md

@@ -798,7 +798,7 @@ sequenceDiagram
 
 **Architecture:**
 - **Rust:** `sentry` crate initialized in `lib.rs::setup()` via `telemetry::init_sentry_from_settings()`
-- **JS:** `@sentry/browser` + `posthog-js` initialized lazily by `useTelemetry` hook
+- **JS:** `@sentry/react` + `posthog-js` initialized lazily by `useTelemetry` hook
 - **Settings:** `telemetry_consent`, `crash_reporting_enabled`, `analytics_enabled`, `anonymous_id` in `Settings` struct
 - **Consent:** `TelemetryConsentDialog` shown when `telemetry_consent === null`
 
@@ -826,9 +826,13 @@ flowchart LR
 - **Canary**: `useUpdater` hook fetches `latest-canary.json` via HTTP, compares versions, and opens the GitHub release page for manual download
 - Canary versions use semver prerelease: `0.YYYYMMDD.N-canary`
 
-### Feature Flags (Local V1)
+### Feature Flags (PostHog + Release Channels)
 
-Feature flags use a local-only system with no external dependencies:
+Feature flags are backed by PostHog and evaluated per release channel:
+
+- **Alpha**: all features always enabled (no PostHog lookup)
+- **Beta**: sees features where the PostHog flag targets `release_channel = beta`
+- **Stable** (default): sees features where the flag targets `release_channel = stable`
 
 ```typescript
 import { useFeatureFlag } from './hooks/useFeatureFlag'
@@ -838,18 +842,14 @@ const enabled = useFeatureFlag('example_flag') // boolean
 
 **Resolution order:**
 1. `localStorage` override: key `ff_<name>` with value `"true"` or `"false"`
-2. Compile-time default in `FLAG_DEFAULTS` map
+2. `isFeatureEnabled(flag)` in `telemetry.ts` → checks release channel, then PostHog, then hardcoded defaults
 
 **How to add a new flag:**
 1. Add the flag name to the `FeatureFlagName` union type in `src/hooks/useFeatureFlag.ts`
-2. Set its default in the `FLAG_DEFAULTS` record
+2. Create the flag on PostHog dashboard with rollout rules per channel
 3. Use `useFeatureFlag('your_flag')` in components
 
-**Design decisions:**
-- No remote fetching, no PostHog dependency — zero privacy concerns
-- `localStorage` overrides allow dev/QA testing without rebuilding
-- Type-safe flag names via TypeScript union type
-- API surface is compatible with future migration to remote flags
+Release channel is selectable in Settings (alpha / beta / stable) and passed to PostHog as a person property via `identify()`. See ADR-0042.
 
 ## Platform Support — iOS / iPadOS (Prototype)
 

docs/adr/0042-posthog-release-channels-feature-flags.md

@@ -0,0 +1,37 @@
+---
+type: ADR
+id: "0042"
+title: "PostHog-based release channels and feature flags"
+status: active
+date: 2026-04-03
+supersedes: "0017"
+---
+## Context
+
+ADR-0017 introduced canary/stable update channels with localStorage-based feature flags. This worked for local development but lacked remote flag management — promoting a feature from beta to stable required a code change and rebuild.
+
+## Decision
+
+**Replace localStorage feature flags with PostHog-based feature flags, evaluated per release channel (alpha/beta/stable). The release channel is a user-selectable setting; PostHog flag rules determine which features are visible for each channel.**
+
+- **Alpha**: all features always enabled (no PostHog lookup needed, works offline)
+- **Beta**: sees features where the PostHog flag targets `release_channel = beta`
+- **Stable** (default): sees features where the PostHog flag targets `release_channel = stable`
+- Promotion = flipping a PostHog flag on the dashboard. Zero code changes, zero rebuilds.
+- `isFeatureEnabled(flagKey)` in `telemetry.ts` is the single evaluation point.
+- localStorage overrides (`ff_<name>`) still work for dev/QA testing (checked first).
+- Offline: PostHog caches flags in localStorage; alpha always works; first-launch-no-network falls back to hardcoded defaults.
+
+## Options considered
+
+* **Option A**: Keep localStorage-only flags (ADR-0017) — no server dependency, but no remote management.
+* **Option B** (chosen): PostHog feature flags — we already use PostHog for analytics, so no new dependency. Remote flag management, per-channel targeting, gradual rollouts via PostHog dashboard.
+* **Option C**: Dedicated feature flag service (LaunchDarkly, Unleash) — more powerful but adds a new vendor dependency.
+
+## Consequences
+
+* `release_channel` added to Settings (persisted via Tauri backend, not vault).
+* `useTelemetry` passes `release_channel` as a PostHog person property on identify.
+* `isFeatureEnabled()` checks channel → PostHog → hardcoded defaults.
+* `useFeatureFlag` hook updated to delegate to `isFeatureEnabled` (after localStorage override check).
+* ADR-0017 is superseded — the canary update channel remains, but feature gating moves from localStorage to PostHog.

