login: add support for bot tokens

go.mod

@@ -27,7 +27,7 @@ require (
 	github.com/rs/zerolog v1.34.0
 	github.com/stretchr/testify v1.11.1
 	github.com/tidwall/gjson v1.18.0
-	go.mau.fi/util v0.9.4-0.20251203150954-89222cf416b4
+	go.mau.fi/util v0.9.4-0.20251206205611-85e6fd6551e0
 	go.mau.fi/webp v0.2.0
 	go.mau.fi/zerozap v0.1.2
 	go.opentelemetry.io/otel v1.38.0
@@ -41,7 +41,7 @@ require (
 	golang.org/x/sync v0.18.0
 	golang.org/x/tools v0.39.0
 	gopkg.in/yaml.v3 v3.0.1
-	maunium.net/go/mautrix v0.26.1-0.20251206105112-4efa4bdac5e3
+	maunium.net/go/mautrix v0.26.1-0.20251207175222-00c58efc5906
 	rsc.io/qr v0.2.0
 )
 

go.sum

@@ -114,8 +114,8 @@ github.com/tidwall/sjson v1.2.5/go.mod h1:Fvgq9kS/6ociJEDnK0Fk1cpYF4FIW6ZF7LAe+6
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
 github.com/yuin/goldmark v1.7.13 h1:GPddIs617DnBLFFVJFgpo1aBfe/4xcvMc3SB5t/D0pA=
 github.com/yuin/goldmark v1.7.13/go.mod h1:ip/1k0VRfGynBgxOz0yCqHrbZXhcjxyuS66Brc7iBKg=
-go.mau.fi/util v0.9.4-0.20251203150954-89222cf416b4 h1:UrHJ6O9Nr+KxuAFNKyTZdGExhtUq09WcYpUlqMwBOic=
+go.mau.fi/util v0.9.4-0.20251206205611-85e6fd6551e0 h1:ESebxPGULuuxxcZigjcBFyyU62tiyY6ivtX17P4BkvY=
-go.mau.fi/util v0.9.4-0.20251203150954-89222cf416b4/go.mod h1:viDmhBOAFfcqDdKSk53EPJV3N4Mi8Jst5/ahGJ/vwsA=
+go.mau.fi/util v0.9.4-0.20251206205611-85e6fd6551e0/go.mod h1:viDmhBOAFfcqDdKSk53EPJV3N4Mi8Jst5/ahGJ/vwsA=
 go.mau.fi/webp v0.2.0 h1:QVMenHw7JDb4vall5sV75JNBQj9Hw4u8AKbi1QetHvg=
 go.mau.fi/webp v0.2.0/go.mod h1:VSg9MyODn12Mb5pyG0NIyNFhujrmoFSsZBs8syOZD1Q=
 go.mau.fi/zeroconfig v0.2.0 h1:e/OGEERqVRRKlgaro7E6bh8xXiKFSXB3eNNIud7FUjU=
@@ -237,7 +237,7 @@ gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 maunium.net/go/mauflag v1.0.0 h1:YiaRc0tEI3toYtJMRIfjP+jklH45uDHtT80nUamyD4M=
 maunium.net/go/mauflag v1.0.0/go.mod h1:nLivPOpTpHnpzEh8jEdSL9UqO9+/KBJFmNRlwKfkPeA=
-maunium.net/go/mautrix v0.26.1-0.20251206105112-4efa4bdac5e3 h1:llPUQswvRVaWkWqwH1P6T51wkj3fWCXu4rxewN0RLsY=
+maunium.net/go/mautrix v0.26.1-0.20251207175222-00c58efc5906 h1:5Y4XfVK3QRi/LIPO0yb0oBoEiba3NAh3ayUmP1byzUY=
-maunium.net/go/mautrix v0.26.1-0.20251206105112-4efa4bdac5e3/go.mod h1:NaesYcOQWFDbixVYywCVS+Twlzab9hOUpFNlCBlvciE=
+maunium.net/go/mautrix v0.26.1-0.20251207175222-00c58efc5906/go.mod h1:pzwIT42s+BhBjEYovmcOt69VlNW2RkJ6pCyZjYQHKIc=
 rsc.io/qr v0.2.0 h1:6vBLea5/NRMVTz8V66gipeLycZMl/+UlFmk8DvqQ6WY=
 rsc.io/qr v0.2.0/go.mod h1:IF+uZjkb9fqyeF/4tlBoynqmQxUoPfWEKh921coOuXs=

