Connect a Managed Deep Agent to Slack

A Slack channel lets people invoke a Managed Deep Agent through app mentions, direct messages, and replies in an active Slack thread. Managed Deep Agents verifies Slack events, maps each conversation to a thread, runs the agent as the resolved caller, and posts the response back to Slack. Slack is a bring-your-own-app integration. You define a Slack app manifest in the agent project.

Managed Deep Agents is in public beta and available on LangSmith Cloud in the US region only.

Project structure

Slack setup uses a channel declaration, an editable manifest template, and a generated manifest:

my-agent/
  agent.py
  channels/
    slack.py
  slack-app-manifest.json
  .mda/
    slack/
      app-manifest.json

Add a Slack channel

Export a channel created with channels.slack():

channels/slack.py

from managed_deepagents import channels

channel = channels.slack()

The file name sets the channel name to slack and mounts its Events API route at /channels/slack/events. You can use another file name when you need a different configured name.

Create and deploy the Slack app

After setting up the Slack channel, you need to create and deploy your Slack app.

Deploy your Managed Deep Agent

First, deploy your Managed Deep Agent.

mda deploy .

Wait for the deployment to finish. The agent is deployed even though Slack is not active yet.

Generate the app manifest template

Run a command to generate the Slack app manifest template.

mda channel add slack .

MDA finds the existing deployment and writes two files:

A “template” manifest to slack-app-manifest.json
The full manifest to .mda/slack/app-manifest.json

The template manifest is what you should edit directly to change scopes, etc. The full manifest is generated from this template manifest and includes information about the deployment. If you make changes to the template manifest, you will need rerun mda channel add slack . to regenerate the full template. Do not directly edit the generated file at .mda/slack/app-manifest.json

Create and install the Slack app once

Open https://api.slack.com/apps.
Select Create New App.
Select From an app manifest.
Choose the target Slack workspace.
Import .mda/slack/app-manifest.json and create the app.
Open OAuth & Permissions and select Install to Workspace.
Approve the requested permissions.
Copy the Bot User OAuth Token from OAuth & Permissions.
Copy the Signing Secret from Basic Information → App Credentials.

The Events request URL is already in the generated manifest, so there is no bootstrap manifest and no second manifest import.

Add the Slack credentials

Add the two values to the project .env:

SLACK_SIGNING_SECRET=...
SLACK_BOT_TOKEN=xoxb-...

Do not commit .env and do not copy these values into either manifest.

Redeploy to activate Slack

mda deploy .

This deployment forwards the Slack credentials to the managed runtime and enables authenticated event handling.

Updating Slack Bot Configurations

The previous steps guide you through deploying the first iteration of your Managed Deepagent as a Slack bot. If you want to make any updates to the agent, you just simply rerun mda deploy . to update the deployed app.If you want to make any configuration changes to the Slack application itself, the recommended steps are:

Update the slack-app-manifest.json file locally
Run mda channel add slack . — this will regenerate the manifest with the latest changes. These changes are written to the .mda/slack/app-manifest.json file
On https://api.slack.com/apps → locate your app → App Manifest
Replace the contents of the manifest with the new .mda/slack/app-manifest.json file → Click Save Changes
Navigate to the OAuth & Permissions tab. Click on Reinstall to Workspace

This ensures the manifest in your mda filesystem remains as the source of truth for the Slack app.

Treat slack-app-manifest.json as the source of truth. When you change its scopes, bot events, branding, or other settings, rerun mda deploy . --configure-slack, apply the regenerated .mda/slack/app-manifest.json, and reinstall the app if Slack requests it. The generated files under .mda/ are build artifacts; do not commit them.

Configure Slack behavior

Pass options to channels.slack(...) to control Managed Deep Agents runtime behavior. Configure OAuth scopes and delivered event types in the Slack app, not in the channel declaration.

channels/slack.py

from managed_deepagents import channels

channel = channels.slack(
    auto_reply=True,
    mention_behavior="strip",
    filters={
        "include_conversations": ["C0123456789"],
        "exclude_users": ["slack:T0123456789:U0123456789"],
    },
    conversation={
        "app_mention": "thread",
        "direct_message": "conversation",
    },
)

Option	Default	Description
`auto_reply`	`True`	Post the agent’s final response to the originating Slack thread or conversation.
`mention_behavior`	`"strip"`	Remove Slack mention tokens before passing text to the agent. Set it to `"preserve"` to keep them.
`filters.include_conversations`	All	Accept events only from the listed Slack conversation IDs.
`filters.exclude_conversations`	No exclusions	Ignore events from the listed Slack conversation IDs.
`filters.include_users`	All	Accept events only from the listed fully qualified users, such as `slack:T123:U456`.
`filters.exclude_users`	No exclusions	Ignore events from the listed fully qualified users.
`filters.allow_shared_conversations`	`False`	Controls Slack Connect shared conversations. Setting this to `True` is not currently supported.
`conversation.app_mention`	`"thread"`	Select how app mentions and their follow-up replies map to Managed Deep Agents threads.
`conversation.direct_message`	`"conversation"`	Select how direct messages map to Managed Deep Agents threads.

Conversation mappings accept:

"thread": Reuse one Managed Deep Agents thread for a Slack thread.
"conversation": Reuse one Managed Deep Agents thread for the Slack conversation.
"message": Start a separate Managed Deep Agents thread for each message.

Understand event and thread behavior

The Slack app controls which events reach the deployment. The Slack channel normalizes supported events and applies the configured filters and conversation mapping.

