Slack app guide
Last updated on June 17, 2026
OOMOL lets you connect a Slack workspace once, then make authorized Slack tools available to supported AI agents and reusable Skills through approved tool calls. This guide explains how to install and connect the Slack app, what Slack permissions OOMOL uses, what you can do with it, how to troubleshoot common issues, and how to remove the app.
OOMOL requires users to sign in before connecting external accounts. To install the Slack app, sign in to OOMOL, open the Slack connection page, and choose Connect to start the Slack OAuth authorization flow.
Prerequisites
- An OOMOL account.
- A Slack account in the workspace you want to connect.
- Permission to install or authorize Slack apps in that workspace.
- Access to the OOMOL Console at https://console.oomol.com/.
- If your Slack workspace restricts app installation, a Slack workspace owner or administrator may need to approve the OOMOL app before you can authorize it.
Adding the app
- Sign in to the OOMOL Console.
- Open Slack in App Connections, or open App Connections and search for Slack.
- Select Slack, then choose Connect.
- OOMOL redirects you to Slack. Sign in to Slack if prompted.
- Select the Slack workspace you want to connect if Slack asks you to choose one.
- Review the Slack authorization screen, including the requested permissions.
- Select Allow to authorize OOMOL.
- After Slack redirects you back to OOMOL, confirm that Slack appears as connected in your OOMOL connections.
If any step fails, see Troubleshooting.
After authorization, OOMOL stores the connection needed to call Slack tools on your behalf. You can then use Slack tools from OOMOL-supported agents and reusable Skills through approved tool calls.
What OOMOL does in Slack
The OOMOL Slack app makes Slack actions available after you connect a workspace. Depending on the action you run, OOMOL can read channels and threads that the connected app can access, post messages as the OOMOL app, reply in threads, schedule messages, upload files, open direct messages, and add or remove emoji reactions.
OOMOL does not start using Slack on its own after installation. A Slack tool runs when an authorized user, reusable Skill, supported agent action, or approved OOMOL tool call provides the required destination and content.
After installation
After Slack redirects you back to OOMOL, check that the Slack connection is marked as connected in the OOMOL Console. From there, you can:
- Configure
oo-cliif you want connected Slack tools inside a supported AI agent environment. - Use a test channel to list visible Slack channels, read recent messages, post a demo message, reply in a thread, upload a demo file, or add a test reaction.
- Invite the OOMOL app to any private channel where you want it to read or post, if your workspace policy requires app membership for that channel.
Usage
Slack tools are available only after you connect a Slack workspace. The exact tool list shown in OOMOL may change as the connector is updated, but the current Slack connector includes tools for reading conversations, reading threads, sending messages, replying to threads, scheduling messages, managing messages posted by the bot, working with files, reading users, opening direct messages, and managing emoji reactions.
Use Slack tools with oo-cli
To make connected Slack tools available in a supported AI agent environment, install and configure oo-cli after you sign in to OOMOL.
- Sign in to the OOMOL Console.
- Open the oo-cli installation page.
- Follow the instructions on that page. The page provides a one-click copy prompt for installing and configuring
oo-cliin a supported AI agent environment. - After
oo-cliis configured and Slack is connected in OOMOL, ask the agent to use connected Slack tools with demo channels, messages, and files.
The exact agent prompt can vary by environment. For example, you can ask the agent to list visible Slack channels, read recent messages in a test channel, post a demo message, reply in a thread, or add a reaction to a test message.
Permissions used
OOMOL uses Slack permissions to let an authorized Slack user connect a workspace as an App in OOMOL, then make approved Slack tools available to agents and reusable Skills.
