get-topic-info.md

Get topic info

The ConsensusTopicInfoQuery() returns the following information about a topic:

Info Item	Description
topicId	The ID of the topic
adminKey	Access control for update/delete of the topic. Null if there is no key.
submitKey	Access control for ConsensusService.submitMessage. Null if there is no key.
sequenceNumber	Current sequence number (starting at 1 for the first submitMessage) of messages on the topic.
runningHash	SHA-384 running hash
expirationTime	Effective consensus timestamp at (and after) which submitMessage calls will no longer succeed on the topic and the topic will expire and be marked as deleted.
topicMemo	Short publicly visible memo about the topic. No guarantee of uniqueness.
autoRenewPeriod	The lifetime of the topic and the amount of time to extend the topic's lifetime by
autoRenewAccount	Null if there is no autoRenewAccount.

Constructor	Description
ConsensusTopicInfoQuery()	Initializes the ConsensusTopicInfoQuery object

new ConsensusTopicInfoQuery()

Basic

Method	Type	Description
setTopicId(<topicId>)	TopicId	The ID of the topic to return information for

Example

{% tabs %} {% tab title="Java" %}

// Returns the current sequence numnber for the specified topic
ConsensusTopicInfo topicInfo = new ConsensusTopicInfoQuery()
    .setTopicId(topicId)
    .execute(client);
        
System.out.println(topicInfo.sequenceNumber);

{% endtab %}

{% tab title="JavaScript" %}

const topicInfo = await new ConsensusTopicInfoQuery()
     .setTopicId(topicId)
     .execute(client);
     
console.log(`${topicInfo.sequenceNumber}`)

{% endtab %} {% endtabs %}