---
summary: "Slack setup and runtime behavior (Socket Mode + HTTP Request URLs)"
read_when:
  - Setting up Slack or debugging Slack socket/HTTP mode
title: "Slack"
---

Production-ready for DMs and channels via Slack app integrations. Default mode is Socket Mode; HTTP Request URLs are also supported.

<CardGroup cols={3}>
  <Card title="Pairing" icon="link" href="/channels/pairing">
    Slack DMs default to pairing mode.
  </Card>
  <Card title="Slash commands" icon="terminal" href="/tools/slash-commands">
    Native command behavior and command catalog.
  </Card>
  <Card title="Channel troubleshooting" icon="wrench" href="/channels/troubleshooting">
    Cross-channel diagnostics and repair playbooks.
  </Card>
</CardGroup>

## Choosing Socket Mode or HTTP Request URLs

Both transports are production-ready and reach feature parity for messaging, slash commands, App Home, and interactivity. Pick by deployment shape, not features.

| Concern                      | Socket Mode (default)                                                                                                                                | HTTP Request URLs                                                                                              |
| ---------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------- |
| Public Gateway URL           | Not required                                                                                                                                         | Required (DNS, TLS, reverse proxy or tunnel)                                                                   |
| Outbound network             | Outbound WSS to `wss-primary.slack.com` must be reachable                                                                                            | No outbound WS; inbound HTTPS only                                                                             |
| Tokens needed                | Bot token + App-Level Token with `connections:write`                                                                                                 | Bot token + Signing Secret                                                                                     |
| Dev laptop / behind firewall | Works as-is                                                                                                                                          | Needs a public tunnel (ngrok, Cloudflare Tunnel, Tailscale Funnel) or staging Gateway                          |
| Horizontal scaling           | One Socket Mode session per app per host; multiple Gateways need separate Slack apps                                                                 | Stateless POST handler; multiple Gateway replicas can share one app behind a load balancer                     |
| Multi-account on one Gateway | Supported; each account opens its own WS                                                                                                             | Supported; each account needs a unique `webhookPath` (default `/slack/events`) so registrations do not collide |
| Slash command transport      | Delivered over the WS connection; `slash_commands[].url` is ignored                                                                                  | Slack POSTs to `slash_commands[].url`; field is required for the command to dispatch                           |
| Request signing              | Not used (auth is the App-Level Token)                                                                                                               | Slack signs every request; Mnemo verifies with `signingSecret`                                              |
| Recovery on connection drop  | Slack SDK auto-reconnect is enabled; Mnemo also restarts failed Socket Mode sessions with bounded backoff. Pong-timeout transport tuning applies. | No persistent connection to drop; retries are per-request from Slack                                           |

<Note>
  **Pick Socket Mode** for single-Gateway hosts, dev laptops, and on-prem networks that can reach `*.slack.com` outbound but cannot accept inbound HTTPS.

**Pick HTTP Request URLs** when running multiple Gateway replicas behind a load balancer, when outbound WSS is blocked but inbound HTTPS is allowed, or when you already terminate Slack webhooks at a reverse proxy.
</Note>

## Install

Install Slack before configuring the channel:

```bash
mnemo plugins install @mnemo-bot/slack
```

`plugins install` registers and enables the plugin. The plugin still does nothing until you configure the Slack app and channel settings below. See [Plugins](/tools/plugin) for general plugin behavior and install rules.

## Quick setup

<Tabs>
  <Tab title="Socket Mode (default)">
    <Steps>
      <Step title="Create a new Slack app">
        Open [api.slack.com/apps](https://api.slack.com/apps/new) → **Create New App** → **From a manifest** → select your workspace → paste one of the manifests below → **Next** → **Create**.

        <CodeGroup>

```json Recommended
{
  "display_information": {
    "name": "Mnemo",
    "description": "Slack connector for Mnemo"
  },
  "features": {
    "bot_user": { "display_name": "Mnemo", "always_online": true },
    "app_home": {
      "home_tab_enabled": true,
      "messages_tab_enabled": true,
      "messages_tab_read_only_enabled": false
    },
    "assistant_view": {
      "assistant_description": "Mnemo connects Slack assistant threads to Mnemo agents.",
      "suggested_prompts": [
        { "title": "What can you do?", "message": "What can you help me with?" },
        {
          "title": "Summarize this channel",
          "message": "Summarize the recent activity in this channel."
        },
        { "title": "Draft a reply", "message": "Help me draft a reply." }
      ]
    },
    "slash_commands": [
      {
        "command": "/mnemo",
        "description": "Send a message to Mnemo",
        "should_escape": false
      }
    ]
  },
  "oauth_config": {
    "scopes": {
      "bot": [
        "app_mentions:read",
        "assistant:write",
        "channels:history",
        "channels:read",
        "chat:write",
        "commands",
        "emoji:read",
        "files:read",
        "files:write",
        "groups:history",
        "groups:read",
        "im:history",
        "im:read",
        "im:write",
        "mpim:history",
        "mpim:read",
        "mpim:write",
        "pins:read",
        "pins:write",
        "reactions:read",
        "reactions:write",
        "usergroups:read",
        "users:read"
      ]
    }
  },
  "settings": {
    "socket_mode_enabled": true,
    "event_subscriptions": {
      "bot_events": [
        "app_home_opened",
        "app_mention",
        "assistant_thread_context_changed",
        "assistant_thread_started",
        "channel_rename",
        "member_joined_channel",
        "member_left_channel",
        "message.channels",
        "message.groups",
        "message.im",
        "message.mpim",
        "pin_added",
        "pin_removed",
        "reaction_added",
        "reaction_removed"
      ]
    }
  }
}
```

```json Minimal
{
  "display_information": {
    "name": "Mnemo",
    "description": "Slack connector for Mnemo"
  },
  "features": {
    "bot_user": { "display_name": "Mnemo", "always_online": true },
    "app_home": {
      "home_tab_enabled": true,
      "messages_tab_enabled": true,
      "messages_tab_read_only_enabled": false
    },
    "assistant_view": {
      "assistant_description": "Mnemo connects Slack assistant threads to Mnemo agents.",
      "suggested_prompts": [
        { "title": "What can you do?", "message": "What can you help me with?" },
        {
          "title": "Summarize this channel",
          "message": "Summarize the recent activity in this channel."
        },
        { "title": "Draft a reply", "message": "Help me draft a reply." }
      ]
    },
    "slash_commands": [
      {
        "command": "/mnemo",
        "description": "Send a message to Mnemo",
        "should_escape": false
      }
    ]
  },
  "oauth_config": {
    "scopes": {
      "bot": [
        "app_mentions:read",
        "assistant:write",
        "channels:history",
        "channels:read",
        "chat:write",
        "commands",
        "groups:history",
        "groups:read",
        "im:history",
        "im:read",
        "im:write",
        "users:read"
      ]
    }
  },
  "settings": {
    "socket_mode_enabled": true,
    "event_subscriptions": {
      "bot_events": [
        "app_home_opened",
        "app_mention",
        "assistant_thread_context_changed",
        "assistant_thread_started",
        "message.channels",
        "message.groups",
        "message.im"
      ]
    }
  }
}
```

        </CodeGroup>

        <Note>
          **Recommended** matches the Slack plugin's full feature set: App Home, slash commands, files, reactions, pins, group DMs, and emoji/usergroup reads. Pick **Minimal** when workspace policy restricts scopes — it covers DMs, channel/group history, mentions, and slash commands but drops files, reactions, pins, group-DM (`mpim:*`), `emoji:read`, and `usergroups:read`. See [Manifest and scope checklist](#manifest-and-scope-checklist) for per-scope rationale and additive options like extra slash commands.
        </Note>

        After Slack creates the app:

        - **Basic Information -> App-Level Tokens -> Generate Token and Scopes**: add `connections:write`, save, copy the App-Level Token.
        - **Install App -> Install to Workspace**: copy the Bot User OAuth Token.

