Authoritative Feature Parity Matrix v0.9.1

Last Updated: 2026-02-08 Document Purpose: Map feature parity across 6 competitor platforms (WhatsApp, Telegram, Signal, Discord, Slack, Rocket.Chat) to nself-chat implementation tasks with explicit acceptance criteria.

Key Principle: Every row describes a feature behavior that exists in at least one competitor. Each task ID references the specific .claude/TODO.md work item. Acceptance tests are deterministic, non-flaky, and platform-specific.

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Table of Contents

1. Authentication & Account Security
2. Core Messaging
3. Channels & Organization
4. Direct Messaging & Contacts
5. Calls & Real-time Communication
6. Media & Files
7. Search & Discovery
8. Moderation & Trust & Safety
9. Security & Privacy (E2EE)
10. Integrations & Bots
11. Monetization & Access Control
12. Compliance & Governance

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Authentication & Account Security

User Registration & Account Creation

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Phone-number registration	✅ Required	✅ Required	✅ Required	❌ No	❌ No	❌ No	31	User registers via +1 area code, SMS OTP verification succeeds, account created with phone as identifier
Email + password registration	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	✅ Yes	31	User registers with [email protected], password set, login succeeds with email+pass
Magic link / passwordless email	❌ No	❌ No	✅ Available	✅ Available	✅ Available	✅ Available	31	User enters email, receives link, clicks link, session created without password
OAuth / Single Sign-On	❌ No	❌ No	❌ No	✅ Google/GitHub	✅ Google/GitHub/SAML	✅ SAML/OpenID	21, 31	User clicks "Sign in with Google", OAuth flow completes, account linked, login succeeds
Two-Factor Authentication (TOTP)	❌ No	✅ Optional	✅ Required	✅ Optional	✅ Optional	✅ Optional	23, 80	User enables TOTP, QR code scannable by authenticator app, time-based token validates on login
Backup codes for 2FA recovery	❌ No	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	80	User generates 10 backup codes, saves them, uses one during 2FA challenge, code invalidated
Device registration & device list	❌ No	✅ Active sessions list	✅ Linked devices	✅ Sessions	✅ Sessions	✅ Sessions	31	User signs in on Device A, Device B; device list shows both with last-seen timestamp; user can revoke Device B
Session timeout & auto-logout	✅ 30 days	✅ Configurable	✅ Configurable	✅ 30 days	✅ 30 days	✅ Configurable	31	User logs in, waits for inactivity threshold (configurable), automatic logout triggers, re-auth required
Remember device (skip 2FA on trusted device)	❌ No	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	80	After 2FA success on Device A, user can mark "trust 30 days", subsequent logins skip 2FA on that device

Profile & Account Management

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Profile photo (avatar)	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	32	User uploads JPG avatar, avatar displays in all chat contexts, change propagates across clients within 2s
Profile bio / status message	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	32	User sets bio to "📍 NYC", displays in profile card, emoji renders correctly, max 160 chars enforced
Username / display name	✅ Optional	✅ Required	✅ No unique	❌ Unique username	✅ Unique	✅ Unique	32	Telegram: user sets username @alice, search finds by @alice, no dupes allowed; Discord: unique username enforced by server
Account visibility (private/public)	✅ Privacy modes	✅ Yes	✅ Yes (privacy presets)	✅ No	✅ Workspace-only	✅ Yes	32, 85	User toggles "Allow strangers to find me", search/profile visibility changes; old setting respects toggle within 1s
Profile photo history / gallery	❌ No	❌ No	❌ No	❌ No	✅ Yes	❌ No	32	Slack: user's past 10 profile photos are queryable via /list profile-photos; photos retain timestamp
Account deletion (GDPR right to be forgotten)	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	69	User requests account deletion, all messages/media purged, account locked, deletion confirmed via email
Username change/rename policy	✅ Anytime	✅ Once per 7d	✅ No rename	❌ Unique, can change	✅ Unique, can change	✅ Can change	32	Telegram: rename throttled to 1 per week per user; Discord: rename allowed anytime; nChat enforces preset policy

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Core Messaging

Message Types & Rich Content

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Text messages (UTF-8 / emoji)	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	36	User sends "Hello 🌍 العربية 中文", message stored, retrieved, emoji/RTL renders correctly on all clients
Message formatting (bold/italic/code/strikethrough)	❌ No	✅ Yes (Markdown)	❌ No	✅ Yes (rich text)	✅ Yes (Markdown)	✅ Yes (Markdown)	36	User sends *bold* _italic_ code ~strike~, rendering matches sender intent on all clients within 1s
Code block with syntax highlighting	❌ No	✅ Yes	❌ No	✅ Yes	✅ Yes	✅ Yes	36	User sends triple-backtick block with javascript language tag, syntax highlighting applies, copy preserves formatting
Quotes / reply-to message	❌ No	✅ Yes	✅ Yes	✅ Yes (with context)	✅ Yes	✅ Yes	36, 47	User replies to message M1, reply shows "replying to M1 text", tapping reply navigates to M1, reply survives M1 edit/deletion
Message forwarding	✅ Yes	✅ Yes	✅ Yes	❌ No	❌ No	✅ Yes	36	User forwards M1 to new channel, forwarded message shows "Forwarded from X", sender attribution preserved
Pinned messages	✅ Yes	✅ Yes	✅ Yes	✅ Yes (per-channel)	✅ Yes	✅ Yes	39	User pins M1 in channel, pin count updates, pinned messages list accessible, only channel mods can pin
Starred / Saved messages (personal)	❌ "Starred" not common	✅ Saved	✅ Saved	❌ No	✅ Save to self	✅ Bookmarks	39	User saves M1, appears in personal "Saved" view, persists across sessions, only user can see
Message reactions / emoji reactions	✅ Yes	✅ Yes	✅ Yes	✅ Yes (multi-emoji)	✅ Yes	✅ Yes	38	User adds 👍 reaction to M1, reaction appears instantly, duplicate reactions from same user rejected, can remove
Thread / conversation branching	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	✅ Yes	35, 47	User replies in thread to M1, thread message does not appear in channel, thread unread count increments, reply notification sent to thread subscribers
Poll messages	❌ No	✅ Yes	❌ No	✅ Yes	✅ Yes	✅ Yes	36	User creates poll "Lunch spot?" with options ["Tacos", "Pizza"], options render, votes tallied, results update real-time

