Manage comments and replies

Comments are user-provided feedback on a file, such as a reader of a word-processing document suggesting how to rephrase a sentence. There are two types of comments: anchored comments and unanchored comments. An anchored comment is associated with a specific location, such as a sentence in a word-processing document, within a specific version of a document. Conversely, an unanchored comment is just associated with the document.

Replies are attached to comments and represent a user's response to the comment. The Google Drive API lets your users add comments and replies to documents created by your app. Collectively, a comment with replies is known as a discussion.

Use the fields parameter

For all methods (excluding delete) on the comments resource, you must set the fields system parameter to specify the fields to return in the response. In most Drive resource methods this action is only required to return non-default fields, but it's mandatory for the comments resource. If you omit the fields parameter, the method returns an error. For more information, see Return specific fields.

Comment constraints

The following constraints are enforced when working with anchored and unanchored comments with the Drive API:

Comment type File type
Anchored
  • Developers can define their own format for the anchor specification.
  • The anchor is saved and returned when retrieving the comment, but Google Workspace editor apps treat these comments as unanchored comments.
  • When retrieving comments on Google Workspace files (such as Google Docs, Google Sheets, or Google Slides) created in the editor, the anchor field contains editor-specific internal anchor data (such as a workbook-range JSON string on Sheets files). The Drive API treats this data as opaque and can't resolve internal document regions, cell coordinates, or slide elements. To work with anchored comments directly on these file types, use their respective APIs: Google Docs API, Google Sheets API, or Google Slides API.
Unanchored
  • Supported on Google Workspace documents, which show them in the "All Comments" view.
  • Unanchored comments are not shown on PDFs rendered in the Drive file previewer, though they are saved and can be retrieved through the Drive API.

Add an anchored comment

When you add a comment, you might want to anchor it to a region in the file. An anchor defines a region in a file to which a comment refers. The comments resource defines the anchor field as a JSON string.

To add an anchored comment:

  1. (Optional). Call the list method on the revisions resource to list every revisionID for a document. Only follow this step if you want to anchor a comment to any revision other than the latest revision. If you want to use the latest revision, use head for the revisionID.

  2. Call the create method on the comments resource with the fileId parameter, a comments resource containing the comment, and a JSON anchor string defined by your application.

The following code sample shows how to create an anchored comment:

Python

import json

from google.oauth2.credentials import Credentials
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError

# --- Configuration ---
# The ID of the file to comment on.
# Example: '1_aBcDeFgHiJkLmNoPqRsTuVwXyZ'
FILE_ID = 'FILE_ID'

# The text content of the comment.
COMMENT_TEXT = 'This is an example of an anchored comment.'

# The line number in your application to anchor the comment to.
# Note: Google Workspace editor apps (such as Google Docs, Sheets, and
# Slides) treat comments created using the Drive API as unanchored
# comments. Custom anchors are intended for your own applications or
# custom file viewers.
ANCHOR_LINE = 10
# --- End of user-configuration section ---

SCOPES = ["https://www.googleapis.com/auth/drive"]

creds = Credentials.from_authorized_user_file("token.json", SCOPES)

def create_anchored_comment():
    """
    Create an anchored comment with a custom application-defined anchor.

    Returns:
        The created comment object or None if an error occurred.
    """
    try:
        # Build the Drive API service
        service = build("drive", "v3", credentials=creds)

        # Define a custom anchor specification for your application.
        # The Drive API stores the anchor as an opaque string. Your custom
        # application or file viewer can parse this JSON string to position
        # the comment in your UI.
        anchor_data = {
            'line': ANCHOR_LINE,
            'revision': 'head'
        }

        # The comment body. The 'anchor' field must be a serialized
        # JSON string.
        comment_body = {
            'content': COMMENT_TEXT,
            'anchor': json.dumps(anchor_data)
        }

        # Create the comment request.
        comment = (
            service.comments()
            .create(fileId=FILE_ID, fields="*", body=comment_body)
            .execute()
        )

        print(f"Comment ID: {comment.get('id')}")
        return comment

    except HttpError as error:
        print(f"An error occurred: {error}")
        return None

create_anchored_comment()

The Drive API returns an instance of the comments resource object which includes the anchor string.

Add an unanchored comment

To add an unanchored comment, call the create method with the fileId parameter and a comments resource containing the comment.

The comment is inserted as plain text, but the response body provides an htmlContent field containing content formatted for display.