      </Step>

      <Step title="Configure Mnemo">

        Recommended SecretRef setup:

```bash
export SLACK_APP_TOKEN=slack-app-token-example
export SLACK_BOT_TOKEN=slack-bot-token-example
cat > slack.socket.patch.json5 <<'JSON5'
{
  channels: {
    slack: {
      enabled: true,
      mode: "socket",
      appToken: { source: "env", provider: "default", id: "SLACK_APP_TOKEN" },
      botToken: { source: "env", provider: "default", id: "SLACK_BOT_TOKEN" },
    },
  },
}
JSON5
mnemo config patch --file ./slack.socket.patch.json5 --dry-run
mnemo config patch --file ./slack.socket.patch.json5
```

        Env fallback (default account only):

```bash
SLACK_APP_TOKEN=slack-app-token-example
SLACK_BOT_TOKEN=slack-bot-token-example
```

      </Step>

      <Step title="Start gateway">

```bash
mnemo gateway
```

      </Step>
    </Steps>

  </Tab>

  <Tab title="HTTP Request URLs">
    <Steps>
      <Step title="Create a new Slack app">
        Open [api.slack.com/apps](https://api.slack.com/apps/new) → **Create New App** → **From a manifest** → select your workspace → paste one of the manifests below → replace `https://gateway-host.example.com/slack/events` with your public Gateway URL → **Next** → **Create**.

        <CodeGroup>

```json Recommended
{
  "display_information": {
    "name": "Mnemo",
    "description": "Slack connector for Mnemo"
  },
  "features": {
    "bot_user": { "display_name": "Mnemo", "always_online": true },
    "app_home": {
      "home_tab_enabled": true,
      "messages_tab_enabled": true,
      "messages_tab_read_only_enabled": false
    },
    "assistant_view": {
      "assistant_description": "Mnemo connects Slack assistant threads to Mnemo agents.",
      "suggested_prompts": [
        { "title": "What can you do?", "message": "What can you help me with?" },
        {
          "title": "Summarize this channel",
          "message": "Summarize the recent activity in this channel."
        },
        { "title": "Draft a reply", "message": "Help me draft a reply." }
      ]
    },
    "slash_commands": [
      {
        "command": "/mnemo",
        "description": "Send a message to Mnemo",
        "should_escape": false,
        "url": "https://gateway-host.example.com/slack/events"
      }
    ]
  },
  "oauth_config": {
    "scopes": {
      "bot": [
        "app_mentions:read",
        "assistant:write",
        "channels:history",
        "channels:read",
        "chat:write",
        "commands",
        "emoji:read",
        "files:read",
        "files:write",
        "groups:history",
        "groups:read",
        "im:history",
        "im:read",
        "im:write",
        "mpim:history",
        "mpim:read",
        "mpim:write",
        "pins:read",
        "pins:write",
        "reactions:read",
        "reactions:write",
        "usergroups:read",
        "users:read"
      ]
    }
  },
  "settings": {
    "event_subscriptions": {
      "request_url": "https://gateway-host.example.com/slack/events",
      "bot_events": [
        "app_home_opened",
        "app_mention",
        "assistant_thread_context_changed",
        "assistant_thread_started",
        "channel_rename",
        "member_joined_channel",
        "member_left_channel",
        "message.channels",
        "message.groups",
        "message.im",
        "message.mpim",
        "pin_added",
        "pin_removed",
        "reaction_added",
        "reaction_removed"
      ]
    },
    "interactivity": {
      "is_enabled": true,
      "request_url": "https://gateway-host.example.com/slack/events",
      "message_menu_options_url": "https://gateway-host.example.com/slack/events"
    }
  }
}
```

```json Minimal
{
  "display_information": {
    "name": "Mnemo",
    "description": "Slack connector for Mnemo"
  },
  "features": {
    "bot_user": { "display_name": "Mnemo", "always_online": true },
    "app_home": {
      "home_tab_enabled": true,
      "messages_tab_enabled": true,
      "messages_tab_read_only_enabled": false
    },
    "assistant_view": {
      "assistant_description": "Mnemo connects Slack assistant threads to Mnemo agents.",
      "suggested_prompts": [
        { "title": "What can you do?", "message": "What can you help me with?" },
        {
          "title": "Summarize this channel",
          "message": "Summarize the recent activity in this channel."
        },
        { "title": "Draft a reply", "message": "Help me draft a reply." }
      ]
    },
    "slash_commands": [
      {
        "command": "/mnemo",
        "description": "Send a message to Mnemo",
        "should_escape": false,
        "url": "https://gateway-host.example.com/slack/events"
      }
    ]
  },
  "oauth_config": {
    "scopes": {
      "bot": [
        "app_mentions:read",
        "assistant:write",
        "channels:history",
        "channels:read",
        "chat:write",
        "commands",
        "groups:history",
        "groups:read",
        "im:history",
        "im:read",
        "im:write",
        "users:read"
      ]
    }
  },
  "settings": {
    "event_subscriptions": {
      "request_url": "https://gateway-host.example.com/slack/events",
      "bot_events": [
        "app_home_opened",
        "app_mention",
        "assistant_thread_context_changed",
        "assistant_thread_started",
        "message.channels",
        "message.groups",
        "message.im"
      ]
    },
    "interactivity": {
      "is_enabled": true,
      "request_url": "https://gateway-host.example.com/slack/events",
      "message_menu_options_url": "https://gateway-host.example.com/slack/events"
    }
  }
}
```

        </CodeGroup>

        <Note>
          **Recommended** matches the Slack plugin's full feature set; **Minimal** drops files, reactions, pins, group-DM (`mpim:*`), `emoji:read`, and `usergroups:read` for restrictive workspaces. See [Manifest and scope checklist](#manifest-and-scope-checklist) for per-scope rationale.
        </Note>

        <Info>
          The three URL fields (`slash_commands[].url`, `event_subscriptions.request_url`, and `interactivity.request_url` / `message_menu_options_url`) all point at the same Mnemo endpoint. Slack's manifest schema requires them named separately, but Mnemo routes by payload type so a single `webhookPath` (default `/slack/events`) is enough. Slash commands without `slash_commands[].url` will silently no-op in HTTP mode.
        </Info>

        After Slack creates the app:

        - **Basic Information → App Credentials**: copy the **Signing Secret** for request verification.
        - **Install App -> Install to Workspace**: copy the Bot User OAuth Token.