Message Actions & State

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Edit message (with history)	✅ Yes, shows "(edited)"	✅ Yes, edit history	✅ Yes, shows edit time	✅ Yes	✅ Yes	✅ Yes	37	User edits M1, message shows "(edited)", edit window is configurable per preset, old version queryable in history
Delete message (self only)	✅ Yes (1hr window)	✅ Yes (any time)	✅ Yes (1hr default)	✅ Yes (2wk window)	✅ Yes (no limit for self)	✅ Yes	37	User deletes M1 within window, message removed from channel for all users, deletion audit logged, notification sent to viewers
Delete message for everyone	✅ Yes (1min)	❌ No	✅ Yes	❌ No	❌ No	✅ Yes	37	WhatsApp: user deletes M1 within 1 minute, disappears from all recipients; nChat respects per-preset delete window
Undo / message recall	❌ No	❌ No	❌ No	❌ No	✅ Undo in composer	❌ No	37	Slack: user types message, hits Undo key, message text reverts before send; nChat supports per-preset
Read receipts (1-check, 2-check, 3-check)	✅ Yes (double-blue)	✅ Yes	✅ Yes	✅ Yes (implicit seen)	✅ Yes	✅ Yes	46	Message shows 1 check (sent), 2 checks (delivered), 3 checks (read); user can disable per preset in privacy settings
Typing indicators	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	46	User A types in channel, "User A is typing..." appears for other users, indicator hides after 3s inactivity
Message delivery state (pending/sent/delivered/read)	✅ All 4 states	✅ All 4 states	✅ All 4 states	✅ Implicit	✅ Implicit	✅ All states	37, 46	Message queued locally (pending), sent to server (sent), reaches recipient (delivered), viewed (read); icon changes per state

Message Scheduling & Reminders

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Scheduled send (send later)	❌ No	✅ Yes (custom time)	❌ No	❌ No	✅ Yes (workflow)	✅ Yes	45	User schedules message for "2026-02-09 09:00 UTC", message appears at exact time in channel, timezone applied correctly
Edit scheduled message	❌ No	✅ Yes	❌ No	❌ No	❌ No	✅ Yes	45	User edits scheduled message text before send time, updated text sent at scheduled time
Cancel scheduled message	❌ No	✅ Yes	❌ No	❌ No	❌ No	✅ Yes	45	User cancels scheduled message, does not send, removed from scheduled list
Message reminders / notification scheduling	❌ No	❌ No	❌ No	❌ No	✅ Remind me feature	✅ Reminders plugin	45	Slack: user clicks "Remind me about this", reminder sent at specified time, clicking reminder navigates to message

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Channels & Organization

Channel Types & Hierarchy

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Public channels (discoverable)	❌ No	✅ Yes (@channel_name)	❌ No	✅ Yes (#channel)	✅ Yes (#channel)	✅ Yes	34, 35	User searches for public channel, finds it, joins, can post if permissions allow, discovery respects age/category filters
Private channels (invite-only)	✅ Group creation	✅ Yes (private groups)	✅ Group creation	✅ Yes (#private)	✅ Yes (#private)	✅ Yes	34, 35	User creates private channel, invites members, non-members cannot see/search, invite link controls who can join
Direct messages (1-on-1)	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	34	User DMs contact, conversation persists, messages encrypted by default, DM list shows unread count
Group chats (3-50 members)	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes (channels)	✅ Yes	34	User creates group chat with 5 people, group name settable, group photo settable, member list visible to all
Supergroups / Large groups (50+ members)	❌ WhatsApp groups max ~256	✅ Yes (100k+)	❌ No	✅ Guilds (100k+)	✅ Workspaces (1000k+)	✅ Rooms (unlimited)	34	Telegram: creates supergroup, 1000 members join, message performance stable, moderation tools available
Communities / Server meta-hierarchy	✅ Yes (Communities)	✅ Yes (Topics in supergroups)	❌ No	✅ Yes (Guild)	✅ Yes (Workspace)	✅ Yes (Teams)	34, 35, 62	Discord: creates Guild, adds Channels, Channel Folders; User navigates hierarchy, unread counts per category
Channel categories / folders	❌ No	✅ Yes (Topics)	❌ No	✅ Yes (Category)	❌ No	✅ Yes	35	User organizes 10 channels into "Projects" folder, folder collapses/expands, unread count aggregates
Archived channels	✅ Yes	✅ Yes	❌ No	✅ Yes	✅ Yes	✅ Yes	35, 63	User archives channel, channel hidden from main list, accessible from "Archived Channels" view, read-only for non-owners
Channel topics / channel descriptions	✅ Group desc	✅ Yes	✅ Yes	✅ Yes (#topic)	✅ Yes (channel topic)	✅ Yes	35	User sets channel description to "Q&A for #projects", description appears in channel header, updatable by mods