pkg/connector/backfill.go

@@ -185,6 +185,9 @@ func (t *TelegramClient) stopTakeout(ctx context.Context) error {
 }
 
 func (t *TelegramClient) FetchMessages(ctx context.Context, fetchParams bridgev2.FetchMessagesParams) (*bridgev2.FetchMessagesResponse, error) {
+	if t.metadata.IsBot {
+		return nil, fmt.Errorf("bots cannot backfill messages")
+	}
 	log := zerolog.Ctx(ctx).With().Str("method", "FetchMessages").Logger()
 	ctx = log.WithContext(ctx)
 

pkg/connector/chatinfo.go

@@ -105,7 +105,7 @@ func (t *TelegramClient) getDMChatInfo(ctx context.Context, userID int64) (*brid
 			MemberMap:   map[networkid.UserID]bridgev2.ChatMember{},
 			PowerLevels: t.getDMPowerLevels(ghost),
 		},
-		CanBackfill:  true,
+		CanBackfill:  !t.metadata.IsBot,
 		ExtraUpdates: updatePortalLastSyncAt,
 	}
 	chatInfo.Members.MemberMap.Add(bridgev2.ChatMember{EventSender: t.mySender()})
@@ -142,7 +142,7 @@ type memberFetchMeta struct {
 func (t *TelegramClient) wrapChatInfo(portalID networkid.PortalID, rawChat tg.ChatClass) (*bridgev2.ChatInfo, *memberFetchMeta, error) {
 	info := bridgev2.ChatInfo{
 		Type:        ptr.Ptr(database.RoomTypeDefault),
-		CanBackfill: true,
+		CanBackfill: !t.metadata.IsBot,
 		Members: &bridgev2.ChatMemberList{
 			ExcludeChangesFromTimeline: true,
 			MemberMap:                  bridgev2.ChatMemberMap{},

pkg/connector/client.go

@@ -711,8 +711,7 @@ func (t *TelegramClient) FillBridgeState(state status.BridgeState) status.Bridge
 	if state.Info == nil {
 		state.Info = make(map[string]any)
 	}
-	meta := t.userLogin.Metadata.(*UserLoginMetadata)
+	state.Info["is_bot"] = t.metadata.IsBot
-	state.Info["is_bot"] = meta.IsBot
+	state.Info["login_method"] = t.metadata.LoginMethod
-	state.Info["login_method"] = meta.LoginMethod
 	return state
 }

pkg/connector/handlematrix.go

@@ -555,11 +555,9 @@ func (t *TelegramClient) PreHandleMatrixReaction(ctx context.Context, msg *bridg
 		return resp, fmt.Errorf("failed to get available reactions: %w", err)
 	} else if _, ok := availableReactions[keyNoVariation]; ok {
 		log.Debug().Msg("Not using custom emoji reaction since the emoji is available")
-	} else {
+	} else if documentID, ok := emojis.GetEmojiDocumentID(keyNoVariation); ok && !t.metadata.IsBot {
-		if documentID, ok := emojis.GetEmojiDocumentID(keyNoVariation); ok {
+		log.Debug().Msg("Using custom emoji reaction")
-			log.Debug().Msg("Using custom emoji reaction")
+		emojiID = ids.MakeEmojiIDFromDocumentID(documentID)
-			emojiID = ids.MakeEmojiIDFromDocumentID(documentID)
-		}
 	}
 
 	log.Debug().Str("emoji_id", string(emojiID)).Msg("Pre-handled reaction")
@@ -684,10 +682,15 @@ func (t *TelegramClient) HandleMatrixReadReceipt(ctx context.Context, msg *bridg
 	var readMentionsErr, readReactionsErr, readMessagesErr error
 	var wg sync.WaitGroup
 