The exact scopes shown during Slack OAuth are the source of truth for your installation. Depending on the tools enabled for your workspace, OOMOL may request permissions in these categories:
| Slack permission area | Used by | Why OOMOL uses it |
|---|---|---|
| Workspace and conversation metadata | List Conversations, List Channels, Get Conversation | Show conversations and channels that the connected Slack app can access, so a user or agent can choose the right destination before reading or posting. |
| Message history | Get Channel Messages, Get Thread | Read messages and thread replies from conversations visible to the connected Slack app when a user or approved agent action asks for that context. |
| Message posting and management | Post Message, Post Ephemeral Message, Reply Message, Update Message, Schedule Message, Delete Message | Send messages, reply in threads, schedule messages, and manage messages posted by the connected Slack app when a user, Skill, or approved agent action provides the content and destination. |
| File access | Upload File, List Files, Get File, Delete File | Upload files to Slack, list files visible to the app, read file metadata, or delete files when an approved tool call requests those actions. |
| User information and direct messages | List Users, Get User, Open Conversation | Identify Slack users visible to the app and open or resume direct-message conversations when a user, Skill, or agent selects a Slack user. |
| Emoji reactions | Add Reaction, Get Reactions, Remove Reaction | Add, read, or remove emoji reactions on Slack messages when a user, Skill, or approved agent action requests that interaction. |
If a Slack administrator does not grant a required permission, the Slack connection can fail, or tools that depend on that permission may be unavailable until the permission is granted.
Supported Slack tools
| Tool | Supported function | Typical use case | Prerequisites |
|---|---|---|---|
| List Conversations | List Slack conversations visible to the connected app. | Let an agent choose the right channel, private channel, group message, or direct message before taking another action. | Slack is connected in OOMOL and the connected app has access to the conversations. |
| List Channels | List public Slack channels visible to the connected app. | Find the right public channel for a report, alert, summary, or follow-up message. | Slack is connected in OOMOL and public channels are visible to the connected app. |
| Get Conversation | Read Slack conversation metadata. | Confirm a conversation name, ID, type, membership, or other available metadata before another action uses it. | Slack is connected in OOMOL and the conversation is visible to the connected app. |
| Get Channel Messages | Get recent messages from a Slack conversation. | Summarize recent updates, collect support requests, or prepare a follow-up from a test or approved work channel. | Slack is connected in OOMOL and the connected app can read the conversation history. |
| Get Thread | Get messages in a Slack thread. | Summarize a discussion, prepare a reply, or extract action items from a thread. | Slack is connected in OOMOL and the connected app can read the thread. |
| Post Message | Post a Slack message using plain text or Block Kit blocks. | Send a status update, alert, summary, or task result to a selected channel. | Slack is connected in OOMOL, the destination is known, and the user, Skill, or agent provides the message content. |
| Post Ephemeral Message | Post a message visible only to one user in a conversation. | Send a private confirmation or prompt to one Slack user without posting it for everyone. | Slack is connected in OOMOL, the target conversation and user are known, and the app has permission to post. |
| Reply Message | Reply to a Slack thread. | Add a task result, answer, summary, or follow-up directly inside an existing discussion. | Slack is connected in OOMOL, the parent message is known, and the app can post in the conversation. |
| Update Message | Update a Slack message posted by the bot. | Correct, replace, or refresh a bot-posted status message. | Slack is connected in OOMOL and the target message was posted by the connected app. |
| Schedule Message | Schedule a Slack message to be posted later. | Queue reminders, handoff notes, or updates for a future time. | Slack is connected in OOMOL, the destination and scheduled time are valid, and the app can post there. |
| Delete Message | Delete a Slack message posted by the bot. | Remove a bot-posted test message, obsolete alert, or incorrect update. | Slack is connected in OOMOL and the target message can be deleted by the connected app. |
| Upload File | Upload a file to Slack from a file URL. | Share a report, exported result, image, or document in a selected conversation. | Slack is connected in OOMOL, the destination is known, and the file URL is accessible to the connector runtime. |
| List Files | List Slack files visible to the connected app. | Find files shared in a channel or by a user before another action uses them. | Slack is connected in OOMOL and the app can see the requested files. |
| Get File | Read Slack file metadata. | Check a file name, owner, type, or available metadata before deciding what to do next. | Slack is connected in OOMOL and the file is visible to the connected app. |
| Delete File | Delete a Slack file when the connected app is allowed to do so. | Remove a test file or bot-uploaded file when a user requests cleanup. | Slack is connected in OOMOL and the connected app has permission to delete the file. |
| List Users | List Slack users visible to the connected app. | Find a user before sending an ephemeral message or opening a direct message. | Slack is connected in OOMOL and users are visible to the connected app. |
| Get User | Read Slack user metadata. | Confirm the correct Slack user before a Skill or agent references that person. | Slack is connected in OOMOL and the user is visible to the connected app. |
| Open Conversation | Open or resume a direct message with one Slack user. | Prepare a direct-message task after the user has selected a Slack user. | Slack is connected in OOMOL and the app can open or access the direct message. |
| Add Reaction | Add an emoji reaction to a Slack message. | Mark a message as acknowledged, queued, completed, or needing follow-up. | Slack is connected in OOMOL and the message is visible to the connected app. |
| Get Reactions | Get reactions for a Slack message. | Check whether a message has been acknowledged or triaged by reaction. | Slack is connected in OOMOL and the message is visible to the connected app. |
| Remove Reaction | Remove an emoji reaction from a Slack message. | Clear a reaction that is no longer accurate. | Slack is connected in OOMOL and the connected app can remove the reaction. |
Read conversations and threads
Use case: let an agent review recent Slack messages or a specific thread before summarizing updates, extracting action items, preparing a reply, or routing work to another connected tool.