Channel Governance & Roles

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Member list / roster	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	35, 61	User opens channel member list, sees all members, member count accurate, last-seen timestamp visible
Member joining / invitation flow	✅ Yes	✅ Yes	✅ Yes	✅ Invite link	✅ Invite link/email	✅ Invite link	35	User generates invite link with expiry, shares it, recipient clicks link, joins channel, link expires after 7d
Member roles (owner, admin, moderator, member)	✅ Admin/regular	✅ Administrator/Restricted/Member	❌ Admin/regular	✅ Owner/Mod/Member	✅ Owner/Admin/Member	✅ Owner/Moderator/Member	35, 61	User promotes @alice to moderator, @alice can mute/kick users, @alice cannot delete channel, role changes audited
Permission matrix (who can post/edit/pin/mute/delete)	✅ Yes	✅ Yes	✅ Yes	✅ Fine-grained	✅ Fine-grained	✅ Fine-grained	61	Admin toggles "Only mods can post", member attempts to post, rejected with permission error, error message helpful
Mute channel / notification settings per channel	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	46, 122	User mutes #general, no notifications, channel marked muted in sidebar, unmuting re-enables notifications
Default channel (onboarding members to #welcome)	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	✅ Yes	63	New team member auto-added to #welcome, sees pinned onboarding messages, can leave if desired
Member request to join (pending approval)	❌ No	❌ No	❌ No	✅ Yes	✅ No	✅ Yes	35	Rocket.Chat: user requests to join private channel, owner/mod sees pending request, approves, member joins

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Direct Messaging & Contacts

Contact Management

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Import contacts from phone/address book	✅ Yes	✅ Yes	✅ Yes	❌ No	❌ No	❌ No	33	User grants contacts permission, WhatsApp shows "Contacts with WhatsApp", user can start DM with matched contact
Contact discovery via phone/email	✅ Phone match	✅ Phone/username	✅ Phone	❌ Username	✅ Email	✅ Email	33	User searches for "+1-555-0123" in Signal, finds linked user, can start DM, privacy mode respected
Block contact / blocklist	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	33	User blocks @bob, @bob cannot message user, cannot see user in search, blocked list is queryable by user
Unblock contact / manage blocklist	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	33	User unblocks @bob, @bob can message again, appears in search, unblock is silent (no notification sent)
Invite contact (not yet user)	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	33	User invites contact via SMS/email, contact receives invite with download link, join succeeds, contact auto-added to user's list
Hide DM conversations	✅ Yes	✅ Yes	✅ Yes	✅ Archive (implicit)	✅ Close	✅ Yes	34	User hides DM with @charlie, DM moves to "Hidden", user can view hidden list and restore, messages still received
Mute DM notifications	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	46	User mutes DM with @dave, no notifications, DM still visible in list but marked muted, unmuting re-enables notifications
DM request / message request (optional)	✅ Yes (Optional)	❌ No	✅ Message requests	✅ No	✅ No	✅ Yes	34	Signal: user has unknown sender message in "Message Requests", user can accept (move to inbox) or decline (delete)

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Calls & Real-time Communication

Voice & Video Calls

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
1-on-1 voice call	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	51	User A calls User B, B receives call notification, B answers, both hear each other clearly, call can be ended by either
1-on-1 video call	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	51	User A video calls User B, video stream renders, audio/video sync within 100ms, front/back camera toggle works
Group voice call (3+ people)	✅ Yes	✅ Yes (VoIP)	❌ Not multi	✅ Yes	✅ Yes	✅ Yes	52	5 users join voice call, all hear each other, speaker indicator shows active speaker, one user leaves, remaining 4 stay connected
Group video call	✅ Yes (mobile)	✅ Yes	❌ Not multi	✅ Yes	✅ Yes	✅ Yes	52	4 users join video call, grid layout shows 4 videos, focus on speaker, video paused by one user, playback performance stable
Screen share	✅ iOS only	✅ Yes	❌ No	✅ Yes	✅ Yes	✅ Yes	53	User A shares screen, User B sees desktop/app, A can stop share, B can capture screenshot (with/without permission per preset)
Virtual backgrounds	✅ iOS/Android	✅ No	❌ No	✅ Yes (Discord Nitro)	✅ Yes	✅ Yes	53	User uploads custom background image, background applies to video, camera feed blends correctly, performance stable at 30fps
Mute/unmute during call	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	51, 52	User mutes, audio stream stops, "muted" indicator shows to other users, user can unmute anytime, unmute successful within 200ms
Camera on/off toggle	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	51, 52	User disables camera, video feed blacks out, indicator shows "camera off", other users notified, user can re-enable anytime
Call recording	✅ Yes (by default)	✅ Yes (notify)	✅ Manual	✅ Yes (server-side)	✅ Yes (by permission)	✅ Yes	58	Call recorded, both parties notified at start, recording stored securely, ACL controls who can access, deletion respects retention policy
Call history / call log	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	51, 52	User opens call history, sees past calls with timestamp/duration/participants, can re-call, call log persists across devices within SLA

Stage Channels & Live Events (Discord/Slack/Rocket.Chat)

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Stage channels (listener/speaker modes)	❌ No	❌ No	❌ No	✅ Yes	❌ No	✅ Yes	54	Discord: 100 listeners, 5 speakers in stage channel, listener requests to speak (raise hand), speaker approves, new speaker joins unmuted
Host/mod controls (mute/remove speakers)	❌ No	❌ No	❌ No	✅ Yes	❌ No	✅ Yes	54	Host mutes disruptive speaker, speaker audio muted for all, speaker notified, speaker can request unmute via raise hand
Raise hand feature	❌ No	❌ No	❌ No	✅ Yes	❌ No	✅ Yes	54	Listener raises hand, notification sent to host, host sees hand-raise queue, host can promote listener or dismiss
Live chat alongside stage	❌ No	❌ No	❌ No	✅ Yes	✅ Huddle chat	✅ Yes	54, 55	Chat messages appear in side panel alongside stage video, chat persists after stage ends, searchable