      </Step>

      <Step title="Configure Mnemo">

        Recommended SecretRef setup:

```bash
export SLACK_BOT_TOKEN=slack-bot-token-example
export SLACK_SIGNING_SECRET=...
cat > slack.http.patch.json5 <<'JSON5'
{
  channels: {
    slack: {
      enabled: true,
      mode: "http",
      botToken: { source: "env", provider: "default", id: "SLACK_BOT_TOKEN" },
      signingSecret: { source: "env", provider: "default", id: "SLACK_SIGNING_SECRET" },
      webhookPath: "/slack/events",
    },
  },
}
JSON5
mnemo config patch --file ./slack.http.patch.json5 --dry-run
mnemo config patch --file ./slack.http.patch.json5
```

        <Note>
        Use unique webhook paths for multi-account HTTP

        Give each account a distinct `webhookPath` (default `/slack/events`) so registrations do not collide.
        </Note>

      </Step>

      <Step title="Start gateway">

```bash
mnemo gateway
```

      </Step>
    </Steps>

  </Tab>
</Tabs>

## Socket Mode transport tuning

Mnemo sets the Slack SDK client pong timeout to 15 seconds by default for Socket Mode. Override the transport settings only when you need workspace- or host-specific tuning:

```json5
{
  channels: {
    slack: {
      mode: "socket",
      socketMode: {
        clientPingTimeout: 20000,
        serverPingTimeout: 30000,
        pingPongLoggingEnabled: false,
      },
    },
  },
}
```

Use this only for Socket Mode workspaces that log Slack websocket pong/server-ping timeouts or run on hosts with known event-loop starvation. `clientPingTimeout` is the pong wait after the SDK sends a client ping; `serverPingTimeout` is the wait for Slack server pings. App messages and events remain application state, not transport liveness signals.

Notes:

- `socketMode` is ignored in HTTP Request URL mode.
- Base `channels.slack.socketMode` settings apply to all Slack accounts unless overridden. Per-account overrides use `channels.slack.accounts.<accountId>.socketMode`; because this is an object override, include every socket tuning field you want for that account.
- Only `clientPingTimeout` has an Mnemo default (`15000`). `serverPingTimeout` and `pingPongLoggingEnabled` are passed to the Slack SDK only when configured.
- Socket Mode restart backoff starts around 2 seconds and caps around 30 seconds. Consecutive recoverable start/start-wait failures stop after 12 attempts; after a successful connection, later recoverable disconnects start a fresh retry cycle. Non-recoverable Slack auth errors such as `invalid_auth`, revoked tokens, or missing scopes fail fast instead of retrying forever.

## Manifest and scope checklist

The base Slack app manifest is the same for Socket Mode and HTTP Request URLs. Only the `settings` block (and the slash command `url`) differs.

Base manifest (Socket Mode default):

```json
{
  "display_information": {
    "name": "Mnemo",
    "description": "Slack connector for Mnemo"
  },
  "features": {
    "bot_user": { "display_name": "Mnemo", "always_online": true },
    "app_home": {
      "home_tab_enabled": true,
      "messages_tab_enabled": true,
      "messages_tab_read_only_enabled": false
    },
    "assistant_view": {
      "assistant_description": "Mnemo connects Slack assistant threads to Mnemo agents.",
      "suggested_prompts": [
        { "title": "What can you do?", "message": "What can you help me with?" },
        {
          "title": "Summarize this channel",
          "message": "Summarize the recent activity in this channel."
        },
        { "title": "Draft a reply", "message": "Help me draft a reply." }
      ]
    },
    "slash_commands": [
      {
        "command": "/mnemo",
        "description": "Send a message to Mnemo",
        "should_escape": false
      }
    ]
  },
  "oauth_config": {
    "scopes": {
      "bot": [
        "app_mentions:read",
        "assistant:write",
        "channels:history",
        "channels:read",
        "chat:write",
        "commands",
        "emoji:read",
        "files:read",
        "files:write",
        "groups:history",
        "groups:read",
        "im:history",
        "im:read",
        "im:write",
        "mpim:history",
        "mpim:read",
        "mpim:write",
        "pins:read",
        "pins:write",
        "reactions:read",
        "reactions:write",
        "usergroups:read",
        "users:read"
      ]
    }
  },
  "settings": {
    "socket_mode_enabled": true,
    "event_subscriptions": {
      "bot_events": [
        "app_home_opened",
        "app_mention",
        "assistant_thread_context_changed",
        "assistant_thread_started",
        "channel_rename",
        "member_joined_channel",
        "member_left_channel",
        "message.channels",
        "message.groups",
        "message.im",
        "message.mpim",
        "pin_added",
        "pin_removed",
        "reaction_added",
        "reaction_removed"
      ]
    }
  }
}
```

For **HTTP Request URLs mode**, replace `settings` with the HTTP variant and add `url` to each slash command. Public URL required:

```json
{
  "features": {
    "slash_commands": [
      {
        "command": "/mnemo",
        "description": "Send a message to Mnemo",
        "should_escape": false,
        "url": "https://gateway-host.example.com/slack/events"
      }
    ]
  },
  "settings": {
    "event_subscriptions": {
      "request_url": "https://gateway-host.example.com/slack/events",
      "bot_events": [
        "app_home_opened",
        "app_mention",
        "assistant_thread_context_changed",
        "assistant_thread_started",
        "channel_rename",
        "member_joined_channel",
        "member_left_channel",
        "message.channels",
        "message.groups",
        "message.im",
        "message.mpim",
        "pin_added",
        "pin_removed",
        "reaction_added",
        "reaction_removed"
      ]
    },
    "interactivity": {
      "is_enabled": true,
      "request_url": "https://gateway-host.example.com/slack/events",
      "message_menu_options_url": "https://gateway-host.example.com/slack/events"
    }
  }
}
```

### Additional manifest settings

Surface different features that extend the above defaults.

The default manifest enables the Slack App Home **Home** tab and subscribes to `app_home_opened`. When a workspace member opens the Home tab, Mnemo publishes a safe default Home view with `views.publish`; no conversation payload or private configuration is included. The **Messages** tab remains enabled for Slack DMs. The manifest also enables Slack assistant threads with `features.assistant_view`, `assistant:write`, `assistant_thread_started`, and `assistant_thread_context_changed`; assistant threads route to their own Mnemo thread sessions and keep Slack-provided thread context available to the agent.

<AccordionGroup>
  <Accordion title="Optional native slash commands">

    Multiple [native slash commands](#commands-and-slash-behavior) can be used instead of a single configured command with nuance:

    - Use `/agentstatus` instead of `/status` because the `/status` command is reserved.
    - No more than 25 slash commands can be made available at once.

    Replace your existing `features.slash_commands` section with a subset of [available commands](/tools/slash-commands#command-list):

