Get topic info
Topic info returns the following values for a topic. Queries do not change the state of the topic or require network consensus. The information is returned from a single node processing the query.
Topic Info Response:
Field | Description |
Topic ID | The ID of the topic |
Admin Key | Access control for update/delete of the topic. Null if there is no key. |
Submit Key | Access control for ConsensusService.submitMessage. Null if there is no key. |
Sequence Number | Current sequence number (starting at 1 for the first submitMessage) of messages on the topic. |
Running Hash | SHA-384 running hash |
Expiration Time | 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. |
Topic Memo | Short publicly visible memo about the topic. No guarantee of uniqueness. |
Auto Renew Period | The lifetime of the topic and the amount of time to extend the topic's lifetime by |
Auto Renew Account | Null if there is no autoRenewAccount. |
Ledger ID |
Query Signing Requirements
- The client operator private key is required to sign the query request
Query Fees
Method | Type | Requirement |
|---|---|---|
setTopicId(<topicId>) | TopicId | Required |
<TopicInfo>.adminKey | Optional | |
<TopicInfo>.submitKey | Optional | |
<TopicInfo>.topicId | Optional | |
<TopicInfo>.sequenceNumber | long | Optional |
<TopicInfo>.runningHash | ByteString | Optional |
<TopicInfo>.memo | String | Optional |
<TopicInfo>.ledgerId | LedgerId | Optional |
<TopicInfo>.expirationTime | Instant | Optional |
<TopicInfo>.autoRenewAccount | Optional | |
<TopicInfo>.autoRenewPeriod | Instant | Optional |
Java
JavaScript
Go
//Create the account info query
TopicInfoQuery query = new TopicInfoQuery()
.setTopicId(newTopicId);
//Submit the query to a Hedera network
TopicInfo info = query.execute(client);
//Print the account key to the console
System.out.println(info);
//v2.0.0
//Create the account info query
const query = new TopicInfoQuery()
.setTopicId(newTopicId);
//Submit the query to a Hedera network
const info = await query.execute(client);
//Print the account key to the console
console.log(info);
//v2.0.0
//Create the account info query
query, err := hedera.NewTopicInfoQuery().
SetTopicID(topicID)
//Submit the query to a Hedera network
info, err := query.Execute(client)
if err != nil {
panic(err)
}
//Print the account key to the console
println(info)
//v2.0.0
Sample Output:
TopicInfo{
topicId=0.0.102736,
topicMemo=,
runningHash=[
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0. 0, 0,0,0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,0, 0, 0, 0, 0, 0, 0
],
sequenceNumber=0,
expirationTime=2021-02-09T03:17:07.258292001Z,
adminKey=null,
submitKey=null,
autoRenewPeriod=PT2160H,
autoRenewAccountId=null
}
Last modified 6mo ago