directory: support public channels and relay-based groups (#6840)

* directory: support public channels and relay-based groups (plan) * types * amend types * directory types, resolve known link * implementation, test fails * fix test * fix test * more test * minimal test * more test * debug test * clean up * remove debug logs * refactor * use group/channel terms correctly * remove unsupported commands * manage profile update * owner left the channel * more tests, correct response to sent link * re-registration * /help and /link commands * correct listing for channels * fix test * fix bot api * refactor * do not include link data in GLPKnown * refactor * diff * undo refactor * simplify * remove harness test * remove flip * add v6.5 app requirement for channels * add website support * update bot api types * correct member count, fix test * members -> subscribers * add link to channel description * fix css * move version note --------- Co-authored-by: Evgeny @ SimpleX Chat <259188159+evgeny-simplex@users.noreply.github.com>
2026-07-03 19:51:56 +00:00 · 2026-04-23 13:30:26 +01:00
parent a3fde4daa1
commit f3547878cc
19 changed files with 999 additions and 198 deletions
@@ -33,10 +33,10 @@ import qualified Data.Text as T
 import Data.Text.Encoding (encodeUtf8)
 import Directory.Store
 import Simplex.Chat.Controller
-import Simplex.Chat.Markdown (displayNameTextP)
+import Simplex.Chat.Markdown (MarkdownList, displayNameTextP)
 import Simplex.Chat.Messages
 import Simplex.Chat.Messages.CIContent
-import Simplex.Chat.Protocol (MsgContent (..))
+import Simplex.Chat.Protocol (LinkOwnerSig, MsgChatLink, MsgContent (..))
 import Simplex.Chat.Types
 import Simplex.Chat.Types.Shared
 import Simplex.Messaging.Agent.Protocol (AgentErrorType (..))
@@ -57,6 +57,8 @@ data DirectoryEvent
  | DEContactLeftGroup ContactId GroupInfo
  | DEServiceRemovedFromGroup GroupInfo
  | DEGroupDeleted GroupInfo
+  | DEChatLinkReceived {contact :: Contact, chatItemId :: ChatItemId, chatLink :: MsgChatLink, ownerSig :: Maybe LinkOwnerSig}
+  | DEMemberUpdated {groupInfo :: GroupInfo, fromMember :: GroupMember, toMember :: GroupMember}
  | DEUnsupportedMessage Contact ChatItemId
  | DEItemEditIgnored Contact
  | DEItemDeleteIgnored Contact
@@ -91,11 +93,14 @@ crDirectoryEvent_ = \case
  CEvtLeftMember {groupInfo, member} -> (`DEContactLeftGroup` groupInfo) <$> memberContactId member
  CEvtDeletedMemberUser {groupInfo} -> Just $ DEServiceRemovedFromGroup groupInfo
  CEvtGroupDeleted {groupInfo} -> Just $ DEGroupDeleted groupInfo
+  CEvtUnknownMemberAnnounced {groupInfo, unknownMember, announcedMember} -> Just $ DEMemberUpdated {groupInfo, fromMember = unknownMember, toMember = announcedMember}
+  CEvtGroupMemberUpdated {groupInfo, fromMember, toMember} -> Just $ DEMemberUpdated {groupInfo, fromMember, toMember}
  CEvtChatItemUpdated {chatItem = AChatItem _ SMDRcv (DirectChat ct) _} -> Just $ DEItemEditIgnored ct
  CEvtChatItemsDeleted {chatItemDeletions = ((ChatItemDeletion (AChatItem _ SMDRcv (DirectChat ct) _) _) : _), byUser = False} -> Just $ DEItemDeleteIgnored ct
-  CEvtNewChatItems {chatItems = (AChatItem _ SMDRcv (DirectChat ct) ci@ChatItem {content = CIRcvMsgContent mc, meta = CIMeta {itemLive}}) : _} ->
+  CEvtNewChatItems {chatItems = (AChatItem _ SMDRcv (DirectChat ct) ci@ChatItem {content = CIRcvMsgContent mc, formattedText = ft, meta = CIMeta {itemLive}}) : _} ->
    Just $ case (mc, itemLive) of
-      (MCText t, Nothing) -> DEContactCommand ct ciId $ fromRight err $ A.parseOnly (directoryCmdP <* A.endOfInput) $ T.dropWhileEnd isSpace t
+      (MCText t, Nothing) -> DEContactCommand ct ciId $ fromRight err $ A.parseOnly (directoryCmdP ft <* A.endOfInput) $ T.dropWhileEnd isSpace t
+      (MCChat {chatLink, ownerSig}, Nothing) -> DEChatLinkReceived {contact = ct, chatItemId = ciId, chatLink, ownerSig}
      _ -> DEUnsupportedMessage ct ciId
    where
      ciId = chatItemId' ci
@@ -149,7 +154,7 @@ data DirectoryHelpSection = DHSRegistration | DHSCommands

 data DirectoryCmd (r :: DirectoryRole) where
  DCHelp :: DirectoryHelpSection -> DirectoryCmd 'DRUser
-  DCSearchGroup :: Text -> DirectoryCmd 'DRUser
+  DCSearchGroup :: Text -> Maybe MarkdownList -> DirectoryCmd 'DRUser
  DCSearchNext :: DirectoryCmd 'DRUser
  DCAllGroups :: DirectoryCmd 'DRUser
  DCRecentGroups :: DirectoryCmd 'DRUser
@@ -181,11 +186,11 @@ data ADirectoryCmd = forall r. ADC (SDirectoryRole r) (DirectoryCmd r)

 deriving instance Show ADirectoryCmd

-directoryCmdP :: Parser ADirectoryCmd
-directoryCmdP =
+directoryCmdP :: Maybe MarkdownList -> Parser ADirectoryCmd
+directoryCmdP ft =
  (A.char '/' *> cmdStrP)
    <|> (A.char '.' $> ADC SDRUser DCSearchNext)
-    <|> (ADC SDRUser . DCSearchGroup <$> A.takeText)
+    <|> (ADC SDRUser . (`DCSearchGroup` ft) <$> A.takeText)
  where
    cmdStrP =
      (tagP >>= \(ADCT u t) -> ADC u <$> (cmdP t <|> pure (DCCommandError t)))
@@ -304,7 +309,7 @@ directoryCmdP =
 directoryCmdTag :: DirectoryCmd r -> Text
 directoryCmdTag = \case
  DCHelp _ -> "help"
-  DCSearchGroup _ -> "search"
+  DCSearchGroup {} -> "search"
  DCSearchNext -> "next"
  DCAllGroups -> "all"
  DCRecentGroups -> "new"
@@ -27,7 +27,7 @@ import Data.List (isPrefixOf)
 import Data.Maybe (catMaybes, fromMaybe)
 import Data.Text (Text)
 import qualified Data.Text as T
-import Data.Text.Encoding (encodeUtf8)
+import Data.Text.Encoding (decodeUtf8, encodeUtf8)
 import Data.Time.Clock
 import Data.Time.Clock.System
 import Data.Time.Format.ISO8601 (iso8601Show)
@@ -53,16 +53,24 @@ listingImageFolder :: String
 listingImageFolder = "images"

 data DirectoryEntryType = DETGroup
-  { admission :: Maybe GroupMemberAdmission,
+  { groupType :: Maybe GroupType,
+    admission :: Maybe GroupMemberAdmission,
    summary :: GroupSummary
  }

 $(JQ.deriveJSON (taggedObjectJSON $ dropPrefix "DET") ''DirectoryEntryType)

+data PublicLink = PublicLink
+  { connFullLink :: Maybe ConnReqContact,
+    connShortLink :: Maybe ShortLinkContact
+  }
+
+$(JQ.deriveJSON defaultJSON ''PublicLink)
+
 data DirectoryEntry = DirectoryEntry
  { entryType :: DirectoryEntryType,
    displayName :: Text,
-    groupLink :: CreatedLinkContact,
+    groupLink :: PublicLink,
    shortDescr :: Maybe MarkdownList,
    welcomeMessage :: Maybe MarkdownList,
    imageFile :: Maybe String,
@@ -90,8 +98,15 @@ recentRoundedTime roundTo now t

 groupDirectoryEntry :: UTCTime -> GroupInfo -> Maybe GroupLink -> Maybe (DirectoryEntry, Maybe (FilePath, ImageFileData))
 groupDirectoryEntry now GroupInfo {groupProfile, chatTs, createdAt, groupSummary} gLink_ =
-  let GroupProfile {displayName, shortDescr, description, image, memberAdmission} = groupProfile
-      entryType = DETGroup memberAdmission groupSummary
+  let GroupProfile {displayName, shortDescr, description, image, memberAdmission, publicGroup} = groupProfile
+      gt = (\PublicGroupProfile {groupType} -> groupType) <$> publicGroup
+      entryType = DETGroup gt memberAdmission groupSummary
+      description' = case publicGroup of
+        Just PublicGroupProfile {groupType = gt', groupLink = sLnk} ->
+          let gtStr = case gt' of GTChannel -> "channel"; _ -> "group"
+              linkLine = "Link to join the " <> gtStr <> " " <> displayName <> ": " <> decodeUtf8 (strEncode sLnk)
+           in Just $ maybe linkLine (<> "\n\n" <> linkLine) description
+        Nothing -> description
      entry groupLink =
        let de =
              DirectoryEntry
@@ -99,22 +114,30 @@ groupDirectoryEntry now GroupInfo {groupProfile, chatTs, createdAt, groupSummary
                  displayName,
                  groupLink,
                  shortDescr = toFormattedText <$> shortDescr,
-                  welcomeMessage = toFormattedText <$> description,
+                  welcomeMessage = toFormattedText <$> description',
                  imageFile = fst <$> imgData,
                  activeAt = recentRoundedTime 900 now $ fromMaybe createdAt chatTs,
                  createdAt = recentRoundedTime 86400 now createdAt
                }
            imgData = imgFileData groupLink =<< image
         in (de, imgData)
-   in (entry . connLinkContact) <$> gLink_
+   in case publicGroup of
+        Just PublicGroupProfile {groupLink = sLnk} ->
+          Just $ entry $ PublicLink Nothing (Just sLnk)
+        Nothing ->
+          entry . toPublicLink . connLinkContact <$> gLink_
  where
-    imgFileData :: CreatedConnLink 'CMContact -> ImageData -> Maybe (FilePath, ByteString)
-    imgFileData groupLink (ImageData img) =
+    toPublicLink (CCLink fullLink shortLink) = PublicLink (Just fullLink) shortLink
+    imgFileData :: PublicLink -> ImageData -> Maybe (FilePath, ByteString)
+    imgFileData PublicLink {connFullLink, connShortLink} (ImageData img) =
      let (img', imgExt) =
            fromMaybe (img, ".jpg") $
              (,".jpg") <$> T.stripPrefix "data:image/jpg;base64," img
                <|> (,".png") <$> T.stripPrefix "data:image/png;base64," img
-          imgName = B.unpack $ B64URL.encodeUnpadded $ BA.convert $ (CH.hash :: ByteString -> Digest MD5) $ strEncode (connFullLink groupLink)
+          linkHash = case connFullLink of
+            Just fl -> strEncode fl
+            Nothing -> maybe "" strEncode connShortLink
+          imgName = B.unpack $ B64URL.encodeUnpadded $ BA.convert $ (CH.hash :: ByteString -> Digest MD5) linkHash
          imgFile = listingImageFolder </> imgName <> imgExt
       in case B64.decode $ encodeUtf8 img' of
            Right img'' -> Just (imgFile, img'')
@@ -19,6 +19,7 @@ module Directory.Service
 where

 import Control.Concurrent (forkIO)
+import Control.Concurrent.Async (race_)
 import Control.Concurrent.STM
 import Control.Exception (SomeException, try)
 import Control.Logger.Simple
@@ -31,7 +32,7 @@ import Data.Either (fromRight)
 import Data.List (find, intercalate)
 import Data.List.NonEmpty (NonEmpty (..))
 import qualified Data.Map.Strict as M
-import Data.Maybe (fromMaybe, isJust, isNothing)
+import Data.Maybe (fromMaybe, isJust, isNothing, maybeToList)
 import qualified Data.Set as S
 import Data.Text (Text)
 import qualified Data.Text as T
@@ -51,12 +52,12 @@ import Simplex.Chat.Bot
 import Simplex.Chat.Bot.KnownContacts
 import Simplex.Chat.Controller
 import Simplex.Chat.Core
-import Simplex.Chat.Markdown (Format (..), FormattedText (..), parseMaybeMarkdownList, viewName)
+import Simplex.Chat.Markdown (Format (..), FormattedText (..), SimplexLinkType (..), parseMaybeMarkdownList, viewName)
 import Simplex.Chat.Messages
 import Simplex.Chat.Options
-import Simplex.Chat.Protocol (MsgContent (..), memberSupportVoiceVersion)
+import Simplex.Chat.Protocol (GroupShortLinkData (..), LinkOwnerSig (..), MsgChatLink (..), MsgContent (..), memberSupportVoiceVersion)
 import Simplex.Chat.Store.Direct (getContact)
-import Simplex.Chat.Store.Groups (getGroupLink, getGroupMember, setGroupCustomData) -- TODO remove setGroupCustomData
+import Simplex.Chat.Store.Groups (getGroupLink, getGroupMember, getGroupMemberByMemberId, setGroupCustomData) -- TODO remove setGroupCustomData
 import Simplex.Chat.Store.Profiles (GroupLinkInfo (..), getGroupLinkInfo)
 import Simplex.Chat.Store.Shared (StoreError (..))
 import Simplex.Chat.Terminal (terminalChatConfig)
@@ -65,7 +66,7 @@ import Simplex.Chat.Types
 import Simplex.Chat.Types.Preferences
 import Simplex.Chat.Types.Shared
 import Simplex.Chat.View (serializeChatError, serializeChatResponse, simplexChatContact, viewContactName, viewGroupName)
-import Simplex.Messaging.Agent.Protocol (AConnectionLink (..), ConnectionLink (..), CreatedConnLink (..), SConnectionMode (..), sameConnReqContact, sameShortLinkContact)
+import Simplex.Messaging.Agent.Protocol (AConnectionLink (..), ACreatedConnLink (..), ConnectionLink (..), CreatedConnLink (..), SConnectionMode (..), sameConnReqContact, sameShortLinkContact)
 import qualified Simplex.Messaging.Crypto.File as CF
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.TMap (TMap)
@@ -164,7 +165,7 @@ directoryServiceCLI st opts = do
    [ simplexChatCLI' terminalChatConfig {chatHooks} (mkChatOpts opts) Nothing,
      processEvents eventQ env
    ]
-      <> updateListingsThread_ opts env
+      <> maybeToList (updateListingsThread_ opts env)
  where
    processEvents eventQ env = forever $ do
      (cc, resp) <- atomically $ readTQueue eventQ
@@ -174,8 +175,8 @@ directoryServiceCLI st opts = do
 updateListingDelay :: Int
 updateListingDelay = 5 * 60 * 1000000 -- update every 5 minutes

