UI plugins

The Perfetto UI can be extended with plugins. These plugins are shipped part of Perfetto.

Create a plugin

The guide below explains how to create a plugin for the Perfetto UI.

Prepare for UI development

First we need to prepare the UI development environment. You will need to use a MacOS or Linux machine. Follow the steps below or see the Getting Started guide for more detail.

git clone https://android.googlesource.com/platform/external/perfetto/ cd perfetto ./tool/install-build-deps --ui

Copy the plugin skeleton

cp -r ui/src/plugins/com.example.Skeleton ui/src/plugins/<your-plugin-name>

Now edit ui/src/plugins/<your-plugin-name>/index.ts. Search for all instances of SKELETON: <instruction> in the file and follow the instructions.

Notes on naming:

Start the dev server


Now navigate to

Upload your plugin for review

Plugin extension points

Plugins can extend a handful of specific places in the UI. The sections below show these extension points and give examples of how they can be used.


Commands are user issuable shortcuts for actions in the UI. They can be accessed via the omnibox.

Follow the create a plugin to get an initial skeleton for your plugin.

To add your first command, add a call to ctx.addCommand() in either your onActivate() or onTraceLoad() hooks. The recommendation is to register commands in onActivate() by default unless they require something from TracePluginContext which is not available on PluginContext.

The tradeoff is that commands registered in onTraceLoad() are only available while a trace is loaded, whereas commands registered in onActivate() are available all the time the plugin is active.

class MyPlugin implements Plugin { onActivate(ctx: PluginContext): void { ctx.addCommand( { id: 'dev.perfetto.ExampleSimpleCommand#LogHelloPlugin', name: 'Log "Hello, plugin!"', callback: () => console.log('Hello, plugin!'), }, ); } onTraceLoad(ctx: TracePluginContext): void { ctx.addCommand( { id: 'dev.perfetto.ExampleSimpleTraceCommand#LogHelloTrace', name: 'Log "Hello, trace!"', callback: () => console.log('Hello, trace!'), }, ); } }

Here id is a unique string which identifies this command. The id should be prefixed with the plugin id followed by a #. All command ids must be unique system-wide. name is a human readable name for the command, which is shown in the command palette. Finally callback() is the callback which actually performs the action.

Commands are removed automatically when their context disappears. Commands registered with the PluginContext are removed when the plugin is deactivated, and commands registered with the TracePluginContext are removed when the trace is unloaded.






Metric Visualisations




NOTE: It is important to consider version skew when using persistent state.

Plugins can persist information into permalinks. This allows plugins to gracefully handle permalinking and is an opt-in - not automatic - mechanism.

Persistent plugin state works using a Store<T> where T is some JSON serializable object. Store is implemented here. Store allows for reading and writing T. Reading:

interface Foo { bar: string; } const store: Store<Foo> = getFooStoreSomehow(); // store.state is immutable and must not be edited. const foo = store.state.foo; const bar = foo.bar; console.log(bar);


interface Foo { bar: string; } const store: Store<Foo> = getFooStoreSomehow(); store.edit((draft) => { draft.foo.bar = 'Hello, world!'; }); console.log(store.state.foo.bar); // > Hello, world!

First define an interface for your specific plugin state.

interface MyState { favouriteSlices: MySliceInfo[]; }

This interface will be used as type parameter to the Plugin and TracePluginContext interfaces.

class MyPlugin implements Plugin<MyState> { migrate(initialState: unknown): MyState { // ... } async onTraceLoad(ctx: TracePluginContext<MyState>): Promise<void> { // You can access the store on ctx.store } async onTraceUnload(ctx: TracePluginContext<MyState>): Promise<void> { // You can access the store on ctx.store } // ... }

migrate() is called after onActivate() just before onTraceLoad(). There are two cases to consider:

In case of a new trace migrate() is called with undefined. In this case you should return a default version of MyState:

class MyPlugin implements Plugin<MyState> { migrate(initialState: unknown): MyState { if (initialState === undefined) { return { favouriteSlices: []; }; } // ... } // ... }

In the permalink case migrate() is called with the state of the plugin store at the time the permalink was generated. This may be from a older or newer version of the plugin. Plugin's must not make assumptions about the contents of initialState.

In this case you need to carefully validate the state object.

TODO: Add validation example.


Guide to the plugin API

The plugin interfaces are defined in ui/src/public/index.ts.

Default plugins


Misc notes