    <Tabs>
      <Tab title="Socket Mode (default)">

```json
{
  "slash_commands": [
    {
      "command": "/new",
      "description": "Start a new session",
      "usage_hint": "[model]"
    },
    {
      "command": "/reset",
      "description": "Reset the current session"
    },
    {
      "command": "/compact",
      "description": "Compact the session context",
      "usage_hint": "[instructions]"
    },
    {
      "command": "/stop",
      "description": "Stop the current run"
    },
    {
      "command": "/session",
      "description": "Manage thread-binding expiry",
      "usage_hint": "idle <duration|off> or max-age <duration|off>"
    },
    {
      "command": "/think",
      "description": "Set the thinking level",
      "usage_hint": "<level>"
    },
    {
      "command": "/verbose",
      "description": "Toggle verbose output",
      "usage_hint": "on|off|full"
    },
    {
      "command": "/fast",
      "description": "Show or set fast mode",
      "usage_hint": "[status|on|off]"
    },
    {
      "command": "/reasoning",
      "description": "Toggle reasoning visibility",
      "usage_hint": "[on|off|stream]"
    },
    {
      "command": "/elevated",
      "description": "Toggle elevated mode",
      "usage_hint": "[on|off|ask|full]"
    },
    {
      "command": "/exec",
      "description": "Show or set exec defaults",
      "usage_hint": "host=<auto|sandbox|gateway|node> security=<deny|allowlist|full> ask=<off|on-miss|always> node=<id>"
    },
    {
      "command": "/approve",
      "description": "Approve or deny pending approval requests",
      "usage_hint": "<id> <decision>"
    },
    {
      "command": "/model",
      "description": "Show or set the model",
      "usage_hint": "[name|#|status]"
    },
    {
      "command": "/models",
      "description": "List providers/models",
      "usage_hint": "[provider] [page] [limit=<n>|size=<n>|all]"
    },
    {
      "command": "/help",
      "description": "Show the short help summary"
    },
    {
      "command": "/commands",
      "description": "Show the generated command catalog"
    },
    {
      "command": "/tools",
      "description": "Show what the current agent can use right now",
      "usage_hint": "[compact|verbose]"
    },
    {
      "command": "/agentstatus",
      "description": "Show runtime status, including provider usage/quota when available"
    },
    {
      "command": "/tasks",
      "description": "List active/recent background tasks for the current session"
    },
    {
      "command": "/context",
      "description": "Explain how context is assembled",
      "usage_hint": "[list|detail|json]"
    },
    {
      "command": "/whoami",
      "description": "Show your sender identity"
    },
    {
      "command": "/skill",
      "description": "Run a skill by name",
      "usage_hint": "<name> [input]"
    },
    {
      "command": "/btw",
      "description": "Ask a side question without changing session context",
      "usage_hint": "<question>"
    },
    {
      "command": "/side",
      "description": "Ask a side question without changing session context",
      "usage_hint": "<question>"
    },
    {
      "command": "/usage",
      "description": "Control the usage footer or show cost summary",
      "usage_hint": "off|tokens|full|cost"
    }
  ]
}
```

      </Tab>
      <Tab title="HTTP Request URLs">
        Use the same `slash_commands` list as Socket Mode above, and add `"url": "https://gateway-host.example.com/slack/events"` to every entry. Example:

```json
{
  "slash_commands": [
    {
      "command": "/new",
      "description": "Start a new session",
      "usage_hint": "[model]",
      "url": "https://gateway-host.example.com/slack/events"
    },
    {
      "command": "/help",
      "description": "Show the short help summary",
      "url": "https://gateway-host.example.com/slack/events"
    }
  ]
}
```

        Repeat that `url` value on every command in the list.

      </Tab>
    </Tabs>

  </Accordion>
  <Accordion title="Optional authorship scopes (write operations)">
    Add the `chat:write.customize` bot scope if you want outgoing messages to use the active agent identity (custom username and icon) instead of the default Slack app identity.

    If you use an emoji icon, Slack expects `:emoji_name:` syntax.

  </Accordion>
  <Accordion title="Optional user-token scopes (read operations)">
    If you configure `channels.slack.userToken`, typical read scopes are:

    - `channels:history`, `groups:history`, `im:history`, `mpim:history`
    - `channels:read`, `groups:read`, `im:read`, `mpim:read`
    - `users:read`
    - `reactions:read`
    - `pins:read`
    - `emoji:read`
    - `search:read` (if you depend on Slack search reads)

  </Accordion>
</AccordionGroup>

## Token model

- `botToken` + `appToken` are required for Socket Mode.
- HTTP mode requires `botToken` + `signingSecret`.
- `botToken`, `appToken`, `signingSecret`, and `userToken` accept plaintext
  strings or SecretRef objects.
- Config tokens override env fallback.
- `SLACK_BOT_TOKEN` / `SLACK_APP_TOKEN` env fallback applies only to the default account.
- `userToken` is config-only (no env fallback) and defaults to read-only behavior (`userTokenReadOnly: true`).

Status snapshot behavior:

- Slack account inspection tracks per-credential `*Source` and `*Status`
  fields (`botToken`, `appToken`, `signingSecret`, `userToken`).
- Status is `available`, `configured_unavailable`, or `missing`.
- `configured_unavailable` means the account is configured through SecretRef
  or another non-inline secret source, but the current command/runtime path
  could not resolve the actual value.
- In HTTP mode, `signingSecretStatus` is included; in Socket Mode, the
  required pair is `botTokenStatus` + `appTokenStatus`.

<Tip>
For actions/directory reads, user token can be preferred when configured. For writes, bot token remains preferred; user-token writes are only allowed when `userTokenReadOnly: false` and bot token is unavailable.
</Tip>

## Actions and gates

Slack actions are controlled by `channels.slack.actions.*`.

Available action groups in current Slack tooling:

| Group      | Default |
| ---------- | ------- |
| messages   | enabled |
| reactions  | enabled |
| pins       | enabled |
| memberInfo | enabled |
| emojiList  | enabled |

Current Slack message actions include `send`, `upload-file`, `download-file`, `read`, `edit`, `delete`, `pin`, `unpin`, `list-pins`, `member-info`, and `emoji-list`. `download-file` accepts Slack file IDs shown in inbound file placeholders and returns image previews for images or local file metadata for other file types.

## Access control and routing

<Tabs>
  <Tab title="DM policy">
    `channels.slack.dmPolicy` controls DM access. `channels.slack.allowFrom` is the canonical DM allowlist.

    - `pairing` (default)
    - `allowlist`
    - `open` (requires `channels.slack.allowFrom` to include `"*"`)
    - `disabled`

    DM flags:

    - `dm.enabled` (default true)
    - `channels.slack.allowFrom`
    - `dm.allowFrom` (legacy)
    - `dm.groupEnabled` (group DMs default false)
    - `dm.groupChannels` (optional MPIM allowlist)

    Multi-account precedence:

    - `channels.slack.accounts.default.allowFrom` applies only to the `default` account.
    - Named accounts inherit `channels.slack.allowFrom` when their own `allowFrom` is unset.
    - Named accounts do not inherit `channels.slack.accounts.default.allowFrom`.

    Legacy `channels.slack.dm.policy` and `channels.slack.dm.allowFrom` still read for compatibility. `mnemo doctor --fix` migrates them to `dmPolicy` and `allowFrom` when it can do so without changing access.

    Pairing in DMs uses `mnemo pairing approve slack <code>`.

  </Tab>

  <Tab title="Channel policy">
    `channels.slack.groupPolicy` controls channel handling:

    - `open`
    - `allowlist`
    - `disabled`

    Channel allowlist lives under `channels.slack.channels` and **must use stable Slack channel IDs** (for example `C12345678`) as config keys.

    Runtime note: if `channels.slack` is completely missing (env-only setup), runtime falls back to `groupPolicy="allowlist"` and logs a warning (even if `channels.defaults.groupPolicy` is set).

    Name/ID resolution:

    - channel allowlist entries and DM allowlist entries are resolved at startup when token access allows
    - unresolved channel-name entries are kept as configured but ignored for routing by default
    - inbound authorization and channel routing are ID-first by default; direct username/slug matching requires `channels.slack.dangerouslyAllowNameMatching: true`

    <Warning>
    Name-based keys (`#channel-name` or `channel-name`) do **not** match under `groupPolicy: "allowlist"`. The channel lookup is ID-first by default, so a name-based key will never route successfully and all messages in that channel will be silently blocked. This differs from `groupPolicy: "open"`, where the channel key is not required for routing and a name-based key appears to work.