package.json

@@ -42,7 +42,7 @@
     "@radix-ui/react-slot": "^1.2.4",
     "@radix-ui/react-tabs": "^1.1.13",
     "@radix-ui/react-tooltip": "^1.2.8",
-    "@sentry/browser": "^10.45.0",
+    "@sentry/react": "^10.47.0",
     "@tailwindcss/vite": "^4.1.18",
     "@tauri-apps/api": "^2.10.1",
     "@tauri-apps/plugin-dialog": "^2.6.0",

pnpm-lock.yaml

@@ -77,9 +77,9 @@ importers:
       '@radix-ui/react-tooltip':
         specifier: ^1.2.8
         version: 1.2.8(@types/react-dom@19.2.3(@types/react@19.2.14))(@types/react@19.2.14)(react-dom@19.2.4(react@19.2.4))(react@19.2.4)
-      '@sentry/browser':
-        specifier: ^10.45.0
-        version: 10.45.0
+      '@sentry/react':
+        specifier: ^10.47.0
+        version: 10.47.0(react@19.2.4)
       '@tailwindcss/vite':
         specifier: ^4.1.18
         version: 4.1.18(vite@7.3.1(@types/node@24.10.13)(jiti@2.6.1)(lightningcss@1.30.2))
@@ -1785,30 +1785,36 @@ packages:
     cpu: [x64]
     os: [win32]
 
-  '@sentry-internal/browser-utils@10.45.0':
-    resolution: {integrity: sha512-ZPZpeIarXKScvquGx2AfNKcYiVNDA4wegMmjyGVsTA2JPmP0TrJoO3UybJS6KGDeee8V3I3EfD/ruauMm7jOFQ==}
+  '@sentry-internal/browser-utils@10.47.0':
+    resolution: {integrity: sha512-bVFRAeJWMBcBCvJKIFCMJ1/yQToL4vPGqfmlnDZeypcxkqUDKQ/Y3ziLHXoDL2sx0lagcgU2vH1QhCQ67Aujjw==}
     engines: {node: '>=18'}
 
-  '@sentry-internal/feedback@10.45.0':
-    resolution: {integrity: sha512-vCSurazFVq7RUeYiM5X326jA5gOVrWYD6lYX2fbjBOMcyCEhDnveNxMT62zKkZDyNT/jyD194nz/cjntBUkyWA==}
+  '@sentry-internal/feedback@10.47.0':
+    resolution: {integrity: sha512-pdvMmi4dQpX5S/vAAzrhHPIw3T3HjUgDNgUiCBrlp7N9/6zGO2gNPhUnNekP+CjgI/z0rvf49RLqlDenpNrMOg==}
     engines: {node: '>=18'}
 
-  '@sentry-internal/replay-canvas@10.45.0':
-    resolution: {integrity: sha512-nvq/AocdZTuD7y0KSiWi3gVaY0s5HOFy86mC/v1kDZmT/jsBAzN5LDkk/f1FvsWma1peqQmpUqxvhC+YIW294Q==}
+  '@sentry-internal/replay-canvas@10.47.0':
+    resolution: {integrity: sha512-A5OY8friSe6g8WAK4L8IeOPiEd9D3Ps40DzRH5j2f6SUja0t90mKMvHRcRf8zq0d4BkdB+JM7tjOkwxpuv8heA==}
     engines: {node: '>=18'}
 
-  '@sentry-internal/replay@10.45.0':
-    resolution: {integrity: sha512-vjosRoGA1bzhVAEO1oce+CsRdd70quzBeo7WvYqpcUnoLe/Rv8qpOMqWX3j26z7XfFHMExWQNQeLxmtYOArvlw==}
+  '@sentry-internal/replay@10.47.0':
+    resolution: {integrity: sha512-ScdovxP7hJxgMt70+7hFvwT02GIaIUAxdEM/YPsayZBeCoAukPW8WiwztJfoKtsfPyKJ5A6f0H3PIxTPcA9Row==}
     engines: {node: '>=18'}
 
-  '@sentry/browser@10.45.0':
-    resolution: {integrity: sha512-e/a8UMiQhqqv706McSIcG6XK+AoQf9INthi2pD+giZfNRTzXTdqHzUT5OIO5hg8Am6eF63nDJc+vrYNPhzs51Q==}
+  '@sentry/browser@10.47.0':
+    resolution: {integrity: sha512-rC0agZdxKA5XWfL4VwPOr/rJMogXDqZgnVzr93YWpFn9DMZT/7LzxSJVPIJwRUjx3bFEby3PcTa3YaX7pxm1AA==}
     engines: {node: '>=18'}
 
-  '@sentry/core@10.45.0':
-    resolution: {integrity: sha512-s69UXxvefeQxuZ5nY7/THtTrIEvJxNVCp3ns4kwoCw1qMpgpvn/296WCKVmM7MiwnaAdzEKnAvLAwaxZc2nM7Q==}
+  '@sentry/core@10.47.0':
+    resolution: {integrity: sha512-nsYRAx3EWezDut+Zl+UwwP07thh9uY7CfSAi2whTdcJl5hu1nSp2z8bba7Vq/MGbNLnazkd3A+GITBEML924JA==}
     engines: {node: '>=18'}
 
+  '@sentry/react@10.47.0':
+    resolution: {integrity: sha512-ZtJV6xxF8jUVE9e3YQUG3Do0XapG1GjniyLyqMPgN6cNvs/HaRJODf7m60By+VGqcl5XArEjEPTvx8CdPUXDfA==}
+    engines: {node: '>=18'}
+    peerDependencies:
+      react: ^16.14.0 || 17.x || 18.x || 19.x
+
   '@shikijs/types@3.22.0':
     resolution: {integrity: sha512-491iAekgKDBFE67z70Ok5a8KBMsQ2IJwOWw3us/7ffQkIBCyOQfm/aNwVMBUriP02QshIfgHCBSIYAl3u2eWjg==}
 
@@ -5941,33 +5947,39 @@ snapshots:
   '@rollup/rollup-win32-x64-msvc@4.57.1':
     optional: true
 
-  '@sentry-internal/browser-utils@10.45.0':
+  '@sentry-internal/browser-utils@10.47.0':
     dependencies:
-      '@sentry/core': 10.45.0
+      '@sentry/core': 10.47.0
 
-  '@sentry-internal/feedback@10.45.0':
+  '@sentry-internal/feedback@10.47.0':
     dependencies:
-      '@sentry/core': 10.45.0
+      '@sentry/core': 10.47.0
 
-  '@sentry-internal/replay-canvas@10.45.0':
+  '@sentry-internal/replay-canvas@10.47.0':
     dependencies:
-      '@sentry-internal/replay': 10.45.0
-      '@sentry/core': 10.45.0
+      '@sentry-internal/replay': 10.47.0
+      '@sentry/core': 10.47.0
 
-  '@sentry-internal/replay@10.45.0':
