If text is sent with image, the text is not shown (Discord -> Matrix)

[SwirlyStone5877]

Describe the bug
If you go onto a Discord channel with a Matterbridge instance bridged to a Matrix room, then send a message containing some text and an image, the text is not shown at all.

To Reproduce
Steps to reproduce the behavior:

1. log onto discord
2. send text with image
3. watch your text disappear on matrix

Expected behavior
The text should be sent along with the image, either in the message with the username (compatible with more clients) or as an image caption.

Screenshots/debug logs
Screenshot of Cinny (Matrix client): https://fs.swirly.architectenterprises.net/screenshot_Kbr7ISbIlpjCr98n.png

Environment (please complete the following information):

• OS: Linux
• Matterbridge version: version: 1.26.1-dev (commit e7fc6f8338db15d85904f4fb0ae2dd54fc8a8723)

Additional context
Config file: https://fs.swirly.architectenterprises.net/matterbridge-config.toml ([discord.yumetaro] is the relevant one in this case)
Note: unlike last time I am the one running this bridge.

[selfhoster1312]

Hello, if you have the debug log that would be very useful! We are indeed reworking attachments handling, and dealing with captions was part of that. The problem is without debug logs it's very hard to understand whether the bug is on the discord side failing to set the text, or the matrix side failing to relay it.

Also, sorry for the newbie question as i don't use discord, was the text on discord an actual text message or a message caption? Are captions a thing on discord at all? I seem to remember one discussion where we mentioned you can have a text message with several images but no individual caption… is that correct?

[SwirlyStone5877]

Ah, apologies... Will provide debug logs when I can.
As for your question: yes, text on discord works like a message caption. You can't have captions for individual attachments, more like a """global""" caption.

[SwirlyStone5877]

Is this enough?