-updateListingsThread_ :: DirectoryOpts -> ServiceState -> [IO ()]
-updateListingsThread_ opts env = maybe [] (\f -> [updateListingsThread f]) $ webFolder opts
+updateListingsThread_ :: DirectoryOpts -> ServiceState -> Maybe (IO ())
+updateListingsThread_ opts env = updateListingsThread <$> webFolder opts
  where
    updateListingsThread f = do
      cc <- atomically $ takeTMVar $ updateListingsJob env
@@ -234,13 +235,10 @@ directoryService st opts cfg = do
            acceptMember = Just $ acceptMemberHook opts env
          }
  simplexChatCore cfg {chatHooks} (mkChatOpts opts) $ \user cc ->
-    raceAny_ $
-      [ forever $ void getLine,
-        forever $ do
-          (_, resp) <- atomically . readTBQueue $ outputQ cc
-          directoryServiceEvent st opts env user cc resp
-      ]
-        <> updateListingsThread_ opts env
+    maybe id race_ (updateListingsThread_ opts env) $
+      forever $ do
+        (_, resp) <- atomically . readTBQueue $ outputQ cc
+        directoryServiceEvent st opts env user cc resp

 acceptMemberHook :: DirectoryOpts -> ServiceState -> GroupInfo -> GroupLinkInfo -> Profile -> IO (Either GroupRejectionReason (GroupAcceptance, GroupMemberRole))
 acceptMemberHook
@@ -298,6 +296,8 @@ directoryServiceEvent st opts@DirectoryOpts {adminUsers, superUsers, serviceName
    DEContactLeftGroup ctId g -> deContactLeftGroup ctId g
    DEServiceRemovedFromGroup g -> deServiceRemovedFromGroup g
    DEGroupDeleted g -> deGroupDeleted g
+    DEChatLinkReceived {contact = ct, chatLink, ownerSig} -> deChatLinkReceived ct chatLink ownerSig
+    DEMemberUpdated {groupInfo = g, fromMember, toMember} -> deMemberUpdated g fromMember toMember
    DEUnsupportedMessage _ct _ciId -> pure ()
    DEItemEditIgnored _ct -> pure ()
    DEItemDeleteIgnored _ct -> pure ()
@@ -325,7 +325,19 @@ directoryServiceEvent st opts@DirectoryOpts {adminUsers, superUsers, serviceName
          let msg = "Error: " <> err <> ", group: " <> tshow groupId <> " " <> localDisplayName <> ", " <> T.pack e
          notifyAdminUsers msg
          logError msg
-    groupInfoText p@GroupProfile {description = d} = groupNameDescr p <> maybe "" ("\nWelcome message:\n" <>) d
+    groupInfoText p@GroupProfile {description = d, publicGroup} = groupNameDescr p <> maybe "" ("\nWelcome message:\n" <>) d <> linkToJoin
+      where
+        linkToJoin = case publicGroup of
+          Just pg@PublicGroupProfile {groupLink} ->
+            "\nLink to join " <> groupTypeStr' pg <> ": " <> strEncodeTxt groupLink
+              <> "\nYou need SimpleX Chat app v6.5 to join."
+          Nothing -> ""
+    membersCountStr GroupProfile {publicGroup} GroupSummary {currentMembers, publicMemberCount} =
+      let count = fromMaybe currentMembers publicMemberCount
+          label = case publicGroup of
+            Just PublicGroupProfile {groupType = GTChannel} -> " subscribers"
+            _ -> " members"
+       in tshow count <> label
    knockingStr :: Maybe GroupMemberAdmission -> [Text]
    knockingStr = \case
      Just GroupMemberAdmission {review = Just MCAll} -> ["New members are reviewed by admins"]
@@ -342,6 +354,9 @@ directoryServiceEvent st opts@DirectoryOpts {adminUsers, superUsers, serviceName
    groupReference' groupId displayName = "ID " <> tshow groupId <> " (" <> displayName <> ")"
    groupAlreadyListed GroupInfo {groupProfile = p} =
      "The group " <> groupNameDescr p <> " is already listed in the directory, please choose another name."
+    ifPublicGroup :: GroupInfo -> IO () -> IO () -> IO ()
+    ifPublicGroup GroupInfo {groupProfile = GroupProfile {publicGroup}} reject action =
+      if isJust publicGroup then reject else action

    getDuplicateGroup :: GroupInfo -> IO (Either String DuplicateGroup)
    getDuplicateGroup GroupInfo {groupId, groupProfile = GroupProfile {displayName}} =
@@ -375,7 +390,7 @@ directoryServiceEvent st opts@DirectoryOpts {adminUsers, superUsers, serviceName
      sendMessage cc ct $
        ("Welcome to " <> serviceName <> "!\n\n")
          <> "🔍 Send search string to find groups - try _security_.\n\
-             \/help - how to submit your group.\n\
+             \/help - how to submit your group or channel.\n\
             \/new - recent groups.\n\n\
             \[Directory rules](https://simplex.chat/docs/directory.html)."

@@ -461,37 +476,68 @@ directoryServiceEvent st opts@DirectoryOpts {adminUsers, superUsers, serviceName
              byMember = case memberContactId m of
                Just ctId | ctId `isOwner` gr -> "" -- group registration owner, not any group owner.
                _ -> " by " <> mName -- owner notification from directory will include the name.
-          case groupRegStatus of
-            GRSPendingConfirmation -> pure ()
-            GRSProposed -> pure ()
-            GRSPendingUpdate ->
-              groupProfileUpdate >>= \case
-                GPNoServiceLink ->
-                  notifyOwner gr $ "The profile updated for " <> userGroupRef <> byMember <> ", but the group link is not added to the welcome message."
-                GPServiceLinkAdded _ -> groupLinkAdded gr byMember
-                GPServiceLinkRemoved ->
-                  notifyOwner gr $
-                    "The group link of " <> userGroupRef <> " is removed from the welcome message" <> byMember <> ", please add it."
-                GPHasServiceLink {} -> groupLinkAdded gr byMember
-                GPServiceLinkError -> do
-                  notifyOwner gr $
-                    ("Error: " <> serviceName <> " has no group link for " <> userGroupRef)
-                      <> " after profile was updated"
-                      <> byMember
-                      <> ". Please report the error to the developers."
-                  logError $ "Error: no group link for " <> userGroupRef
-            GRSPendingApproval n -> processProfileChange gr byMember False $ n + 1
-            GRSActive -> processProfileChange gr byMember True 1
-            GRSSuspended -> processProfileChange gr byMember False 1
-            GRSSuspendedBadRoles -> processProfileChange gr byMember False 1
-            GRSRemoved -> pure ()
+          case publicGroup p' of
+            Just pg -> case groupRegStatus of
+              GRSPendingApproval n -> publicGroupProfileChange pg gr byMember $ n + 1
+              GRSActive -> publicGroupProfileChange pg gr byMember 1
+              _ -> pure ()
+            Nothing -> case groupRegStatus of
+              GRSPendingConfirmation -> pure ()
+              GRSProposed -> pure ()
+              GRSPendingUpdate ->
+                groupProfileUpdate >>= \case
+                  GPNoServiceLink ->
+                    notifyOwner gr $ "The profile updated for " <> userGroupRef <> byMember <> ", but the group link is not added to the welcome message."
+                  GPServiceLinkAdded _ -> groupLinkAdded gr byMember
+                  GPServiceLinkRemoved ->
+                    notifyOwner gr $
+                      "The group link of " <> userGroupRef <> " is removed from the welcome message" <> byMember <> ", please add it."
+                  GPHasServiceLink {} -> groupLinkAdded gr byMember
+                  GPServiceLinkError -> do
+                    notifyOwner gr $
+                      ("Error: " <> serviceName <> " has no group link for " <> userGroupRef)
+                        <> " after profile was updated"
+                        <> byMember
+                        <> ". Please report the error to the developers."
+                    logError $ "Error: no group link for " <> userGroupRef
+              GRSPendingApproval n -> processProfileChange gr byMember False $ n + 1
+              GRSActive -> processProfileChange gr byMember True 1
+              GRSSuspended -> processProfileChange gr byMember False 1
+              GRSSuspendedBadRoles -> processProfileChange gr byMember False 1
+              GRSRemoved -> pure ()
      where
        GroupInfo {groupId, groupProfile = p} = fromGroup
        GroupInfo {groupProfile = p'} = toGroup
        sameProfile
-          GroupProfile {displayName = n, fullName = fn, shortDescr = sd, image = i, description = d, memberAdmission = ma}
-          GroupProfile {displayName = n', fullName = fn', shortDescr = sd', image = i', description = d', memberAdmission = ma'} =
-            n == n' && fn == fn' && i == i' && sd == sd' && (T.words <$> d) == (T.words <$> d') && ma == ma'
+          GroupProfile {displayName = n, fullName = fn, shortDescr = sd, image = i, description = d, memberAdmission = ma, publicGroup = pg}
+          GroupProfile {displayName = n', fullName = fn', shortDescr = sd', image = i', description = d', memberAdmission = ma', publicGroup = pg'} =
+            n == n' && fn == fn' && i == i' && sd == sd' && (T.words <$> d) == (T.words <$> d') && ma == ma' && pg == pg'
+        publicGroupProfileChange pg@PublicGroupProfile {groupLink} gr byMember n' = do
+          let gt = groupTypeStr' pg
+              userGroupRef = userGroupReference gr toGroup
+              groupRef = groupReference toGroup
+              link = ACL SCMContact $ CLShort groupLink
+              updatedNotification gr' g' = do
+                notifyOwner gr' $
+                  ("The " <> gt <> " " <> userGroupRef <> " is updated" <> byMember)
+                    <> ".\nIt is hidden from the directory until approved."
+                notifyAdminUsers $ "The " <> gt <> " " <> groupRef <> " is updated" <> byMember <> "."
+                sendToApprove g' gr' n'
+          sendChatCmd cc (APIConnectPlan userId (Just link) True Nothing) >>= \case
+            Right (CRConnectionPlan _ _ (CPGroupLink (GLPKnown {groupInfo = g'}))) ->
+              case dbOwnerMemberId gr of
+                Just ownerGMId ->
+                  withDB "getGroupMember" cc (\db -> withExceptT show $ getGroupMember db (vr cc) user groupId ownerGMId) >>= \case
+                    Right ownerMember
+                      | let GroupMember {memberRole = role} = ownerMember, role >= GROwner ->
+                          setGroupStatus notifyAdminUsers st env cc groupId (GRSPendingApproval n') (`updatedNotification` g')
+                      | otherwise -> do
+                          setGroupStatus notifyAdminUsers st env cc groupId GRSSuspendedBadRoles $ \_ -> pure ()
+                          notifyOwner gr $ "The registration owner is no longer an owner. Registration suspended."
+                    Left _ -> logError $ "could not find owner member for " <> groupRef
+                Nothing -> logError $ "no owner member set for " <> groupRef
+            _ ->
+              setGroupStatus notifyAdminUsers st env cc groupId (GRSPendingApproval n') (`updatedNotification` toGroup)
        groupLinkAdded gr byMember =
          getDuplicateGroup toGroup >>= \case
            Left e -> notifyOwner gr $ "Error: getDuplicateGroup. Please notify the developers.\n" <> T.pack e
@@ -644,7 +690,7 @@ directoryServiceEvent st opts@DirectoryOpts {adminUsers, superUsers, serviceName
              -- /audio is matched as text, not as DirectoryCmd, because it is only valid
              -- in group context at captcha stage, while DirectoryCmd is for DM commands.
              isAudioCmd = T.strip msgText == "/audio"
-              cmd = fromRight (ADC SDRUser DCUnknownCommand) $ A.parseOnly (directoryCmdP <* A.endOfInput) $ T.strip msgText
+              cmd = fromRight (ADC SDRUser DCUnknownCommand) $ A.parseOnly (directoryCmdP Nothing <* A.endOfInput) $ T.strip msgText
          atomically (TM.lookup gmId $ pendingCaptchas env) >>= \case
            Nothing
              | isAudioCmd && canSendVoiceCaptcha g m -> sendMemberCaptcha g m (Just ciId) noCaptcha 0 CMAudio
@@ -661,7 +707,7 @@ directoryServiceEvent st opts@DirectoryOpts {adminUsers, superUsers, serviceName
                        sendComposedMessages_ cc sendRef [(Just ciId, MCText audioAlreadyEnabled)]
                    else sendComposedMessages_ cc sendRef [(Just ciId, MCText voiceCaptchaUnavailable)]
              | otherwise -> case cmd of
-                  ADC SDRUser (DCSearchGroup _) -> do
+                  ADC SDRUser (DCSearchGroup {}) -> do
                    ts <- getCurrentTime
                    if
                      | ts `diffUTCTime` sentAt > captchaTTL -> sendMemberCaptcha g m (Just ciId) captchaExpired (attempts - 1) captchaMode
@@ -704,11 +750,12 @@ directoryServiceEvent st opts@DirectoryOpts {adminUsers, superUsers, serviceName
      useMemberFilter image $ passCaptcha a

    sendToApprove :: GroupInfo -> GroupReg -> GroupApprovalId -> IO ()
-    sendToApprove GroupInfo {groupId, groupProfile = p@GroupProfile {displayName, image = image'}, groupSummary} GroupReg {dbContactId, promoted} gaId = do
+    sendToApprove GroupInfo {groupId, groupProfile = p@GroupProfile {displayName, image = image', publicGroup = pg_}, groupSummary} GroupReg {dbContactId, promoted} gaId = do
      ct_ <- getContact' cc user dbContactId
-      let membersStr = "_" <> tshow (currentMembers groupSummary) <> " members_\n"
+      let gt = maybe "group" groupTypeStr' pg_
+          membersStr = "_" <> membersCountStr p groupSummary <> "_\n"
          text =
-            either (\_ -> "The group ID " <> tshow groupId <> " submitted: ") (\c -> localDisplayName' c <> " submitted the group ID " <> tshow groupId <> ": ") ct_
+            either (\_ -> "The " <> gt <> " ID " <> tshow groupId <> " submitted: ") (\c -> localDisplayName' c <> " submitted the " <> gt <> " ID " <> tshow groupId <> ": ") ct_
              <> ("\n" <> groupInfoText p <> "\n" <> membersStr <> "\nTo approve send:")
          msg = maybe (MCText text) (\image -> MCImage {text, image}) image'
      withAdminUsers $ \cId -> do
@@ -771,63 +818,205 @@ directoryServiceEvent st opts@DirectoryOpts {adminUsers, superUsers, serviceName
            >>= mapM_ (\cm@GroupMember {memberRole} -> when (memberRole == GROwner && memberActive cm) action)

    deContactRemovedFromGroup :: ContactId -> GroupInfo -> IO ()
-    deContactRemovedFromGroup ctId g@GroupInfo {groupId} = do
+    deContactRemovedFromGroup ctId g@GroupInfo {groupId, groupProfile = GroupProfile {publicGroup = pg_}} = do
+      let gt = maybe "group" groupTypeStr' pg_
      logInfo $ "contact ID " <> tshow ctId <> " removed from group " <> viewGroupName g
-      withGroupReg g "contact removed" $ \gr -> do
+      withGroupReg g "contact removed" $ \gr ->
        when (ctId `isOwner` gr) $
          setGroupStatus notifyAdminUsers st env cc groupId GRSRemoved $ \gr' -> do
-            notifyOwner gr' $ "You are removed from the group " <> userGroupReference gr' g <> ".\n\nThe group is no longer listed in the directory."
-            notifyAdminUsers $ "The group " <> groupReference g <> " is de-listed (group owner is removed)."
+            notifyOwner gr' $ "You are removed from the " <> gt <> " " <> userGroupReference gr' g <> ".\n\nThe " <> gt <> " is no longer listed in the directory."
+            notifyAdminUsers $ "The " <> gt <> " " <> groupReference g <> " is de-listed (" <> gt <> " owner is removed)."
+            when (isJust pg_) $ leavePublicGroup g