Huddles & Lightweight Calls (Slack)

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Huddle (quick video call from DM/channel)	❌ No	❌ No	❌ No	❌ No	✅ Yes	❌ No	55	Slack: user clicks "Huddle" button in #general, video call starts instantly for channel members who join, can share screen, low latency (<500ms)

Livestream & Webcast (Telegram/Rocket.Chat)

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Livestream to channel / webcast	❌ No	✅ Yes (Live Event)	❌ No	❌ No	❌ No	✅ Yes	57	Telegram: user starts livestream in channel, viewers join from chat, viewer count updates, streamer can end/suspend, recording available
Viewer reactions during livestream	❌ No	✅ Yes	❌ No	❌ No	❌ No	✅ Yes	57	Viewers send emoji reactions, reactions appear in stream UI with counts, streamer can mute reactions, reactions logged
Live chat during broadcast	❌ No	✅ Yes	❌ No	❌ No	❌ No	✅ Yes	57	Chat messages appear alongside broadcast, streamer can read/respond, slow chat mode available, message moderation tools available

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Media & Files

Image & Photo Handling

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Image upload (JPG/PNG/GIF/WebP)	✅ All	✅ All	✅ All	✅ All	✅ All	✅ All	42	User uploads 5MB JPG, thumbnail generated, image appears in chat, original quality preserved in download
Image compression on send	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	42	User uploads 50MB uncompressed image, sent at optimized size (~5MB), quality acceptable, EXIF metadata stripped
Inline image preview	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	42	User sends image, preview appears in message, clicking preview opens full-screen viewer, swipe navigation works
Gallery / shared media browser	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	42, 121	User opens "Shared Media" in channel, browses all images/videos chronologically, search by date/keyword, download/delete from gallery
Pinch-to-zoom and full-screen viewer	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	43	User views image, pinches to zoom (mobile), rotates phone to landscape, zoom persists, swipe navigates next image
Image reactions / sticker reactions	✅ Yes (limited)	✅ Stickers	✅ Yes	✅ Custom emojis	✅ Custom reactions	✅ Custom reactions	38, 42	User adds sticker reaction to image message, sticker appears below message, sticker pack preview available

Video & Audio Handling

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Video upload & inline playback	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	42	User uploads 100MB MP4 video, thumbnail generated, inline player appears, playback controls (play/pause/seek) work
Video transcoding (format conversion)	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	42	User uploads MOV from iPhone, transcoded to H.264/AAC MP4, playback works on all devices, bitrate adaptive per connection
Video download & offline access	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	48	User downloads video via "Save Video" option, available in offline mode, playback works without network
Streaming video without full download	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	42	User plays video, streaming begins at 5MB buffer, seeking works within buffered range, bandwidth adaptive
Audio file upload	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	42	User uploads MP3/WAV/M4A audio file, player appears with title/artist, playback 0-100% works
Voice message / audio recording	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	42	User records voice memo (3min), waveform appears, recipient can play/pause/seek, download optional
Automatic audio transcription	❌ No	❌ No	❌ No	❌ No	✅ Yes (Slack AI)	❌ No	42	Slack: voice message auto-transcribed, transcript appears below audio, searchable via transcript text

Document & File Handling

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
File upload (PDF/DOC/ZIP)	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	42	User uploads 50MB ZIP file, file link appears, recipient can download, file preview available if supported format
PDF preview & annotation	❌ No	✅ Yes	❌ No	❌ No	✅ Yes	✅ Yes	42	Slack: user uploads PDF, preview shows page 1, user can navigate pages, annotation tools available
Document metadata extraction	❌ No	✅ Yes	❌ No	✅ Yes	✅ Yes	✅ Yes	42	File preview shows name/size/upload-time, shared media browser shows document thumbnail, searchable by filename
Virus scanning for file uploads	❌ Basic	✅ Yes (ClamAV)	✅ Yes	✅ Yes (VirusTotal)	✅ Yes	✅ Yes	19	User uploads potentially malicious file, scanner detects, file quarantined, notification sent, safe files proceed to storage
EXIF metadata stripping (image privacy)	✅ Yes (auto)	✅ Yes (option)	✅ Yes	✅ Yes	✅ Yes	✅ Yes	20	User uploads image with GPS EXIF data, server strips EXIF, image stored without location metadata, recipient sees image only
File size limits & quota	✅ Yes (per preset)	✅ Yes (2GB file)	✅ Yes	✅ Yes (8MB free)	✅ Yes (quota)	✅ Yes	42	User attempts to upload 100MB file when limit is 50MB, upload rejected, error message shows remaining quota
File sharing expiry / ephemeral files	❌ No	✅ Yes (timer)	❌ No	❌ No	❌ No	❌ No	42	Telegram: file shared with expiry, recipient can download, after expiry link broken, file deleted server-side

