Method: projects.subscriptions.create

Creates a subscription to a given topic. See the resource name rules. If the subscription already exists, returns ALREADY_EXISTS. If the corresponding topic doesn't exist, returns NOT_FOUND.

If the name is not provided in the request, the server will assign a random name for this subscription on the same project as the topic, conforming to the resource name format. The generated name is populated in the returned Subscription object. Note that for REST API requests, you must specify a name in the request.

HTTP request

PUT https://pubsub.googleapis.com/v1/{name}

Path parameters

Parameters
name

string

Name of the subscription. Format is projects/{project}/subscriptions/{sub}.

Request body

The request body contains data with the following structure:

JSON representation
{
  "topic": string,
  "pushConfig": {
    object (PushConfig)
  },
  "ackDeadlineSeconds": number,
  "retainAckedMessages": boolean,
  "messageRetentionDuration": string,
  "labels": {
    string: string,
    ...
  },
  "expirationPolicy": {
    object (ExpirationPolicy)
  }
}
Fields
topic

string

The name of the topic from which this subscription is receiving messages. Format is projects/{project}/topics/{topic}. The value of this field will be _deleted-topic_ if the topic has been deleted.

pushConfig

object (PushConfig)

If push delivery is used with this subscription, this field is used to configure it. An empty pushConfig signifies that the subscriber will pull and ack messages using API methods.

ackDeadlineSeconds

number

The approximate amount of time (on a best-effort basis) Pub/Sub waits for the subscriber to acknowledge receipt before resending the message. In the interval after the message is delivered and before it is acknowledged, it is considered to be outstanding. During that time period, the message will not be redelivered (on a best-effort basis).

For pull subscriptions, this value is used as the initial value for the ack deadline. To override this value for a given message, call subscriptions.modifyAckDeadline with the corresponding ackId if using non-streaming pull or send the ackId in a StreamingModifyAckDeadlineRequest if using streaming pull. The minimum custom deadline you can specify is 10 seconds. The maximum custom deadline you can specify is 600 seconds (10 minutes). If this parameter is 0, a default value of 10 seconds is used.

For push delivery, this value is also used to set the request timeout for the call to the push endpoint.

If the subscriber never acknowledges the message, the Pub/Sub system will eventually redeliver the message.

retainAckedMessages

boolean

Indicates whether to retain acknowledged messages. If true, then messages are not expunged from the subscription's backlog, even if they are acknowledged, until they fall out of the messageRetentionDuration window. This must be true if you would like to subscriptions.seek to a timestamp.

messageRetentionDuration

string (Duration format)

How long to retain unacknowledged messages in the subscription's backlog, from the moment a message is published. If retainAckedMessages is true, then this also configures the retention of acknowledged messages, and thus configures how far back in time a subscriptions.seek can be done. Defaults to 7 days. Cannot be more than 7 days or less than 10 minutes.

A duration in seconds with up to nine fractional digits, terminated by 's'. Example: "3.5s".

labels

map (key: string, value: string)

See Creating and managing labels.

An object containing a list of "key": value pairs. Example: { "name": "wrench", "mass": "1.3kg", "count": "3" }.

expirationPolicy

object (ExpirationPolicy)

A policy that specifies the conditions for this subscription's expiration. A subscription is considered active as long as any connected subscriber is successfully consuming messages from the subscription or is issuing operations on the subscription. If expirationPolicy is not set, a default policy with ttl of 31 days will be used. The minimum allowed value for expirationPolicy.ttl is 1 day.

Response body

If successful, the response body contains a newly created instance of Subscription.

Authorization Scopes

Requires one of the following OAuth scopes:

  • https://www.googleapis.com/auth/pubsub
  • https://www.googleapis.com/auth/cloud-platform

For more information, see the Authentication Overview.

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Cloud Pub/Sub Documentation