time="2026-03-06T07:50:37-06:00" level=debug msg="== Receiving event &discordgo.Message{ID:"1479476302041055505", ChannelID:"1135154500399792200", GuildID:"989923775715885127", Content:"there", Timestamp:time.Date(2026, time.March, 6, 13, 50, 37, 747000000, time.Location("")), EditedTimestamp:<nil>, MentionRoles:[]string{}, TTS:false, MentionEveryone:false, Author:(*discordgo.User)(0x1b60b05ca270), Attachments:[]*discordgo.MessageAttachment{(*discordgo.MessageAttachment)(0x1b60b0952770)}, Components:[]discordgo.MessageComponent{}, Embeds:[]*discordgo.MessageEmbed{}, Mentions:[]*discordgo.User{}, Reactions:[]*discordgo.MessageReactions(nil), Pinned:false, Type:0, WebhookID:"", Member:(*discordgo.Member)(0x1b60b103a0a0), MentionChannels:[]*discordgo.Channel(nil), Activity:(*discordgo.MessageActivity)(nil), Application:(*discordgo.MessageApplication)(nil), MessageReference:(*discordgo.MessageReference)(nil), ReferencedMessage:(*discordgo.Message)(nil), Interaction:(*discordgo.MessageInteraction)(nil), Flags:0, Thread:(*discordgo.Channel)(nil), StickerItems:[]*discordgo.StickerItem(nil)}" func=messageCreate file="bridge/discord/handlers.go:144" prefix=discord
time="2026-03-06T07:50:37-06:00" level=debug msg="Getting HTTP bytes with request: &http.Request{Method:"GET", URL:(*url.URL)(0x1b60b1036510), Proto:"HTTP/1.1", ProtoMajor:1, ProtoMinor:1, Header:http.Header{}, Body:io.ReadCloser(nil), GetBody:(func() (io.ReadCloser, error))(nil), ContentLength:0, TransferEncoding:[]string(nil), Close:false, Host:"cdn.discordapp.com", Form:url.Values(nil), PostForm:url.Values(nil), MultipartForm:(*multipart.Form)(nil), Trailer:http.Header(nil), RemoteAddr:"", RequestURI:"", TLS:(*tls.ConnectionState)(nil), Cancel:(<-chan struct {})(nil), Response:(*http.Response)(nil), Pattern:"", ctx:context.backgroundCtx{emptyCtx:context.emptyCtx{}}, pat:(*http.pattern)(nil), matches:[]string(nil), otherValues:map[string]string(nil)}" func=HttpGetBytes file="bridge/bridge.go:194" prefix=discord
time="2026-03-06T07:50:38-06:00" level=debug msg="Download OK "sddefault.jpg" 16279" func=addAttachmentProcess file="bridge/bridge.go:393" prefix=discord
time="2026-03-06T07:50:38-06:00" level=debug msg="<= Sending message attachments from mtndewfan123 on discord.yumetaro to gateway" func=func1 file="bridge/discord/handlers.go:228" prefix=discord
time="2026-03-06T07:50:38-06:00" level=debug msg="<= Message is config.Message{Text:"there", Channel:"the-central-1", Username:"mtndewfan123", UserID:"1098103795147358268", Avatar:"https://cdn.discordapp.com/avatars/1098103795147358268/1d80763130a3ce162ac9cf8a6111312b.jpg", Account:"discord.yumetaro", Event:"", Protocol:"", Gateway:"", ParentID:"", Timestamp:time.Date(1, time.January, 1, 0, 0, 0, 0, time.UTC), ID:"1479476302041055505", Extra:map[string][]interface {}{"file":[]interface {}{config.FileInfo{Name:"sddefault.jpg", Data:(*[]uint8)(0x1b60b0c5c0a8), Comment:"", URL:"https://cdn.discordapp.com/attachments/1135154500399792200/1479476301655052429/sddefault.jpg?ex=69ac2d2d&is=69aadbad&hm=3fd667d85c9406d38ce2e0b3f6fac3abeb16d755b5fe8b8ce0fad0622b778101&", Size:16279, Avatar:false, SHA:"", NativeID:"1479476301655052429"}}}}" func=func1 file="bridge/discord/handlers.go:229" prefix=discord