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Search & Discovery

Message Search

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Full-text message search	✅ Yes	✅ Yes	✅ Yes (local only)	✅ Yes	✅ Yes	✅ Yes	41, 22	User searches "product launch", results show matching messages with context, results ranked by relevance, sort by date/sender
Search filters (by user/channel/date)	✅ Yes	✅ Yes	✅ Yes	✅ Yes (advanced)	✅ Yes (advanced)	✅ Yes	41, 22	User searches "from:@alice since:2026-01-01 #general", results filtered, advanced syntax documented in help
Saved searches / search history	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	✅ Yes	41	Discord: user saves search "author:@bob", appears in saved list, one-click re-run, 10 saved max
Semantic search (AI-assisted)	❌ No	❌ No	❌ No	❌ No	✅ Slack AI	❌ No	41	Slack: user searches "things we discussed about pricing", results use semantic similarity, not just keyword match
Media-only search	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	41, 42	User searches in #general with "media:image" filter, returns images only, pagination works, download bulk available
Command/code search	❌ No	❌ No	❌ No	❌ No	✅ Yes (code snippets)	✅ Yes	41	Slack: search for code blocks, results syntax-highlighted, one-click copy

Link Preview & Unfurling

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
URL preview / link unfurling	✅ Yes	✅ Yes	❌ No	✅ Yes	✅ Yes	✅ Yes	44	User pastes "https://example.com/page", preview appears with title/description/image, preview non-intrusive
Rich embeds (video/audio/iframe)	❌ Limited	✅ Yes (YouTube/etc)	❌ No	✅ Yes (YouTube)	✅ Yes (many)	✅ Yes	44	User pastes YouTube link, embedded video player appears, playback works without leaving chat, volume controls available
Per-domain preview rules / domain blocklist	❌ No	❌ No	❌ No	❌ No	✅ Yes (admin)	✅ Yes	44	Admin disables previews for domain.com, links to domain.com show URL only, previews for other domains unaffected
Security scan for links	❌ Basic	✅ Yes (safe browsing)	❌ No	✅ Yes	✅ Yes (Google Safe)	✅ Yes	44	User clicks link to phishing site, warning shown, user can proceed with caution or cancel, warning non-blocking

User & Channel Discovery

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
User directory search	✅ Contacts	✅ Yes	✅ Contacts	✅ Yes	✅ Yes	✅ Yes	41, 33	User searches for "@alice", finds user profile, can click to open chat or view profile, exact match prioritized
Channel directory & discovery	❌ No	✅ Yes	❌ No	✅ Yes	✅ Yes	✅ Yes	41, 35	User browses public channels, sorts by members/activity, channel description and member count visible, one-click join
Trending channels / popular content	❌ No	❌ No	❌ No	❌ No	✅ Yes	❌ No	41	Slack: trending tab shows popular channels by activity/members, helps discovery for new users
Command palette (Cmd+K)	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	✅ Yes	41	User presses Cmd+K, fuzzy search appears, searches channels/users/commands, Enter navigates or executes, ESC closes

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Moderation & Trust & Safety

Content Moderation

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Report message / content flagging	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	64	User right-clicks message, selects "Report", reason selected (spam/hate/harassment), submitted to mods, notification sent
Auto-moderation (profanity filter)	❌ No	❌ No	❌ No	✅ Optional	✅ Optional	✅ Yes	65	Moderator enables auto-mod profanity filter, user posts slur, message auto-deleted or flagged, user warned
Spam detection & auto-action	❌ No	✅ Yes	❌ No	✅ Yes	✅ Yes	✅ Yes	65	User rapid-posts 100 messages, spam detector triggers, user muted for 10min, messages suppressed from channel, admin notified
Rate limiting (per-user per-channel)	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	✅ Yes	65	User attempts to post 10 messages/sec, rate limit kicks in, posts queued or rejected with "slow down" error
Message deletion by moderator	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	64, 37	Moderator deletes user's message, message removed from channel for all, deletion logged in moderation audit
User mute / silence (in channel)	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	64	Moderator mutes user @bob in #general, @bob cannot post to #general, can still read/react, mute duration settable
Slowmode (cooldown between posts)	✅ No	❌ No	❌ No	✅ Yes	✅ Yes	✅ Yes	64	Admin enables slowmode 60sec in #announcements, users must wait 60sec between posts, timer shown in composer
User kick / temporary ban	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	64	Moderator kicks user @eve from channel, @eve removed, can rejoin if invited, kick logged
User ban / permanent ban	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	64	Admin bans user @frank from workspace, @frank cannot join/post, ban list queryable, unban available
Ban appeals / moderation appeal process	❌ No	❌ No	❌ No	✅ Optional	❌ No	✅ Yes	64	User banned for "spam", submits appeal with explanation, moderator reviews, decision logged, user notified

Trust & Safety Evidence

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Evidence collection / moderation evidence logs	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	✅ Yes	66	Moderator submits report with evidence (message link, context), report stored immutably, appeal referenced to evidence, tamper-evident
Audit trail for moderation actions	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	✅ Yes	67	Moderator views moderation log, shows "User @bob muted in #general at 2026-02-08 10:30 UTC by @alice", reason logged
Legal hold / evidence preservation	❌ No	❌ No	❌ No	❌ No	✅ Yes (Compliance)	✅ Yes	66	Admin marks channel for legal hold, messages cannot be deleted, deletion attempts blocked, hold logged
Trust & safety escalation workflow	❌ No	❌ No	❌ No	❌ No	❌ No	✅ Yes	64	Moderator escalates report to T&S team, report automatically forwarded, ticket created, SLA enforcement available

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Security & Privacy (E2EE)

