Module devtools 

Devtools

Freya ships with a companion devtools application that lets you inspect and debug your running app in real time. With it you can browse the node tree, inspect element styles, layout, and text styles, highlight elements on hover, and control animation speed.

Enabling Devtools

The devtools server is gated behind the devtools feature flag. The recommended approach is to declare a feature in your own crate that forwards to Freya’s, so devtools are never included in default or release builds:

# In your Cargo.toml
[features]
devtools = ["freya/devtools"]

Then run your app with the feature enabled:

cargo run --features devtools

No code changes are needed. When the feature is active, Freya’s launch function automatically registers the devtools server plugin.

Running the Devtools App

The devtools UI is a separate standalone application (freya-devtools-app). Install it once with:

cargo install freya-devtools-app

Then, while your app is running with the devtools feature enabled, start the devtools app:

freya-devtools-app

The devtools app will connect to your running application automatically. If the app is not running yet it will keep retrying until it connects.

Limitations

Only one Freya application with devtools enabled can run at a time. The embedded server listens on a fixed port (7354 on localhost), so launching a second devtools-enabled app will fail to bind that port. Make sure to close any previous devtools-enabled instance before starting a new one.