TL;DR. By default, no: SlackBridge relays what people post and leaves out every Slack app and bot. On request, SlackBridge support can allow one named Slack app for a bridge. That app's channel posts then arrive in Microsoft Teams marked as an app, and Teams users can address it by typing its name. With Anthropic's Claude, whose documentation says it answers a mention posted by another Slack app, a question typed in Teams can be answered in Slack and the answer comes back to Teams. Relayed app messages have a daily ceiling of 1,000 on Free and 10,000 on Pro; messages from people are never counted.
What's the short version?
- By default, Slack app and bot messages are not relayed. Only what people post crosses the bridge. Emoji reactions an app adds do still arrive in Teams.
- One app per bridge can be allowed on request. SlackBridge support switches it on after the Microsoft Teams side's administrator confirms. The app's posts then arrive in Teams labelled with its name and the word app.
- Teams users can address the allowed app by name. Typing
@claude(or the longer spelling SlackBridge lists) in a new Teams message becomes a real mention of the app in Slack. Anthropic documents that Claude answers such a mention in a Slack thread, and SlackBridge relays that reply back into the Teams thread; this has not yet been confirmed on a live bridge. - Relayed app messages have a daily ceiling: 1,000 per bridge per day on Free, 10,000 on Pro. Messages from people are never counted.
Why app messages are left out
SlackBridge checks every Slack message for the marker Slack puts on posts made by an app or bot, and stops there. This is how SlackBridge avoids relaying its own posts back and forth, and it means a workspace full of integrations (build notifications, ticket bots, reminders) does not flood the bridged Teams channel. There is no per-bridge switch for "all apps".
Reactions are handled on a different path. An app that reacts to a bridged message, for example Claude acknowledging a question with an emoji, has that reaction delivered to Teams like a person's would be.
Allowing one app for a bridge
SlackBridge can allow one named Slack app per bridge. It is an on-request option, not a dashboard setting:
- Email support@slackbridge.com with the Slack channel, the Teams channel, and the app's name (for example Claude).
- SlackBridge asks the administrator on the Microsoft Teams side of that bridge to confirm that the app's output may appear in their channel, and waits for the reply.
- SlackBridge verifies the app's identity with Slack and enables it for that bridge only.
From then on:
- The app's channel posts are relayed to the bridged Teams channel. They are shown with the app's name and icon and the word app, for example Claude (app), so readers in Teams can tell an app wrote them.
- The app is added to the bridge's list of addressable names, labelled the same way, so Teams users can mention it.
- Every other app and bot stays excluded, exactly as before.
An app's messages never carry bridged mentions of people: if an app writes someone's name, it arrives in Teams as plain text and notifies nobody.
What the app must be able to do
For the question-and-answer loop with Claude to work, on the Slack side:
- Claude is installed in the Slack workspace on a paid Claude plan and has been invited into the bridged Slack channel.
- Claude's "Respond automatically" setting is on for that channel.
- The bridge is bidirectional and bridged mentions are on. They are on by default when the two organisations' names give SlackBridge two different name suffixes; if your bridge shows no addressable names, ask support to switch mentions on.
- The Microsoft Teams channel is a standard channel. Mentions never work in private or shared Teams channels.
Asking Claude from Microsoft Teams
Start a new message in the bridged Teams channel, type the name SlackBridge lists for the app, then the question, and send it:
@claude What were the three action items from yesterday's call?
The long spelling, which carries your Slack workspace's word, for example @claude_acme, always works once the app is enrolled, typed in full and within the mention limits below. The short one, @claude, is offered only when nobody on either side of the bridge could be meant by it, for example when no one in either channel has the first name Claude. To see the spelling your bridge lists, type @SlackBridge members in the Teams channel: SlackBridge replies with the Slack side of the bridge, where the app is listed as, for example, Claude (app).
Teams will not suggest the name while you type, because the app is not in your Microsoft 365 tenant. Type it as plain text and do not pick anything from the Teams suggestion popup; SlackBridge reads the plain text after the message is sent and turns it into a real Slack mention.
What happens next:
- SlackBridge posts your message into the Slack channel with a real mention of the app.
