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 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 can define their own format for the anchor specification. The anchor is saved and returned when retrieving the comment, however Google Workspace editor apps treat these comments as un-anchored comments.
Unanchored	Supported on Google Workspace documents, which will 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 to the latest revision of a document

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.

Important: Anchors are immutable, and their position relative to the content of a document cannot be guaranteed between revisions. We recommend you use anchors in documents where the position doesn't change, such as image files or read-only documents.

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 containing the revisionID (r) and region (a).

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

Python

from google.oauth2.credentials import Credentials
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 to anchor the comment to.
# Note: Line numbers are based on the revision.
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 on a specific line in a Google Doc.

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

        # Define the anchor region for the comment.
        # For Google Docs, the region is typically defined by 'line' and 'revision'.
        # Other file types might use different region classifiers.
        anchor = {
            'region': {
                'kind': 'drive#commentRegion',
                'line': ANCHOR_LINE,
                'rev': 'head'
            }
        }

        # The comment body.
        comment_body = {
            'content': COMMENT_TEXT,
            'anchor': anchor
        }

        # 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.

Note: We recommend you check that a user has the correct permissions to add comments. Further, only the creator of a comment or a reply can delete or edit a comment or a reply. Errors occur when a person in a non-creator role tries to delete or edit a comment. To avoid these errors, check the author.me field of the comments resource.

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.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 specific line in a Google Doc.

    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()

Important: We recommend you check that a user has the correct permissions to add comments. Further, only the creator of a comment or a reply can delete or edit a comment or a reply. Errors occur when a user in a non-creator role tries to delete or edit a comment. To avoid these errors, check the author.me field of the comments resource to make sure the user making the request is the author of the comment and then verify their permissions relative to the 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 includedDeleted 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

Related topics

• Files and folders overview
• Manage file revisions