Google Chat API overview

This section explain how a Google Chat app can call the Chat API, which lets Chat apps do things such as create a space, add people to it, and post a message without being prompted by a Chat app interaction event.


Calling the Chat API asynchronously requires authentication. Each Chat API method requires either user authentication (to perform actions or access data on behalf of a user) or app authentication (to perform actions or access data as a Chat app). Some methods support both user authentication and app authentication.

To learn more about authentication in Chat, see Authentication overview.

API resources and methods

REST resources and methods grant asynchronous access to Chat spaces, space members, messages, message reactions, and message attachments.


Spaces are places where people and apps can converse and share files. There are several types of spaces. Direct messages (DMs) are 1:1 conversations between two users or a user and a Chat app. Group chats are conversations between three or more users and Chat apps. Named spaces are persistent places where people send messages, share files, and collaborate.

The spaces resource represents a space.

Spaces support the following methods:

  • Create a space, a place where people and apps can converse and share files.
  • Set up a space to create the space, and add people and Chat apps to that space.
  • Get a space to see details about a space.
  • List spaces to see a paginated, filterable list of spaces.
  • Update a space to change attributes about a space, like its user-visible display name, description, and guidelines.
  • Delete a space when it's no longer needed.
  • Find a direct message (DM) to return a DM between two users, or a DM between a user and the calling Chat apps.

Members are users and Chat apps that have joined or are invited to a space.

The spaces.members resource represents a member.

Members support the following methods:


Messages include text and card communications posted in spaces. Messages can have files attached to them. People can react to messages by appending emoji to them.

The spaces.messages resource represents a message.

Messages support the following methods:


Reactions represent the emoji people use to react to a message, such as 👍, 🚲, and 🌞.

The spaces.messages.reactions resource represents a reaction.

Reactions support the following methods:

Media and attachments

Media represents a file uploaded to Google Chat, like images, videos, and documents.

The media resource represents media attached to messages.

Attachments are instances of media (files) attached to messages.

The spaces.messages.attachments resource represents an attachment. An attachment includes the media and associated metadata attached to a message.

Media and attachments support the following methods:

Space events

Space events represent changes to a space or its child resources, including its members, messages, and reactions.

The spaces.spaceEvent resource represents a space event.

Space events support the following methods:

User read states

User read states are singleton resources that represent details about a specified user's last read message in a Google Chat space or a message thread.

The users.spaces resource represents a user's read state in a space.

The users.spaces.threads resource represents a user's read state in a message thread.

User read states support the following methods: