Slack

Connect Slack when you want an agent in direct messages, public or private channels, multiparty DMs, threads, or the Slack Assistant panel. Slack uses a signed webhook for events and native slash commands.

What the channel supports

Prerequisites

• An existing Manyfold agent.
• Permission to create and install a Slack app in the workspace.
• Permission to invite the app to each target channel.

Set up from Manyfold’s manifest

The generated manifest becomes available after a Manyfold channel has its channel-specific inbound URL. It is useful when you are recreating/migrating an app or want Slack to validate the complete configuration in one operation.

For a new setup, use this bootstrap flow:

1. Create and install a minimal bootstrap Slack app so you have an xoxb- token and signing secret.
2. Use those credentials to create the Slack channel in Manyfold and obtain its inbound URL.
3. Open the channel detail page and choose Copy manifest JSON.
4. In Slack API Apps, choose Create New App -> From an app manifest.
5. Select the workspace, paste the JSON, review it, and create the app.
6. Under OAuth & Permissions, install or reinstall the app to the workspace.
7. Replace the bootstrap credentials in the Manyfold channel with the final app’s Bot User OAuth Token and signing secret.
8. Remove the bootstrap app if it is no longer used, then run the channel registration and test actions.

The manifest configures the Request URL, all event subscriptions, all 11 slash commands, and the scopes needed for files. Slash command names are workspace-wide; if another app already owns a name such as /new, rename that command in the manifest before installing.

Manual Slack app setup

Create an app from scratch, add a bot user, and add these bot token scopes:

Under Event Subscriptions, set the channel’s Manyfold inbound URL as the Request URL and subscribe to:

Create each command listed by /help under Slash Commands and point every command to the same Manyfold inbound URL. After changing scopes, events, or commands, reinstall the app to the workspace.

Connect it to Manyfold

1. Open Settings -> Channels.
2. Create a channel and choose Slack.
3. Select the agent and enter a label.
4. Paste the xoxb- Bot User OAuth Token and signing secret.
5. Create the channel.
6. Copy its inbound URL into Slack’s Event Subscriptions and slash commands, unless you used the generated manifest.
7. Install/reinstall the Slack app and invite it to each target channel.
8. Run Register, then Test.

Registration uses auth.test to store the bot user and workspace IDs. Messages from a different workspace are rejected, so register again after moving or reinstalling the app in another workspace.

Messages and files

• Text and Slack file shares can drive the agent; a file-only message is accepted.
• Incoming files use Slack’s authenticated download URLs. Manyfold accepts up to 10 files, 25 MB per file, and 100 MB total per message; unsupported or oversized files are skipped while the remaining message continues.
• When Attach files the agent links is on, a workspace file linked in the final answer is uploaded to the same channel or thread.
• Long replies are split into chunks. Continuation chunks stay in the active Slack thread.
• Slack markdown links and basic emphasis are rendered in Slack’s native format.

File input still depends on the selected agent framework supporting attachments.

Threads and commands

• With Thread isolation on, each channel thread, Assistant conversation, or manual DM thread maps to its own session. Plain DMs keep one flat session per user.
• Auto-thread answers a top-level channel mention in a new thread rooted at that message. It requires thread isolation and does not apply to DMs or slash commands.
• Native slash commands use Slack’s command payload and return a private ephemeral response. Slack’s slash-command composer does not include thread context, so native commands operate on the channel-level scope rather than the open thread.
• Typed commands still use the normal message flow. See Session switching for the full command list.

Settings

Access control

Find a Slack user ID from the member profile’s three-dot menu with Copy member ID. Operators automatically have chat permission. Slack identities are external actors and are not linked to Manyfold accounts.

Verify

Run Test to verify the token with auth.test and confirm the channel is active. Then:

1. DM the app.
2. Invite it to a channel and @mention it.
3. Run /help from Slack’s command menu.
4. Upload a small file if file input is required.

Troubleshooting

• Request URL verification fails: confirm the signing secret and use the current inbound URL from Manyfold.
• Bot ignores DMs or a channel type: add the corresponding message.* event and history scope, then reinstall the app.
• Bot receives a channel message but cannot reply: invite it to the channel and confirm chat:write.
• Slash command is missing or returns to the wrong app: add commands, create the command with this channel’s URL, and resolve any workspace-wide name conflict.
• Scope or event changes do not apply: reinstall the Slack app.
• File input fails: confirm files:read; for output confirm files:write and Attach files the agent links.
• Users are silently ignored: check Allowed user IDs and confirm the app is still installed in the workspace recorded by the channel.
• Replies appear in the wrong scope: check Thread isolation, Auto-thread, and Share session in channel.

See also

• Connect channels
• Session switching
• Telegram
• Lark and Feishu
• Discord
• Matrix
• Slack app manifests
• Slack Events API