+  '@sentry-internal/replay@10.47.0':
     dependencies:
-      '@sentry-internal/browser-utils': 10.45.0
-      '@sentry/core': 10.45.0
+      '@sentry-internal/browser-utils': 10.47.0
+      '@sentry/core': 10.47.0
 
-  '@sentry/browser@10.45.0':
+  '@sentry/browser@10.47.0':
     dependencies:
-      '@sentry-internal/browser-utils': 10.45.0
-      '@sentry-internal/feedback': 10.45.0
-      '@sentry-internal/replay': 10.45.0
-      '@sentry-internal/replay-canvas': 10.45.0
-      '@sentry/core': 10.45.0
+      '@sentry-internal/browser-utils': 10.47.0
+      '@sentry-internal/feedback': 10.47.0
+      '@sentry-internal/replay': 10.47.0
+      '@sentry-internal/replay-canvas': 10.47.0
+      '@sentry/core': 10.47.0
 
-  '@sentry/core@10.45.0': {}
+  '@sentry/core@10.47.0': {}
+
+  '@sentry/react@10.47.0(react@19.2.4)':
+    dependencies:
+      '@sentry/browser': 10.47.0
+      '@sentry/core': 10.47.0
+      react: 19.2.4
 
   '@shikijs/types@3.22.0':
     dependencies:

src-tauri/src/settings.rs

@@ -14,6 +14,7 @@ pub struct Settings {
     pub analytics_enabled: Option<bool>,
     pub anonymous_id: Option<String>,
     pub update_channel: Option<String>,
+    pub release_channel: Option<String>,
 }
 
 fn settings_path() -> Result<PathBuf, String> {
@@ -67,6 +68,10 @@ fn save_settings_at(path: &PathBuf, settings: Settings) -> Result<(), String> {
             .update_channel
             .map(|k| k.trim().to_string())
             .filter(|k| !k.is_empty()),
+        release_channel: settings
+            .release_channel
+            .map(|k| k.trim().to_string())
+            .filter(|k| !k.is_empty()),
     };
 
     let json = serde_json::to_string_pretty(&cleaned)

src/App.tsx

@@ -57,6 +57,7 @@ import { openNoteInNewWindow } from './utils/openNoteWindow'
 import { isNoteWindow, getNoteWindowParams } from './utils/windowMode'
 import { GitRequiredModal } from './components/GitRequiredModal'
 import { RenameDetectedBanner, type DetectedRename } from './components/RenameDetectedBanner'
+import { trackEvent } from './lib/telemetry'
 import './App.css'
 
 // Type declarations for mock content storage and test overrides
@@ -118,6 +119,14 @@ function App() {
   useVaultConfig(resolvedPath)
   const { settings, loaded: settingsLoaded, saveSettings } = useSettings()
   useTelemetry(settings, settingsLoaded)
+
+  const vaultOpenedRef = useRef('')
+  useEffect(() => {
+    if (vault.entries.length > 0 && gitRepoState !== 'checking' && resolvedPath !== vaultOpenedRef.current) {
+      vaultOpenedRef.current = resolvedPath
+      trackEvent('vault_opened', { has_git: gitRepoState === 'ready' ? 1 : 0, note_count: vault.entries.length })
+    }
+  }, [vault.entries.length, gitRepoState, resolvedPath])
   const { mcpStatus, installMcp } = useMcpStatus(resolvedPath, setToastMessage)
 
   const autoSync = useAutoSync({
@@ -331,6 +340,7 @@ function App() {
     const filename = definition.name.toLowerCase().replace(/[^a-z0-9]+/g, '-').replace(/(^-|-$)/g, '') + '.yml'
     const target = isTauri() ? invoke : mockInvoke
     await target('save_view_cmd', { vaultPath: resolvedPath, filename, definition })
+    trackEvent('view_created')
     await vault.reloadViews()
     setToastMessage(`View "${definition.name}" created`)
     handleSetSelection({ kind: 'view', filename })

src/components/Editor.css

@@ -333,6 +333,9 @@
   letter-spacing: var(--headings-h1-letter-spacing, -0.015em);
   color: var(--foreground);
   padding: 0;
+  resize: none;
+  overflow: hidden;
+  font-family: inherit;
 }
 
 .title-field__input::placeholder {

src/components/RawEditorView.tsx

@@ -1,4 +1,5 @@
 import { useRef, useState, useCallback, useEffect, useMemo } from 'react'
+import { trackEvent } from '../lib/telemetry'
 import type { EditorView } from '@codemirror/view'
 import { preFilterWikilinks, deduplicateByPath, MIN_QUERY_LENGTH } from '../utils/wikilinkSuggestions'
 import { attachClickHandlers, enrichSuggestionItems } from '../utils/suggestionEnrichment'
@@ -136,6 +137,7 @@ export function RawEditorView({ content, path, entries, onContentChange, onSave,
       changes: { from: 0, to: doc.length, insert: newText },
       selection: { anchor: newCursor },
     })
+    trackEvent('wikilink_inserted')
