Defining capability requirements

As discussed in Channel capabilities, capability requirements are defined per channel in the channel configuration (found in the channel’s most recent configuration block). The channel configuration contains three locations, each of which defines a capability of a different type.

Capability Type Canonical Path JSON Path
Channel /Channel/Capabilities .channel_group.values.Capabilities
Orderer /Channel/Orderer/Capabilities .channel_group.groups.Orderer.values.Capabilities
Application /Channel/Application/Capabilities .channel_group.groups.Application.values. Capabilities

Setting Capabilities

Capabilities are set as part of the channel configuration (either as part of the initial configuration -- which we'll talk about in a moment -- or as part of a reconfiguration).


For more information about how to update a channel configuration, check out Updating a channel configuration.

Because new channels copy the configuration of the ordering system channel by default, new channels will automatically be configured to work with the orderer and channel capabilities of the ordering system channel and the application capabilities specified by the channel creation transaction.

Capabilities in an Initial Configuration

In the configtx.yaml file distributed in the config directory of the release artifacts, there is a Capabilities section which enumerates the possible capabilities for each capability type (Channel, Orderer, and Application).

Note that there is a Capabilities section defined at the root level (for the channel capabilities), and at the Orderer level (for orderer capabilities).

When defining the orderer system channel there is no Application section, as those capabilities are defined during the creation of an application channel.