    deContactLeftGroup :: ContactId -> GroupInfo -> IO ()
-    deContactLeftGroup ctId g@GroupInfo {groupId} = do
+    deContactLeftGroup ctId g@GroupInfo {groupId, groupProfile = GroupProfile {publicGroup = pg_}} = do
+      let gt = maybe "group" groupTypeStr' pg_
      logInfo $ "contact ID " <> tshow ctId <> " left group " <> viewGroupName g
-      -- TODO combine
      withGroupReg g "contact left" $ \gr ->
        when (ctId `isOwner` gr) $
          setGroupStatus notifyAdminUsers st env cc groupId GRSRemoved $ \gr' -> do
-            notifyOwner gr' $ "You left the group " <> userGroupReference gr g <> ".\n\nThe group is no longer listed in the directory."
-            notifyAdminUsers $ "The group " <> groupReference g <> " is de-listed (group owner left)."
+            notifyOwner gr' $ "You left the " <> gt <> " " <> userGroupReference gr' g <> ".\n\nThe " <> gt <> " is no longer listed in the directory."
+            notifyAdminUsers $ "The " <> gt <> " " <> groupReference g <> " is de-listed (" <> gt <> " owner left)."
+            when (isJust pg_) $ leavePublicGroup g

    deServiceRemovedFromGroup :: GroupInfo -> IO ()
-    deServiceRemovedFromGroup g@GroupInfo {groupId} = do
+    deServiceRemovedFromGroup g@GroupInfo {groupId, groupProfile = GroupProfile {publicGroup = pg_}} = do
+      let gt = maybe "group" groupTypeStr' pg_
      logInfo $ "service removed from group " <> viewGroupName g
      setGroupStatus notifyAdminUsers st env cc groupId GRSRemoved $ \gr -> do
-        notifyOwner gr $ serviceName <> " is removed from the group " <> userGroupReference gr g <> ".\n\nThe group is no longer listed in the directory."
-        notifyAdminUsers $ "The group " <> groupReference g <> " is de-listed (directory service is removed)."
+        notifyOwner gr $ serviceName <> " is removed from the " <> gt <> " " <> userGroupReference gr g <> ".\n\nThe " <> gt <> " is no longer listed in the directory."
+        notifyAdminUsers $ "The " <> gt <> " " <> groupReference g <> " is de-listed (directory service is removed)."

    deGroupDeleted :: GroupInfo -> IO ()
-    deGroupDeleted g@GroupInfo {groupId} = do
+    deGroupDeleted g@GroupInfo {groupId, groupProfile = GroupProfile {publicGroup = pg_}} = do
+      let gt = maybe "group" groupTypeStr' pg_
      logInfo $ "group removed " <> viewGroupName g
      setGroupStatus notifyAdminUsers st env cc groupId GRSRemoved $ \gr -> do
-        notifyOwner gr $ "The group " <> userGroupReference gr g <> " is deleted.\n\nThe group is no longer listed in the directory."
-        notifyAdminUsers $ "The group " <> groupReference g <> " is de-listed (group is deleted)."
+        notifyOwner gr $ "The " <> gt <> " " <> userGroupReference gr g <> " is deleted.\n\nThe " <> gt <> " is no longer listed in the directory."
+        notifyAdminUsers $ "The " <> gt <> " " <> groupReference g <> " is de-listed (" <> gt <> " is deleted)."
+
+    deChatLinkReceived :: Contact -> MsgChatLink -> Maybe LinkOwnerSig -> IO ()
+    deChatLinkReceived ct (MCLGroup {connLink, groupProfile = GroupProfile {publicGroup = Just PublicGroupProfile {groupType}}}) (Just ownerSig@LinkOwnerSig {ownerId = Just (B64UrlByteString oIdBytes)}) =
+      case groupType of
+        GTUnknown tag -> sendMessage cc ct $ "Unsupported group type: " <> T.pack (show tag)
+        gt -> do
+          let link = ACL SCMContact $ CLShort connLink
+              mId = MemberId oIdBytes
+              gt' = groupTypeStr gt
+          sendChatCmd cc (APIConnectPlan userId (Just link) True (Just ownerSig)) >>= \case
+            Right (CRConnectionPlan _ (ACCL SCMContact ccLink) plan) ->
+              handleGroupLinkPlan ct ccLink mId ownerSig gt' plan
+            _ -> sendMessage cc ct "Error: could not connect. Please report it to directory admins."
+    deChatLinkReceived ct (MCLGroup {groupProfile = GroupProfile {publicGroup = Just pg}}) _ =
+      sendMessage cc ct $ "To add a " <> groupTypeStr' pg <> " to directory you must be the owner."
+    deChatLinkReceived ct _ _ =
+      sendMessage cc ct "Only channels can be added to directory via link."
+
+    groupTypeStr :: GroupType -> Text
+    groupTypeStr = \case
+      GTChannel -> "channel"
+      GTGroup -> "group"
+      GTUnknown _ -> "group"
+
+    groupTypeStr' :: PublicGroupProfile -> Text
+    groupTypeStr' PublicGroupProfile {groupType} = groupTypeStr groupType
+
+    leavePublicGroup :: GroupInfo -> IO ()
+    leavePublicGroup GroupInfo {groupId} =
+      void $ sendChatCmd cc (APILeaveGroup groupId)
+
+    handleGroupLinkPlan :: Contact -> CreatedLinkContact -> MemberId -> LinkOwnerSig -> Text -> ConnectionPlan -> IO ()
+    handleGroupLinkPlan ct ccLink mId ownerSig gt = \case
+      CPGroupLink glp -> case glp of
+        GLPOk {groupSLinkData_, ownerVerification} -> case (groupSLinkData_, ownerVerification) of
+          (Just groupSLinkData, Just OVVerified) -> joinAndRegisterPublicGroup ct ccLink mId gt groupSLinkData
+          (_, Just (OVFailed reason)) -> sendMessage cc ct $ "Link signature verification failed: " <> reason <> ".\nYou must be the " <> gt <> " owner to register it."
+          (Nothing, _) -> sendMessage cc ct $ "Error: no " <> gt <> " information available via the link."
+          _ -> sendMessage cc ct $ "Error: could not verify " <> gt <> " ownership. Please report it to directory admins."
+        GLPKnown {groupInfo = g, groupUpdated, ownerVerification} -> case ownerVerification of
+          Just OVVerified -> deReregistration ct g groupUpdated ownerSig
+          Just (OVFailed reason) -> sendMessage cc ct $ "Link signature verification failed: " <> reason <> ".\nYou must be the " <> gt <> " owner to register it."
+          Nothing -> sendMessage cc ct $ "Error: could not verify " <> gt <> " ownership."
+        GLPConnectingProhibit _ -> sendMessage cc ct $ "Already connecting to this " <> gt <> "."
+        GLPConnectingConfirmReconnect -> sendMessage cc ct $ "Already connecting to this " <> gt <> "."
+        GLPNoRelays _ -> sendMessage cc ct $ T.toTitle gt <> " has no active relays. Please try again later."
+        GLPOwnLink _ -> sendMessage cc ct "Unexpected error. Please report it to directory admins."
+      _ -> sendMessage cc ct "Unexpected error. Please report it to directory admins."
+
+    joinAndRegisterPublicGroup :: Contact -> CreatedLinkContact -> MemberId -> Text -> GroupShortLinkData -> IO ()
+    joinAndRegisterPublicGroup ct ccLink mId gt groupSLinkData = do
+      let GroupShortLinkData {groupProfile = GroupProfile {displayName}} = groupSLinkData
+          ownerContact = GroupOwnerContact {contactId = contactId' ct, memberId = mId}
+      sendMessage cc ct $ "Joining the " <> gt <> " " <> displayName <> "…"
+      sendChatCmd cc (APIPrepareGroup userId ccLink False groupSLinkData) >>= \case
+        Right (CRNewPreparedChat _ (AChat SCTGroup (Chat (GroupChat gInfo _) _ _))) -> do
+          let gId = groupId' gInfo
+          addGroupReg notifyAdminUsers st cc ct gInfo GRSProposed $ \_ -> pure ()
+          sendChatCmd cc (APIConnectPreparedGroup gId False (Just ownerContact) Nothing) >>= \case
+            Right CRStartedConnectionToGroup {groupInfo = gInfo'} ->
+              withDB "getGroupMember" cc (\db -> withExceptT show $ getGroupMemberByMemberId db (vr cc) user gInfo' mId) >>= \case
+                Right ownerMember ->
+                  void $ setGroupRegOwner cc gId ownerMember
+                Left e -> do
+                  logError $ "could not find owner member: " <> T.pack e
+                  sendMessage cc ct "Error: could not find owner member after joining. Please report it to directory admins."
+            _ -> sendMessage cc ct $ "Error joining " <> gt <> " " <> displayName <> ", please re-send the link!"
+        _ -> sendMessage cc ct $ "Error joining " <> gt <> " " <> displayName <> ", please re-send the link!"
+
+    deReregistration :: Contact -> GroupInfo -> Bool -> LinkOwnerSig -> IO ()
+    deReregistration ct g@GroupInfo {groupId, groupProfile = GroupProfile {publicGroup = pg_}} profileChanged LinkOwnerSig {ownerId = Just (B64UrlByteString oIdBytes)} = do
+      let mId = MemberId oIdBytes
+          gt = maybe "group" groupTypeStr' pg_
+      withDB "getGroupMemberByMemberId" cc (\db -> withExceptT show $ getGroupMemberByMemberId db (vr cc) user g mId) >>= \case
+        Right ownerMember@GroupMember {memberRole = role, memberStatus} ->
+          if
+            | role >= GROwner && memberStatus /= GSMemUnknown ->
+                getGroupReg cc groupId >>= \case
+                  Right gr
+                    | contactId' ct `isOwner` gr -> sameOwnerReregistration gr gt
+                    | otherwise -> sendMessage cc ct $ "This " <> gt <> " is registered by another owner."
+                  Left _ ->
+                    addGroupReg notifyAdminUsers st cc ct g (GRSPendingApproval 1) $ \gr -> do
+                      void $ setGroupRegOwner cc groupId ownerMember
+                      sendToApprove g gr 1
+            | role < GROwner -> sendMessage cc ct $ "You must be the " <> gt <> " owner to register it."
+            | otherwise -> sendMessage cc ct $ "Waiting for the owner member to be connected to the " <> gt <> "."
+        Left _ -> sendMessage cc ct $ "Error: could not verify " <> gt <> " ownership. Please report it to directory admins."
+      where
+        sameOwnerReregistration gr gt = case groupRegStatus gr of
+          GRSProposed -> sendMessage cc ct $ "Registration is in progress, waiting for the owner member to be connected to the " <> gt <> "."
+          GRSPendingConfirmation -> pendingApprovalTransition gr gt 1
+          GRSPendingUpdate -> pendingApprovalTransition gr gt 1
+          GRSPendingApproval n
+            | profileChanged -> pendingApprovalTransition gr gt $ n + 1
+            | otherwise -> sendMessage cc ct $ T.toTitle gt <> " is already pending approval."
+          GRSActive
+            | profileChanged -> pendingApprovalTransition gr gt 1
+            | otherwise -> sendMessage cc ct $ T.toTitle gt <> " is already listed in the directory."
+          GRSSuspended -> sendMessage cc ct $ T.toTitle gt <> " is suspended by admin. Please contact support."
+          GRSSuspendedBadRoles -> pendingApprovalTransition gr gt 1
+          GRSRemoved -> pendingApprovalTransition gr gt 1
+        pendingApprovalTransition gr gt n = do
+          let userGroupRef = userGroupReference gr g
+          setGroupStatus notifyAdminUsers st env cc groupId (GRSPendingApproval n) $ \gr' -> do
+            notifyOwner gr' $
+              "The " <> gt <> " " <> userGroupRef <> " is submitted for approval.\nIt is hidden from the directory until approved."
+            sendToApprove g gr' n
+    deReregistration ct _ _ _ =
+      sendMessage cc ct "Error: could not verify ownership. Please report it to directory admins."
+
+    deMemberUpdated :: GroupInfo -> GroupMember -> GroupMember -> IO ()
+    deMemberUpdated g@GroupInfo {groupId, groupProfile = GroupProfile {displayName, publicGroup}} fromMember toMember =
+      withGroupReg g "owner member announced" $ \gr@GroupReg {groupRegStatus, dbOwnerMemberId} ->
+        when (groupRegStatus == GRSProposed && (dbOwnerMemberId == Just (groupMemberId' fromMember) || dbOwnerMemberId == Just (groupMemberId' toMember))) $
+          let GroupMember {memberRole = role} = toMember
+              gt = maybe "group" groupTypeStr' publicGroup
+           in if role >= GROwner
+                then setGroupStatus notifyAdminUsers st env cc groupId (GRSPendingApproval 1) $ \gr' -> do
+                  notifyOwner gr' $ "Joined the " <> gt <> " " <> displayName <> ". Registration is pending approval — it may take up to 48 hours."
+                  sendToApprove g gr' 1
+                else do
+                  setGroupStatus notifyAdminUsers st env cc groupId GRSRemoved $ \_ -> pure ()
+                  sendMessage' cc (dbContactId gr) "The signing key does not belong to a current owner. Registration cancelled."