    Always use the Slack channel ID as the key. To find it: right-click the channel in Slack → **Copy link** — the ID (`C...`) appears at the end of the URL.

    Correct:

    ```json5
    {
      channels: {
        slack: {
          groupPolicy: "allowlist",
          channels: {
            C12345678: { allow: true, requireMention: true },
          },
        },
      },
    }
    ```

    Incorrect (silently blocked under `groupPolicy: "allowlist"`):

    ```json5
    {
      channels: {
        slack: {
          groupPolicy: "allowlist",
          channels: {
            "#eng-my-channel": { allow: true, requireMention: true },
          },
        },
      },
    }
    ```
    </Warning>

  </Tab>

  <Tab title="Mentions and channel users">
    Channel messages are mention-gated by default.

    Mention sources:

    - explicit app mention (`<@botId>`)
    - Slack user-group mention (`<!subteam^S...>`) when the bot user is a member of that user group; requires `usergroups:read`
    - mention regex patterns (`agents.list[].groupChat.mentionPatterns`, fallback `messages.groupChat.mentionPatterns`)
    - implicit reply-to-bot thread behavior (disabled when `thread.requireExplicitMention` is `true`)

    Per-channel controls (`channels.slack.channels.<id>`; names only via startup resolution or `dangerouslyAllowNameMatching`):

    - `requireMention`
    - `users` (allowlist)
    - `allowBots`
    - `skills`
    - `systemPrompt`
    - `tools`, `toolsBySender`
    - `toolsBySender` key format: `channel:`, `id:`, `e164:`, `username:`, `name:`, or `"*"` wildcard
      (legacy unprefixed keys still map to `id:` only)

    `allowBots` is conservative for channels and private channels: bot-authored room messages are accepted only when the sending bot is explicitly listed in that room's `users` allowlist, or when at least one explicit Slack owner ID from `channels.slack.allowFrom` is currently a room member. Wildcards and display-name owner entries do not satisfy owner presence. Owner presence uses Slack `conversations.members`; make sure the app has the matching read scope for the room type (`channels:read` for public channels, `groups:read` for private channels). If the member lookup fails, Mnemo drops the bot-authored room message.

    Accepted bot-authored Slack messages use shared [bot loop protection](/channels/bot-loop-protection). Configure `channels.defaults.botLoopProtection` for the default budget, then override with `channels.slack.botLoopProtection` or `channels.slack.channels.<id>.botLoopProtection` when a workspace or channel needs a different limit.

  </Tab>
</Tabs>

## Threading, sessions, and reply tags

- DMs route as `direct`; channels as `channel`; MPIMs as `group`.
- Slack route bindings accept raw peer IDs plus Slack target forms such as `channel:C12345678`, `user:U12345678`, and `<@U12345678>`.
- With default `session.dmScope=main`, Slack DMs collapse to agent main session.
- Channel sessions: `agent:<agentId>:slack:channel:<channelId>`.
- Ordinary top-level channel messages stay on the per-channel session, even when `replyToMode` is non-`off`.
- Slack thread replies use the parent Slack `thread_ts` for session suffixes (`:thread:<threadTs>`), even when outbound reply threading is disabled with `replyToMode="off"`.
- Mnemo seeds an eligible top-level channel root into `agent:<agentId>:slack:channel:<channelId>:thread:<rootTs>` when that root is expected to start a visible Slack thread, so the root and later thread replies share one Mnemo session. This applies to `app_mention` events, explicit bot or configured mention-pattern matches, and `requireMention: false` channels with non-`off` `replyToMode`.
- `channels.slack.thread.historyScope` default is `thread`; `thread.inheritParent` default is `false`.
- `channels.slack.thread.initialHistoryLimit` controls how many existing thread messages are fetched when a new thread session starts (default `20`; set `0` to disable).
- `channels.slack.thread.requireExplicitMention` (default `false`): when `true`, suppress implicit thread mentions so the bot only responds to explicit `@bot` mentions inside threads, even when the bot already participated in the thread. Without this, replies in a bot-participated thread bypass `requireMention` gating.

Reply threading controls:

- `channels.slack.replyToMode`: `off|first|all|batched` (default `off`)
- `channels.slack.replyToModeByChatType`: per `direct|group|channel`
- legacy fallback for direct chats: `channels.slack.dm.replyToMode`

Manual reply tags are supported:

- `[[reply_to_current]]`
- `[[reply_to:<id>]]`

For explicit Slack thread replies from the `message` tool, set `replyBroadcast: true` with `action: "send"` and `threadId` or `replyTo` to ask Slack to also broadcast the thread reply to the parent channel. This maps to Slack's `chat.postMessage` `reply_broadcast` flag and is only supported for text or Block Kit sends, not media uploads.

When a `message` tool call runs inside a Slack thread and targets the same channel, Mnemo normally inherits the current Slack thread according to `replyToMode`. Set `topLevel: true` on `action: "send"` or `action: "upload-file"` to force a new parent-channel message instead. `threadId: null` is accepted as the same top-level opt-out.

<Note>
`replyToMode="off"` disables outbound Slack reply threading, including explicit `[[reply_to_*]]` tags. It does not flatten inbound Slack thread sessions: messages already posted inside a Slack thread still route to the `:thread:<threadTs>` session. This differs from Telegram, where explicit tags are still honored in `"off"` mode. Slack threads hide messages from the channel while Telegram replies stay visible inline.
</Note>

## Ack reactions

`ackReaction` sends an acknowledgement emoji while Mnemo is processing an inbound message. `ackReactionScope` decides _when_ that emoji is actually sent.

### Emoji (`ackReaction`)

Resolution order:

- `channels.slack.accounts.<accountId>.ackReaction`
- `channels.slack.ackReaction`
- `messages.ackReaction`
- agent identity emoji fallback (`agents.list[].identity.emoji`, else `"eyes"` / 👀)

Notes:

- Slack expects shortcodes (for example `"eyes"`).
- Use `""` to disable the reaction for the Slack account or globally.

### Scope (`messages.ackReactionScope`)

The Slack provider reads scope from `messages.ackReactionScope` (default `"group-mentions"`). There is no Slack-account or Slack-channel-level override today; the value is global to the gateway.

Values:

- `"all"`: react in DMs and groups.
- `"direct"`: react in DMs only.
- `"group-all"`: react on every group message (no DMs).
- `"group-mentions"` (default): react in groups, but only when the bot is mentioned (or in group mentionables that opted in). **DMs are excluded.**
- `"off"` / `"none"`: never react.

<Note>
The default scope (`"group-mentions"`) does not fire ack reactions in direct messages. To see the configured `ackReaction` (for example `"eyes"`) on inbound Slack DMs, set `messages.ackReactionScope` to `"direct"` or `"all"`. `messages.ackReactionScope` is read at Slack provider startup, so a gateway restart is needed for the change to take effect.
</Note>

```json5
{
  messages: {
    ackReaction: "eyes",
    ackReactionScope: "all", // react in DMs and groups
  },
}
```

## Text streaming

`channels.slack.streaming` controls live preview behavior:

- `off`: disable live preview streaming.
- `partial` (default): replace preview text with the latest partial output.
- `block`: append chunked preview updates.
- `progress`: show progress status text while generating, then send final text.
- `streaming.preview.toolProgress`: when draft preview is active, route tool/progress updates into the same edited preview message (default: `true`). Set `false` to keep separate tool/progress messages.
- `streaming.preview.commandText` / `streaming.progress.commandText`: set to `status` to keep compact tool-progress lines while hiding raw command/exec text (default: `raw`).