     setAutocomplete(null)
 
     if (debounceRef.current) clearTimeout(debounceRef.current)

src/components/SettingsPanel.tsx

@@ -2,6 +2,7 @@ import { useState, useRef, useCallback, useEffect } from 'react'
 import { X, Eye, EyeSlash, GithubLogo, SignOut } from '@phosphor-icons/react'
 import { GitHubDeviceFlow } from './GitHubDeviceFlow'
 import type { Settings } from '../types'
+import { trackEvent } from '../lib/telemetry'
 
 interface SettingsPanelProps {
   open: boolean
@@ -125,6 +126,7 @@ function SettingsPanelInner({ settings, onSave, onClose }: Omit<SettingsPanelPro
   const [githubUsername, setGithubUsername] = useState(settings.github_username)
   const [pullInterval, setPullInterval] = useState(settings.auto_pull_interval_minutes ?? 5)
   const [updateChannel, setUpdateChannel] = useState(settings.update_channel ?? 'stable')
+  const [releaseChannel, setReleaseChannel] = useState(settings.release_channel ?? 'stable')
   const [crashReporting, setCrashReporting] = useState(settings.crash_reporting_enabled ?? false)
   const [analytics, setAnalytics] = useState(settings.analytics_enabled ?? false)
   const panelRef = useRef<HTMLDivElement>(null)
@@ -149,9 +151,14 @@ function SettingsPanelInner({ settings, onSave, onClose }: Omit<SettingsPanelPro
     analytics_enabled: analytics,
     anonymous_id: (crashReporting || analytics) ? (settings.anonymous_id ?? crypto.randomUUID()) : settings.anonymous_id,
     update_channel: updateChannel === 'stable' ? null : updateChannel,
-  }), [openaiKey, googleKey, githubToken, githubUsername, pullInterval, updateChannel, crashReporting, analytics, settings.telemetry_consent, settings.anonymous_id])
+    release_channel: releaseChannel === 'stable' ? null : releaseChannel,
+  }), [openaiKey, googleKey, githubToken, githubUsername, pullInterval, updateChannel, releaseChannel, crashReporting, analytics, settings.telemetry_consent, settings.anonymous_id])
 
   const handleSave = () => {
+    const prevAnalytics = settings.analytics_enabled ?? false
+    const newAnalytics = analytics
+    if (!prevAnalytics && newAnalytics) trackEvent('telemetry_opted_in')
+    if (prevAnalytics && !newAnalytics) trackEvent('telemetry_opted_out')
     onSave(buildSettings())
     onClose()
   }
@@ -200,6 +207,7 @@ function SettingsPanelInner({ settings, onSave, onClose }: Omit<SettingsPanelPro
           onGitHubConnected={handleGitHubConnected} onGitHubDisconnect={handleGitHubDisconnect}
           pullInterval={pullInterval} setPullInterval={setPullInterval}
           updateChannel={updateChannel} setUpdateChannel={setUpdateChannel}
+          releaseChannel={releaseChannel} setReleaseChannel={setReleaseChannel}
           crashReporting={crashReporting} setCrashReporting={setCrashReporting}
           analytics={analytics} setAnalytics={setAnalytics}
         />
@@ -235,6 +243,7 @@ interface SettingsBodyProps {
   onGitHubDisconnect: () => void
   pullInterval: number; setPullInterval: (v: number) => void
   updateChannel: string; setUpdateChannel: (v: string) => void
+  releaseChannel: string; setReleaseChannel: (v: string) => void
   crashReporting: boolean; setCrashReporting: (v: boolean) => void
   analytics: boolean; setAnalytics: (v: boolean) => void
 }
@@ -318,6 +327,24 @@ function SettingsBody(props: SettingsBodyProps) {
         </select>
       </div>
 
+      <div style={{ display: 'flex', flexDirection: 'column', gap: 6 }}>
+        <label style={{ fontSize: 12, fontWeight: 500, color: 'var(--foreground)' }}>Release channel</label>
+        <select
+          value={props.releaseChannel}
+          onChange={(e) => props.setReleaseChannel(e.target.value)}
+          className="border border-border bg-transparent text-foreground rounded"
+          style={{ fontSize: 13, padding: '8px 10px', outline: 'none', fontFamily: 'inherit' }}
+          data-testid="settings-release-channel"
+        >
+          <option value="stable">Stable</option>
+          <option value="beta">Beta</option>
+          <option value="alpha">Alpha (bleeding edge)</option>
+        </select>
+        <div style={{ fontSize: 11, color: 'var(--muted-foreground)', lineHeight: 1.4 }}>
+          Alpha users see all features. Beta/Stable see features as they are promoted.
