Chrome DevTools Kotlin Client

Description

Chrome DevTools Kotlin Client is a DevTools client - in Kotlin. It can be used for instrumenting, inspecting, debuging and profiling Chromium, Chrome and other Blink-based browsers. [1]

For more information on DevTools, see https://chromedevtools.github.io/devtools-protocol/.

Usage

Note: This API retains full compatibility with the original chrome-devtools-java-client, but all methods are defined as suspend functions, making them non-blocking.

suspend fun main() {
    // Create chrome launcher.
    val launcher = ChromeLauncher()

    // Launch chrome either as headless (true) or regular (false).
    val chromeService = launcher.launch(false)

    // Create empty tab ie about:blank.
    val tab = chromeService.createTab()

    // Get DevTools service to this tab
    val devToolsService = chromeService.createDevToolsService(tab)

    // Get individual commands
    val page = devToolsService.page
    val tracing = devToolsService.tracing

    val dataCollectedList = mutableListOf<Any>()

    // Add tracing data to dataCollectedList
    tracing.onDataCollected { event: DataCollected ->
        dataCollectedList.addAll(event.value)
    }

    // When tracing is complete, dump dataCollectedList to JSON file.
    tracing.onTracingComplete {
        // Dump tracing to file.
        val path = Paths.get("/tmp/tracing.json")
        println("Tracing completed! Dumping to $path")

        val om = ObjectMapper()
        om.writeValue(path.toFile(), dataCollectedList)

        devToolsService.close()
    }

    page.onLoadEventFired { tracing.end() }

    page.enable()
    tracing.start()
    page.navigate("https://github.com")
}

• Examples

Running unit tests

make verify

Sonar analysis

make sonar-analysis

Download latest protocol

Run following:

make download-latest-protocol

This will download browser_protocol.json and js_protocol.json (protocol definitions) from https://github.com/ChromeDevTools/devtools-protocol repo.

Modules

Module	Description	Serialization
cdt-kotlin-client	Chrome DevTools Kotlin client (Jackson @JsonProperty annotations)	Jackson
cdt-kotlin-client-serialization	Chrome DevTools Kotlin client (kotlinx.serialization @Serializable/@SerialName)	kotlinx.serialization
cdt-kotlin-client-ktor	Ktor-based transport implementation	—
cdt-kotlin-protocol-builder	Code generator that produces the client sources from protocol JSON	—

Choosing a module

• Use cdt-kotlin-client when you need Jackson compatibility (e.g., existing projects that already use Jackson).
• Use cdt-kotlin-client-serialization when you prefer kotlinx.serialization — it has zero Jackson/Gson dependency and is a natural fit for Kotlin-first projects.

Update protocol (generate Kotlin files from protocol definitions)

Make sure you have correct or latest protocol definitions. See Download latest protocol on how to update protocol definitions to latest version.

Standard (Jackson) client

Run following:

make update-protocol

kotlinx.serialization client

Run following:

make update-protocol-serialization

PowerShell (Windows)

# Standard mode (Jackson)
.\bin\generate-kotlin.ps1

# Serialization mode (kotlinx.serialization)
.\bin\generate-kotlin.ps1 -Serialization

# Skip rebuild of the builder JAR
.\bin\generate-kotlin.ps1 -Serialization -SkipBuild

# Custom output directory
.\bin\generate-kotlin.ps1 -Serialization -OutputProject "my-client"

This will build the tools for parsing and generating Kotlin files, cdt-kotlin-protocol-builder project. The input for this tool are protocol definitions files: browser_protocol.json and js_protocol.json. The generated Kotlin files will be present in the target module. After building Kotlin files, the target module will be compiled. If everything goes successfully, consider the protocol updated. :)

Updating copyright license header

To go over each module and each source java file to update copyright license header, run:

make update-copyright-license-header

License

Chrome DevTools Kotlin Client is licensed under the Apache License, Version 2.0. See LICENSE for the full license text.