What is the Hedera mirror network?
The Hedera Mirror Network is a parallel network dedicated to propagating the state and transaction history of the Hedera Main Network. The Hedera mirror network consists of nodes which, like the main network nodes, maintain the consensus state but also, optionally, some portion of the historical transactions. Mirror nodes provide value-added services such as providing audit support, access to historical data, transaction analytics, and more.
Mirror nodes explained
Hedera mirror network nodes provide an efficient way to get the state of the ledger out to many more users and applications, in a short period of time, without having a major impact on the performance of consensus nodes.
Hedera offers a REST API to easily query a mirror node that is hosted by Hedera, removing the complexity of having to run your own. This is actively being tested by a limited group of partners and will be expanded soon.
Additionally, application developers might choose to host their own mirror node. The history of the state of the ledger, maintained on a mirror node, is configurable by the application developer. A developer may choose to maintain every state change and offer access to this data as a service for other developers; Mirror node hosts are free to develop additional APIs for providing new kinds of services that they create. Or the developer might have a single smart contract deployed for a specific use case, and choose to host a mirror node that only maintains a history of events from that smart contract.
Hedera mirror nodes vs consensus nodes
The Hedera mirror network is a set of nodes that maintain all of the same requirements and most of the functionality of the main Hedera network consensus nodes. The primary differences in functionality is that mirror nodes:
- May persist transaction history.
- Should be thought of as “read-only” nodes; transactions cannot be submitted to a mirror node via the Hedera API.
Mirror nodes will gossip, calculate consensus, timestamp and order, verify signatures and maintain state, but because they are unable to create events, mirror nodes have no effect on the hashgraph structure. Therefore, they have no ability to submit transactions for consensus and they do not have voting power.
Consensus Nodes | Both | Mirror Nodes |
Can submit HAPI (Hedera API) transactions to the Hedera network | Gossips transactions throughout the network | Maintain the state and optionally some or all of the history of transactions |
Influences consensus on transactions | Calculates and maintains consensus state | Value-added services (managed read-only node, etc.) |
Create events in the hashgraph | Calculates & returns state proofs (coming soon) | Enables analytical insight into an application’s state / transactions |
Requires HBAR cryptocurrency payment for transactions & queries | Accepts HAPI (Hedera API) queries | Publish and subscribe capabilities |
Learn more and get started
To learn more about Hedera’s mirror network, check out the Github repository: https://github.com/hashgraph/hedera-mirror-node and the official mirror node documentation: https://docs.hedera.com/hedera/core-concepts/mirror-nodes
For access to external mirror node APIs, supported by Hedera and the community, please visit: https://www.hedera.com/explorers/