Method: projects.subscriptions.modifyAckDeadline

Modifies the ack deadline for a specific message. This method is useful to indicate that more time is needed to process a message by the subscriber, or to make the message available for redelivery if the processing was interrupted. Note that this does not modify the subscription-level ackDeadlineSeconds used for subsequent messages.

HTTP request

Path parameters



Required. The name of the subscription. Format is projects/{project}/subscriptions/{sub}.

Request body

The request body contains data with the following structure:

JSON representation
  "ackIds": [
  "ackDeadlineSeconds": integer


Required. List of acknowledgment IDs.



Required. The new ack deadline with respect to the time this request was sent to the Pub/Sub system. For example, if the value is 10, the new ack deadline will expire 10 seconds after the subscriptions.modifyAckDeadline call was made. Specifying zero might immediately make the message available for delivery to another subscriber client. This typically results in an increase in the rate of message redeliveries (that is, duplicates). The minimum deadline you can specify is 0 seconds. The maximum deadline you can specify in a single request is 600 seconds (10 minutes).

Response body

If successful, the response body is empty.

Authorization scopes

Requires one of the following OAuth scopes:


For more information, see the Authentication Overview.