The following code sample shows how to create an unanchored comment:

Python


from google.oauth2.credentials import Credentials
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError

# --- Configuration ---
# The ID of the file to comment on.
# Example: '1_aBcDeFgHiJkLmNoPqRsTuVwXyZ'
FILE_ID = 'FILE_ID'

# The text content of the comment.
COMMENT_TEXT = 'This is an example of an unanchored comment.'
# --- End of user-configuration section ---

SCOPES = ["https://www.googleapis.com/auth/drive"]

creds = Credentials.from_authorized_user_file("token.json", SCOPES)

def create_unanchored_comment():
    """
    Create an unanchored comment on a file in Drive.

    Returns:
        The created comment object or None if an error occurred.
    """
    try:
        # Build the Drive API service
        service = build("drive", "v3", credentials=creds)

        # The comment body. For an unanchored comment,
        # omit the 'anchor' property.
        comment_body = {
            'content': COMMENT_TEXT
        }

        # Create the comment request.
        comment = (
            service.comments()
            .create(fileId=FILE_ID, fields="*", body=comment_body)
            .execute()
        )

        print(f"Comment ID: {comment.get('id')}")
        return comment

    except HttpError as error:
        print(f"An error occurred: {error}")
        return None

create_unanchored_comment()

Add a reply to a comment

To add a reply to a comment, use the create method on the replies resource with the fileId and commentId parameters. The request body uses the content field to add the reply.

The reply is inserted as plain text, but the response body provides an htmlContent field containing content formatted for display.

The method returns the fields listed in the fields field.

Request

In this example, we provide the fileId and commentId path parameters and multiple fields.

POST https://www.googleapis.com/drive/v3/files/FILE_ID/comments/COMMENT_ID/replies?fields=id,comment

Request body

{
  "content": "This is a reply to a comment."
}

Resolve a comment

A comment can only be resolved by posting a reply to a comment.

To resolve a comment, use the create method on the replies resource with the fileId and commentId parameters.

The request body uses the action field to resolve the comment. You can also set the content field to add a reply that closes the comment.

When a comment is resolved, Drive marks the comments resource as resolved: true. Unlike deleted comments, resolved comments can include the htmlContent or content fields.

When your app resolves a comment, your UI should indicate that the comment has been addressed. For example, your app might:

  • Disallow further replies and dim all previous replies plus the original comment.
  • Hide resolved comments.

Request

In this example, we provide the fileId and commentId path parameters and multiple fields.

POST https://www.googleapis.com/drive/v3/files/FILE_ID/comments/COMMENT_ID/replies?fields=id,comment

Request body

{
  "action": "resolve",
  "content": "This comment has been resolved."
}

Get a comment

To get a comment on a file, use the get method on the comments resource with the fileId and commentId parameters. If you don't know the comment ID, you can list all comments using the list method.

The method returns an instance of a comments resource.

To include deleted comments in the results, set the includeDeleted query parameter to true.

Request

In this example, we provide the fileId and commentId path parameters and multiple fields.

GET https://www.googleapis.com/drive/v3/files/FILE_ID/comments/COMMENT_ID?fields=id,comment,modifiedTime,resolved

List comments

To list comments on a file, use the list method on the comments resource with the fileId parameter. The method returns a list of comments.

Pass the following query parameters to customize pagination of, or filter, comments:

  • includeDeleted: Set to true to include deleted comments. Deleted comments don't include the htmlContent or content fields.

  • pageSize: The maximum number of comments to return per page.

  • pageToken: A page token, received from a previous list call. Provide this token to retrieve the subsequent page.

  • startModifiedTime: The minimum value of the modifiedTime field for the result comments.

Request

In this example, we provide the fileId path parameter, the includeDeleted query parameter, and multiple fields.

GET https://www.googleapis.com/drive/v3/files/FILE_ID/comments?includeDeleted=true&fields=(id,comment,kind,modifiedTime,resolved)

Update a comment

To update a comment on a file, use the update method on the comments resource with the fileId and commentId parameters. The request body uses the content field to update the comment.

The boolean resolved field on the comments resource is read-only. A comment can only be resolved by posting a reply to a comment. For more information, see Resolve a comment.

The method returns the fields listed in the fields query parameter.

Request

In this example, we provide the fileId and commentId path parameters and multiple fields.

PATCH https://www.googleapis.com/drive/v3/files/FILE_ID/comments/COMMENT_ID?fields=id,comment

Request body

{
  "content": "This comment is now updated."
}

Delete a comment

To delete a comment on a file, use the delete method on the comments resource with the fileId and commentId parameters.

When a comment is deleted, Drive marks the comment resource as deleted: true. Deleted comments don't include the htmlContent or content fields.

Request

In this example, we provide the fileId and commentId path parameters.

DELETE https://www.googleapis.com/drive/v3/files/FILE_ID/comments/COMMENT_ID