Prerequisites:
- Slack is connected in OOMOL.
- The connected Slack app can access the target conversation or thread.
- The agent, Skill, or tool call has the correct channel, conversation, message, or thread identifier.
What the tools do:
- Read conversation metadata, recent messages, and thread replies that are visible to the connected Slack app.
- Return Slack data made available through the connected workspace authorization.
- Do not post, update, delete, or react to messages during read-only actions.
Send and manage messages
Use case: let an agent post a status update, reply to a thread, schedule a reminder, send an ephemeral message to one user, or update a bot-posted message after a task finishes.
Prerequisites:
- Slack is connected in OOMOL.
- The target channel, conversation, user, message, or thread is known.
- The user, Skill, or agent has provided the message content and approved the destination.
What the tools do:
- Post plain-text messages or Block Kit messages when content is provided.
- Reply inside existing threads when a parent message is provided.
- Schedule messages for a future time when Slack accepts the destination and timestamp.
- Update or delete messages only when the connected app is allowed to manage the target message.
Work with files and reactions
Use case: let an agent share a file in Slack, inspect file metadata, or add a reaction that marks a message as acknowledged, queued, completed, or needing follow-up.
Prerequisites:
- Slack is connected in OOMOL.
- The target conversation, file, message, or reaction name is known.
- For file upload, the file must be available through a URL that the connector runtime can fetch.
What the tools do:
- Upload files to Slack when a file URL and destination are provided.
- Read file metadata and reactions that are visible to the connected app.
- Add or remove reactions when Slack permits the connected app to do so.
- Delete files only when the connected app is allowed to delete the target file.
Testing the app
You can test the Slack app with a Slack workspace where you are allowed to install apps. Use a test channel and demo messages so you can safely test read, post, update, file, and reaction actions.
Sample test prompts
- List Slack public channels visible to the connected app.
- Get recent messages from the
#oomol-testchannel. - Post
Hello from OOMOLto the#oomol-testchannel. - Reply to the latest test message with
Received. - Add the
white_check_markreaction to a test message. - Get reactions for the test message.
- Schedule a Slack message in the test channel for later today.
- Upload a demo file to the test channel.
- List Slack users visible to the connected app.
- Open a direct message with a test user.
Use only demo data during testing. Do not use real customer, employee, or confidential Slack content in test prompts.
Troubleshooting
I cannot add the Slack app
- Make sure you are signed in to the correct OOMOL account.
- Make sure you are signing in to the Slack workspace you want to connect.
- If your Slack workspace requires app approval, ask a Slack workspace owner or administrator to approve the OOMOL app.
- Try disconnecting any failed or partial Slack connection in OOMOL, then connect again.
- If the issue continues, contact OOMOL support and include the OOMOL account email, the Slack workspace name or ID if available, the time of the attempt, and any error message or screenshot.
A Slack tool cannot find a channel or conversation
- Confirm that the connected Slack app can access the target conversation.
- If the target is a private channel, confirm that the connected app has been added to that channel or has the required workspace permissions.
- Confirm that the request is using the correct conversation ID, channel name, or search input.
- If you recently changed Slack permissions, reconnect Slack in OOMOL so the authorization state is refreshed.
A Slack tool cannot read messages
- Confirm that the connected Slack app has permission to read the target conversation history.
- Confirm that the app is present in the private channel if the message is in a private channel.
- Check that the request is using the correct message timestamp, thread timestamp, or conversation ID.
- If the workspace recently changed app scopes or channel access, reconnect Slack in OOMOL.
