Using Inspect

Component Inspection enables Fuchsia components to expose structured diagnostic information about themselves using the Inspect API. Fuchsia provides this information through the developer tools and bug reports to assist in diagnosing issues or monitoring performance.

Components expose inspection metrics as a tree of named Nodes, each containing a set of Properties as key/value pairs. Properties support a variety of numeric, string, and array data types. The component inspector libraries provide an interface to your component's root node where you can attach additional properties of interest to your application.

![Tree diagram showing how component inspection provides structured metrics data as a tree of “nodes,” where each node can contain one or more key/value “properties.”] (/docs/get-started/images/fidl/component-inspect.png){: width=“583”}

You can retrieve the current set of metrics published to Inspect using the developer tools:

• ffx inspect: Lets you interactively query the Inspect state using component selectors. This is helpful for debugging components during development.
• ffx target snapshot: Captures a debug snapshot archive of the entire system, which contains the Inspect data in JSON format.

ffx inspect show core/foo-example

core/foo-example:
  metadata:
    filename = fuchsia.inspect.Tree
    component_url = fuchsia-pkg://fuchsia.com/foo-example#meta/foo-example.cm
    timestamp = 55457379176
  payload:
    root:
      version = 1.0
      request_metrics:
        request_count = 3
        error = timeout

Note: For more details on using the Inspect API, see Fuchsia component inspection.