Hide raw command/exec text while keeping compact progress lines:

```json
{
  "channels": {
    "slack": {
      "streaming": {
        "mode": "progress",
        "progress": {
          "toolProgress": true,
          "commandText": "status"
        }
      }
    }
  }
}
```

`channels.slack.streaming.nativeTransport` controls Slack native text streaming when `channels.slack.streaming.mode` is `partial` (default: `true`).

Slack native progress task cards are opt-in for progress mode. Set `channels.slack.streaming.progress.nativeTaskCards` to `true` with `channels.slack.streaming.mode="progress"` to send a Slack-native plan/task card while work is running, then update the same task card at completion. Without this flag, progress mode keeps the portable draft-preview behavior.

- A reply thread must be available for native text streaming and Slack assistant thread status to appear. Thread selection still follows `replyToMode`.
- Channel, group-chat, and top-level DM roots can still use the normal draft preview when native streaming is unavailable or no reply thread exists.
- Top-level Slack DMs stay off-thread by default, so they do not show Slack's thread-style native stream/status preview; Mnemo posts and edits a draft preview in the DM instead.
- Media and non-text payloads fall back to normal delivery.
- Media/error finals cancel pending preview edits; eligible text/block finals flush only when they can edit the preview in place.
- If streaming fails mid-reply, Mnemo falls back to normal delivery for remaining payloads.

Use draft preview instead of Slack native text streaming:

```json5
{
  channels: {
    slack: {
      streaming: {
        mode: "partial",
        nativeTransport: false,
      },
    },
  },
}
```

Opt in to Slack native progress task cards:

```json5
{
  channels: {
    slack: {
      streaming: {
        mode: "progress",
        progress: {
          nativeTaskCards: true,
          render: "rich",
        },
      },
    },
  },
}
```

Legacy keys:

- `channels.slack.streamMode` (`replace | status_final | append`) is a legacy runtime alias for `channels.slack.streaming.mode`.
- boolean `channels.slack.streaming` is a legacy runtime alias for `channels.slack.streaming.mode` and `channels.slack.streaming.nativeTransport`.
- legacy `channels.slack.nativeStreaming` is a runtime alias for `channels.slack.streaming.nativeTransport`.
- Run `mnemo doctor --fix` to rewrite persisted Slack streaming config to the canonical keys.

## Typing reaction fallback

`typingReaction` adds a temporary reaction to the inbound Slack message while Mnemo is processing a reply, then removes it when the run finishes. This is most useful outside of thread replies, which use a default "is typing..." status indicator.

Resolution order:

- `channels.slack.accounts.<accountId>.typingReaction`
- `channels.slack.typingReaction`

Notes:

- Slack expects shortcodes (for example `"hourglass_flowing_sand"`).
- The reaction is best-effort and cleanup is attempted automatically after the reply or failure path completes.

## Media, chunking, and delivery

<AccordionGroup>
  <Accordion title="Inbound attachments">
    Slack file attachments are downloaded from Slack-hosted private URLs (token-authenticated request flow) and written to the media store when fetch succeeds and size limits permit. File placeholders include the Slack `fileId` so agents can fetch the original file with `download-file`.

    Downloads use bounded idle and total timeouts. If Slack file retrieval stalls or fails, Mnemo keeps processing the message and falls back to the file placeholder.

    Runtime inbound size cap defaults to `20MB` unless overridden by `channels.slack.mediaMaxMb`.

  </Accordion>

  <Accordion title="Outbound text and files">
    - text chunks use `channels.slack.textChunkLimit` (default 4000)
    - `channels.slack.chunkMode="newline"` enables paragraph-first splitting
    - file sends use Slack upload APIs and can include thread replies (`thread_ts`)
    - outbound media cap follows `channels.slack.mediaMaxMb` when configured; otherwise channel sends use MIME-kind defaults from media pipeline

  </Accordion>

  <Accordion title="Delivery targets">
    Preferred explicit targets:

    - `user:<id>` for DMs
    - `channel:<id>` for channels

    Text/block-only Slack DMs can post directly to user IDs; file uploads and threaded sends open the DM via Slack conversation APIs first because those paths require a concrete conversation ID.

  </Accordion>
</AccordionGroup>

## Commands and slash behavior

Slash commands appear in Slack as either a single configured command or multiple native commands. Configure `channels.slack.slashCommand` to change command defaults:

- `enabled: false`
- `name: "mnemo"`
- `sessionPrefix: "slack:slash"`
- `ephemeral: true`

```txt
/mnemo /help
```

Native commands require [additional manifest settings](#additional-manifest-settings) in your Slack app and are enabled with `channels.slack.commands.native: true` or `commands.native: true` in global configurations instead.

- Native command auto-mode is **off** for Slack so `commands.native: "auto"` does not enable Slack native commands.

```txt
/help
```

Native argument menus use an adaptive rendering strategy that shows a confirmation modal before dispatching a selected option value:

- up to 5 options: button blocks
- 6-100 options: static select menu
- more than 100 options: external select with async option filtering when interactivity options handlers are available
- exceeded Slack limits: encoded option values fall back to buttons

```txt
/think
```

Slash sessions use isolated keys like `agent:<agentId>:slack:slash:<userId>` and still route command executions to the target conversation session using `CommandTargetSessionKey`.

## Interactive replies

Slack can render agent-authored interactive reply controls, but this feature is disabled by default.
For new agent, CLI, and plugin output, prefer the shared
`presentation` buttons or select blocks. They use the same Slack interaction
path while also degrading on other channels.

Enable it globally:

```json5
{
  channels: {
    slack: {
      capabilities: {
        interactiveReplies: true,
      },
    },
  },
}
```

Or enable it for one Slack account only:

```json5
{
  channels: {
    slack: {
      accounts: {
        ops: {
          capabilities: {
            interactiveReplies: true,
          },
        },
      },
    },
  },
}
```

When enabled, agents can still emit deprecated Slack-only reply directives:

- `[[slack_buttons: Approve:approve, Reject:reject]]`
- `[[slack_select: Choose a target | Canary:canary, Production:production]]`

These directives compile into Slack Block Kit and route clicks or selections
back through the existing Slack interaction event path. Keep them for old
prompts and Slack-specific escape hatches; use shared presentation for new
portable controls.

The directive compiler APIs are also deprecated for new producer code:

- `compileSlackInteractiveReplies(...)`
- `parseSlackOptionsLine(...)`
- `isSlackInteractiveRepliesEnabled(...)`
- `buildSlackInteractiveBlocks(...)`

Use `presentation` payloads and `buildSlackPresentationBlocks(...)` for new
Slack-rendered controls.

Notes:

- This is Slack-specific legacy UI. Other channels do not translate Slack Block
  Kit directives into their own button systems.
- The interactive callback values are Mnemo-generated opaque tokens, not raw agent-authored values.
- If generated interactive blocks would exceed Slack Block Kit limits, Mnemo falls back to the original text reply instead of sending an invalid blocks payload.