    deUserCommand :: Contact -> ChatItemId -> DirectoryCmd 'DRUser -> IO ()
    deUserCommand ct ciId = \case
      DCHelp DHSRegistration ->
        sendMessage cc ct $
-          "You must be the group owner to add it to the directory:\n\n\
-          \1️⃣ *Invite* "
+          "You must be the group or channel owner to add it to the directory.\n\n\
+          \*To register a channel*, use _Share via chat_ to send its link to "
+            <> serviceName
+            <> " bot.\n\n\
+               \*To register a group*:\n\
+               \1️⃣ *Invite* "
            <> serviceName
            <> " bot to your group as *admin* - it will create a link for new members to join.\n\
-               \2️⃣ *Add* this link to the group's welcome message.\n\
-               \3️⃣ We *review* your group. Once *approved*, anybody can find it.\n\n\
-               \_We usually approve within a day, except holidays_. [More details](https://simplex.chat/docs/directory.html#adding-groups-to-the-directory)."
+               \2️⃣ *Add* this link to the group's welcome message.\n\n\
+               \Once your group or channel *approved*, it can be found here or at [simplex.chat/directory](https://simplex.chat/directory).\n\n\
+               \_We usually review within a day, except holidays_. [More details](https://simplex.chat/docs/directory.html#adding-groups-to-the-directory)."
      DCHelp DHSCommands ->
        sendMessage cc ct $
          "/'help commands' - receive this help message.\n\
-          \/help - how to register your group to be added to directory.\n\
+          \/help - how to register your group or channel to be added to directory.\n\
          \/list - list the groups you registered.\n\
          \`/role <ID>` - view and set default member role for your group.\n\
          \`/filter <ID>` - view and set spam filter settings for group.\n\
          \`/link <ID>` - view and upgrade group link.\n\
          \`/delete <ID>:<NAME>` - remove the group you submitted from directory, with _ID_ and _name_ as shown by /list command.\n\n\
          \To search for groups, send the search text."
-      DCSearchGroup s ->
-        sendFoundListedGroups (STSearch s) Nothing "No groups found" $ \gs n ->  -- $ sendSearchResults s
+      DCSearchGroup s ft ->
+        sendFoundListedGroups (STSearch s) Nothing notFound $ \gs n ->
          let more = if n > length gs then ", sending top " <> tshow (length gs) else ""
           in "Found " <> tshow n <> " group(s)" <> more <> "."
+        where
+          notFound
+            | hasSimplexGroupLink ft = "No groups found.\nTo register a group or a channel, please use \"Share via chat\" feature."
+            | otherwise = "No groups found"
+          hasSimplexGroupLink = \case
+            Just fts -> any isGroupLink fts
+            Nothing -> False
+          isGroupLink (FormattedText (Just SimplexLink {linkType}) _) = linkType == XLGroup || linkType == XLChannel
+          isGroupLink _ = False
      DCSearchNext ->
        atomically (TM.lookup (contactId' ct) searchRequests) >>= \case
          Just SearchRequest {searchType, searchTime, lastGroup} -> do
@@ -858,14 +1047,17 @@ directoryServiceEvent st opts@DirectoryOpts {adminUsers, superUsers, serviceName
          Left e -> sendReply $ "Error reading groups: " <> T.pack e
          Right gs -> sendGroupsInfo ct ciId isAdmin (gs, length gs)
      DCDeleteGroup gId gName ->
-        (if isAdmin then withGroupAndReg sendReply else withUserGroupReg) gId gName $ \GroupInfo {groupProfile = GroupProfile {displayName}} GroupReg {dbGroupId} -> do
+        (if isAdmin then withGroupAndReg sendReply else withUserGroupReg) gId gName $ \g@GroupInfo {groupProfile = GroupProfile {displayName, publicGroup = pg_}} GroupReg {dbGroupId} -> do
+          let gt = maybe "group" groupTypeStr' pg_
          delGroupReg cc dbGroupId >>= \case
            Right () -> do
              logGDelete st dbGroupId
-              sendReply $ (if isAdmin then "The group " else "Your group ") <> displayName <> " is deleted from the directory"
-            Left e -> sendReply $ "Error deleting group " <> displayName <> ": " <> T.pack e
+              sendReply $ (if isAdmin then "The " <> gt <> " " else "Your " <> gt <> " ") <> displayName <> " is deleted from the directory"
+              when (isJust pg_) $ leavePublicGroup g
+            Left e -> sendReply $ "Error deleting " <> gt <> " " <> displayName <> ": " <> T.pack e
      DCMemberRole gId gName_ mRole_ ->
-        (if isAdmin then withGroupAndReg_ sendReply else withUserGroupReg_) gId gName_ $ \g _gr -> do
+        (if isAdmin then withGroupAndReg_ sendReply else withUserGroupReg_) gId gName_ $ \g _gr ->
+          ifPublicGroup g (sendReply "This command is not available for public groups.") $ do
          let GroupInfo {groupProfile = GroupProfile {displayName = n}} = g
          case mRole_ of
            Nothing ->
@@ -885,7 +1077,8 @@ directoryServiceEvent st opts@DirectoryOpts {adminUsers, superUsers, serviceName
          initialRole n mRole = "The initial member role for the group " <> n <> " is set to *" <> textEncode mRole <> "*\n"
          onlyViaLink gLink = "*Please note*: it applies only to members joining via this link: " <> groupLinkText gLink
      DCGroupFilter gId gName_ acceptance_ ->
-        (if isAdmin then withGroupAndReg_ sendReply else withUserGroupReg_) gId gName_ $ \g _gr -> do
+        (if isAdmin then withGroupAndReg_ sendReply else withUserGroupReg_) gId gName_ $ \g _gr ->
+          ifPublicGroup g (sendReply "This command is not available for public groups.") $ do
          let GroupInfo {groupProfile = GroupProfile {displayName = n}} = g
              a = groupMemberAcceptance g
          case acceptance_ of
@@ -916,39 +1109,42 @@ directoryServiceEvent st opts@DirectoryOpts {adminUsers, superUsers, serviceName
            Just PCAll -> "_enabled_"
            Just PCNoImage -> "_enabled for profiles without image_"
      DCShowUpgradeGroupLink gId gName_ ->
-        (if isAdmin then withGroupAndReg_ sendReply else withUserGroupReg_) gId gName_ $ \GroupInfo {groupId, localDisplayName = gName} _ -> do
-          let groupRef = groupReference' gId gName
-          withGroupLinkResult groupRef (sendChatCmd cc $ APIGetGroupLink groupId) $
-            \GroupLink {connLinkContact = gLink@(CCLink _ sLnk_), acceptMemberRole, shortLinkDataSet, shortLinkLargeDataSet = BoolDef slLargeDataSet} -> do
-              let shouldBeUpgraded = isNothing sLnk_ || not shortLinkDataSet || not slLargeDataSet
-              sendReply $
-                T.unlines $
-                  [ "The link to join the group " <> groupRef <> ":",
-                    groupLinkText gLink,
-                    "New member role: " <> textEncode acceptMemberRole
-                  ]
-                    <> ["The link is being upgraded..." | shouldBeUpgraded]
-              when shouldBeUpgraded $ do
-                let send = sendComposedMessage cc ct Nothing . MCText . T.unlines
-                withGroupLinkResult groupRef (sendChatCmd cc $ APIAddGroupShortLink groupId) $
-                  \GroupLink {connLinkContact = CCLink _ sLnk_'} -> case (sLnk_, sLnk_') of
-                    (Just _, Just _) ->
-                      send ["The group link is upgraded for: " <> groupRef, "No changes to group needed."]
-                    (Nothing, Just sLnk) ->
-                      sendComposedMessages
-                        cc
-                        (SRDirect $ contactId' ct)
-                        [ MCText $
-                            T.unlines
-                              [ "Please replace the old link in welcome message of your group " <> groupRef,
-                                "If this is the only change, the group will remain listed in directory without re-approval.",
-                                "",
-                                "The new link:"
-                              ],
-                          MCText $ strEncodeTxt sLnk
-                        ]
-                    (_, Nothing) ->
-                      send ["The short link is not created for " <> groupRef, "Please report it to the developers."]
+        (if isAdmin then withGroupAndReg_ sendReply else withUserGroupReg_) gId gName_ $ \GroupInfo {groupId, groupProfile = GroupProfile {publicGroup = pg_}, localDisplayName = gName} _ -> case pg_ of
+          Just pg@PublicGroupProfile {groupLink} ->
+            sendReply $ "The link to join the " <> groupTypeStr' pg <> " " <> groupReference' gId gName <> ":\n" <> strEncodeTxt groupLink
+          Nothing -> do
+            let groupRef = groupReference' gId gName
+            withGroupLinkResult groupRef (sendChatCmd cc $ APIGetGroupLink groupId) $
+              \GroupLink {connLinkContact = gLink@(CCLink _ sLnk_), acceptMemberRole, shortLinkDataSet, shortLinkLargeDataSet = BoolDef slLargeDataSet} -> do
+                let shouldBeUpgraded = isNothing sLnk_ || not shortLinkDataSet || not slLargeDataSet
+                sendReply $
+                  T.unlines $
+                    [ "The link to join the group " <> groupRef <> ":",
+                      groupLinkText gLink,
+                      "New member role: " <> textEncode acceptMemberRole
+                    ]
+                      <> ["The link is being upgraded..." | shouldBeUpgraded]
+                when shouldBeUpgraded $ do
+                  let send = sendComposedMessage cc ct Nothing . MCText . T.unlines
+                  withGroupLinkResult groupRef (sendChatCmd cc $ APIAddGroupShortLink groupId) $
+                    \GroupLink {connLinkContact = CCLink _ sLnk_'} -> case (sLnk_, sLnk_') of
+                      (Just _, Just _) ->
+                        send ["The group link is upgraded for: " <> groupRef, "No changes to group needed."]
+                      (Nothing, Just sLnk) ->
+                        sendComposedMessages
+                          cc
+                          (SRDirect $ contactId' ct)
+                          [ MCText $
+                              T.unlines
+                                [ "Please replace the old link in welcome message of your group " <> groupRef,
+                                  "If this is the only change, the group will remain listed in directory without re-approval.",
+                                  "",
+                                  "The new link:"
+                                ],
+                            MCText $ strEncodeTxt sLnk
+                          ]
+                      (_, Nothing) ->
+                        send ["The short link is not created for " <> groupRef, "Please report it to the developers."]
        where
          withGroupLinkResult groupRef a cb =
            a >>= \case
@@ -1000,8 +1196,8 @@ directoryServiceEvent st opts@DirectoryOpts {adminUsers, superUsers, serviceName
          where
            msgs = replyMsg :| map foundGroup gs <> [moreMsg | moreGroups > 0]
            replyMsg = (Just ciId, MCText reply)
-            foundGroup (GroupInfo {groupId, groupProfile = p@GroupProfile {image = image_, memberAdmission}, groupSummary = GroupSummary {currentMembers}}, _) =
-              let membersStr = "_" <> tshow currentMembers <> " members_"
+            foundGroup (GroupInfo {groupId, groupProfile = p@GroupProfile {image = image_, memberAdmission}, groupSummary}, _) =
+              let membersStr = "_" <> membersCountStr p groupSummary <> "_"
                  showId = if isAdmin then tshow groupId <> ". " else ""
                  text = T.unlines $ [showId <> groupInfoText p, membersStr] ++ knockingStr memberAdmission
               in (Nothing, maybe (MCText text) (\image -> MCImage {text, image}) image_)
@@ -1014,40 +1210,49 @@ directoryServiceEvent st opts@DirectoryOpts {adminUsers, superUsers, serviceName
            withGroupAndReg sendReply groupId n $ \g gr@GroupReg {userGroupRegId = ugrId, promoted} ->
              case groupRegStatus gr of
                GRSPendingApproval gaId
-                  | gaId == groupApprovalId ->
+                  | gaId == groupApprovalId -> do
+                      let GroupInfo {groupProfile = GroupProfile {publicGroup = pg_}} = g
+                          isPublicGroup_ = isJust pg_
+                          gt = maybe "group" groupTypeStr' pg_
                      getDuplicateGroup g >>= \case
                        Left e -> sendReply $ "Error: getDuplicateGroup. Please notify the developers.\n" <> T.pack e
-                        Right DGReserved -> sendReply $ "The group " <> groupRef <> " is already listed in the directory."
-                        _ -> getGroupRolesStatus g gr >>= \case
-                          Right GRSOk -> do
-                            let grPromoted'
-                                  | promoted || knownCt `elem` superUsers = fromMaybe promoted promote
-                                  | otherwise = False
-                            setGroupStatusPromo sendReply st env cc gr GRSActive grPromoted' $ do
-                              let approved = "The group " <> userGroupReference' gr n <> " is approved"
-                              notifyOwner gr $
-                                (approved <> " and listed in directory - please moderate it!\n")
-                                  <> "_Please note_: if you change the group profile it will be hidden from directory until it is re-approved.\n\n"
-                                  <> "Supported commands:\n"
-                                  <> ("/'filter " <> tshow ugrId <> "' - to configure anti-spam filter.\n")
-                                  <> ("/'role " <> tshow ugrId <> "' - to set default member role.\n")
-                                  <> ("/'link " <> tshow ugrId <> "' - to view/upgrade group link.")
-                              invited <-
-                                forM ownersGroup $ \og@KnownGroup {localDisplayName = ogName} -> do
-                                  inviteToOwnersGroup og gr $ \case
-                                    Right () -> do
-                                      owner <- groupOwnerInfo groupRef $ dbContactId gr
-                                      pure $ "Invited " <> owner <> " to owners' group " <> viewName ogName
-                                    Left err -> pure err
-                              sendReply $ "Group approved" <> (if grPromoted' then " (promoted)" else "") <> "!" <> maybe "" ("\n" <>) invited
-                              notifyOtherSuperUsers $ approved <> " by " <> viewName (localDisplayName' ct) <> maybe "" ("\n" <>) invited
-                          Right GRSServiceNotAdmin -> replyNotApproved serviceNotAdmin
-                          Right GRSContactNotOwner -> replyNotApproved "user is not an owner."
-                          Right GRSBadRoles -> replyNotApproved $ "user is not an owner, " <> serviceNotAdmin
-                          Left e -> sendReply $ "Error: getGroupRolesStatus. Please notify the developers.\n" <> T.pack e
-                          where
-                            replyNotApproved reason = sendReply $ "Group is not approved: " <> reason
-                            serviceNotAdmin = serviceName <> " is not an admin."
+                        Right DGReserved -> sendReply $ "The " <> gt <> " " <> groupRef <> " is already listed in the directory."
+                        _ -> do
+                          rolesOk <- if isPublicGroup_ then pure (Right GRSOk) else getGroupRolesStatus g gr
+                          case rolesOk of
+                            Right GRSOk -> do
+                              let grPromoted'
+                                    | promoted || knownCt `elem` superUsers = fromMaybe promoted promote
+                                    | otherwise = False
+                              setGroupStatusPromo sendReply st env cc gr GRSActive grPromoted' $ do
+                                let approved = "The " <> gt <> " " <> userGroupReference' gr n <> " is approved"
+                                let commands
+                                      | isPublicGroup_ = ""
+                                      | otherwise =
+                                          "\n\nSupported commands:\n"
+                                            <> ("/'filter " <> tshow ugrId <> "' - to configure anti-spam filter.\n")
+                                            <> ("/'role " <> tshow ugrId <> "' - to set default member role.\n")
+                                            <> ("/'link " <> tshow ugrId <> "' - to view/upgrade group link.")
+                                notifyOwner gr $
+                                  (approved <> " and listed in directory - please moderate it!\n")
+                                    <> "_Please note_: if you change the " <> gt <> " profile it will be hidden from directory until it is re-approved."
+                                    <> commands
+                                invited <-
+                                  forM ownersGroup $ \og@KnownGroup {localDisplayName = ogName} -> do
+                                    inviteToOwnersGroup og gr $ \case
+                                      Right () -> do
+                                        owner <- groupOwnerInfo groupRef $ dbContactId gr
+                                        pure $ "Invited " <> owner <> " to owners' group " <> viewName ogName
+                                      Left err -> pure err
+                                sendReply $ T.toTitle gt <> " approved" <> (if grPromoted' then " (promoted)" else "") <> "!" <> maybe "" ("\n" <>) invited
+                                notifyOtherSuperUsers $ approved <> " by " <> viewName (localDisplayName' ct) <> maybe "" ("\n" <>) invited
+                            Right GRSServiceNotAdmin -> replyNotApproved serviceNotAdmin
+                            Right GRSContactNotOwner -> replyNotApproved "user is not an owner."
+                            Right GRSBadRoles -> replyNotApproved $ "user is not an owner, " <> serviceNotAdmin
+                            Left e -> sendReply $ "Error: getGroupRolesStatus. Please notify the developers.\n" <> T.pack e
+                            where
+                              replyNotApproved reason = sendReply $ "Group is not approved: " <> reason
+                              serviceNotAdmin = serviceName <> " is not an admin."
                  | otherwise -> sendReply "Incorrect approval code"
                _ -> sendReply $ "Error: the group " <> groupRef <> " is not pending approval."
            where
@@ -1189,7 +1394,7 @@ directoryServiceEvent st opts@DirectoryOpts {adminUsers, superUsers, serviceName
              GroupReg {userGroupRegId, groupRegStatus} = gr
              useGroupId = if isAdmin then groupId else userGroupRegId
              statusStr = "Status: " <> groupRegStatusText groupRegStatus
-              membersStr = "_" <> tshow (currentMembers groupSummary) <> " members_"
+              membersStr = "_" <> membersCountStr p groupSummary <> "_"
              cmds = "/'role " <> tshow useGroupId <> "', /'filter " <> tshow useGroupId <> "'"
              ownerStr = maybe "" (("Owner: " <>) . either (("getContact error: " <>) . T.pack) localDisplayName') ct_
              text = T.unlines $ [tshow useGroupId <> ". " <> groupInfoText p] ++ [ownerStr | isAdmin] ++ [membersStr, statusStr] ++ knockingStr memberAdmission ++ [cmds]
@@ -1285,6 +1285,7 @@ Determine SimpleX link type and if the bot is already connected via this link.
 **Parameters**:
 - userId: int64
 - connectionLink: string?
+- resolveKnown: bool
 - linkOwnerSig: [LinkOwnerSig](./TYPES.md#linkownersig)?

