Linking Slack as a source

The Slack connector syncs channels, users, and messages from your Slack workspace into PostHog's data warehouse.

You connect it using your own Slack app: you create an app in your workspace, install it, and paste its bot token into PostHog. Using your own app keeps message syncing within Slack's API terms, which restrict third-party apps from bulk-exporting message data.

Available tables

Prerequisites

You need permission to create and install a Slack app in your workspace. If your workspace requires admin approval for new apps, ask an admin to approve it.

Adding a data source

1. Create your Slack app

1. Open Slack apps and click From a manifest.
2. Pick your workspace and click Next.
3. Paste the manifest below into the editor, click Next, then Create:

{
  "display_information": {
    "name": "PostHog data warehouse",
    "description": "Sync Slack channels, users, and messages to PostHog data warehouse"
  },
  "oauth_config": {
    "scopes": {
      "bot": [
        "channels:read",
        "channels:join",
        "groups:read",
        "channels:history",
        "groups:history",
        "users:read",
        "users:read.email",
        "reactions:read"
      ]
    }
  },
  "settings": {
    "org_deploy_enabled": false,
    "socket_mode_enabled": false,
    "token_rotation_enabled": false
  }
}

These bot scopes let the app list channels and users (channels:read, groups:read, users:read, users:read.email), read messages and reactions in channels the bot joins (channels:history, groups:history, reactions:read), and join public channels on your behalf for the "Automatically join public channels" option (channels:join).

2. Install the app and copy the token

1. In the left sidebar, click Install App, then Install to Workspace, and authorize.
2. Copy the Bot User OAuth Token — it starts with xoxb-.

3. Connect the source in PostHog

1. In PostHog, go to the Data pipeline page and select the Sources tab.
2. Click + New source and select Slack by clicking the Link button.
3. Paste the Bot User OAuth Token into the Bot User OAuth Token field.
4. Leave Automatically join public channels on (the default) to have the bot join every public channel for you, so their messages sync without inviting it to each one. Turn it off to pick channels manually.
5. Optional: Add a prefix to your table names.
6. Select the tables you want to sync. Each channel appears as its own table you can enable or disable individually.
7. Click Import.

4. Make sure the bot is in your channels

The bot only sees channels it belongs to.

• Public channels: with Automatically join public channels on (the default), the bot joins them for you (including channels created later, on the next sync). If you turned it off, invite it to each one.
• Private channels: always invite the bot manually — it can't add itself.

To invite the bot, run /invite @PostHog data warehouse in the channel, or add it from the channel's Integrations settings.

Setting up the webhook for message syncing

Because channel message tables rely entirely on webhooks, your Slack app needs to forward message events to PostHog. Without this step, your channel tables stay empty. You add these events to the same app you created above.

1. Go to your Slack source in the data pipeline sources tab and click the Webhook tab.
2. Copy the webhook URL shown.
3. Open your app in Slack apps, go to Event Subscriptions, and toggle it on.
4. Paste the webhook URL into the Request URL field. Slack sends a verification challenge — wait for the green Verified check.
5. Under Subscribe to bot events, add message.channels and message.groups.
6. Click Save Changes. Reinstall the app if Slack prompts you to.
7. Go to Basic Information > App Credentials, copy the Signing Secret.
8. Back in PostHog, paste the signing secret into the Signing secret field on the Webhook tab and save.

PostHog uses the signing secret to verify that incoming events actually came from Slack. Once the webhook is active, new messages in the channels the bot has joined start appearing in their tables.

Migrating from the legacy connection

Slack sources created before bring-your-own-app used a shared PostHog Slack app. To move an existing source onto your own app:

1. Create and install your own Slack app using the manifest above.
2. Open your existing Slack source, paste the new Bot User OAuth Token into the token field, and save.
3. Re-add the webhook Event Subscriptions to your new app (see webhook setup) and update the signing secret.

The source switches to your app as soon as the token is saved. If you'd rather start fresh, delete the old source and add a new one instead.

Common issues

Bot not in the channel

The bot only receives events and reads history for channels it has joined. If a channel table stays empty or a sync reports not_in_channel, invite the bot to that channel with /invite @PostHog data warehouse. Private channels must be joined manually.

Webhook shows "Doesn't respond"

When you enable Event Subscriptions, Slack sends a verification challenge to your webhook URL. If this initial handshake fails, the status stays stuck on Doesn't respond.

To fix this:

1. Go to your Slack app settings and select your app.
2. Click Features > Event Subscriptions in the left sidebar.
3. Re-enter or re-paste the Request URL from PostHog's webhook tab.
4. Slack should show a green Verified checkmark.

If verification keeps failing:

• Confirm the webhook URL is correct (copy it fresh from PostHog).
• Check that your PostHog source is still active and hasn't been deleted.
• Confirm you set the signing secret on the webhook tab, or the handshake is rejected once a secret is expected.

See Slack's Events API documentation for more on how URL verification works.

Invalid or revoked token

If a sync reports invalid_auth or token_revoked, the bot token is no longer valid — for example the app was reinstalled or removed. Copy a fresh Bot User OAuth Token from Settings > Install App in your Slack app and update it on the source.

Configuration