+	isBot := t.metadata.IsBot
+
 	// Read mentions
 	wg.Add(1)
 	go func() {
 		defer wg.Done()
+		if isBot {
+			return
+		}
 		_, readMentionsErr = t.client.API().MessagesReadMentions(ctx, &tg.MessagesReadMentionsRequest{
 			Peer:     inputPeer,
 			TopMsgID: topicID,
@@ -698,6 +701,9 @@ func (t *TelegramClient) HandleMatrixReadReceipt(ctx context.Context, msg *bridg
 	wg.Add(1)
 	go func() {
 		defer wg.Done()
+		if isBot {
+			return
+		}
 		_, readMentionsErr = t.client.API().MessagesReadReactions(ctx, &tg.MessagesReadReactionsRequest{
 			Peer:     inputPeer,
 			TopMsgID: topicID,
@@ -709,6 +715,10 @@ func (t *TelegramClient) HandleMatrixReadReceipt(ctx context.Context, msg *bridg
 	go func() {
 		defer wg.Done()
 
+		if isBot {
+			return
+		}
+
 		message := msg.ExactMessage
 		if message == nil {
 			message, readMessagesErr = t.main.Bridge.DB.Message.GetLastPartAtOrBeforeTime(ctx, msg.Portal.PortalKey, time.Now())

pkg/connector/handletelegram.go

@@ -1035,7 +1035,9 @@ func (t *TelegramClient) getAvailableReactionsForCapability(ctx context.Context)
 }
 
 func (t *TelegramClient) getAvailableReactions(ctx context.Context) (map[string]struct{}, error) {
-	if !t.IsLoggedIn() {
+	if t.metadata.IsBot {
+		return nil, nil
+	} else if !t.IsLoggedIn() {
 		return nil, errors.New("you must be logged in to get available reactions")
 	}
 

pkg/connector/login.go

@@ -41,7 +41,7 @@ import (
 const (
 	LoginFlowIDPhone    = "phone"
 	LoginFlowIDQR       = "qr"
-	LoginFlowIDBotToken = "bot_token"
+	LoginFlowIDBotToken = "bot"
 
 	LoginStepIDComplete = "fi.mau.telegram.login.complete"
 )
@@ -76,6 +76,11 @@ func (tg *TelegramConnector) GetLoginFlows() []bridgev2.LoginFlow {
 			Description: "Login by scanning a QR code from your phone",
 			ID:          LoginFlowIDQR,
 		},
+		{
+			Name:        "Bot token",
+			Description: "Log in as a bot using the bot token provided by BotFather.",
+			ID:          LoginFlowIDBotToken,
+		},
 	}
 }
 
@@ -86,6 +91,8 @@ func (tg *TelegramConnector) CreateLogin(ctx context.Context, user *bridgev2.Use
 		flowID: flowID,
 	}
 	switch flowID {
+	case LoginFlowIDBotToken:
+		return &BotLogin{baseLogin: bl}, nil
 	case LoginFlowIDPhone:
 		return &PhoneLogin{baseLogin: bl}, nil
 	case LoginFlowIDQR:
@@ -205,6 +212,9 @@ func (bl *baseLogin) finalizeLogin(
 	client := ul.Client.(*TelegramClient)
 
 	go func() {
+		if metadata.IsBot {
+			return
+		}
 		log := ul.Log.With().Str("action", "post-login sync").Logger()
 		err := client.clientInitialized.Wait(ctx)
 		if err != nil {
@@ -215,6 +225,9 @@ func (bl *baseLogin) finalizeLogin(
 	}()
 
 	go func() {
+		if metadata.IsBot {
+			return
+		}
 		log := ul.Log.With().Str("component", "post-login takeout").Logger()
 		client.takeoutLock.Lock()
 		defer client.takeoutLock.Unlock()