+        </div>
+      </div>
+
       <div style={{ height: 1, background: 'var(--border)' }} />
 
       <div>

src/components/SingleEditorView.tsx

@@ -1,4 +1,5 @@
 import { useEffect, useCallback, useMemo, useRef } from 'react'
+import { trackEvent } from '../lib/telemetry'
 import { useCreateBlockNote, SuggestionMenuController } from '@blocknote/react'
 import { BlockNoteView } from '@blocknote/mantine'
 import { useEditorTheme } from '../hooks/useTheme'
@@ -87,6 +88,7 @@ export function SingleEditorView({ editor, entries, onNavigateWikilink, onChange
       { type: 'wikilink' as const, props: { target } },
       " ",
     ])
+    trackEvent('wikilink_inserted')
   }, [editor])
 
   const getWikilinkItems = useCallback(async (query: string): Promise<WikilinkSuggestionItem[]> => {

src/components/TitleField.tsx

@@ -62,11 +62,21 @@ function useOptimisticTitle(title: string, onTitleChange: (t: string) => void) {
  * Displays the title as an editable field and shows the resulting filename below.
  */
 export function TitleField({ title, filename, editable = true, notePath, vaultPath, onTitleChange }: TitleFieldProps) {
-  const inputRef = useRef<HTMLInputElement>(null)
+  const inputRef = useRef<HTMLTextAreaElement>(null)
   const [isFocused, setIsFocused] = useState(false)
   const { value, isEditing, handleFocus, commitTitle, revert, setEdit } =
     useOptimisticTitle(title, onTitleChange)
 
+  // Auto-resize textarea to fit content
+  const autoResize = useCallback(() => {
+    const el = inputRef.current
+    if (!el) return
+    el.style.height = 'auto'
+    el.style.height = el.scrollHeight + 'px'
+  }, [])
+
+  useEffect(() => { autoResize() }, [value, autoResize])
+
   useEffect(() => {
     const handler = (e: Event) => {
       const detail = (e as CustomEvent).detail
@@ -106,11 +116,12 @@ export function TitleField({ title, filename, editable = true, notePath, vaultPa
 
   return (
     <div className="title-field" data-testid="title-field">
-      <input
+      <textarea
         ref={inputRef}
         className="title-field__input"
         value={value}
-        onChange={e => setEdit(e.target.value)}
+        rows={1}
+        onChange={e => { setEdit(e.target.value); autoResize() }}
         onFocus={() => { setIsFocused(true); handleFocus() }}
         onBlur={() => { setIsFocused(false); commitTitle() }}
         onKeyDown={handleKeyDown}

src/hooks/useAppKeyboard.ts

@@ -1,5 +1,6 @@
 import { useEffect } from 'react'
 import type { ViewMode } from './useViewMode'
+import { trackEvent } from '../lib/telemetry'
 
 interface KeyboardActions {
   onQuickOpen: () => void
@@ -104,6 +105,7 @@ export function useAppKeyboard({
       // Cmd+Shift+F: full-text search (distinct from Cmd+F browser find)
       if ((e.metaKey || e.ctrlKey) && e.shiftKey && e.key === 'f') {
         e.preventDefault()
+        trackEvent('search_used')
         onSearch()
         return
       }

src/hooks/useAutoSync.ts

@@ -2,6 +2,7 @@ import { useCallback, useEffect, useRef, useState } from 'react'
 import { invoke } from '@tauri-apps/api/core'
 import { isTauri, mockInvoke } from '../mock-tauri'
 import type { GitPullResult, GitPushResult, GitRemoteStatus, LastCommitInfo, SyncStatus } from '../types'
+import { trackEvent } from '../lib/telemetry'
 
 const DEFAULT_INTERVAL_MS = 5 * 60_000
 
@@ -219,5 +220,10 @@ export function useAutoSync({
   const pausePull = useCallback(() => { pauseRef.current = true }, [])
   const resumePull = useCallback(() => { pauseRef.current = false }, [])
 
-  return { syncStatus, lastSyncTime, conflictFiles, lastCommitInfo, remoteStatus, triggerSync: performPull, pullAndPush, pausePull, resumePull, handlePushRejected }
+  const triggerSync = useCallback(() => {
+    trackEvent('sync_triggered')
+    performPull()
+  }, [performPull])
+
+  return { syncStatus, lastSyncTime, conflictFiles, lastCommitInfo, remoteStatus, triggerSync, pullAndPush, pausePull, resumePull, handlePushRejected }
 }

src/hooks/useCommitFlow.ts

@@ -1,5 +1,6 @@
 import { useCallback, useState } from 'react'
 import type { GitPushResult } from '../types'
+import { trackEvent } from '../lib/telemetry'
 
 interface CommitFlowConfig {
   savePending: () => Promise<void | boolean>
@@ -25,6 +26,7 @@ export function useCommitFlow({ savePending, loadModifiedFiles, commitAndPush, s
       await savePending()
       const result = await commitAndPush(message)
       if (result.status === 'ok') {
+        trackEvent('commit_made')
         setToastMessage('Committed and pushed')
       } else if (result.status === 'rejected') {
         setToastMessage('Committed, but push rejected — remote has new commits. Pull first.')

