> ## Documentation Index
> Fetch the complete documentation index at: https://docs.happyuptime.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Slack identity

Link Happy Uptime users to Slack users for @-mentions and avatars.

# Slack identity linking

Linking a Happy Uptime user to a Slack user enables:

- `@mention` in incident channels
- DM paging from on-call alerts
- Slack avatars on member rows in the dashboard

## List Slack users

GET `/slack/installations/{installation_id}/users`

Lists Slack workspace users. Cached for 5 minutes.

Substring filter on display name or real name.

```json
{
  "data": [
    {
      "id": "U01ABCD",
      "username": "alice",
      "real_name": "Alice Smith",
      "email": "alice@acme.com",
      "image_72": "https://avatars.slack-edge.com/.../alice.jpg",
      "is_bot": false
    }
  ]
}
```

## Link a user

POST `/users/{user_id}/slack-identity`

```json
{
  "installation_id": "ins_abc",
  "slack_user_id": "U01ABCD"
}
```

Response:

```json
{
  "data": {
    "user_id": "usr_alice",
    "slack_id": "U01ABCD",
    "slack_name": "alice",
    "slack_avatar": "https://avatars.slack-edge.com/.../alice.jpg"
  }
}
```

## Unlink a user

DELETE `/users/{user_id}/slack-identity`

Removes the link. Member rows fall back to gravatar/generated avatar.

## Auto-match by email

POST `/slack/installations/{id}/automatch`

Matches every Happy Uptime user in the org to a Slack user by email. Returns a summary:

```json
{
  "data": {
    "matched": 8,
    "unmatched_users": ["bob@acme.com"],
    "unmatched_slack": ["U01XYZ"]
  }
}
```

Auto-match runs once on Slack install. Re-run after adding users on either side.