Encryption at Rest

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
End-to-end encryption (default for all messages)	✅ Yes	❌ Optional (Secret Chat)	✅ Yes	❌ No	❌ No	✅ Optional	75, 76	WhatsApp: message sent, plaintext never reaches server, recipient decrypts with private key, wiretap reveals ciphertext only
E2EE for groups	✅ Yes	❌ No	✅ Yes	❌ No	❌ No	✅ Optional	76	Group chat with 5 members, all messages E2EE, member joins/leaves, keys rekey automatically, no future content leaked
E2EE for media/attachments	✅ Yes	❌ No (Secret Chat)	✅ Yes	❌ No	❌ No	✅ Optional	77	User sends encrypted image, server stores ciphertext, recipient decrypts client-side, metadata minimized
Forward secrecy / Perfect forward secrecy	✅ Yes (Double Ratchet)	❌ No	✅ Yes (Signal Protocol)	❌ No	❌ No	✅ Yes (optional)	75, 76	Device A sends M1, Device A's key compromised, M1 unrecoverable, future messages M2+ also secure, historical M0 compromised
Encryption key rotation / rekeying	✅ Automatic	✅ No	✅ Automatic	❌ No	❌ No	✅ Configurable	74	User A and User B in E2EE chat, keys rotate per message, old keys destroyed, compromise window minimized per message

Identity Verification

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Safety numbers / verification fingerprints	✅ Yes (60-digit)	✅ Yes (optional)	✅ Yes (QR/fingerprint)	❌ No	❌ No	✅ Optional	79	Signal: user opens safety number for contact, displays QR code, user scans peer's QR with their phone, both see "numbers match"
Verification warnings (number changed)	✅ Yes	✅ Yes	✅ Yes	❌ No	❌ No	✅ Yes	79	Contact's E2EE key changes unexpectedly, system warns "safety number changed", user can verify new key or distrust
Verified badge / trust state UI	❌ No	❌ No	❌ No	❌ No	❌ No	❌ No	79	nChat: verified contact shows checkmark badge in contact card, unverified users show caution icon, verification UI intuitively distinguishes states

Recovery & Backup

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Encrypted backup & restore	✅ Yes	❌ No	✅ Yes	❌ No	❌ No	✅ Yes	78	User creates encrypted backup with passphrase, backup stored encrypted on cloud, restore on new device with passphrase succeeds
Recovery lock / registration lock	✅ No	❌ No	✅ Yes	❌ No	❌ No	❌ No	80	Signal: user enables registration lock with PIN, SIM swap attacker cannot create new account with same phone number without PIN
Backup codes / account recovery codes	❌ No	❌ No	✅ Yes	❌ No	❌ No	❌ No	80	User enables backup codes, downloads/prints codes, stores securely, uses code to recover account if phone lost, code invalidated post-use
Device verification for backup restore	✅ Yes	❌ No	✅ Yes	❌ No	❌ No	✅ Yes	78	User restores from backup on new device, backup decryption requires device verification code, attacker with backup cannot restore without code

Session & Account Security

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Local app lock (PIN/biometric)	✅ Yes	✅ Yes	✅ Yes	❌ No	✅ Optional (mobile)	✅ Yes	81	User sets app lock PIN, reopening app requires PIN, biometric fallback available, inactivity timeout enforces re-lock (5min default)
Panic mode / emergency wipe	❌ No	❌ No	✅ Yes	❌ No	❌ No	❌ No	82	Signal: user enters panic PIN (different from lock PIN), app appears to unlock normally but wipes all messages/keys, device safe
Remote session wipe	❌ No	✅ Yes	✅ Yes	❌ No	✅ Yes (logout all)	✅ Yes	82	User's account compromised, user logs in on secure device, wipes all sessions remotely, compromised device auto-logs out, no local data accessible
Session timeout on lock screen	✅ Yes	✅ Yes	✅ Yes	❌ No	✅ Yes	✅ Yes	31	User locks phone, app session expires after 15min (configurable), re-unlock requires password, unencrypted cache cleared

Transport Security & Infrastructure

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
TLS 1.3 for transport	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	83	Network sniffer cannot decrypt messages in flight, TLS version verified by client (reject TLS <1.2), cipher suite modern (no RC4/MD5)
Certificate pinning	✅ Yes	✅ Yes	✅ Yes	❌ No	❌ No	✅ Optional	83	Attacker presents valid self-signed cert, app rejects handshake, cert pinning prevents MITM, fallback recovery documented
HSTS (HTTP Strict Transport Security)	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	83	Browser receives HSTS header, forces HTTPS for 1 year, http:// requests auto-redirect to https://, downgrade attacks blocked

Metadata & Privacy Controls

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Metadata minimization (reduce server-side data)	✅ Limited	❌ No	✅ Yes	❌ No	❌ No	✅ Optional	85	User disables metadata logging, server stores only timestamp/user-ID (no message content), deletion requests honored, server-logs privacy audit
Sealed sender / sender privacy mode	❌ No	❌ No	✅ Yes (optional)	❌ No	❌ No	❌ No	86	Signal: sender privacy enabled, recipient cannot see sender identity in transport layer (only E2EE decryption reveals), attacker-on-network sees user≠sender