time="2026-03-06T07:50:38-06:00" level=debug msg="mediaserver path placing file: /home/server/fs/files/matterbridge/c36f7f57/sddefault.jpg" func=handleFilesLocal file="gateway/handlers.go:120" prefix=gateway
time="2026-03-06T07:50:38-06:00" level=debug msg="mediaserver download URL = https://fs.swirly.architectenterprises.net/matterbridge/c36f7f57/sddefault.jpg" func=handleFiles file="gateway/handlers.go:99" prefix=gateway
time="2026-03-06T07:50:38-06:00" level=debug msg="=> Sending config.Message{Text:"there", Channel:"the-central-1", Username:"mtndewfan123", UserID:"1098103795147358268", Avatar:"https://cdn.discordapp.com/avatars/1098103795147358268/1d80763130a3ce162ac9cf8a6111312b.jpg", Account:"discord.yumetaro", Event:"", Protocol:"discord", Gateway:"yumetaro-thecentral1", ParentID:"", Timestamp:time.Date(2026, time.March, 6, 7, 50, 38, 179834650, time.Local), ID:"1479476302041055505", Extra:map[string][]interface {}{"file":[]interface {}{config.FileInfo{Name:"sddefault.jpg", Data:(*[]uint8)(0x1b60b0c5c0a8), Comment:"", URL:"https://fs.swirly.architectenterprises.net/matterbridge/c36f7f57/sddefault.jpg", Size:16279, Avatar:false, SHA:"c36f7f57", NativeID:"1479476301655052429"}}}} from discord.yumetaro (the-central-1) to matrix.fc (!rKOmKoXWrMjQVRvdrz:architectenterprises.net)" func=SendMessage file="gateway/gateway.go:513" prefix=gateway
time="2026-03-06T07:50:38-06:00" level=debug msg="=> Receiving config.Message{Text:"there", Channel:"!rKOmKoXWrMjQVRvdrz:architectenterprises.net", Username:"[<strong>mtndewfan123</strong> on discord] <br>", UserID:"1098103795147358268", Avatar:"https://cdn.discordapp.com/avatars/1098103795147358268/1d80763130a3ce162ac9cf8a6111312b.jpg", Account:"discord.yumetaro", Event:"", Protocol:"discord", Gateway:"yumetaro-thecentral1", ParentID:"", Timestamp:time.Date(2026, time.March, 6, 7, 50, 38, 179834650, time.Local), ID:"", Extra:map[string][]interface {}{"file":[]interface {}{config.FileInfo{Name:"sddefault.jpg", Data:(*[]uint8)(0x1b60b0c5c0a8), Comment:"", URL:"https://fs.swirly.architectenterprises.net/matterbridge/c36f7f57/sddefault.jpg", Size:16279, Avatar:false, SHA:"c36f7f57", NativeID:"1479476301655052429"}}}}" func=Send file="bridge/matrix/matrix.go:178" prefix=matrix
time="2026-03-06T07:50:38-06:00" level=debug msg="Channel !rKOmKoXWrMjQVRvdrz:architectenterprises.net maps to channel id !rKOmKoXWrMjQVRvdrz:architectenterprises.net" func=Send file="bridge/matrix/matrix.go:181" prefix=matrix
time="2026-03-06T07:50:38-06:00" level=debug msg="uploading file: sddefault.jpg image/jpeg" func=handleUploadFile file="bridge/matrix/matrix.go:881" prefix=matrix
time="2026-03-06T07:50:38-06:00" level=debug msg="== Receiving message event: &event.Event{StateKey:(*string)(nil), Sender:"@swirly-mattermost:architectenterprises.net", Type:event.Type{Type:"m.room.message", Class:1}, Timestamp:1772805038710, ID:"$BLLv_YenJY3ScRrEtsz3y-RrZnal-x3QFhwCc02NwrY", RoomID:"!rKOmKoXWrMjQVRvdrz:architectenterprises.net", Content:event.Content{VeryRaw:json.RawMessage{0x7b, 0x22, 0x6d, 0x73, 0x67, 0x74, 0x79, 0x70, 0x65, 0x22, 0x3a, 0x22, 0x6d, 0x2e, 0x74, 0x65, 0x78, 0x74, 0x22, 0x2c, 0x22, 0x62, 0x6f, 0x64, 0x79, 0x22, 0x3a, 0x22, 0x5b, 0x6d, 0x74, 0x6e, 0x64, 0x65, 0x77, 0x66, 0x61, 0x6e, 