src/hooks/useDeleteActions.ts

@@ -2,6 +2,7 @@ import { useCallback, useMemo, useState } from 'react'
 import { invoke } from '@tauri-apps/api/core'
 import { isTauri, mockInvoke } from '../mock-tauri'
 import type { VaultEntry } from '../types'
+import { trackEvent } from '../lib/telemetry'
 
 interface ConfirmDeleteState {
   title: string
@@ -50,7 +51,10 @@ export function useDeleteActions({
       onConfirm: async () => {
         setConfirmDelete(null)
         const ok = await deleteNoteFromDisk(path)
-        if (ok) setToastMessage('Note permanently deleted')
+        if (ok) {
+          trackEvent('note_deleted')
+          setToastMessage('Note permanently deleted')
+        }
       },
     })
   }, [deleteNoteFromDisk, setToastMessage])

src/hooks/useEntryActions.ts

@@ -1,6 +1,7 @@
 import { useCallback } from 'react'
 import type { VaultEntry } from '../types'
 import type { FrontmatterOpOptions } from './frontmatterOps'
+import { trackEvent } from '../lib/telemetry'
 
 interface EntryActionsConfig {
   entries: VaultEntry[]
@@ -32,6 +33,7 @@ export function useEntryActions({
     // Optimistic: update UI immediately, write to disk async with rollback on failure
     const trashedAt = Date.now() / 1000
     updateEntry(path, { trashed: true, trashedAt })
+    trackEvent('note_trashed')
     setToastMessage('Note moved to trash')
     const now = new Date().toISOString().slice(0, 10)
     try {
@@ -64,6 +66,7 @@ export function useEntryActions({
     await onBeforeAction?.(path)
     // Optimistic: update UI immediately, write to disk async with rollback on failure
     updateEntry(path, { archived: true })
+    trackEvent('note_archived')
     setToastMessage('Note archived')
     try {
       await handleUpdateFrontmatter(path, '_archived', true, { silent: true })
@@ -129,6 +132,7 @@ export function useEntryActions({
     const entry = entries.find((e) => e.path === path)
     if (!entry) return
     if (entry.favorite) {
+      trackEvent('note_unfavorited')
       updateEntry(path, { favorite: false, favoriteIndex: null })
       try {
         await handleDeleteProperty(path, '_favorite', { silent: true })
@@ -139,6 +143,7 @@ export function useEntryActions({
         setToastMessage('Failed to unfavorite — rolled back')
       }
     } else {
+      trackEvent('note_favorited')
       const maxIndex = entries.filter((e) => e.favorite).reduce((max, e) => Math.max(max, e.favoriteIndex ?? 0), 0)
       const newIndex = maxIndex + 1
       updateEntry(path, { favorite: true, favoriteIndex: newIndex })

src/hooks/useFeatureFlag.ts

@@ -1,19 +1,15 @@
 /**
- * Local feature flag hook (V1 — no remote fetching).
+ * Feature flag hook backed by PostHog + release channels.
  *
  * Flags are resolved in order:
  *   1. localStorage override (`ff_<name>`) — for dev/QA testing
- *   2. Compile-time defaults in FLAG_DEFAULTS
- *
- * To add a new flag: add its name to the FeatureFlagName union and
- * set its default in FLAG_DEFAULTS.
+ *   2. PostHog feature flags (evaluated by release channel)
+ *   3. Alpha channel always returns true (sees all features)
  */
 
-export type FeatureFlagName = 'example_flag'
+import { isFeatureEnabled } from '../lib/telemetry'
 
-const FLAG_DEFAULTS: Record<FeatureFlagName, boolean> = {
-  example_flag: false,
-}
+export type FeatureFlagName = 'example_flag'
 
 export function useFeatureFlag(flag: FeatureFlagName): boolean {
   try {
@@ -22,5 +18,5 @@ export function useFeatureFlag(flag: FeatureFlagName): boolean {
   } catch {
     // localStorage may be unavailable in some contexts
   }
-  return FLAG_DEFAULTS[flag] ?? false
+  return isFeatureEnabled(flag)
 }

src/hooks/useNoteCreation.ts

@@ -3,6 +3,7 @@ import { invoke } from '@tauri-apps/api/core'
 import { isTauri, addMockEntry } from '../mock-tauri'
 import type { VaultEntry } from '../types'
 import { resolveEntry } from '../utils/wikilink'
+import { trackEvent } from '../lib/telemetry'
 
 export interface NewEntryParams {
   path: string
@@ -250,6 +251,7 @@ export function useNoteCreation(config: NoteCreationConfig, tabDeps: CreationTab
   const handleCreateNote = useCallback((title: string, type: string) => {
     const template = resolveTemplate(entries, type)
     persistNew(resolveNewNote(title, type, config.vaultPath, template))
+    trackEvent('note_created', { has_type: type !== 'Note' ? 1 : 0, creation_path: 'plus_button' })
   }, [entries, persistNew, config.vaultPath])
 
   const handleCreateNoteImmediate = useCallback((type?: string) => {
@@ -257,6 +259,7 @@ export function useNoteCreation(config: NoteCreationConfig, tabDeps: CreationTab
       entries, vaultPath: config.vaultPath, pendingNames: pendingNamesRef.current,
       openTabWithContent, addEntry, trackUnsaved: config.trackUnsaved, markContentPending: config.markContentPending,
     }, type)
