Hedera Consensus Service gRPC API
The Hedera Consensus Service (HCS) gRPC API is a public mirror node managed by Hedera. It offers the ability to subscribe to HCS topics and receive messages for the topic subscribed.
HCS Mirror Node Endpoints: PREVIEWNET: previewnet.mirrornode.hedera.com:443 TESTNET: testnet.mirrornode.hedera.com:443 MAINNET: mainnet-public.mirrornode.hedera.com:443
Requests for the public mainnet mirror node are throttled at 100 requests per second (rps). This may change in the future depending upon performance or security considerations. At this time, no authentication is required.
Community-supported mirror node information can be found here:
If you building your client with a predefined Hedera network (previewnet, testnet, mainnet), you do not need to define the mirror client as it is built in. If you would like to modify the mirror node client, you can use
// You will need to upgrade to v2.0.6 or higher
Client client = Client.forMainnet();
// You will need to upgrade to v2.0.23 or higher
const client = Client.forMainnet()
Concurrent Subscription Limit A single client can make a maximum of 5 concurrent subscription calls per connection.
Please click the link below to see how you can subscribe to a topic.