0x31, 0x32, 0x33, 0x20, 0x6f, 0x6e, 0x20, 0x64, 0x69, 0x73, 0x63, 0x6f, 0x72, 0x64, 0x5d, 0x20, 0x22, 0x2c, 0x22, 0x66, 0x6f, 0x72, 0x6d, 0x61, 0x74, 0x22, 0x3a, 0x22, 0x6f, 0x72, 0x67, 0x2e, 0x6d, 0x61, 0x74, 0x72, 0x69, 0x78, 0x2e, 0x63, 0x75, 0x73, 0x74, 0x6f, 0x6d, 0x2e, 0x68, 0x74, 0x6d, 0x6c, 0x22, 0x2c, 0x22, 0x66, 0x6f, 0x72, 0x6d, 0x61, 0x74, 0x74, 0x65, 0x64, 0x5f, 0x62, 0x6f, 0x64, 0x79, 0x22, 0x3a, 0x22, 0x5b, 0x3c, 0x73, 0x74, 0x72, 0x6f, 0x6e, 0x67, 0x3e, 0x6d, 0x74, 0x6e, 0x64, 0x65, 0x77, 0x66, 0x61, 0x6e, 0x31, 0x32, 0x33, 0x3c, 0x2f, 0x73, 0x74, 0x72, 0x6f, 0x6e, 0x67, 0x3e, 0x20, 0x6f, 0x6e, 0x20, 0x64, 0x69, 0x73, 0x63, 0x6f, 0x72, 0x64, 0x5d, 0x20, 0x3c, 0x62, 0x72, 0x3e, 0x22, 0x7d}, Raw:map[string]interface {}{"body":"[mtndewfan123 on discord] ", "format":"org.matrix.custom.html", "formatted_body":"[<strong>mtndewfan123</strong> on discord] <br>", "msgtype":"m.text"}, Parsed:(*event.MessageEventContent)(0x1b60b0c311e0)}, Redacts:"", Unsigned:event.Unsigned{PrevContent:(*event.Content)(nil), PrevSender:"", Membership:"join", ReplacesState:"", Age:25, TransactionID:"mautrix-go_1772805038469439355_1", Relations:(*event.Relations)(nil), RedactedBecause:(*event.Event)(nil), InviteRoomState:[]*event.Event(nil), BeeperHSOrder:0, BeeperHSSuborder:0, BeeperHSOrderString:(*event.BeeperEncodedOrder)(nil), BeeperFromBackup:false, ElementSoftFailed:false, ElementPolicyServerSpammy:false}, Mautrix:event.MautrixInfo{EventSource:34, TrustState:0, ForwardedKeys:false, WasEncrypted:false, TrustSource:(*id.Device)(nil), ReceivedAt:time.Date(1, time.January, 1, 0, 0, 0, 0, time.UTC), EditedAt:time.Date(1, time.January, 1, 0, 0, 0, 0, time.UTC), LastEditID:"", DecryptionDuration:0, CheckpointSent:false, IgnoreState:false}, ToUserID:"", ToDeviceID:""}" func=handleMessageEvent file="bridge/matrix/matrix.go:666" prefix=matrix
time="2026-03-06T07:50:39-06:00" level=debug msg="sendImage mxc://architectenterprises.net/RkuXmIQNDrpERPuqvrltHfKp" func=handleUploadFile file="bridge/matrix/matrix.go:922" prefix=matrix
time="2026-03-06T07:50:39-06:00" level=debug msg="Image format detected: jpeg (640x480)" func=handleUploadFile file="bridge/matrix/matrix.go:930" prefix=matrix
time="2026-03-06T07:50:39-06:00" level=debug msg="result: &mautrix.RespMediaUpload{ContentURI:id.ContentURI{Homeserver:"architectenterprises.net", FileID:"RkuXmIQNDrpERPuqvrltHfKp"}}" func=handleUploadFile file="bridge/matrix/matrix.go:972" prefix=matrix
time="2026-03-06T07:50:39-06:00" level=debug msg="=> Send from discord.yumetaro (the-central-1) to matrix.fc (!rKOmKoXWrMjQVRvdrz:architectenterprises.net) took 1.190440356s" func=func1 file="gateway/gateway.go:522" prefix=gateway
time="2026-03-06T07:50:39-06:00" level=debug msg="== Receiving message event: &event.Event{StateKey:(*string)(nil), Sender:"@swirly-mattermost:architectenterprises.net", Type:event.Type{Type:"m.room.message", Class:1}, Timestamp:1772805039409, ID:"$RlIIyf4Vmfo3uASgEaUAyXtkVSmHS0jfn_Rp6obXn14", RoomID:"!rKOmKoXWrMjQVRvdrz:architectenterprises.net", Content:event.Content{VeryRaw:json.RawMessage{0x7b, 0x22, 0x6d, 0x73, 0x67, 0x74, 0x79, 0x70, 0x65, 0x22, 0x3a, 0x22, 0x6d, 0x2e, 0x69, 0x6d, 0x61, 0x67, 0x65, 0x22, 0x2c, 0x22, 0x62, 0x6f, 0x64, 0x79, 0x22, 0x3a, 