 **Syntax**:
@@ -2290,6 +2290,8 @@ ConnectingProhibit:
 Known:
 - type: "known"
 - groupInfo: [GroupInfo](#groupinfo)
+- groupUpdated: bool
+- ownerVerification: [OwnerVerification](#ownerverification)?

 NoRelays:
 - type: "noRelays"
@@ -2513,6 +2515,7 @@ Public:

 **Enum type**:
 - "channel"
+- "group"


 ---
@@ -294,7 +294,7 @@ chatTypesDocsData =
    (sti @GroupShortLinkInfo, STRecord, "", [], "", ""),
    (sti @GroupSummary, STRecord, "", [], "", ""),
    (sti @GroupSupportChat, STRecord, "", [], "", ""),
-    (sti @GroupType, STEnum1, "GT", ["GTUnknown"], "", ""),
+    (sti @GroupType, STEnum, "GT", ["GTUnknown"], "", ""),
    (sti @HandshakeError, STEnum, "", [], "", ""),
    (sti @InlineFileMode, STEnum, "IFM", [], "", ""),
    (sti @InvitationLinkPlan, STUnion, "ILP", [], "", ""),
@@ -471,6 +471,7 @@ export namespace APIAddContact {
 export interface APIConnectPlan {
  userId: number // int64
  connectionLink?: string
+  resolveKnown: boolean
  linkOwnerSig?: T.LinkOwnerSig
 }

@@ -2610,6 +2610,8 @@ export namespace GroupLinkPlan {
  export interface Known extends Interface {
    type: "known"
    groupInfo: GroupInfo
+    groupUpdated: boolean
+    ownerVerification?: OwnerVerification
  }

  export interface NoRelays extends Interface {
@@ -2776,6 +2778,7 @@ export interface GroupSupportChat {

 export enum GroupType {
  Channel = "channel",
+  Group = "group",
 }

 export enum HandshakeError {
@@ -0,0 +1,324 @@
+# Directory Service — Public Group Registration via Chat Cards
+
+## Goal
+
+Enable directory registration of public groups (channels and future group types) via MCChat cards shared in DM with the bot. Replaces the admin-invitation flow with a signature-verified card flow.
+
+## Background
+
+### Current group registration flow
+1. Owner invites bot as admin member
+2. Bot joins, creates group link, asks owner to add link to welcome message
+3. Owner updates profile with link → bot sends for admin approval
+4. Admin approves → group listed
+
+This requires the bot to be admin. Public groups don't need this — they already have a public link, and ownership is proven via `ownerSig` on the MCChat card.
+
+### Public group identity
+- `PublicGroupProfile {groupType :: GroupType, groupLink :: ShortLinkContact, publicGroupId :: B64UrlByteString}`
+- `publicGroupId = sha256(rootKey)` — immutable identity
+- `GroupType`: currently `GTChannel`, adding `GTGroup` for forward compatibility
+- `GroupKeys {publicGroupId, groupRootKey, memberPrivKey}` — owner's signing keys
+- `ownerId` in `LinkOwnerSig` = `B64UrlByteString (unMemberId memberId)` — the owner's MemberId bytes
+
+### ownerId-to-member mapping
+- `LinkOwnerSig.ownerId = Just (B64UrlByteString unMemberId)` — same raw bytes as `MemberId`
+- `createLinkOwnerMember` (called during `APIConnectPreparedGroup`, Commands.hs:2129) creates a member record with `memberRole = GROwner`, `memberStatus = GSMemUnknown`, `memberContactId = Nothing`
+- `GroupMemberId` is available immediately after `APIConnectPreparedGroup`
+- `getGroupMemberIdViaMemberId db user gInfo (MemberId ownerId)` looks up `GroupMemberId` from `MemberId`
+
+### Owner member activation
+When a relay announces the pre-created `GSMemUnknown` member, `CEvtUnknownMemberAnnounced` fires (Subscriber.hs:2872, via `xGrpMemNew`). The member's profile and role are updated from the announcement's `MemberInfo` (via `updateUnknownMemberAnnounced`, Groups.hs:3010) — the role reflects the member's actual current role, not the pre-created `GROwner`. This event is not currently handled in directory Events.hs.
+
+### connectPlan and known groups
+`apiConnectPlan` with `linkOwnerSig` returns:
+- `GLPOk {groupSLinkData_, ownerVerification}` — new group
+- `GLPKnown {groupInfo}` — bot already a member
+- `GLPOwnLink` / `GLPConnectingProhibit` / `GLPConnectingConfirmReconnect` / `GLPNoRelays`
+
+**Gap**: For `GLPKnown`, `groupShortLinkPlan` short-circuits via `knownLinkPlans` — never resolves link data, never verifies signature.
+
+**Fix**: Add an optional parameter to `APIConnectPlan` (before `sig=`, since JSON must be last) that forces link data re-resolution even for known groups. With this parameter, `GLPKnown` includes `ownerVerification` and freshly loaded `groupSLinkData`. The loaded profile may differ from stored — the bot treats the server's current data as authoritative and updates its stored profile accordingly.
+
+**Future**: Add a signed version counter to link data to detect rollback attacks (malicious server serving old signed profiles). The bot would store the highest version seen and reject/flag version reductions. For now, the server is treated as authoritative.
+
+### Owner-contact association via APIConnectPreparedGroup
+`createLinkOwnerMember` (called during `APIConnectPreparedGroup`) currently creates owner members with `memberContactId = Nothing`. Add an optional `(contactId, ownerId)` paired parameter to `APIConnectPreparedGroup`: when the link was received in a DM, pass the sender's `contactId` and the `ownerId` from `LinkOwnerSig`. The core sets `memberContactId` on the specific owner member whose `memberId` matches `ownerId`.
+
+This makes ALL existing directory event routing work: `DEContactRoleChanged`, `DEContactRemovedFromGroup`, `DEContactLeftGroup` all resolve via `memberContactId` — no new event types needed for owner tracking.
+
+Also benefits regular UI: when a user taps an owner's link in a DM, the contact association is created, improving the experience (e.g., showing the contact in the group member list).
+
+## Registration flow for public groups
+
+1. Owner taps "Share via chat" on their public group → sends MCChat card to bot in DM
+2. Bot receives `CEvtNewChatItems` with `MCChat` content in direct chat → `DEChatLinkReceived`
+3. Bot validates card (see validation matrix)
+4. Bot calls `apiConnectPlan` with `connLink`, `linkOwnerSig`, and force-resolve flag
+5. On `GLPOk` + `Verified`: bot replies "Joining {channel/group} {name}..." and joins via `APIPrepareGroup` then `APIConnectPreparedGroup` (passing owner's `contactId` and `ownerId`). On error: replies "Error joining {channel/group} {name}, please re-send the link!" (same pattern as existing group flow, Service.hs:368-370).
+6. After `APIConnectPreparedGroup`, bot stores `dbOwnerMemberId` (via `getGroupMemberIdViaMemberId` — `createLinkOwnerMember` created the record during connect). Registration status: `GRSProposed`.
+7. When `CEvtUnknownMemberAnnounced` fires for the owner member → `DEOwnerMemberAnnounced` → bot transitions to `GRSPendingApproval`, replies "Joined {channel/group} {name}. Registration is pending approval — it may take up to 48 hours.", sends to admins for approval
+8. Admin approves → `GRSActive`
+
+## Scenario matrix: card received in DM
+
+### Event
+
+One event: `DEChatLinkReceived { contact :: Contact, chatItemId :: ChatItemId, chatLink :: MsgChatLink, ownerSig :: Maybe LinkOwnerSig }`.
+
+Handler validates and replies based on content.
+
+### Card validation (handler level)
+
+| Condition | Action |
+|---|---|
+| `chatLink` is not MCLGroup, or MCLGroup but no `publicGroup` in profile | Reply: "Only channels can be added to directory via link." |
+| MCLGroup + publicGroup but `ownerSig` is `Nothing` | Reply: "To add a {channel/group} to directory you must be the owner." |
+| MCLGroup + publicGroup + `ownerSig` is `Just` | Proceed to connectPlan |
+
+### connectPlan results
+
+| Plan result | ownerVerification | Action |
+|---|---|---|
+| `GLPOk` + sLinkData | `Verified` | Reply "Joining {channel/group} {name}...", join (with contactId + ownerId), register as `GRSProposed` |
+| `GLPOk` + sLinkData | `Failed reason` | Reply: "Link signature verification failed: {reason}.\nYou must be the {channel/group} owner to register it." |
+| `GLPOk` + sLinkData | `Nothing` | Reply: "Error: could not verify {channel/group} ownership. Please report it to directory admins." |
+| `GLPOk` no sLinkData | — | Reply: "Error: no {channel/group} information available via the link." |
+| `GLPKnown` | `Verified` | Bot already member — handle as re-registration (see below) |
+| `GLPKnown` | `Failed reason` | Reply: "Link signature verification failed: {reason}.\nYou must be the {channel/group} owner to register it." |
+| `GLPKnown` | `Nothing` | Reply: "Error: could not verify ownership." |
+| `GLPConnectingProhibit` | — | Reply: "Already connecting to this {channel/group}." |
+| `GLPConnectingConfirmReconnect` | — | Reply: "Already connecting to this {channel/group}." |
+| `GLPOwnLink` | — | Log error. Reply: "Unexpected error. Please report it to directory admins." |
+| `GLPNoRelays` | — | Reply: "{Channel/Group} has no active relays. Please try again later." |
+
+### Owner member activation after joining
+
+Bot is in `GRSProposed`. The pre-created owner member has `GSMemUnknown` status. When the relay announces this member, `CEvtUnknownMemberAnnounced` fires → mapped to `DEOwnerMemberAnnounced` in directory events.
+
+| Condition | Action |
+|---|---|
+| `CEvtUnknownMemberAnnounced` for member matching `dbOwnerMemberId`, announced role is `GROwner` | Transition to `GRSPendingApproval`, notify submitting contact, send for admin approval |
+| `CEvtUnknownMemberAnnounced` for member matching `dbOwnerMemberId`, announced role < `GROwner` | Reply: "The signing key does not belong to a current owner. Registration cancelled." Set `GRSRemoved`. |
+| Owner member never announced | Registration stays in `GRSProposed`. No timeout — manual cleanup via admin. |
+
+### Re-registration (GLPKnown — bot already member, signature verified at plan)
+
+With the `connectPlan` fix, `GLPKnown` now includes `ownerVerification` and fresh `groupSLinkData`. Only proceed if `Verified`.
+
+Bot extracts `ownerId`, looks up member via `getGroupMemberIdViaMemberId`, confirms `memberRole >= GROwner` AND `memberStatus` is active (not `GSMemUnknown`). The pre-created member has `GROwner` role from creation, so role alone is insufficient — the member must have been announced by a relay to confirm actual presence in the group.
+
+Look up existing `GroupReg` by `groupId`:
+
+| Existing registration | Ownership verified | Action |
+|---|---|---|
+| No GroupReg found | Yes | Create new registration as `GRSPendingApproval` |
+| GroupReg exists, same owner contact | Yes | Handle based on current status (see status matrix) |
+| GroupReg exists, different contact | Sender is verified owner AND previous registrant no longer owner (check `dbOwnerMemberId` member's current role) | Transfer: update `dbContactId` and `dbOwnerMemberId`, proceed as same-owner case |
+| GroupReg exists, different contact | Sender is verified owner BUT previous registrant still owner | Reply: "This {channel/group} is registered by another owner." |
+| GroupReg exists, different contact | Sender NOT verified owner | Reply: "You must be the {channel/group} owner to register it." Additionally: check if previous registrant (via `dbOwnerMemberId`) is still owner. If not → suspend (`GRSSuspendedBadRoles`). |
+
+### Re-registration by same owner — status matrix
+
+| Current status | Action |
+|---|---|
+| `GRSProposed` | Only if owner member is active (not `GSMemUnknown`): transition to `GRSPendingApproval`, send for approval. If still `GSMemUnknown`: reply "Waiting for owner to connect to the {channel/group}." |
+| `GRSPendingConfirmation` | Transition to `GRSPendingApproval`, send for approval (only if previously registered via admin-invitation flow) |
+| `GRSPendingUpdate` | Transition to `GRSPendingApproval`, send for approval (only if previously registered via admin-invitation flow) |
+| `GRSPendingApproval n` | Check if profile changed (fresh profile from connectPlan vs bot's current DB). If yes: increment approval ID, re-send. If no: reply "Already pending approval." |
+| `GRSActive` | Check if profile changed. If yes: transition to `GRSPendingApproval`, re-send. If no: reply "Already listed in the directory." |
+| `GRSSuspended` | Reply: "{Channel/Group} is suspended by admin. Contact support." |
+| `GRSSuspendedBadRoles` | Ownership re-verified at plan. Transition to `GRSPendingApproval`, send for approval. |
+| `GRSRemoved` | Re-register as `GRSPendingApproval` |
+
+### Profile change detection
+