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Integrations & Bots

Bot Framework & Lifecycle

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Bot accounts / bot user types	❌ No	✅ Yes (Bot API)	❌ No	✅ Yes	✅ Yes	✅ Yes	101, 104	Bot account created, appears in member list, can post/read/moderate, cannot log in, auth via token/API key
Slash commands / command registration	❌ No	✅ Yes (/command)	❌ No	✅ Yes (/command)	✅ Yes (/command)	✅ Yes	102	User types /weather NYC, command handler invoked, bot responds with forecast, command parameters validated, auth checked
Slash command options & autocomplete	❌ No	✅ Yes	❌ No	✅ Yes	✅ Yes	✅ Yes	102	User types /remind me in , autocomplete shows options (5min/1hr/tomorrow), user selects, command formatted correctly
Incoming webhooks	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	✅ Yes	103	Webhook URL generated, external service POSTs message payload to webhook, message appears in channel, signature verified
Outgoing webhooks	❌ No	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	103	User posts message in channel, trigger rule matches, webhook POSTs to external service, external service responds with action
Webhook retries & replay protection	❌ No	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	103	Webhook delivery fails, automatic retry with exponential backoff (3x), duplicate delivery detected by nonce, not replayed
Bot OAuth / app install flow	❌ No	✅ Yes	❌ No	✅ Yes	✅ Yes	✅ Yes	104	User clicks "Add to Discord", bot auth screen requests scopes (read:messages, post:messages), user approves, bot installed with granted scopes
Bot permission model / scopes	❌ No	✅ Yes	❌ No	✅ Yes (granular)	✅ Yes (granular)	✅ Yes	104	Bot requested read:messages and post:messages, bot cannot delete messages, attempting delete fails with "insufficient scope" error
Bot rate limiting / quotas	❌ No	✅ Yes	❌ No	✅ Yes	✅ Yes	✅ Yes	104	Bot rate-limited to 100 posts/min, exceeds limit, subsequent posts rejected with rate-limit error, quota resets hourly

Workflow Automation

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Workflow builder UI	❌ No	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	105	Slack: user opens workflow builder, drags trigger (message posted), action (send message), condition (if author=@bot), workflow saves, active
Workflow triggers (message/reaction/schedule)	❌ No	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	105	Workflow triggers on "reaction added" to message, runs action "send DM to user with summary", trigger fires <1s after reaction, audit logged
Workflow approvals	❌ No	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	105	Workflow action requires approval, approver receives notification, approves action, workflow continues, rejection blocks action and logs reason
Workflow scheduling / delayed actions	❌ No	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	105	Workflow action scheduled for "tomorrow at 9am", action executes at exact time, timezone applied correctly, can be cancelled before execution
Workflow error handling & retries	❌ No	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	105	Workflow action fails (API down), automatic retry 3x with exponential backoff, after retries exhausted, error notification sent, logged

External Integrations

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Slack workspace integration	❌ No	❌ No	❌ No	✅ Yes	✅ Native	❌ No	106	Rocket.Chat: connect to Slack workspace, channel bridging enabled, messages sync bidirectionally, reactions sync
GitHub integration (PR notifications)	❌ No	✅ Yes (via bot)	❌ No	✅ Yes	✅ Yes (native)	✅ Yes	106	User installs GitHub app, PR opened, notification posted in #github channel, PR details/link included, status updates sync
Google Calendar / meeting integration	❌ No	❌ No	❌ No	✅ Yes (via calendar app)	✅ Yes (calendar)	✅ Yes	106	Calendar event created, notification posted to channel, event details with join link included, RSVP sync to calendar
Jira issue tracking integration	❌ No	❌ No	❌ No	❌ No	✅ Yes (native)	✅ Yes	106	Jira issue created, notification posted in Slack, issue link clickable, status transitions notify channel, comments sync optional
Google Drive / file storage integration	❌ No	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	106	User shares Google Drive folder, preview appears in chat, file updates sync, collaborative editing link included

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Monetization & Access Control

Subscription & Billing Model

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Free tier	✅ Yes (forever)	✅ Yes (forever)	✅ Yes (forever)	✅ Yes	❌ 7-day trial	✅ Yes	91	User creates account, all features free, no prompts to upgrade unless feature is paywall-locked
Paid subscription tier (monthly)	❌ No	✅ Yes (Telegram Premium)	❌ No	❌ No	✅ Yes (Pro)	❌ No	92	User subscribes to Premium ($5/mo), monthly charge auto-renews on card, subscription active immediately, can cancel anytime
Trial period (free trial)	❌ No	✅ 7 days (Premium)	❌ No	❌ No	✅ 7 days (Pro)	❌ No	92	User starts Pro trial, 7-day countdown shown, trial expires, subscription auto-converts to paid (with payment method), can cancel before conversion
Proration (partial refund for mid-cycle upgrades)	❌ No	❌ No	❌ No	❌ No	✅ Yes	❌ No	92	User on Free tier, upgrades to Pro on day 5 of cycle, pro-rated charge = $5 * (25/30), next charge day 1 of new cycle
Graceful degradation (expired card)	❌ No	❌ No	❌ No	❌ No	✅ Yes	❌ No	92	User's subscription payment fails, user moves to "Past Due" state, limited features (no creation), payment retried, success re-enables features
One-time payments / credits	❌ No	✅ Yes (in-app purchases)	❌ No	❌ No	❌ No	❌ No	91	Telegram: user purchases emoji pack for $0.99 via one-time IAP, emoji available immediately, not recurring
Usage-metered billing (overage charges)	❌ No	❌ No	❌ No	❌ No	✅ Yes (per workspace overage)	❌ No	93	User on Pro plan with 100 seats, adds 110 members, overage charges $5/seat/month, next invoice includes overage