### Plugin-owned modal submissions

Slack plugins that register an interactive handler can also receive modal
`view_submission` and `view_closed` lifecycle events before Mnemo compacts
the payload for the agent-visible system event. Use one of these routing
patterns when opening a Slack modal:

- Set `callback_id` to `mnemo:<namespace>:<payload>`.
- Or keep an existing `callback_id` and put `pluginInteractiveData:
"<namespace>:<payload>"` in the modal `private_metadata`.

The handler receives `ctx.interaction.kind` as `view_submission` or
`view_closed`, normalized `inputs`, and the full raw `stateValues` object from
Slack. Callback-id-only routing is enough to invoke the plugin handler; include
the existing modal `private_metadata` user/session routing fields when the
modal should also produce an agent-visible system event. The agent receives a
compact, redacted `Slack interaction: ...` system event. If the handler returns
`systemEvent.summary`, `systemEvent.reference`, or `systemEvent.data`, those
fields are included in that compact event so the agent can reference
plugin-owned storage without seeing the complete form payload.

## Native approvals in Slack

Slack can act as a native approval client with interactive buttons and interactions, instead of falling back to the Web UI or terminal.

- Exec and plugin approvals can render as Slack-native Block Kit prompts.
- `channels.slack.execApprovals.*` remains the native exec approval client enablement and DM/channel routing config.
- Exec approval DMs use `channels.slack.execApprovals.approvers` or `commands.ownerAllowFrom`.
- Plugin approvals use Slack-native buttons when Slack is enabled as a native approval client for the originating session, or when `approvals.plugin` routes to the originating Slack session or a Slack target.
- Plugin approval DMs use Slack plugin approvers from `channels.slack.allowFrom`, named-account `allowFrom`, or the account default route.
- Approver authorization is still enforced: exec-only approvers cannot approve plugin requests unless they are also plugin approvers.

This uses the same shared approval button surface as other channels. When `interactivity` is enabled in your Slack app settings, approval prompts render as Block Kit buttons directly in the conversation.
When those buttons are present, they are the primary approval UX; Mnemo
should only include a manual `/approve` command when the tool result says chat
approvals are unavailable or manual approval is the only path.

Config path:

- `channels.slack.execApprovals.enabled`
- `channels.slack.execApprovals.approvers` (optional; falls back to `commands.ownerAllowFrom` when possible)
- `channels.slack.execApprovals.target` (`dm` | `channel` | `both`, default: `dm`)
- `agentFilter`, `sessionFilter`

Slack auto-enables native exec approvals when `enabled` is unset or `"auto"` and at least one
exec approver resolves. Slack can also handle native plugin approvals through this native-client
path when Slack plugin approvers resolve and the request matches the native-client filters. Set
`enabled: false` to disable Slack as a native approval client explicitly. Set `enabled: true` to
force native approvals on when approvers resolve. Disabling Slack exec approvals does not disable
native Slack plugin approval delivery that is enabled through `approvals.plugin`; plugin approval
delivery uses Slack plugin approvers instead.

Default behavior with no explicit Slack exec approval config:

```json5
{
  commands: {
    ownerAllowFrom: ["slack:U12345678"],
  },
}
```

Explicit Slack-native config is only needed when you want to override approvers, add filters, or
opt into origin-chat delivery:

```json5
{
  channels: {
    slack: {
      execApprovals: {
        enabled: true,
        approvers: ["U12345678"],
        target: "both",
      },
    },
  },
}
```

Shared `approvals.exec` forwarding is separate. Use it only when exec approval prompts must also
route to other chats or explicit out-of-band targets. Shared `approvals.plugin` forwarding is also
separate; Slack native delivery suppresses that fallback only when Slack can handle the plugin
approval request natively.

Same-chat `/approve` also works in Slack channels and DMs that already support commands. See [Exec approvals](/tools/exec-approvals) for the full approval forwarding model.

## Events and operational behavior

- Message edits/deletes are mapped into system events.
- Thread broadcasts ("Also send to channel" thread replies) are processed as normal user messages.
- Reaction add/remove events are mapped into system events.
- Member join/leave, channel created/renamed, and pin add/remove events are mapped into system events.
- `channel_id_changed` can migrate channel config keys when `configWrites` is enabled.
- Channel topic/purpose metadata is treated as untrusted context and can be injected into routing context.
- Thread starter and initial thread-history context seeding are filtered by configured sender allowlists when applicable.
- Block actions and modal interactions emit structured `Slack interaction: ...` system events with rich payload fields:
  - block actions: selected values, labels, picker values, and `workflow_*` metadata
  - modal `view_submission` and `view_closed` events with routed channel metadata and form inputs

## Configuration reference

Primary reference: [Configuration reference - Slack](/gateway/config-channels#slack).

<Accordion title="High-signal Slack fields">

- mode/auth: `mode`, `botToken`, `appToken`, `signingSecret`, `webhookPath`, `accounts.*`
- DM access: `dm.enabled`, `dmPolicy`, `allowFrom` (legacy: `dm.policy`, `dm.allowFrom`), `dm.groupEnabled`, `dm.groupChannels`
- compatibility toggle: `dangerouslyAllowNameMatching` (break-glass; keep off unless needed)
- channel access: `groupPolicy`, `channels.*`, `channels.*.users`, `channels.*.requireMention`
- threading/history: `replyToMode`, `replyToModeByChatType`, `thread.*`, `historyLimit`, `dmHistoryLimit`, `dms.*.historyLimit`
- delivery: `textChunkLimit`, `chunkMode`, `mediaMaxMb`, `streaming`, `streaming.nativeTransport`, `streaming.preview.toolProgress`
- unfurls: `unfurlLinks` (default: `false`), `unfurlMedia` for `chat.postMessage` link/media preview control; set `unfurlLinks: true` to opt back into link previews
- ops/features: `configWrites`, `commands.native`, `slashCommand.*`, `actions.*`, `userToken`, `userTokenReadOnly`

</Accordion>

## Troubleshooting

<AccordionGroup>
  <Accordion title="No replies in channels">
    Check, in order:

    - `groupPolicy`
    - channel allowlist (`channels.slack.channels`) — **keys must be channel IDs** (`C12345678`), not names (`#channel-name`). Name-based keys silently fail under `groupPolicy: "allowlist"` because channel routing is ID-first by default. To find an ID: right-click the channel in Slack → **Copy link** — the `C...` value at the end of the URL is the channel ID.
    - `requireMention`
    - per-channel `users` allowlist
    - `messages.groupChat.visibleReplies`: normal group/channel requests default to `"automatic"`. If you opted into `"message_tool"` and logs show assistant text with no `message(action=send)` call, the model missed the visible message-tool path. Final text stays private in this mode; inspect the gateway verbose log for suppressed payload metadata, or set it to `"automatic"` if you want every normal assistant final reply posted through the legacy path.
    - `messages.groupChat.unmentionedInbound`: if it is `"room_event"`, unmentioned allowed channel chatter is ambient context and stays silent unless the agent calls the `message` tool. See [Ambient room events](/channels/ambient-room-events).

```json5
{
  messages: {
    groupChat: {
      visibleReplies: "automatic",
    },
  },
}
```

    Useful commands:

```bash
mnemo channels status --probe
mnemo logs --follow
mnemo doctor
```

  </Accordion>

  <Accordion title="DM messages ignored">
    Check:

    - `channels.slack.dm.enabled`
    - `channels.slack.dmPolicy` (or legacy `channels.slack.dm.policy`)
    - pairing approvals / allowlist entries (`dmPolicy: "open"` still requires `channels.slack.allowFrom: ["*"]`)
    - group DMs use MPIM handling; enable `channels.slack.dm.groupEnabled` and, if configured, include the MPIM in `channels.slack.dm.groupChannels`
    - Slack Assistant DM events: verbose logs mentioning `drop message_changed`
      usually mean Slack sent an edited Assistant-thread event without a
      recoverable human sender in message metadata

```bash
mnemo pairing list slack
```

  </Accordion>

  <Accordion title="Socket mode not connecting">
    Validate bot + app tokens and Socket Mode enablement in Slack app settings.
    The App-Level Token needs `connections:write`, and the Bot User OAuth Token
    bot token must belong to the same Slack app/workspace as the app token.