+    trackEvent('note_created', { has_type: type ? 1 : 0, creation_path: type ? 'type_section' : 'cmd_n' })
   }, [entries, openTabWithContent, addEntry, config.vaultPath, config.trackUnsaved, config.markContentPending])
 
   const handleCreateNoteForRelationship = useCallback((title: string): Promise<boolean> => {
@@ -269,7 +272,10 @@ export function useNoteCreation(config: NoteCreationConfig, tabDeps: CreationTab
 
   const handleOpenDailyNote = useCallback(() => openDailyNote(entries, handleSelectNote, persistNew, config.vaultPath), [entries, handleSelectNote, persistNew, config.vaultPath])
 
-  const handleCreateType = useCallback((typeName: string) => persistNew(resolveNewType(typeName, config.vaultPath)), [persistNew, config.vaultPath])
+  const handleCreateType = useCallback((typeName: string) => {
+    persistNew(resolveNewType(typeName, config.vaultPath))
+    trackEvent('type_created')
+  }, [persistNew, config.vaultPath])
 
   /** Create a Type entry file silently (no tab opened). Adds to state and persists to disk. */
   const createTypeEntrySilent = useCallback(async (typeName: string): Promise<VaultEntry> => {

src/hooks/useRawMode.ts

@@ -1,5 +1,6 @@
 import { useState, useCallback, useEffect } from 'react'
 import { getVaultConfig, updateVaultConfigField, subscribeVaultConfig } from '../utils/vaultConfigStore'
+import { trackEvent } from '../lib/telemetry'
 
 interface UseRawModeParams {
   activeTabPath: string | null
@@ -32,6 +33,7 @@ export function useRawMode({ activeTabPath, onFlushPending, onBeforeRawEnd }: Us
   const rawMode = rawEnabled && activeTabPath !== null
 
   const handleToggleRaw = useCallback(async () => {
+    trackEvent('raw_mode_toggled')
     if (rawEnabled) {
       onBeforeRawEnd?.()
       setRawEnabled(false)

src/hooks/useSettings.test.ts

@@ -15,6 +15,7 @@ const defaultSettings: Settings = {
   analytics_enabled: null,
   anonymous_id: null,
   update_channel: null,
+  release_channel: null,
 }
 
 const savedSettings: Settings = {
@@ -28,6 +29,7 @@ const savedSettings: Settings = {
   analytics_enabled: null,
   anonymous_id: null,
   update_channel: null,
+  release_channel: null,
 }
 
 let mockSettingsStore: Settings = { ...defaultSettings }

src/hooks/useSettings.ts

@@ -18,6 +18,7 @@ const EMPTY_SETTINGS: Settings = {
   analytics_enabled: null,
   anonymous_id: null,
   update_channel: null,
+  release_channel: null,
 }
 
 export function useSettings() {

src/hooks/useTelemetry.test.ts

@@ -13,13 +13,15 @@ vi.mock('../lib/telemetry', () => ({
   teardownSentry: () => mockTeardownSentry(),
   initPostHog: (...args: unknown[]) => mockInitPostHog(...args),
   teardownPostHog: () => mockTeardownPostHog(),
+  updatePostHogIdentify: vi.fn(),
+  setReleaseChannel: vi.fn(),
 }))
 
 const baseSettings: Settings = {
   openai_key: null, google_key: null,
   github_token: null, github_username: null, auto_pull_interval_minutes: null,
   telemetry_consent: null, crash_reporting_enabled: null,
-  analytics_enabled: null, anonymous_id: null, update_channel: null,
+  analytics_enabled: null, anonymous_id: null, update_channel: null, release_channel: null,
 }
 
 describe('useTelemetry', () => {
@@ -50,7 +52,7 @@ describe('useTelemetry', () => {
     renderHook(() =>
       useTelemetry({ ...baseSettings, analytics_enabled: true, anonymous_id: 'test-uuid' }, true)
     )
-    expect(mockInitPostHog).toHaveBeenCalledWith('test-uuid')
+    expect(mockInitPostHog).toHaveBeenCalledWith('test-uuid', 'stable')
   })
 
   it('tears down Sentry when crash reporting is disabled after being enabled', () => {

src/hooks/useTelemetry.ts

@@ -1,7 +1,7 @@
 import { useEffect, useRef } from 'react'
 import { invoke } from '@tauri-apps/api/core'
 import { isTauri, mockInvoke } from '../mock-tauri'
-import { initSentry, teardownSentry, initPostHog, teardownPostHog } from '../lib/telemetry'
+import { initSentry, teardownSentry, initPostHog, teardownPostHog, updatePostHogIdentify, setReleaseChannel } from '../lib/telemetry'
 import type { Settings } from '../types'
 
 function tauriCall(command: string): Promise<void> {
@@ -29,13 +29,18 @@ export function useTelemetry(settings: Settings, loaded: boolean): void {
       tauriCall('reinit_telemetry').catch(() => {})
     }
 
+    const channel = settings.release_channel ?? 'stable'
+    setReleaseChannel(channel)
+
     if (analyticsEnabled && id && !prevAnalytics.current) {
-      initPostHog(id)
+      initPostHog(id, channel)
     } else if (!analyticsEnabled && prevAnalytics.current) {
       teardownPostHog()
+    } else if (analyticsEnabled && id) {
+      updatePostHogIdentify(channel)
     }
 
     prevCrash.current = crashEnabled
     prevAnalytics.current = analyticsEnabled
-  }, [loaded, settings.crash_reporting_enabled, settings.analytics_enabled, settings.anonymous_id])
+  }, [loaded, settings.crash_reporting_enabled, settings.analytics_enabled, settings.anonymous_id, settings.release_channel])