+For re-registration: compare the freshly loaded profile (from connectPlan's re-resolved `groupSLinkData`) against the group's current profile in the bot's database.
+
+For XGrpInfo updates: re-resolve the link via `apiConnectPlan` with `resolve=on`, compare freshly loaded link profile against bot's stored profile.
+
+Uses the same `sameProfile` comparison as existing group flow (Service.hs:491-494), extended with `publicGroup` field: `displayName`, `fullName`, `shortDescr`, `image`, `description`, `memberAdmission`, `publicGroup` — any difference triggers re-approval. The `publicGroup` field includes `groupLink` (ShortLinkContact), so link regeneration by the owner also triggers re-approval.
+
+## Profile updates via XGrpInfo (bot is subscriber)
+
+Bot receives `DEGroupUpdated` when any member updates the group profile. Works for subscribers.
+
+For public groups: skip "link in welcome message" check. First check if the profile actually changed using the same `sameProfile` comparison as for regular groups (`displayName`, `fullName`, `shortDescr`, `image`, `description`, `memberAdmission`). Only if changed, call `apiConnectPlan` with `resolve=on` to re-resolve the link data. Compare the resolved link profile against the bot's stored profile.
+
+Note: `xGrpInfo` (Subscriber.hs:3172) prevents `publicGroup` removal and `publicGroupId` changes for channels — these cases can never occur. The `groupLink` (ShortLinkContact) CAN change if the owner regenerates the link; the bot's DB is updated via XGrpInfo and subsequent re-resolution uses the current link.
+
+| Current status | Profile changed (link data vs stored) | Action |
+|---|---|---|
+| `GRSProposed` | Any | No action (waiting for owner activation) |
+| `GRSPendingApproval n` | Yes | Increment approval ID, re-send for approval |
+| `GRSPendingApproval n` | No | No action |
+| `GRSActive` | Yes | Transition to `GRSPendingApproval`, notify owner, re-send |
+| `GRSActive` | No | No action |
+| `GRSSuspended` | Any | No action |
+| `GRSSuspendedBadRoles` | Any | No action |
+| `GRSRemoved` | Any | No action |
+
+## Owner tracking
+
+### Owner-contact association
+
+When the bot connects via `APIConnectPreparedGroup` with the submitting contact's `contactId` and `ownerId`, the core sets `memberContactId` on the specific pre-created owner member whose `memberId` matches `ownerId`. This makes all existing event routing work: `DEContactRoleChanged`, `DEContactRemovedFromGroup`, `DEContactLeftGroup` resolve via `memberContactId`.
+
+### Owner changes
+
+| Event | Detection | Action |
+|---|---|---|
+| Owner loses owner role | `DEContactRoleChanged` (works via `memberContactId` set at connect time) | Transition to `GRSSuspendedBadRoles`, notify |
+| Owner leaves group | `DEContactLeftGroup` | Transition to `GRSRemoved`, notify, leave group |
+| Owner removed from group | `DEContactRemovedFromGroup` | Transition to `GRSRemoved`, notify, leave group |
+| Non-owner sends card, current registrant no longer owner | Re-registration flow detects stale ownership | Suspend (`GRSSuspendedBadRoles`). Non-owner's card also checked: if their `ownerId` resolves to a non-owner member, and the current registrant is also not owner → suspend. |
+| New owner sends card, current registrant no longer owner | Re-registration flow, verified | Transfer registration |
+
+## Commands for public group registrations
+
+Bot is subscriber (not admin):
+- `/filter` — Reply: "This command is not available for public groups."
+- `/role` — Reply: "This command is not available for public groups."
+- `/link` — Show `PublicGroupProfile.groupLink` with appropriate message.
+- `/delete` — Remove registration, bot leaves group (`APILeaveGroup`).
+- `/list` — Works as before, includes public group registrations.
+
+## De-registration
+
+| Event | Action |
+|---|---|
+| Owner sends `/delete ID:NAME` | Delete registration, reply confirmation, leave group |
+| Bot removed (`DEServiceRemovedFromGroup`) | Set `GRSRemoved`, notify |
+| Group deleted (`DEGroupDeleted`) | Set `GRSRemoved`, notify |
+| Owner leaves (`DEContactLeftGroup`) | Set `GRSRemoved`, notify, leave group |
+| Owner removed (`DEContactRemovedFromGroup`) | Set `GRSRemoved`, notify, leave group |
+| Admin sends `/suspend ID:NAME` | Set `GRSSuspended`, notify, do NOT leave group |
+
+Bot leaves group only for public group registrations (regular groups preserve existing behavior).
+
+## Code changes
+
+### 1. GroupType — add GTGroup
+
+`Types.hs`:
+```haskell
+data GroupType = GTChannel | GTGroup | GTUnknown Text
+```
+
+### 2. connectPlan — force-resolve parameter
+
+Add optional parameter to `APIConnectPlan` (before `sig=`): `resolve=on`. When present, `groupShortLinkPlan` skips the `knownLinkPlans` shortcut and always resolves link data. `GLPKnown` extended with `ownerVerification` and `groupSLinkData_`:
+```haskell
+GLPKnown {groupInfo :: GroupInfo, ownerVerification :: Maybe OwnerVerification, groupSLinkData_ :: Maybe GroupShortLinkData}
+```
+
+Parser: `/_connect plan <userId> [resolve=on] <link> [sig=<json>]`
+
+### 3. APIConnectPreparedGroup — optional (contactId, ownerId)
+
+Add optional paired `(contactId, ownerId)` parameter to `APIConnectPreparedGroup`. When present, `createLinkOwnerMember` (called during connect, Commands.hs:2129) sets `memberContactId` on the specific owner member whose `memberId` matches the provided `ownerId`.
+
+Current parser (Commands.hs:5045): `/_connect group #<groupId> [incognito=on] [<msgContent>]`
+New parser: `/_connect group #<groupId> [contact=<contactId> owner=<ownerId>] [incognito=on] [<msgContent>]`
+
+`contact` and `owner` are paired — both required together. `ownerId` identifies which pre-created owner member gets the `memberContactId` set (multiple owners possible via OwnerAuth chain).
+
+Current type (Controller.hs:479): `APIConnectPreparedGroup GroupId IncognitoEnabled (Maybe MsgContent)`
+New type: `APIConnectPreparedGroup GroupId (Maybe (ContactId, B64UrlByteString)) IncognitoEnabled (Maybe MsgContent)`
+
+This also benefits the UI: when tapping an owner's link in a DM, the contactId is threaded through the connect alert to `APIConnectPreparedGroup`, creating the association.
+
+### 4. Events.hs — new events
+
+`DEChatLinkReceived` — fires for ALL MCChat messages in DM (any `MsgChatLink` variant, signed or unsigned):
+```haskell
+| DEChatLinkReceived
+    { contact :: Contact,
+      chatItemId :: ChatItemId,
+      chatLink :: MsgChatLink,
+      ownerSig :: Maybe LinkOwnerSig
+    }
+```
+
+`DEOwnerMemberAnnounced` (from `CEvtUnknownMemberAnnounced`):
+```haskell
+| DEOwnerMemberAnnounced GroupInfo GroupMember GroupMember
+    -- ^ groupInfo, unknownMember, announcedMember
+```
+
+In `crDirectoryEvent_`, extend `CEvtNewChatItems` for direct chat:
+```haskell
+(MCChat {chatLink, ownerSig}, Nothing) -> DEChatLinkReceived ct ciId chatLink ownerSig
+```
+
+Add `CEvtUnknownMemberAnnounced` handler:
+```haskell
+CEvtUnknownMemberAnnounced {groupInfo, unknownMember, announcedMember} ->
+  Just $ DEOwnerMemberAnnounced groupInfo unknownMember announcedMember
+```
+
+### 5. Service.hs — public group link handler
+
+`deChatLinkReceived`: validates card, calls `apiConnectPlan` (with `resolve=on`), handles per scenario matrix. The link string comes from `MCLGroup.connLink` (`ShortLinkContact`) formatted as URI — passed via command string, parsed inside the handler. For `GLPOk` + `Verified`: joins (with contactId + ownerId), stores `dbOwnerMemberId`, registers as `GRSProposed`. On join error: replies to owner (same pattern as Service.hs:368-370). For `GLPKnown` + `Verified`: re-registration flow.
+
+### 6. Service.hs — owner member announced handler
+
+`deOwnerMemberAnnounced`: checks if the announced member's `GroupMemberId` matches `dbOwnerMemberId` of any `GRSProposed` registration. If yes and role is `GROwner`: transition to `GRSPendingApproval`, notify, send for approval. If role < `GROwner`: cancel.
+
+### 7. Service.hs — deGroupUpdated changes
+
+For public groups (`groupProfile.publicGroup` present), skip "link in welcome message" check. On profile change, call `apiConnectPlan` with `resolve=on` to get authoritative link data. Compare resolved profile against stored. If different, trigger re-approval.
+
+### 8. Service.hs — command restrictions and de-registration
+
+Check `groupProfile.publicGroup` for `/filter`, `/role`. On `/delete` for public groups, call `APILeaveGroup`. Same for owner departure/removal events.
+
+### 9. Help message update
+
+```
+To register a channel, share its link with this bot using the "Share via chat" button.
+To register a group, invite this bot as admin.
+```
+
+### 10. Approval message for admins
+
+Include: group name, description, image, member count, "Registered via link sharing (signed by owner)", publicGroupId.
+
+### 11. Tests
+
+**Registration:**
+- Share signed card → bot joins, owner announced, pending approval
+- Share unsigned card → "must be owner" reply
+- Share non-MCLGroup / non-public-group card → "only channels" reply
+- Share card with invalid signature → rejection with reason
+- Share card, owner never announced → stays GRSProposed
+- Share card, owner announced but role < GROwner → cancelled
+
+**Re-registration (GLPKnown, verified):**
+- Same owner re-shares, active → "already listed"
+- Same owner re-shares, pending → "already pending"
+- Same owner re-shares with changed profile → re-approval
+- Different contact, verified owner, previous no longer owner → transfer
+- Different contact, verified owner, previous still owner → "registered by another owner"
+- Different contact, not owner → rejection + stale ownership check
+- Same owner re-shares while GRSProposed, owner still GSMemUnknown → "waiting for owner"
+
+**Profile updates:**
+- XGrpInfo on active public group → re-approval
+- XGrpInfo on pending public group → increment approval ID
+- XGrpInfo on public group skips link-in-welcome check
+
+**Owner tracking (via contactId association):**
+- Owner role changed → suspension
+- Owner leaves → removal, bot leaves
+- Owner removed → removal, bot leaves
+
+**De-registration:**
+- `/delete` by owner → removal, bot leaves
+- Bot removed → removal
+- Admin `/suspend` → suspension, bot stays
+
+**Commands:**
+- `/filter` on public group → disabled
+- `/role` on public group → disabled
+- `/link` on public group → shows public link
@@ -470,13 +470,13 @@ data ChatCommand
  | AddContact IncognitoEnabled
  | APISetConnectionIncognito Int64 IncognitoEnabled
  | APIChangeConnectionUser Int64 UserId -- new user id to switch connection to
-  | APIConnectPlan {userId :: UserId, connectionLink :: Maybe AConnectionLink, linkOwnerSig :: Maybe LinkOwnerSig} -- Maybe AConnectionLink is used to report link parsing failure as special error
+  | APIConnectPlan {userId :: UserId, connectionLink :: Maybe AConnectionLink, resolveKnown :: Bool, linkOwnerSig :: Maybe LinkOwnerSig} -- Maybe AConnectionLink is used to report link parsing failure as special error
  | APIPrepareContact UserId ACreatedConnLink ContactShortLinkData
  | APIPrepareGroup UserId CreatedLinkContact DirectLink GroupShortLinkData
  | APIChangePreparedContactUser ContactId UserId
  | APIChangePreparedGroupUser GroupId UserId
  | APIConnectPreparedContact {contactId :: ContactId, incognito :: IncognitoEnabled, msgContent_ :: Maybe MsgContent}
-  | APIConnectPreparedGroup GroupId IncognitoEnabled (Maybe MsgContent)
+  | APIConnectPreparedGroup {groupId :: GroupId, incognito :: IncognitoEnabled, ownerContact :: Maybe GroupOwnerContact, msgContent_ :: Maybe MsgContent}
  | APIConnect {userId :: UserId, incognito :: IncognitoEnabled, preparedLink_ :: Maybe ACreatedConnLink} -- Maybe is used to report link parsing failure as special error
  | Connect {incognito :: IncognitoEnabled, connLink_ :: Maybe AConnectionLink}
  | APIConnectContactViaAddress UserId IncognitoEnabled ContactId
@@ -1037,7 +1037,7 @@ data GroupLinkPlan
  | GLPOwnLink {groupInfo :: GroupInfo}
  | GLPConnectingConfirmReconnect
  | GLPConnectingProhibit {groupInfo_ :: Maybe GroupInfo}
-  | GLPKnown {groupInfo :: GroupInfo}
+  | GLPKnown {groupInfo :: GroupInfo, groupUpdated :: Bool, ownerVerification :: Maybe OwnerVerification}
  | GLPNoRelays {groupSLinkData_ :: Maybe GroupShortLinkData}
  deriving (Show)