    If `mnemo channels status --probe --json` shows `botTokenStatus` or
    `appTokenStatus: "configured_unavailable"`, the Slack account is
    configured but the current runtime could not resolve the SecretRef-backed
    value.

    Logs such as `slack socket mode failed to start; retry ...` are recoverable
    start failures. Missing scopes, revoked tokens, and invalid auth fail fast
    instead. A `slack token mismatch ...` log means the bot token and app token
    appear to belong to different Slack apps; fix the Slack app credentials.

  </Accordion>

  <Accordion title="HTTP mode not receiving events">
    Validate:

    - signing secret
    - webhook path
    - Slack Request URLs (Events + Interactivity + Slash Commands)
    - unique `webhookPath` per HTTP account
    - the public URL terminates TLS and forwards requests to the Gateway path
    - the Slack app `request_url` path exactly matches `channels.slack.webhookPath` (default `/slack/events`)

    If `signingSecretStatus: "configured_unavailable"` appears in account
    snapshots, the HTTP account is configured but the current runtime could not
    resolve the SecretRef-backed signing secret.

    A repeated `slack: webhook path ... already registered` log means two HTTP
    accounts are using the same `webhookPath`; give each account a distinct path.

  </Accordion>

  <Accordion title="Native/slash commands not firing">
    Verify whether you intended:

    - native command mode (`channels.slack.commands.native: true`) with matching slash commands registered in Slack
    - or single slash command mode (`channels.slack.slashCommand.enabled: true`)

    Slack does not create or remove slash commands automatically. `commands.native: "auto"` does not enable Slack native commands; use `true` and create the matching commands in the Slack app. In HTTP mode, every Slack slash command must include the Gateway URL. In Socket Mode, command payloads arrive over the websocket and Slack ignores `slash_commands[].url`.

    Also check `commands.useAccessGroups`, DM authorization, channel allowlists,
    and per-channel `users` allowlists. Slack returns ephemeral errors for
    blocked slash-command senders, including:

    - `This channel is not allowed.`
    - `You are not authorized to use this command here.`

  </Accordion>
</AccordionGroup>

## Attachment vision reference

Slack can attach downloaded media to the agent turn when Slack file downloads succeed and size limits permit. Image files can be passed through the media understanding path or directly to a vision-capable reply model; other files are retained as downloadable file context rather than treated as image input.

### Supported media types

| Media type                     | Source               | Current behavior                                                                  | Notes                                                                     |
| ------------------------------ | -------------------- | --------------------------------------------------------------------------------- | ------------------------------------------------------------------------- |
| JPEG / PNG / GIF / WebP images | Slack file URL       | Downloaded and attached to the turn for vision-capable handling                   | Per-file cap: `channels.slack.mediaMaxMb` (default 20 MB)                 |
| PDF files                      | Slack file URL       | Downloaded and exposed as file context for tools such as `download-file` or `pdf` | Slack inbound does not convert PDFs into image-vision input automatically |
| Other files                    | Slack file URL       | Downloaded when possible and exposed as file context                              | Binary files are not treated as image input                               |
| Thread replies                 | Thread starter files | Root-message files can be hydrated as context when the reply has no direct media  | File-only starters use an attachment placeholder                          |
| Multi-image messages           | Multiple Slack files | Each file is evaluated independently                                              | Slack processing is capped at eight files per message                     |

### Inbound pipeline

When a Slack message with file attachments arrives:

1. Mnemo downloads the file from Slack's private URL using the bot token.
2. The file is written to the media store on success.
3. Downloaded media paths and content types are added to the inbound context.
4. Image-capable model/tool paths can use image attachments from that context.
5. Non-image files remain available as file metadata or media references for tools that can handle them.

### Thread-root attachment inheritance

When a message arrives in a thread (has a `thread_ts` parent):

- If the reply itself has no direct media and the included root message has files, Slack can hydrate the root files as thread-starter context.
- Direct reply attachments take precedence over root-message attachments.
- A root message that has only files and no text is represented with an attachment placeholder so the fallback can still include its files.

### Multi-attachment handling

When a single Slack message contains multiple file attachments:

- Each attachment is processed independently through the media pipeline.
- Downloaded media references are aggregated into the message context.
- Processing order follows Slack's file order in the event payload.
- A failure in one attachment's download does not block others.

### Size, download, and model limits

- **Size cap**: Default 20 MB per file. Configurable via `channels.slack.mediaMaxMb`.
- **Download failures**: Files that Slack cannot serve, expired URLs, inaccessible files, oversize files, and Slack auth/login HTML responses are skipped instead of being reported as unsupported formats.
- **Vision model**: Image analysis uses the active reply model when it supports vision, or the image model configured at `agents.defaults.imageModel`.

### Known limits

| Scenario                               | Current behavior                                                             | Workaround                                                                 |
| -------------------------------------- | ---------------------------------------------------------------------------- | -------------------------------------------------------------------------- |
| Expired Slack file URL                 | File skipped; no error shown                                                 | Re-upload the file in Slack                                                |
| Vision model not configured            | Image attachments are stored as media references, but not analyzed as images | Configure `agents.defaults.imageModel` or use a vision-capable reply model |
| Very large images (> 20 MB by default) | Skipped per size cap                                                         | Increase `channels.slack.mediaMaxMb` if Slack allows                       |
| Forwarded/shared attachments           | Text and Slack-hosted image/file media are best-effort                       | Re-share directly in the Mnemo thread                                   |
| PDF attachments                        | Stored as file/media context, not automatically routed through image vision  | Use `download-file` for file metadata or the `pdf` tool for PDF analysis   |

### Related documentation

- [Media understanding pipeline](/nodes/media-understanding)
- [PDF tool](/tools/pdf)
- Epic: [#51349](https://github.com/mnemo/mnemo/issues/51349) — Slack attachment vision enablement
- Regression tests: [#51353](https://github.com/mnemo/mnemo/issues/51353)
- Live verification: [#51354](https://github.com/mnemo/mnemo/issues/51354)

## Related

<CardGroup cols={2}>
  <Card title="Pairing" icon="link" href="/channels/pairing">
    Pair a Slack user to the gateway.
  </Card>
  <Card title="Groups" icon="users" href="/channels/groups">
    Channel and group DM behavior.
  </Card>
  <Card title="Channel routing" icon="route" href="/channels/channel-routing">
    Route inbound messages to agents.
  </Card>
  <Card title="Security" icon="shield" href="/gateway/security">
    Threat model and hardening.
  </Card>
  <Card title="Configuration" icon="sliders" href="/gateway/configuration">
    Config layout and precedence.
  </Card>
  <Card title="Slash commands" icon="terminal" href="/tools/slash-commands">
    Command catalog and behavior.
  </Card>
</CardGroup>
