Chaincode can also post events to notify a subscribing application to process further client actions. For example, after purchase orders, invoices, and delivery records have been matched by chaincode, it can post an event so that a subscribing application can process related payments and update an internal ERP system.

OBP supports the following types of events, which can be subscribed via a REST proxy:

• transaction: Events for a transaction ID
• txOnChannel: Events for every new transaction on a channel
• txOnNetwork: Events for every new transaction in the entire network
• blockOnChannel: Events for every block on a particular channel
• blockOnNetwork: Events for the creation of a new block in the entire network
• chaincodeEvent: Custom events emitted by chaincode logic