@@ -1046,6 +1046,12 @@ data OwnerVerification
  | OVFailed {reason :: Text}
  deriving (Show)

+data GroupOwnerContact = GroupOwnerContact
+  { contactId :: ContactId,
+    memberId :: MemberId
+  }
+  deriving (Show)
+
 type DirectLink = Bool

 data GroupShortLinkInfo = GroupShortLinkInfo
@@ -1978,9 +1978,9 @@ processChatCommand vr nm = \case
          createDirectConnection db newUser agConnId ccLink' Nothing ConnNew Nothing subMode initialChatVersion PQSupportOn
        deleteAgentConnectionAsync (aConnId' conn)
        pure conn'
-  APIConnectPlan userId (Just cLink) linkOwnerSig_ -> withUserId userId $ \user ->
-    uncurry (CRConnectionPlan user) <$> connectPlan user cLink linkOwnerSig_
-  APIConnectPlan _ Nothing _ -> throwChatError CEInvalidConnReq
+  APIConnectPlan userId (Just cLink) resolveKnown linkOwnerSig_ -> withUserId userId $ \user ->
+    uncurry (CRConnectionPlan user) <$> connectPlan user cLink resolveKnown linkOwnerSig_
+  APIConnectPlan _ Nothing _ _ -> throwChatError CEInvalidConnReq
  APIPrepareContact userId accLink contactSLinkData -> withUserId userId $ \user -> do
    let ContactShortLinkData {profile, message, business} = contactSLinkData
    welcomeSharedMsgId <- forM message $ \_ -> getSharedMsgId
@@ -2100,7 +2100,7 @@ processChatCommand vr nm = \case
              toView $ CEvtNewChatItems user [ci]
            pure $ CRStartedConnectionToContact user ct' customUserProfile
          CVRConnectedContact ct' -> pure $ CRContactAlreadyExists user ct'
-  APIConnectPreparedGroup groupId incognito msgContent_ -> withUser $ \user -> do
+  APIConnectPreparedGroup {groupId, incognito, ownerContact, msgContent_} -> withUser $ \user -> do
    gInfo <- withFastStore $ \db -> getGroupInfo db vr user groupId
    case gInfo of
      GroupInfo {preparedGroup = Nothing} -> throwCmdError "group doesn't have link to connect"
@@ -2126,8 +2126,12 @@ processChatCommand vr nm = \case
        gInfo' <- withFastStore $ \db -> do
          gInfo' <- updatePreparedRelayedGroup db vr user gInfo mainCReq cReqHash incognitoProfile rootKey memberPrivKey publicMemberCount_
          -- Pre-emptively create owner members with trusted keys from link data
-          forM_ owners $ \OwnerAuth {ownerId, ownerKey} ->
-            void $ createLinkOwnerMember db vr user gInfo' (MemberId ownerId) ownerKey
+          forM_ owners $ \OwnerAuth {ownerId, ownerKey} -> do
+            let ctId_ = case ownerContact of
+                  Just GroupOwnerContact {contactId, memberId}
+                    | memberId == MemberId ownerId -> Just contactId
+                  _ -> Nothing
+            void $ createLinkOwnerMember db vr user gInfo' ctId_ (MemberId ownerId) ownerKey
          pure gInfo'
        rs <- mapConcurrently (connectToRelay gInfo') relays
        let relayFailed = \case (_, _, Left _) -> True; _ -> False
@@ -2221,7 +2225,7 @@ processChatCommand vr nm = \case
  Connect incognito (Just cLink@(ACL m cLink')) -> withUser $ \user -> do
    -- TODO [relays] member: /c api to support groups with relays
    -- TODO   - possibly by going through APIPrepareGroup -> APIConnectPreparedGroup
-    (ccLink, plan) <- connectPlan user cLink Nothing `catchAllErrors` \e -> case cLink' of CLFull cReq -> pure (ACCL m (CCLink cReq Nothing), CPInvitationLink (ILPOk Nothing Nothing)); _ -> throwError e
+    (ccLink, plan) <- connectPlan user cLink False Nothing `catchAllErrors` \e -> case cLink' of CLFull cReq -> pure (ACCL m (CCLink cReq Nothing), CPInvitationLink (ILPOk Nothing Nothing)); _ -> throwError e
    connectWithPlan user incognito ccLink plan
  Connect _ Nothing -> throwChatError CEInvalidConnReq
  APIConnectContactViaAddress userId incognito contactId -> withUserId userId $ \user -> do
@@ -3978,8 +3982,8 @@ processChatCommand vr nm = \case
            pure (gId, chatSettings)
        _ -> throwCmdError "not supported"
      processChatCommand vr nm $ APISetChatSettings (ChatRef cType chatId Nothing) $ updateSettings chatSettings
-    connectPlan :: User -> AConnectionLink -> Maybe LinkOwnerSig -> CM (ACreatedConnLink, ConnectionPlan)
-    connectPlan user (ACL SCMInvitation cLink) sig_ = case cLink of
+    connectPlan :: User -> AConnectionLink -> Bool -> Maybe LinkOwnerSig -> CM (ACreatedConnLink, ConnectionPlan)
+    connectPlan user (ACL SCMInvitation cLink) _ sig_ = case cLink of
      CLFull cReq -> invitationReqAndPlan cReq Nothing Nothing Nothing
      CLShort l -> do
        let l' = serverShortLink l
@@ -4000,7 +4004,7 @@ processChatCommand vr nm = \case
        invitationReqAndPlan cReq sLnk_ cld ov = do
          plan <- invitationRequestPlan user cReq cld ov `catchAllErrors` (pure . CPError)
          pure (ACCL SCMInvitation (CCLink cReq sLnk_), plan)
-    connectPlan user (ACL SCMContact cLink) sig_ = case cLink of
+    connectPlan user (ACL SCMContact cLink) resolveKnown sig_ = case cLink of
      CLFull cReq -> do
        plan <- contactOrGroupRequestPlan user cReq `catchAllErrors` (pure . CPError)
        pure (ACCL SCMContact $ CCLink cReq Nothing, plan)
@@ -4033,9 +4037,11 @@ processChatCommand vr nm = \case
        where
          l' = serverShortLink l
          con cReq = ACCL SCMContact $ CCLink cReq (Just l')
-          gPlan (cReq, g) = if memberRemoved (membership g) then Nothing else Just (con cReq, CPGroupLink (GLPKnown g))
+          gPlan (cReq, g) = if memberRemoved (membership g) then Nothing else Just (con cReq, CPGroupLink (GLPKnown g False Nothing))
          groupShortLinkPlan =
            knownLinkPlans >>= \case
+              Just (_, CPGroupLink (GLPKnown g _ _))
+                | resolveKnown -> resolveKnownGroup g
              Just r -> pure r
              Nothing -> do
                (fd, cData@(ContactLinkData _ UserContactData {direct, owners, relays})) <- getShortLinkConnReq' nm user l'
@@ -4045,8 +4051,6 @@ processChatCommand vr nm = \case
                  else do
                    let FixedLinkData {linkConnReq = cReq, linkEntityId, rootKey} = fd
                        linkInfo = GroupShortLinkInfo {direct, groupRelays = relays, publicGroupId = B64UrlByteString <$> linkEntityId}
-                    -- Cross-validate linkEntityId and publicGroupId from profile:
-                    -- for channels both must be present and match, for p2p groups both must be absent
                    let profilePGId = groupSLinkData_ >>= \GroupShortLinkData {groupProfile = GroupProfile {publicGroup}} ->
                          fmap (\PublicGroupProfile {publicGroupId} -> publicGroupId) publicGroup
                    case (B64UrlByteString <$> linkEntityId, profilePGId) of
@@ -4061,6 +4065,15 @@ processChatCommand vr nm = \case
                liftIO (getGroupInfoViaUserShortLink db vr user l') >>= \case
                  Just (cReq, g) -> pure $ Just (con cReq, CPGroupLink (GLPOwnLink g))
                  Nothing -> (gPlan =<<) <$> getGroupViaShortLinkToConnect db vr user l'
+              resolveKnownGroup g@GroupInfo {groupProfile = p} = do
+                (fd@FixedLinkData {rootKey = rk}, cData@(ContactLinkData _ UserContactData {owners})) <- getShortLinkConnReq' nm user l'
+                groupSLinkData_ <- liftIO $ decodeLinkUserData cData
+                let ov = verifyLinkOwner rk owners l' sig_
+                (g', updated) <- case groupSLinkData_ of
+                  Just GroupShortLinkData {groupProfile}
+                    | p /= groupProfile -> (,True) <$> withStore (\db -> updateGroupProfile db user g groupProfile)
+                  _ -> pure (g, False)
+                pure (con (linkConnReq fd), CPGroupLink (GLPKnown g' updated ov))
    connectWithPlan :: User -> IncognitoEnabled -> ACreatedConnLink -> ConnectionPlan -> CM ChatResponse
    connectWithPlan user@User {userId} incognito ccLink plan
      | connectionPlanProceed plan = do
@@ -4140,10 +4153,10 @@ processChatCommand vr nm = \case
            (Just gInfo, _) -> groupPlan gInfo linkInfo gld ov
    groupPlan :: GroupInfo -> Maybe GroupShortLinkInfo -> Maybe GroupShortLinkData -> Maybe OwnerVerification -> CM ConnectionPlan
    groupPlan gInfo@GroupInfo {membership} linkInfo gld ov
-      | memberStatus membership == GSMemRejected = pure $ CPGroupLink (GLPKnown gInfo)
+      | memberStatus membership == GSMemRejected = pure $ CPGroupLink (GLPKnown gInfo False ov)
      | not (memberActive membership) && not (memberRemoved membership) =
          pure $ CPGroupLink (GLPConnectingProhibit $ Just gInfo)
-      | memberActive membership = pure $ CPGroupLink (GLPKnown gInfo)
+      | memberActive membership = pure $ CPGroupLink (GLPKnown gInfo False ov)
      | otherwise = pure $ CPGroupLink (GLPOk linkInfo gld ov)
    contactCReqSchemas :: ConnReqUriData -> (ConnReqContact, ConnReqContact)
    contactCReqSchemas crData =
@@ -5051,13 +5064,13 @@ chatCommandP =
      (">#" <|> "> #") *> (SendGroupMessageQuote <$> displayNameP <* A.space <* char_ '@' <*> (Just <$> displayNameP) <* A.space <*> quotedMsg <*> msgTextP),
      "/_contacts " *> (APIListContacts <$> A.decimal),
      "/contacts" $> ListContacts,
-      "/_connect plan " *> (APIConnectPlan <$> A.decimal <* A.space <*> ((Just <$> strP) <|> A.takeTill (== ' ') $> Nothing) <*> optional (" sig=" *> jsonP)),
+      "/_connect plan " *> (APIConnectPlan <$> A.decimal <* A.space <*> ((Just <$> strP) <|> A.takeTill (== ' ') $> Nothing) <*> ((" resolve=" *> onOffP) <|> pure False) <*> optional (" sig=" *> jsonP)),
      "/_prepare contact " *> (APIPrepareContact <$> A.decimal <* A.space <*> connLinkP <* A.space <*> jsonP),
      "/_prepare group " *> (APIPrepareGroup <$> A.decimal <* A.space <*> connLinkP' <*> (" direct=" *> onOffP <|> pure True) <* A.space <*> jsonP),
      "/_set contact user @" *> (APIChangePreparedContactUser <$> A.decimal <* A.space <*> A.decimal),
      "/_set group user #" *> (APIChangePreparedGroupUser <$> A.decimal <* A.space <*> A.decimal),
      "/_connect contact @" *> (APIConnectPreparedContact <$> A.decimal <*> incognitoOnOffP <*> optional (A.space *> msgContentP)),
-      "/_connect group #" *> (APIConnectPreparedGroup <$> A.decimal <*> incognitoOnOffP <*> optional (A.space *> msgContentP)),
+      "/_connect group #" *> (APIConnectPreparedGroup <$> A.decimal <*> incognitoOnOffP <*> optional (A.space *> ownerContactP) <*> optional (A.space *> msgContentP)),
      "/_connect " *> (APIAddContact <$> A.decimal <*> incognitoOnOffP),
      "/_connect " *> (APIConnect <$> A.decimal <*> incognitoOnOffP <* A.space <*> connLinkP_),
      "/_set incognito :" *> (APISetConnectionIncognito <$> A.decimal <* A.space <*> onOffP),
@@ -5187,6 +5200,7 @@ chatCommandP =
      ((Just <$> connLinkP) <|> A.takeTill (== ' ') $> Nothing)
    incognitoP = (A.space *> ("incognito" <|> "i")) $> True <|> pure False
    incognitoOnOffP = (A.space *> "incognito=" *> onOffP) <|> pure False
+    ownerContactP = "contact=" *> (GroupOwnerContact <$> A.decimal <* " owner=" <*> strP)
    imagePrefix = (<>) <$> "data:" <*> ("image/png;base64," <|> "image/jpg;base64,")
    imageP = safeDecodeUtf8 <$> ((<>) <$> imagePrefix <*> (B64.encode <$> base64P))
    chatTypeP = A.char '@' $> CTDirect <|> A.char '#' $> CTGroup <|> A.char '*' $> CTLocal <|> A.char ':' $> CTContactConnection
@@ -2917,8 +2917,9 @@ processAgentMessageConn vr user@User {userId} corrId agentConnId agentMessage =
        GCHostMember ->
          withStore' (\db -> runExceptT $ getGroupMemberByMemberId db vr user gInfo memId) >>= \case
            Right existingMember
-              | useRelays' gInfo ->
-                  void $ withStore $ \db -> updatePreparedChannelMember db vr user existingMember memInfo
+              | useRelays' gInfo -> do
+                  updatedMember <- withStore $ \db -> updatePreparedChannelMember db vr user existingMember memInfo
+                  toView $ CEvtGroupMemberUpdated user gInfo existingMember updatedMember
              | otherwise ->
                  messageError "x.grp.mem.intro ignored: member already exists"
            Left _
@@ -2966,8 +2966,8 @@ createNewUnknownGroupMember db vr user@User {userId, userContactId} GroupInfo {g
  where
    VersionRange minV maxV = vr

-createLinkOwnerMember :: DB.Connection -> VersionRangeChat -> User -> GroupInfo -> MemberId -> C.PublicKeyEd25519 -> ExceptT StoreError IO GroupMember
-createLinkOwnerMember db vr user@User {userId, userContactId} GroupInfo {groupId} memberId ownerKey = do
+createLinkOwnerMember :: DB.Connection -> VersionRangeChat -> User -> GroupInfo -> Maybe ContactId -> MemberId -> C.PublicKeyEd25519 -> ExceptT StoreError IO GroupMember
+createLinkOwnerMember db vr user@User {userId, userContactId} GroupInfo {groupId} contactId_ memberId ownerKey = do
  currentTs <- liftIO getCurrentTime
  let memberProfile = profileFromName $ nameFromMemberId memberId
  (localDisplayName, profileId) <- createNewMemberProfile_ db user memberProfile currentTs
@@ -2983,7 +2983,7 @@ createLinkOwnerMember db vr user@User {userId, userContactId} GroupInfo {groupId
        VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)
      |]
      ( (groupId, indexInGroup, memberId, GROwner, GCPreMember, GSMemUnknown, Binary B.empty, fromInvitedBy userContactId IBUnknown)
-          :. (userId, localDisplayName, Nothing :: (Maybe Int64), profileId, ownerKey, currentTs, currentTs)
+          :. (userId, localDisplayName, contactId_, profileId, ownerKey, currentTs, currentTs)
          :. (minV, maxV)
      )
  groupMemberId <- liftIO $ insertedRowId db
@@ -769,15 +769,18 @@ fromLocalProfile LocalProfile {displayName, fullName, shortDescr, image, contact

 data GroupType
  = GTChannel
+  | GTGroup
  | GTUnknown Text
  deriving (Eq, Show)

 instance TextEncoding GroupType where
  textEncode = \case
    GTChannel -> "channel"
+    GTGroup -> "group"
    GTUnknown tag -> tag
  textDecode s = Just $ case s of
    "channel" -> GTChannel
+    "group" -> GTGroup
    tag -> GTUnknown tag

 instance FromField GroupType where fromField = fromTextField_ textDecode
@@ -2103,7 +2103,7 @@ viewConnectionPlan ChatConfig {logLevel, testView} _connLink = \case
    GLPConnectingConfirmReconnect -> [grpLink "connecting, allowed to reconnect"]
    GLPConnectingProhibit Nothing -> [grpLink "connecting"]
    GLPConnectingProhibit (Just g) -> connecting g
-    GLPKnown g@GroupInfo {preparedGroup, membership = m} -> case preparedGroup of
+    GLPKnown g@GroupInfo {preparedGroup, membership = m} _ _ -> case preparedGroup of
      Just PreparedGroup {connLinkStartedConnection} -> case memberStatus m of
        GSMemUnknown
          | connLinkStartedConnection -> connecting g
@@ -7,7 +7,9 @@
 module Bots.DirectoryTests where

 import ChatClient
+import ChatTests.ChatRelays (withRelay)
 import ChatTests.DBUtils
+import ChatTests.Groups (memberJoinChannel, prepareChannel1Relay)
 import ChatTests.Utils
 import Control.Concurrent (forkIO, killThread, threadDelay)
 import Control.Exception (finally)
@@ -85,6 +87,12 @@ directoryServiceTests = do
  describe "help commands" $ do
    it "should not list audio command" testHelpNoAudio
    it "should reject audio command in DM" testAudioCommandInDM
+  describe "public group registration" $ do
+    it "should register channel via shared link card" testRegisterChannelViaCard
+    it "should suggest share via chat when link sent as text" testLinkAsTextSearch
+    it "should reject card shared by non-owner" testNonOwnerSharesCard
+    it "should delete channel registration and leave" testDeleteChannelRegistration
+    it "should handle re-registration when already listed" testReregistrationAlreadyListed

 directoryProfile :: Profile
 directoryProfile = Profile {displayName = "SimpleX Directory", fullName = "", shortDescr = Nothing, image = Nothing, contactLink = Nothing, peerType = Just CPTBot, preferences = Nothing}
@@ -1771,7 +1779,7 @@ u `connectVia` dsLink = do
  u .<# "> Welcome to SimpleX Directory!"
  u <## ""
  u <## "🔍 Send search string to find groups - try security."
-  u <## "/help - how to submit your group."
+  u <## "/help - how to submit your group or channel."
  u <## "/new - recent groups."
  u <## ""
  u <## "[Directory rules](https://simplex.chat/docs/directory.html)."
@@ -1922,7 +1930,7 @@ testHelpNoAudio ps =
      -- commands help should not mention /audio
      bob #> "@'SimpleX Directory' /help commands"
      bob <# "'SimpleX Directory'> /'help commands' - receive this help message."
-      bob <## "/help - how to register your group to be added to directory."
+      bob <## "/help - how to register your group or channel to be added to directory."
      bob <## "/list - list the groups you registered."
      bob <## "`/role <ID>` - view and set default member role for your group."
      bob <## "`/filter <ID>` - view and set spam filter settings for group."
@@ -1940,6 +1948,201 @@ testAudioCommandInDM ps =
      bob <# "'SimpleX Directory'> > /audio"
      bob <## "      Unknown command"