Feature Paywall & Entitlements

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Feature gating by plan	❌ No	✅ Yes (Premium features)	❌ No	❌ No	✅ Yes (Pro features)	❌ No	94, 91	Telegram Premium: advanced search available, free users see "upgrade to unlock" hint, clicking navigates to Premium offer
Role-based paywall enforcement	❌ No	❌ No	❌ No	✅ Yes (Nitro+ perks)	✅ Yes (admin features)	✅ Yes	94, 61	User attempts to create private channel without Pro, error "feature requires Pro", user can upgrade, after upgrade succeeds
Channel-level access control	❌ No	❌ No	❌ No	✅ Yes	✅ Yes (paid channels)	✅ Yes	94	Premium channel created, free users cannot join, join button shows "requires Pro", click redirects to upgrade, after purchase can join
Bypass for workspace owners	❌ No	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	94	Owner can use all features regardless of seat count, admin features unlimited, employees bound by their seat entitlement
Entitlement revocation (downgrade)	❌ No	❌ No	❌ No	❌ No	✅ Yes	❌ No	91	User on Pro downgrades to Free, advanced search disabled, user notified, chat history preserved, export available before loss

Crypto & Token-Gated Access

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Wallet connection (MetaMask / WalletConnect)	❌ No	❌ No	❌ No	❌ No	❌ No	❌ No	27	User clicks "Connect Wallet", WalletConnect flow opens, user approves in MetaMask, wallet address linked to account
Token-gated channel access	❌ No	❌ No	❌ No	❌ No	❌ No	❌ No	97	Channel requires 1 NFT from collection X, user clicks join, wallet checked for NFT holdings, access granted if met, revoked if holdings drop
NFT verification & proof-of-ownership	❌ No	❌ No	❌ No	❌ No	❌ No	❌ No	28	User claims NFT ownership, chain/collection/token ID verified, verified badge added to profile, can be revoked if transfer detected
Crypto payment for subscription	❌ No	❌ No	❌ No	❌ No	❌ No	❌ No	96	User subscribes to Pro with cryptocurrency, invoice generated, user transfers amount to address, payment detected <5 confirmations, subscription activated

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Compliance & Governance

Data Retention & Deletion

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Message retention policy (configurable)	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	68	Admin sets retention to "30 days", messages older than 30d auto-deleted, policy applies to all channels, exceptions creatable
Legal hold / preservation	❌ No	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	66, 68	Admin marks user for legal hold, all messages preserved indefinitely, deletion blocked, hold status logged
User data export (GDPR)	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	69	User requests GDPR export, system generates JSON/CSV of messages/metadata, downloaded within 30d, portable format
Right to be forgotten / account deletion	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	69	User requests deletion, account anonymized, all messages/metadata purged, deletion confirmed via email, no recovery possible
Data deletion confirmation & retention proof	❌ No	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	69	User deletes account, system generates deletion certificate with timestamp, audit log entry immutable, retention policy verified

Audit Logging & Compliance

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Admin audit log	✅ Yes	✅ Yes	❌ No	✅ Yes	✅ Yes	✅ Yes	67	Admin views audit log, shows "User @alice added to #general by @bob at 2026-02-08 10:30 UTC", 1-year retention, exportable
Security audit log	❌ No	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	67	Security team views log, shows "Suspicious login from 1.2.3.4 blocked", login attempts, 2FA challenges, all logged
Activity audit log (user actions)	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	✅ Yes	67	User activity logged: message posted, file uploaded, channel created, 90-day retention, queryable by user/timestamp/action
Audit log search & export	❌ No	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	67	Admin searches audit log "action=ban after:2026-02-01", results shown, selected logs exported as CSV for legal/compliance review
Immutable audit records	❌ No	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	66, 67	Audit logs append-only in database, no update/delete on records, tamper detection via cryptographic hash, evidence integrity preserved

Compliance Reporting

Feature	WhatsApp	Telegram	Signal	Discord	Slack	Rocket.Chat	Task ID(s)	Acceptance Test
Compliance export (CCPA/GDPR)	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	✅ Yes	69	GDPR/CCPA export includes user data, messages, metadata, account info, all structured as JSON/CSV, downloadable, attachments optional
Billing reconciliation reports	❌ No	❌ No	❌ No	❌ No	✅ Yes	✅ Yes	99	Finance team exports billing report: invoice count, MRR, ARPU, churn rate, matches accounting ledger, signed audit trail
Entitlement drift analysis	❌ No	❌ No	❌ No	❌ No	✅ Yes	❌ No	99	System detects users with features above entitlement (overage), flags for reconciliation, billing adjustment applied, notification sent

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Implementation Notes

Task ID Mapping

All task IDs reference .claude/TODO.md tasks 31-147 (Phase C through Release). Each acceptance test is deterministic and runnable in automated test suites.

Acceptance Test Properties

1. Deterministic: No wall-clock dependency, use fixed timestamps/IDs
2. Isolated: No external service calls without mocks
3. Idempotent: Repeat runs produce same result
4. Cross-platform: Works on web, mobile, desktop with platform-specific assertions
5. Auditable: Failure output includes file/line/timestamp for investigation

Preset-Specific Behavior

Behaviors differ by preset (WhatsApp/Telegram/Signal/Discord/Slack/Rocket.Chat). Each feature row indicates which platforms implement it, and nChat's implementation matches the selected preset exactly.

Key Assumptions

1. Task completion enables multi-preset support - Feature matrix applies to whichever presets nChat enables
2. Feature parity measured by preset semantics - E.g., Discord "stage channel" behavior differs from Slack "huddle", both in feature matrix
3. Security baseline applies to all presets - E2EE, audit logging, anti-abuse required universally (unless preset disables category)

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Next Steps

1. Review & validate this matrix with stakeholders and competitive research
2. Map coverage gaps - Identify features not yet in TODO.md, create new task IDs
3. Prioritize by preset - e.g., if "Signal preset" is priority, order Task IDs by Signal feature criticality
4. Dependency chain - Feed into Task 7 (dependency graph creation)

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Document Status: CANONICAL - All future parity claims must reference this matrix with evidence from TODO.md and test results.