 }

src/hooks/useVaultSwitcher.ts

@@ -4,6 +4,7 @@ import { isTauri, mockInvoke } from '../mock-tauri'
 import { pickFolder } from '../utils/vault-dialog'
 import { loadVaultList, saveVaultList } from '../utils/vaultListStore'
 import type { VaultOption } from '../components/StatusBar'
+import { trackEvent } from '../lib/telemetry'
 
 export type { PersistedVaultList } from '../utils/vaultListStore'
 
@@ -91,6 +92,7 @@ export function useVaultSwitcher({ onSwitch, onToast }: UseVaultSwitcherOptions)
   }, [])
 
   const switchVault = useCallback((path: string) => {
+    trackEvent('vault_switched')
     setVaultPath(path)
     onSwitchRef.current()
   }, [])

src/lib/telemetry.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect } from 'vitest'
-import { _scrubPathsForTest as scrubPaths } from './telemetry'
+import { _scrubPathsForTest as scrubPaths, trackEvent, isFeatureEnabled, setReleaseChannel } from './telemetry'
 
 describe('telemetry scrubPaths', () => {
   it('redacts macOS absolute paths', () => {
@@ -29,3 +29,35 @@ describe('telemetry scrubPaths', () => {
     expect(scrubPaths(input)).toBe('Failed copying <redacted-path> to <redacted-path>')
   })
 })
+
+describe('trackEvent', () => {
+  it('does not throw when PostHog is not initialized', () => {
+    expect(() => trackEvent('test_event', { count: 1 })).not.toThrow()
+  })
+
+  it('accepts event name with no properties', () => {
+    expect(() => trackEvent('note_created')).not.toThrow()
+  })
+
+  it('accepts event name with string and number properties', () => {
+    expect(() => trackEvent('note_created', { has_type: 1, creation_path: 'cmd_n' })).not.toThrow()
+  })
+})
+
+describe('isFeatureEnabled', () => {
+  it('returns true for alpha channel regardless of flag state', () => {
+    setReleaseChannel('alpha')
+    expect(isFeatureEnabled('any_flag')).toBe(true)
+    expect(isFeatureEnabled('nonexistent_flag')).toBe(true)
+  })
+
+  it('returns false for stable channel when PostHog is not initialized', () => {
+    setReleaseChannel('stable')
+    expect(isFeatureEnabled('some_flag')).toBe(false)
+  })
+
+  it('returns false for beta channel when PostHog is not initialized', () => {
+    setReleaseChannel('beta')
+    expect(isFeatureEnabled('some_flag')).toBe(false)
+  })
+})

src/lib/telemetry.ts

@@ -1,4 +1,4 @@
-import * as Sentry from '@sentry/browser'
+import * as Sentry from '@sentry/react'
 
 const SENTRY_DSN = import.meta.env.VITE_SENTRY_DSN ?? ''
 const POSTHOG_KEY = import.meta.env.VITE_POSTHOG_KEY ?? ''
@@ -40,7 +40,7 @@ export function teardownSentry(): void {
   sentryInitialized = false
 }
 
-export async function initPostHog(anonymousId: string): Promise<void> {
+export async function initPostHog(anonymousId: string, releaseChannel?: string): Promise<void> {
   if (posthogInstance || !POSTHOG_KEY) return
   const posthog = (await import('posthog-js')).default
   posthog.init(POSTHOG_KEY, {
@@ -50,7 +50,7 @@ export async function initPostHog(anonymousId: string): Promise<void> {
     persistence: 'memory',
     disable_session_recording: true,
   })
-  posthog.identify(anonymousId)
+  posthog.identify(anonymousId, releaseChannel ? { release_channel: releaseChannel } : undefined)
   posthogInstance = posthog
 }
 
@@ -61,6 +61,24 @@ export function teardownPostHog(): void {
   posthogInstance = null
 }
 
+export function updatePostHogIdentify(releaseChannel: string): void {
+  posthogInstance?.identify(undefined, { release_channel: releaseChannel })
+}
+
+/** Hardcoded defaults for first launch with no network (PostHog cache empty). */
+const FEATURE_DEFAULTS: Record<string, boolean> = {}
+
+let currentReleaseChannel: string = 'stable'
+
+export function setReleaseChannel(channel: string): void {
+  currentReleaseChannel = channel
+}
+
+export function isFeatureEnabled(flagKey: string): boolean {
+  if (currentReleaseChannel === 'alpha') return true
+  return posthogInstance?.isFeatureEnabled(flagKey) ?? FEATURE_DEFAULTS[flagKey] ?? false
+}
+
 export function trackEvent(name: string, properties?: Record<string, string | number>): void {
   posthogInstance?.capture(name, properties)
 }

src/mock-tauri/mock-handlers.ts

@@ -85,6 +85,7 @@ let mockSettings: Settings = {
   analytics_enabled: null,
   anonymous_id: null,
   update_channel: null,
+  release_channel: null,
 }
 
 let mockLastVaultPath: string | null = null
@@ -210,6 +211,7 @@ export const mockHandlers: Record<string, (args: any) => any> = {
       analytics_enabled: s.analytics_enabled,
       anonymous_id: s.anonymous_id,
       update_channel: s.update_channel,
+      release_channel: s.release_channel,
     }
     return null
   },

src/types.ts

@@ -80,6 +80,7 @@ export interface Settings {
   analytics_enabled: boolean | null
   anonymous_id: string | null
   update_channel: string | null
+  release_channel: string | null
 }
 
 export interface GitPullResult {