+testRegisterChannelViaCard :: HasCallStack => TestParams -> IO ()
+testRegisterChannelViaCard ps =
+  withDirectoryServiceCfg ps testCfg $ \superUser dsLink ->
+    withNewTestChatCfg ps testCfg "bob" bobProfile $ \bob ->
+      withRelay ps $ \relay -> do
+        -- bob connects to directory service first
+        bob `connectVia` dsLink
+        -- bob creates a channel with a relay
+        (_shortLink, _fullLink) <- prepareChannel1Relay "news" bob relay
+        -- bob shares the channel card with directory bot
+        bob ##> "/share chat #news @'SimpleX Directory'"
+        bob <# "@'SimpleX Directory' link to join channel #news (signed):"
+        _ <- getTermLine bob -- short link
+        _ <- getTermLine bob -- ownerSig JSON
+        -- directory bot validates and joins via relay
+        bob <# "'SimpleX Directory'> Joining the channel news…"
+        concurrentlyN_
+          [ do
+              relay <## "'SimpleX Directory': accepting request to join group #news..."
+              relay <## "#news: 'SimpleX Directory' joined the group",
+            bob <## "#news: relay added 'SimpleX Directory_1' to the group"
+          ]
+        -- owner sends a message to trigger member introduction
+        bob <# "'SimpleX Directory'> Joined the channel news. Registration is pending approval — it may take up to 48 hours."
+        superUser <# "'SimpleX Directory'> bob submitted the channel ID 1:"
+        superUser <## "news"
+        superUser <##. "Link to join channel: "
+        superUser <## "You need SimpleX Chat app v6.5 to join."
+        superUser <## "2 subscribers"
+        superUser <## ""
+        superUser <## "To approve send:"
+        superUser <# "'SimpleX Directory'> /approve 1:news 1"
+        -- superuser approves
+        let approve = "/approve 1:news 1"
+        superUser #> ("@'SimpleX Directory' " <> approve)
+        superUser <# ("'SimpleX Directory'> > " <> approve)
+        superUser <## "      Channel approved!"
+        bob <# ("'SimpleX Directory'> The channel ID 1 (news) is approved and listed in directory - please moderate it!")
+        bob <## "Please note: if you change the channel profile it will be hidden from directory until it is re-approved."
+        -- owner updates channel profile, triggering re-approval
+        bob ##> "/gp news news News and Updates"
+        bob <## "description changed to: News and Updates"
+        bob <# "'SimpleX Directory'> The channel ID 1 (news) is updated."
+        bob <## "It is hidden from the directory until approved."
+        relay <## "bob updated group #news: (signed)"
+        relay <## "description changed to: News and Updates"
+        superUser <# "'SimpleX Directory'> The channel ID 1 (news) is updated."
+        superUser <# ("'SimpleX Directory'> bob submitted the channel ID 1:")
+        superUser <## "news (News and Updates)"
+        superUser <##. "Link to join channel: "
+        superUser <## "You need SimpleX Chat app v6.5 to join."
+        superUser <## "3 subscribers"
+        superUser <## ""
+        superUser <## "To approve send:"
+        superUser <# "'SimpleX Directory'> /approve 1:news 1"
+        -- re-approve after profile update
+        let approve2 = "/approve 1:news 1"
+        superUser #> ("@'SimpleX Directory' " <> approve2)
+        superUser <# ("'SimpleX Directory'> > " <> approve2)
+        superUser <## "      Channel approved!"
+        bob <# ("'SimpleX Directory'> The channel ID 1 (news) is approved and listed in directory - please moderate it!")
+        bob <## "Please note: if you change the channel profile it will be hidden from directory until it is re-approved."
+        -- owner leaves channel, triggering de-listing and bot leaving
+        bob ##> "/leave #news"
+        concurrentlyN_
+          [ do
+              bob <## "#news: you left the group"
+              bob <## "use /d #news to delete the group",
+            relay <## "#news: bob left the group (signed)"
+          ]
+        bob <# "'SimpleX Directory'> You left the channel ID 1 (news)."
+        bob <## ""
+        bob <## "The channel is no longer listed in the directory."
+        superUser <# "'SimpleX Directory'> The channel ID 1 (news) is de-listed (channel owner left)."
+        relay <## "#news: 'SimpleX Directory' left the group (signed)"
+
+testLinkAsTextSearch :: HasCallStack => TestParams -> IO ()
+testLinkAsTextSearch ps =
+  withDirectoryServiceCfg ps testCfg $ \_superUser dsLink ->
+    withNewTestChatCfg ps testCfg "bob" bobProfile $ \bob ->
+      withRelay ps $ \relay -> do
+        bob `connectVia` dsLink
+        (shortLink, _fullLink) <- prepareChannel1Relay "news" bob relay
+        bob #> ("@'SimpleX Directory' " <> shortLink)
+        bob <# ("'SimpleX Directory'> > " <> shortLink)
+        bob <## "      No groups found."
+        bob <## "To register a group or a channel, please use \"Share via chat\" feature."
+
+testNonOwnerSharesCard :: HasCallStack => TestParams -> IO ()
+testNonOwnerSharesCard ps =
+  withDirectoryServiceCfg ps testCfg $ \_superUser dsLink ->
+    withNewTestChatCfg ps testCfg "bob" bobProfile $ \bob ->
+      withRelay ps $ \relay ->
+        withNewTestChatCfg ps testCfg "cath" cathProfile $ \cath -> do
+          bob `connectVia` dsLink
+          cath `connectVia` dsLink
+          (shortLink, fullLink) <- prepareChannel1Relay "news" bob relay
+          memberJoinChannel "news" [relay] [bob] shortLink fullLink cath
+          cath ##> "/share chat #news @'SimpleX Directory'"
+          cath <# "@'SimpleX Directory' link to join channel #news:"
+          _ <- getTermLine cath -- short link
+          cath <# "'SimpleX Directory'> To add a channel to directory you must be the owner."
+
+testDeleteChannelRegistration :: HasCallStack => TestParams -> IO ()
+testDeleteChannelRegistration ps =
+  withDirectoryServiceCfg ps testCfg $ \superUser dsLink ->
+    withNewTestChatCfg ps testCfg "bob" bobProfile $ \bob ->
+      withRelay ps $ \relay -> do
+        bob `connectVia` dsLink
+        (_shortLink, _fullLink) <- prepareChannel1Relay "news" bob relay
+        bob ##> "/share chat #news @'SimpleX Directory'"
+        bob <# "@'SimpleX Directory' link to join channel #news (signed):"
+        _ <- getTermLine bob -- short link
+        _ <- getTermLine bob -- ownerSig JSON
+        bob <# "'SimpleX Directory'> Joining the channel news…"
+        concurrentlyN_
+          [ do
+              relay <## "'SimpleX Directory': accepting request to join group #news..."
+              relay <## "#news: 'SimpleX Directory' joined the group",
+            bob <## "#news: relay added 'SimpleX Directory_1' to the group"
+          ]
+        bob <# "'SimpleX Directory'> Joined the channel news. Registration is pending approval — it may take up to 48 hours."
+        superUser <# "'SimpleX Directory'> bob submitted the channel ID 1:"
+        superUser <## "news"
+        superUser <##. "Link to join channel: "
+        superUser <## "You need SimpleX Chat app v6.5 to join."
+        superUser <## "2 subscribers"
+        superUser <## ""
+        superUser <## "To approve send:"
+        superUser <# "'SimpleX Directory'> /approve 1:news 1"
+        let approve = "/approve 1:news 1"
+        superUser #> ("@'SimpleX Directory' " <> approve)
+        superUser <# ("'SimpleX Directory'> > " <> approve)
+        superUser <## "      Channel approved!"
+        bob <# ("'SimpleX Directory'> The channel ID 1 (news) is approved and listed in directory - please moderate it!")
+        bob <## "Please note: if you change the channel profile it will be hidden from directory until it is re-approved."
+        -- owner deletes registration
+        bob #> "@'SimpleX Directory' /delete 1:news"
+        bob
+          <###
+            [ WithTime "'SimpleX Directory'> > /delete 1:news",
+              "      Your channel news is deleted from the directory",
+              "#news: 'SimpleX Directory_1' left the group (signed)"
+            ]
+        relay <## "#news: 'SimpleX Directory' left the group (signed)"
+
+testReregistrationAlreadyListed :: HasCallStack => TestParams -> IO ()
+testReregistrationAlreadyListed ps =
+  withDirectoryServiceCfg ps testCfg $ \superUser dsLink ->
+    withNewTestChatCfg ps testCfg "bob" bobProfile $ \bob ->
+      withRelay ps $ \relay -> do
+        bob `connectVia` dsLink
+        (_shortLink, _fullLink) <- prepareChannel1Relay "news" bob relay
+        -- register and approve
+        bob ##> "/share chat #news @'SimpleX Directory'"
+        bob <# "@'SimpleX Directory' link to join channel #news (signed):"
+        _ <- getTermLine bob -- short link
+        _ <- getTermLine bob -- ownerSig JSON
+        bob <# "'SimpleX Directory'> Joining the channel news…"
+        concurrentlyN_
+          [ do
+              relay <## "'SimpleX Directory': accepting request to join group #news..."
+              relay <## "#news: 'SimpleX Directory' joined the group",
+            bob <## "#news: relay added 'SimpleX Directory_1' to the group"
+          ]
+        bob <# "'SimpleX Directory'> Joined the channel news. Registration is pending approval — it may take up to 48 hours."
+        superUser <# "'SimpleX Directory'> bob submitted the channel ID 1:"
+        superUser <## "news"
+        superUser <##. "Link to join channel: "
+        superUser <## "You need SimpleX Chat app v6.5 to join."
+        superUser <## "2 subscribers"
+        superUser <## ""
+        superUser <## "To approve send:"
+        superUser <# "'SimpleX Directory'> /approve 1:news 1"
+        let approve = "/approve 1:news 1"
+        superUser #> ("@'SimpleX Directory' " <> approve)
+        superUser <# ("'SimpleX Directory'> > " <> approve)
+        superUser <## "      Channel approved!"
+        bob <# ("'SimpleX Directory'> The channel ID 1 (news) is approved and listed in directory - please moderate it!")
+        bob <## "Please note: if you change the channel profile it will be hidden from directory until it is re-approved."
+        -- search finds the channel with its link
+        bob #> "@'SimpleX Directory' news"
+        bob <# "'SimpleX Directory'> > news"
+        bob <## "      Found 1 group(s)."
+        bob <# "'SimpleX Directory'> news"
+        bob <##. "Link to join channel: "
+        bob <## "You need SimpleX Chat app v6.5 to join."
+        bob <## "3 subscribers"
+        -- owner re-shares card while already listed
+        bob ##> "/share chat #news @'SimpleX Directory'"
+        bob <# "@'SimpleX Directory' link to join channel #news (signed):"
+        _ <- getTermLine bob -- short link
+        _ <- getTermLine bob -- ownerSig JSON
+        bob <# "'SimpleX Directory'> Channel is already listed in the directory."
+
 testGetCaptchaStr :: HasCallStack => TestParams -> IO ()
 testGetCaptchaStr _ps = do
  s0 <- getCaptchaStr 0 ""
@@ -19,7 +19,7 @@ import Simplex.Chat.Controller (ChatConfig (..))
 import Simplex.Chat.Library.Internal (roundedFDCount)
 import Simplex.Chat.Mobile.File
 import Simplex.Chat.Options (ChatOpts (..))
-import Simplex.FileTransfer.Server.Env (XFTPServerConfig (..))
+import Simplex.FileTransfer.Server.Env (XFTPServerConfig (..), XFTPStoreConfig (..))
 import Simplex.Messaging.Crypto.File (CryptoFile (..), CryptoFileArgs (..))
 import Simplex.Messaging.Encoding.String
 import System.Directory (copyFile, createDirectoryIfMissing, doesFileExist, getFileSize)
@@ -940,7 +940,7 @@ testXFTPRcvError ps = do
        alice <## "completed uploading file 1 (test.pdf) for bob"

  -- server is up w/t store log - file reception should fail
-  withXFTPServer' xftpServerConfig {storeLogFile = Nothing} $ do
+  withXFTPServer' xftpServerConfig {serverStoreCfg = XSCMemory Nothing, storeLogFile = Nothing} $ do
    withTestChat ps "bob" $ \bob -> do
      bob <## "subscribed 1 connections on server localhost"
      bob ##> "/fr 1 ./tests/tmp"
@@ -20,14 +20,14 @@ active_directory: true
    word-break: break-word;
  }

-  #directory .entry a {
+  #directory .entry a.img-link {
    order: -1;
    object-fit: cover;
    margin-right: 16px;
    margin-bottom: 16px;
  }

-  #directory .entry a img {
+  #directory .entry a.img-link img {
    min-width: 104px;
    min-height: 104px;
    width: 104px;
@@ -165,7 +165,7 @@ function entrySortPriority(entry) {

 function entryMemberCount(entry) {
  return entry.entryType.type == 'group'
-    ? (entry.entryType.summary?.currentMembers ?? 0)
+    ? (entry.entryType.summary?.publicMemberCount ?? entry.entryType.summary?.currentMembers ?? 0)
    : 0
 }

@@ -263,6 +263,13 @@ function displayEntries(entries) {
        }, 0);
      }

+      if (entryType?.groupType) {
+        const noteElement = document.createElement('p');
+        noteElement.innerHTML = 'You need <a href="https://simplex.chat/downloads/">SimpleX Chat app v6.5</a> to join.';
+        noteElement.className = 'text-sm';
+        textContainer.appendChild(noteElement);
+      }
+
      const entryTimestamp = currentSortMode === 'new' && entry.createdAt
        ? showCreatedOn(entry.createdAt)
        : entry.activeAt
@@ -278,7 +285,8 @@ function displayEntries(entries) {
      const memberCount = entryMemberCount(entry);
      if (typeof memberCount == 'number' && memberCount > 0) {
        const memberCountElement = document.createElement('p');
-        memberCountElement.textContent = `${memberCount} members`;
+        const isChannel = entryType?.groupType === 'channel';
+        memberCountElement.textContent = `${memberCount} ${isChannel ? 'subscribers' : 'members'}`;
        memberCountElement.className = 'text-sm';
        textContainer.appendChild(memberCountElement);
      }
@@ -291,6 +299,7 @@ function displayEntries(entries) {
      }

      const imgLinkElement = document.createElement('a');
+      imgLinkElement.className = 'img-link';
      const groupLinkUri = groupLink.connShortLink ?? groupLink.connFullLink
      try {
        imgLinkElement.href = platformSimplexUri(groupLinkUri);