Receiving and sending Messages to Users through a Google Chat App

1. Receiving Events

• Event ingestion via synchronous webhook. You can define an automatic response upon receiving the event through the webhook response.

  

• You can now use the Google Chat API or leverage AI via AI··Task to let the AI automatically format and send the message.

  

• The payload also contains information about the commands defined in the configuration panel, allowing you to set conditions based on the triggered commands.

  

2. Sending Messages as Admin-Installed App

When an app is admin-installed, it has the authority to interact with users across the domain. To send a direct message (DM) to a specific user as the bot, you must follow a three-step sequence: identify the user, locate the specific DM space, and then post the message.

Note

Requirements

• Authentication: Your supporting Mindflow credential must have the appropriate OAuth scopes (e.g., https://www.googleapis.com/auth/chat.messages.create and https://www.googleapis.com/auth/admin.directory.user.readonly).
• Admin Privileges: Since the app is admin-installed, ensure the Service Account or OAuth client used has been granted Domain-Wide Delegation or the necessary permissions in the Google Cloud Console.

Step 1: Collect the User ID

To message a user, you first need their internal Google unique identifier. You can retrieve this by filtering the Directory API using the user’s email address.

Endpoint: GET https://admin.googleapis.com/admin/directory/v1/users

curl --request GET \
  'https://admin.googleapis.com/admin/directory/v1/users?domain=yourdomain.com&query=email:jane.doe@yourdomain.com' \
  --header 'Authorization: Bearer [YOUR_ACCESS_TOKEN]' \
  --header 'Accept: application/json'

• Key Field: From the JSON response, extract the id field (e.g., "12345678901234567890").

Step 2: Find the Direct Message Space

Google Chat requires a spaceName to send a message. For DMs, you use the findDirectMessage method. This looks up the existing DM space between your bot and the target user or creates one if it doesn’t exist.

Endpoint: GET https://chat.googleapis.com/v1/spaces:findDirectMessage

curl --request GET \
  'https://chat.googleapis.com/v1/spaces:findDirectMessage?name=users/12345678901234567890' \
  --header 'Authorization: Bearer [YOUR_ACCESS_TOKEN]' \
  --header 'Accept: application/json'

• Query Param: The name parameter must be formatted as users/{userId} using the ID from Step 1.
• Key Field: Extract the name field from the response (e.g., "spaces/abcd12345").

Step 3: Create and Send the Message

Now that you have the spaceId, you can push the message content to that space.

Endpoint: POST https://chat.googleapis.com/v1/spaces/abcd12345/messages

curl --request POST \
  'https://chat.googleapis.com/v1/spaces/abcd12345/messages' \
  --header 'Authorization: Bearer [YOUR_ACCESS_TOKEN]' \
  --header 'Content-Type: application/json' \
  --data '{
    "text": "Hello! This is a message from your admin-installed bot."
  }'