0x22, 0x73, 0x64, 0x64, 0x65, 0x66, 0x61, 0x75, 0x6c, 0x74, 0x2e, 0x6a, 0x70, 0x67, 0x22, 0x2c, 0x22, 0x75, 0x72, 0x6c, 0x22, 0x3a, 0x22, 0x6d, 0x78, 0x63, 0x3a, 0x2f, 0x2f, 0x61, 0x72, 0x63, 0x68, 0x69, 0x74, 0x65, 0x63, 0x74, 0x65, 0x6e, 0x74, 0x65, 0x72, 0x70, 0x72, 0x69, 0x73, 0x65, 0x73, 0x2e, 0x6e, 0x65, 0x74, 0x2f, 0x52, 0x6b, 0x75, 0x58, 0x6d, 0x49, 0x51, 0x4e, 0x44, 0x72, 0x70, 0x45, 0x52, 0x50, 0x75, 0x71, 0x76, 0x72, 0x6c, 0x74, 0x48, 0x66, 0x4b, 0x70, 0x22, 0x2c, 0x22, 0x69, 0x6e, 0x66, 0x6f, 0x22, 0x3a, 0x7b, 0x22, 0x6d, 0x69, 0x6d, 0x65, 0x74, 0x79, 0x70, 0x65, 0x22, 0x3a, 0x22, 0x69, 0x6d, 0x61, 0x67, 0x65, 0x2f, 0x6a, 0x70, 0x65, 0x67, 0x22, 0x2c, 0x22, 0x77, 0x22, 0x3a, 0x36, 0x34, 0x30, 0x2c, 0x22, 0x68, 0x22, 0x3a, 0x34, 0x38, 0x30, 0x2c, 0x22, 0x73, 0x69, 0x7a, 0x65, 0x22, 0x3a, 0x31, 0x36, 0x32, 0x37, 0x39, 0x7d, 0x7d}, Raw:map[string]interface {}{"body":"sddefault.jpg", "info":map[string]interface {}{"h":480, "mimetype":"image/jpeg", "size":16279, "w":640}, "msgtype":"m.image", "url":"mxc://architectenterprises.net/RkuXmIQNDrpERPuqvrltHfKp"}, Parsed:(*event.MessageEventContent)(0x1b60b1056f20)}, Redacts:"", Unsigned:event.Unsigned{PrevContent:(*event.Content)(nil), PrevSender:"", Membership:"join", ReplacesState:"", Age:26, TransactionID:"mautrix-go_1772805039165142876_2", Relations:(*event.Relations)(nil), RedactedBecause:(*event.Event)(nil), InviteRoomState:[]*event.Event(nil), BeeperHSOrder:0, BeeperHSSuborder:0, BeeperHSOrderString:(*event.BeeperEncodedOrder)(nil), BeeperFromBackup:false, ElementSoftFailed:false, ElementPolicyServerSpammy:false}, Mautrix:event.MautrixInfo{EventSource:34, TrustState:0, ForwardedKeys:false, WasEncrypted:false, TrustSource:(*id.Device)(nil), ReceivedAt:time.Date(1, time.January, 1, 0, 0, 0, 0, time.UTC), EditedAt:time.Date(1, time.January, 1, 0, 0, 0, 0, time.UTC), LastEditID:"", DecryptionDuration:0, CheckpointSent:false, IgnoreState:false}, ToUserID:"", ToDeviceID:""}" func=handleMessageEvent file="bridge/matrix/matrix.go:666" prefix=matrix

[selfhoster1312]

Yes that's perfect. Could you try the PR in #185 and report if that fixes your problem?

[SwirlyStone5877]

Sure, one moment.

[SwirlyStone5877]

Weird... Sends RemoteNickFormat twice but otherwise fine.

[selfhoster1312]

This is a tough problem and we don't have a correct solution yet but on platforms which don't properly support message captions we resend the sender username to make sure people know who the image comes from.

Otherwise you could have race conditions like:

USERA: TEXT
IMAGE SENT BY USERB (without text)
IMAGE SENT BY USERA

Note that it's still possible, just less likely. Not sure what to do about this 🤷

[SwirlyStone5877]

Ah... fair enough. Good thinking.

[SwirlyStone5877]

Been messing with it, and it seems stable enough. Hoping this gets into master soon. Thanks!

[DutchComputerKid]

This also seems to happen to Discord to Telegram forwards, image is sent but the attached text is not

[selfhoster1312]

This also seems to happen to Discord to Telegram forwards, image is sent but the attached text is not

Hello, if you can reproduce this please open a new issue with more detailed information about your configuration, and screenshots of what happens on both sides :)