Get topic messages

Subscribe to a topic ID's messages from a mirror node. You will receive all messages for the specified topic or within the defined start and end time.
Query Fees
Please see the transaction and query fees table for base transaction fee
Please use the Hedera fee estimator to estimate your query fee cost
V2
V1
Constructor
Description
new TopicMessageQuery()
Initializes the TopicMessageQuery object
new TopicMessageQuery()
Methods
Method
Type
Description
Requirement
setTopicId(<topicId>)
TopicId
The topic ID to subscribe to
Required
setStartTime(<startTime>)
Instant
The time to start subscribing to a topic's messages
Optional
setEndTime(<endTime>)
Instant
The time to stop subscribing to a topic's messages
Optional
setLimit(<limit>)
long
The number of messages to return
Optional
subscribe(<client, onNext)
SubscriptionHandle
Client, Consumer<TopicMessage>
Required
Java
//Create the query
new TopicMessageQuery()
    .setTopicId(newTopicId)
    .subscribe(client, topicMessage -> {
        System.out.println("at " + topicMessage.consensusTimestamp + " ( seq = " + topicMessage.sequenceNumber + " ) received topic message of " + topicMessage.contents.length + " bytes");
    });
​
//v2.0.0
JavaScript
//Create the query
new TopicMessageQuery()
        .setTopicId(topicId)
        .setStartTime(0)
        .subscribe(
            client,
            (message) => console.log(Buffer.from(message.contents, "utf8").toString())
        );
//v2.0.0
Go
//Create the query
_, err = hedera.NewTopicMessageQuery().
    SetTopicID(topicID).
    Subscribe(client, func(message hedera.TopicMessage) {
        if string(message.Contents) == content {
        wait = false
    }
})
​
if err != nil {
    panic(err)
}
​
//v2.0.0
Constructor
Description
new MirrorConsensusTopicQuery()
Initializes the MirrorConsensusTopicQuery object
new MirrorConsensusTopicQuery()
Methods
Method
Type
Description
Requirement
setTopicId(<topicId>)
TopicId
The topic ID to subscribe to
Required
setStartTime(<startTime>)
Instant
The time to start subscribing to a topic's messages
Optional
setEndTime(<endTime>)
Instant
The time to stop subscribing to a topic's messages
Optional
setLimit(<limit>)
long
The number of messages to return
Optional
subscribe(<mirrorClient, onNext onError)
MirrorClient, Consumer <MirrorConsensusTopicResponse>, Consumer<Throwable>
Subscribe and get the messages for a topic
Required
Java
new MirrorConsensusTopicQuery()
    .setTopicId(topicId)
    .subscribe(mirrorClient, resp -> {
                String messageAsString = new String(resp.message, StandardCharsets.UTF_8);
​
                System.out.println(resp.consensusTimestamp + " received topic message: " + messageAsString);
            },
            // On gRPC error, print the stack trace
            Throwable::printStackTrace);
//v1.3.2
JavaScript
new MirrorConsensusTopicQuery()
    .setTopicId(topicId)
    .subscribe(
        consensusClient,
        (message) => console.log(message.toString()),
        (error) => console.log(`Error: ${error}`)
    );

Delete a topic

Get topic info

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