A Slack tool cannot post or update a message
- Confirm that the connected Slack app can post in the target conversation.
- Confirm that the tool call has a valid destination and message body.
- For update and delete actions, confirm that the target message was posted by the connected Slack app and can be managed by it.
- If Slack returns a workspace policy or permission error, ask a Slack workspace owner or administrator to review the app permissions.
A Slack file action fails
- For upload actions, confirm that the file URL is accessible to the connector runtime.
- Confirm that the connected Slack app can access the target conversation.
- For delete actions, confirm that the connected app is allowed to delete the target file.
Removing the app
You can remove the Slack app from either OOMOL or Slack. We recommend removing it from both places if you no longer want OOMOL to access Slack.
Remove Slack from OOMOL
- Sign in to the OOMOL Console.
- Open Connections.
- Find Slack in your connected apps.
- Open the Slack connection details.
- Choose Disconnect, Remove, or the equivalent removal action shown in OOMOL.
- Confirm the removal.
Remove OOMOL from Slack
- Sign in to Slack in the connected workspace.
- Open Manage apps or the Slack app management page for your workspace.
- Find OOMOL.
- Open the app details.
- Choose the action to remove, uninstall, or revoke the app.
- Confirm the removal.
If you cannot remove apps in Slack, ask a Slack workspace owner or administrator to remove the app.
What happens after removal
- OOMOL can no longer use Slack tools for your workspace after the Slack connection is removed or de-authorized.
- Agents, Skills, or other tasks that depend on Slack may fail until you reconnect Slack.
- Existing Slack messages, files, channels, and reactions created before removal remain in Slack unless you delete or change them in Slack.
- Removing the app does not delete your OOMOL account.
Data handling
OOMOL accesses Slack data only after a Slack user authorizes the app and a user, Skill, or approved agent action requires Slack. OOMOL uses Slack data only to provide Slack tools requested through OOMOL-supported agents, reusable Skills, and approved tool calls.
- Slack OAuth tokens are stored encrypted.
- Slack OAuth tokens are not exposed to AI agents, prompts, project files, or end users.
- OOMOL may process Slack workspace metadata, conversation metadata, messages, thread replies, files, user metadata, and reactions when a Slack tool is called.
- Slack data may be stored only as needed in user-visible tool results, usage records, execution history, or operational records.
- Stored data is encrypted at rest and transmitted over TLS/SSL.
- OOMOL does not sell your Slack data.
- OOMOL does not use Slack data for advertising.
- OOMOL does not use private customer content to train AI models.
- OOMOL does not continuously sync or replicate Slack workspace data in the background as part of this connector. Slack data is accessed when an authorized user, Skill, or approved agent action calls a Slack tool.
- When you remove or de-authorize the Slack app, OOMOL stops using the revoked Slack authorization. OOMOL deletes or invalidates the stored Slack authorization tokens according to its normal connection removal process.
- Some logs, support records, security records, or billing-related records may be retained as described in the Privacy Policy.
FAQ
Do I need a paid Slack workspace?
Most OOMOL Slack tools require a Slack workspace that allows the requested app permissions. Some Slack features, app approval controls, retention settings, or workspace policies may depend on your Slack plan or organization settings.
Can I connect more than one Slack workspace?
Use the OOMOL Console to check the current connection options available to your account or workspace. If you need help with multiple Slack workspaces, contact support.
Can an agent use Slack automatically after I connect it?
Connecting Slack makes Slack tools available in OOMOL, but tool use still depends on the agent, Skill, permissions, and approvals you choose. Account-based services still require your authorization.
Does OOMOL read every Slack message after I connect it?
No. OOMOL does not continuously sync every Slack message. Slack data is accessed when an authorized user, Skill, or approved agent action calls a Slack tool for a conversation that the connected app can access.
Can OOMOL delete Slack messages or files?
The current Slack connector includes delete actions for messages posted by the bot and files that the connected app is allowed to delete. OOMOL does not delete Slack content unless a user or approved tool call uses a supported delete tool with the required target information.
Contact support
If you need help adding, using, testing, or removing the Slack app, contact OOMOL support:
- Email: support@oomol.com
- Support page: https://oomol.com/en/support/
Please include your OOMOL account email, the Slack workspace name or ID if relevant, the action you were trying to perform, and any error message or screenshot.