- Anthropic documents that Claude replies to a mention posted by another Slack app at the top level of a channel, in a thread under that message, as long as it has been invited to the channel and its automatic responses are on. SlackBridge has not yet confirmed this on a live bridge; this article will say so when it has.
- SlackBridge relays Claude's reply into your Teams thread, labelled Claude (app).
What to expect
- One question per new top-level message. Anthropic documents that Claude reads other apps' thread replies with less context, and does not say whether a mention posted by another app inside a thread is answered. Until that is confirmed on your bridge, ask each question at the top level rather than as a thread follow-up.
- Long tasks show their first text and their final answer. For a longer task Claude posts a checklist in Slack and edits it in place as it works. SlackBridge does not relay edits, so Teams sees the checklist's first text and then the final answer, which Claude posts as a new reply. The live progress stays in Slack.
- Claude stops reading a busy channel. Anthropic documents that Claude stops following a channel after roughly a hundred top-level messages since it last posted, and that a new mention starts it again.
- Files, charts and links follow the bridge's normal file rules. A link arrives as text; a file is copied only where the bridge already copies files.
- Mention limits apply. The app counts as a target like a person: at most ten mentions of it per hour per bridge, after which the name is delivered as plain text for the rest of that hour. A relayed app message that fails to deliver is retried by Slack a few times; those retries count once.
The daily ceiling on relayed app messages
Relayed app messages are the one class of message SlackBridge counts, because an app can post far faster than a person. Per bridge, per UTC day:
| Plan | Relayed app messages per day |
|---|---|
| Free | 1,000 |
| Pro | 10,000 |
Messages from people are never counted and have no limit on any plan.
When a bridge reaches its ceiling:
- The app's further messages that day are not relayed and are not queued. They stay in Slack.
- SlackBridge posts one notice in the Slack thread, in the bridge owner's own workspace, naming the limit and when relay resumes, and one notice in the Microsoft Teams channel explaining why replies stopped. Each is posted once a day; if SlackBridge could not confirm that a notice went through, it tries once more later.
- Relay resumes at 00:00 UTC.
On the Free plan the Slack notice points to the dashboard's Billing page, where Pro raises the ceiling to 10,000. On Pro it points to support.
Frequently asked questions
Why do messages from a Slack app or bot never show up in Microsoft Teams?
SlackBridge checks whether a Slack message was posted by an app or bot and leaves those out, so only what people write crosses the bridge. This is the same on every bridge, with one exception: a single Slack app that SlackBridge support has allowed for that bridge, described in the next answer. Emoji reactions an app adds to a bridged message do still arrive in Teams, because reactions are handled separately from messages.
Can SlackBridge relay one specific app, such as Claude?
Yes, on request. SlackBridge support can allow one named Slack app for a bridge. From then on that app's channel posts are relayed to the bridged Microsoft Teams channel, shown with the app's name and the word app, and Teams users can mention it by typing its name. Every other app and bot stays excluded. Email support@slackbridge.com with the bridge and the app's name; SlackBridge will ask the Microsoft Teams side's administrator to confirm before switching it on.
What do I type in Microsoft Teams to ask Claude?
Start a new message in the bridged Teams channel with the name SlackBridge lists for the app, for example @claude, followed by the question, and send it. Teams will not suggest the name while you type; type it as plain text and do not pick anything from the suggestion popup. To see the spelling your bridge lists, type @SlackBridge members in the Teams channel; SlackBridge replies with the Slack side of the bridge, where the app is listed as Claude (app). Anthropic documents that Claude answers in a Slack thread; SlackBridge relays that reply back into your Teams thread.
Why did Claude not answer my follow-up inside the thread?
Anthropic documents that Claude reads other apps' thread replies with less context than a person's, and does not say whether a mention posted by another app inside a thread is answered. Until that is confirmed on your bridge, ask each question as a new top-level message in the Teams channel.
Is there a limit on relayed app messages?
Yes. A bridge relays up to 1,000 app messages per day on the Free plan and 10,000 per day on Pro, counted per UTC day. When the limit is reached, SlackBridge posts one notice in the Slack thread and one in the Teams channel, and the app's further messages that day are not relayed and are not queued. Relay resumes at 00:00 UTC. Messages from people are never counted and have no limit on any plan.