Slack interaction	Event subscription	Default Managed Deep Agents behavior
App mention	`app_mention`	Start or continue a thread associated with the Slack thread.
Direct message	`message.im`	Reuse a thread associated with the direct-message conversation.
Non-mention reply in a public channel	`message.channels`	Continue the thread only when the agent already has a corresponding Managed Deep Agents thread.
Non-mention reply in a private channel	`message.groups`	Continue the thread only when the agent already has a corresponding Managed Deep Agents thread.

Top-level channel messages that do not mention the bot are ignored. Bot messages, the app’s own messages, unsupported message subtypes, and events rejected by channel filters do not start runs. When Slack delivers the same mention through both app_mention and message.*, Managed Deep Agents drops the duplicate message event. Subscribe to app_mention for mentions and use message.channels or message.groups for non-mention follow-up replies.

Send responses to Slack

With auto_reply enabled, Managed Deep Agents extracts the final assistant response and posts it to the originating Slack conversation after the run completes. Channel-originated runs also expose runtime.channel in tools and middleware. Use it to inspect the normalized event, post an intermediate or final message, or update a previously posted message. It is absent for ordinary HTTP and scheduled runs. The following tool posts the final response explicitly:

tools/send_channel_reply.py

from langchain.tools import tool
from managed_deepagents import ManagedDeepAgentRuntime


@tool
async def send_channel_reply(
    text: str,
    runtime: ManagedDeepAgentRuntime,
) -> str:
    """Send the final response to the originating messaging channel."""
    if runtime.channel is None:
        return "This run did not originate from a messaging channel."
    posted = await runtime.channel.post({"text": text}, {"final": True})
    return posted["id"]

Pass {"final": True} only when the posted message is the final response. It suppresses the automatic reply so the user does not receive the final response twice. A post without that option is an intermediate message and does not suppress auto-reply. runtime.channel.post(...) can post only to the originating Slack thread. Explicit destinations are not supported for channel-originated runs. To send a scheduled result to a specific Slack conversation, use deliver_to.

Understand Slack caller identity

A Slack event runs as an identity derived from the Slack workspace and user, such as slack:T123:U456. This identity is separate from caller identities used for HTTP requests. Slack account linking is not supported.

Deploy changes

Redeploy after changing the channel declaration, secrets, or identity configuration. Include --configure-slack when you change slack-app-manifest.json, the channel name, or the deployment so MDA can regenerate the final manifest with the current Events URL. Apply the generated manifest to the existing Slack app after the deployment completes. Avoid making lasting configuration changes only in the Slack dashboard. A later manifest update can replace settings that are not present in the checked-in template.

Review security and current limits

Managed Deep Agents verifies every Slack request against its raw body and rejects signatures outside Slack’s five-minute replay window.
Slack Connect shared conversations are not supported.
runtime.channel does not expose SLACK_BOT_TOKEN or other provider credentials.
Event deduplication is currently process-local. A multi-replica deployment can invoke the agent more than once when Slack retries an event.

Design channel-triggered tools as idempotent when they perform external side effects. Slack retries and multi-replica processing can produce more than one run for the same logical event.

Troubleshoot Slack channels

--configure-slack reports that it needs exactly one channel: Keep exactly one channels.slack(...) declaration in the project when using the manifest workflow.
MDA cannot read the template: Confirm slack-app-manifest.json is a regular JSON file at the project root. Remove credentials and any settings.event_subscriptions.request_url, and keep Socket Mode disabled.
The first deploy writes a bootstrap manifest and exits: This is expected when the Slack credentials do not exist yet. Create and install the app, add both credentials, then rerun the same command.
MDA does not write the final manifest: Rerun mda deploy . --configure-slack without --no-wait. The CLI needs the deployed Agent Server URL.
Slack cannot verify the request URL: Confirm the deployment is healthy, the URL on the app’s Event Subscriptions page matches https://<agent-server>/channels/<name>/events, and SLACK_SIGNING_SECRET belongs to that app. Redeploy after adding the Slack credentials, then apply the regenerated final manifest.
Mentions do not start runs: Subscribe to app_mention, add app_mentions:read, invite the bot to the conversation, and reinstall the app after changing scopes.
Direct messages do not start runs: Subscribe to message.im and add im:history.
Thread replies do not start runs: Reply inside a thread where the agent previously participated. Subscribe to message.channels or message.groups, add the matching history scope, and confirm the bot remains in the conversation.
The agent runs but does not reply: Confirm auto_reply is enabled and SLACK_BOT_TOKEN has chat:write.

Get started

Agent definition

Build and deploy

Connect a Managed Deep Agent to Slack

Project structure

Add a Slack channel

Create and deploy the Slack app

Configure Slack behavior

Understand event and thread behavior

Send responses to Slack

Understand Slack caller identity

Deploy changes

Review security and current limits

Troubleshoot Slack channels

See also

​Project structure

​Add a Slack channel

​Create and deploy the Slack app

​Configure Slack behavior

​Understand event and thread behavior

​Send responses to Slack

​Understand Slack caller identity

​Deploy changes

​Review security and current limits

​Troubleshoot Slack channels

​See also

Project structure

Add a Slack channel

Create and deploy the Slack app

Configure Slack behavior

Understand event and thread behavior

Send responses to Slack

Understand Slack caller identity

Deploy changes

Review security and current limits

Troubleshoot Slack channels

See also