pkg/connector/loginbot.go

@@ -0,0 +1,109 @@
+// mautrix-telegram - A Matrix-Telegram puppeting bridge.
+// Copyright (C) 2025 Tulir Asokan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package connector
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"github.com/rs/zerolog"
+	"maunium.net/go/mautrix/bridgev2"
+)
+
+const (
+	LoginStepIDBotToken = "fi.mau.telegram.login.bot_token"
+)
+
+type BotLogin struct {
+	*baseLogin
+}
+
+func (bl *BotLogin) StartWithOverride(ctx context.Context, override *bridgev2.UserLogin) (*bridgev2.LoginStep, error) {
+	meta := override.Metadata.(*UserLoginMetadata)
+	if !meta.IsBot {
+		return nil, fmt.Errorf("can't re-login to a non-bot account with bot token")
+	}
+	return bl.Start(ctx)
+}
+
+func (bl *BotLogin) Start(ctx context.Context) (*bridgev2.LoginStep, error) {
+	return &bridgev2.LoginStep{
+		Type:         bridgev2.LoginStepTypeUserInput,
+		StepID:       LoginStepIDBotToken,
+		Instructions: "Please enter the bot token you want to log in as",
+		UserInputParams: &bridgev2.LoginUserInputParams{
+			Fields: []bridgev2.LoginInputDataField{{
+				Type:    bridgev2.LoginInputFieldTypeToken,
+				ID:      LoginStepIDBotToken,
+				Name:    "Bot token",
+				Pattern: `^\d+:[A-Za-z0-9_-]{35}$`,
+			}},
+		},
+	}, nil
+}
+
+func (bl *BotLogin) SubmitUserInput(ctx context.Context, input map[string]string) (*bridgev2.LoginStep, error) {
+	log := zerolog.Ctx(ctx).With().Str("component", "telegram bot login").Logger()
+	ctx = log.WithContext(ctx)
+
+	botToken := input[LoginStepIDBotToken]
+	err := logoutBotAPI(ctx, botToken)
+	if err != nil {
+		return nil, fmt.Errorf("failed to logout from bot API: %w", err)
+	}
+
+	err = bl.makeClient(ctx, nil)
+	if err != nil {
+		return nil, err
+	}
+	authorization, err := bl.client.Auth().Bot(ctx, botToken)
+	if err != nil {
+		bl.Cancel()
+		return nil, err
+	}
+	return bl.finalizeLogin(ctx, authorization, &UserLoginMetadata{IsBot: true})
+}
+
+type botAPIResponse struct {
+	OK          bool   `json:"ok"`
+	ErrorCode   int    `json:"error_code"`
+	Description string `json:"description"`
+}
+
+func logoutBotAPI(ctx context.Context, token string) error {
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, "https://api.telegram.org/bot"+token+"/logOut", nil)
+	if err != nil {
+		return fmt.Errorf("failed to prepare request: %w", err)
+	}
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("failed to send request: %w", err)
+	}
+	var respData botAPIResponse
+	err = json.NewDecoder(resp.Body).Decode(&respData)
+	_ = resp.Body.Close()
+	if err != nil {
+		return fmt.Errorf("failed to decode response: %w", err)
+	} else if !respData.OK && respData.Description != "Logged out" {
+		return fmt.Errorf("response error %d: %s", respData.ErrorCode, respData.Description)
+	}
+	return nil
+}
+
+var _ bridgev2.LoginProcessUserInput = (*BotLogin)(nil)

pkg/connector/reactions.go

@@ -55,11 +55,9 @@ func (t *TelegramClient) computeReactionsList(ctx context.Context, peer tg.PeerC
 	if len(reactionsList) < totalCount {
 		if user, ok := peer.(*tg.PeerUser); ok {
 			reactionsList = splitDMReactionCounts(msgReactions.Results, user.UserID, t.telegramUserID)
-
+		} else if t.metadata.IsBot {
-			// TODO
+			// Can't fetch exact reaction senders as a bot
-			// } else if t.isBot {
+			return
-			// 	// Can't fetch exact reaction senders as a bot
-			// 	return
 
 			// TODO remove redundant peer roundtrip, just add a peer -> input peer helper
 		} else if peer, _, err := t.inputPeerForPortalID(ctx, t.makePortalKeyFromPeer(peer, 0).ID); err != nil {
@@ -209,7 +207,7 @@ func (t *TelegramClient) getReactionLimit(ctx context.Context, sender networkid.
 
 func (t *TelegramClient) maybePollForReactions(ctx context.Context, portal *bridgev2.Portal) error {
 	// Only poll for reactions in supergroups
-	if portal == nil || !portal.Metadata.(*PortalMetadata).IsSuperGroup || portal.RoomType == database.RoomTypeSpace {
+	if t.metadata.IsBot || portal == nil || !portal.Metadata.(*PortalMetadata).IsSuperGroup || portal.RoomType == database.RoomTypeSpace {
 		return nil
 	}