WebInspectorKit

UIKit Web Inspector for WKWebView.

Warning

This package relies on undocumented APIs and runtime behavior, so extra care is needed before using it in App Store-bound projects.

Features

• DOM tree browsing
• Network request logging
• Built-in DOM and Network tabs

Requirements

• Swift 6.3+
• iOS 18.4+ for the built-in UIKit inspector
• iOS 18.4+ or macOS 15.4+ for ProxyKit, DataKit, and the native bridge
• ARM64/ARM64e Apple runtime; Intel Mac / x86_64 simulator environments are not supported.

Platform Notes

• The current implementation targets UIKit on iOS.
• AppKit support is planned to be rebuilt separately.

Products

Product	Use when
WebInspectorKit	You want the built-in UIKit inspector UI.
WebInspectorDataKit	You want observable DOM, Network, Console, Runtime, and CSS models for a custom UI.
WebInspectorDataKitTesting	You want a ready DataKit model scenario with replay, picker, replacement, and failure controls.
WebInspectorProxyKit	You want typed Web Inspector protocol commands and events directly over an inspected WKWebView.
WebInspectorProxyKitTesting	You want to drive ProxyKit's production connection path from a concrete raw WebKit peer in tests.

Quick Start

UIKit

import UIKit
import WebKit
import WebInspectorKit

final class BrowserViewController: UIViewController {
    private let pageWebView = WKWebView(frame: .zero)

    @objc private func presentInspector() {
        let inspector = WebInspectorViewController()
        inspector.modalPresentationStyle = .pageSheet
        if let sheet = inspector.sheetPresentationController {
            sheet.detents = [.medium(), .large()]
            sheet.selectedDetentIdentifier = .medium
        }
        Task { @MainActor in
            try await inspector.attach(to: pageWebView)
            present(inspector, animated: true)
        }
    }
}

Tabs

let inspector = WebInspectorViewController(
    tabs: [.dom, .network]
)

The built-in tab surface exposes DOM and Network tabs. Apps can also add UIKit tabs with an asynchronous UIViewController factory:

let consoleTab = WebInspectorTab(
    id: "app_console",
    title: "Console",
    systemImage: "terminal",
    requiredDomains: [.console]
) { session in
    let messages = try await session.model.consoleMessages()
    return ConsoleViewController(messages: messages)
}

let inspector = WebInspectorViewController(
    tabs: [.dom, .network, consoleTab]
)

Testing the Raw Wire

WebInspectorProxyKitTesting attaches a concrete WebInspectorTestPeer below ProxyKit's real connection core. Commands still pass through the production target registry, router, JSON codecs, model feed, and authority checks. Tests receive raw commands in transport FIFO order and must complete each command exactly once:

import WebInspectorProxyKit
import WebInspectorProxyKitTesting

let runtime = try await WebInspectorProxyTestRuntime.start()

let reload = Task {
    try await runtime.page.page.reload()
}

let command = try await runtime.peer.commands.next()
precondition(command.method == "Page.reload")
try await runtime.peer.reply(to: command)
try await reload.value

await runtime.close()

Use WebInspectorTestJSONObject for raw params and result objects, and use the peer's target lifecycle and event methods when a test needs inbound WebKit traffic. The testing product does not provide a semantic backend or synthetic model-state injection path.

Testing DataKit Models

WebInspectorDataKitTesting composes the raw peer into model-level scenarios. It answers only the protocol bootstrap owned by the scenario; replay and target replacement still traverse ProxyKit's production connection core:

import WebInspectorDataKitTesting

let runtime = try await WebInspectorDataKitTestRuntime.start(
    scenario: .init(
        document: .init(children: [
            .element(id: "button", name: "button")
        ]),
        networkReplay: [
            .init(id: "initial-request", url: "https://example.test/")
        ]
    )
)

let selected = try await runtime.selectElementWithPicker(nodeID: "button")
precondition(selected.localName == "button")
await runtime.close()

Documentation

The DocC workflow publishes package documentation to GitHub Pages.

Document	Purpose
Migration Guide	Version-by-version source migration notes for app code.
WebInspectorUI	UIKit inspector implementation notes and UI/DataKit ownership boundaries.
WebKit Version Mapping	Local notes for mapping iOS WebKit framework versions to public WebKit source refs.

Project Structure

Sources/
  WebInspectorKit/             Public built-in inspector product.
  WebInspectorDataKit/         Observable inspector model product.
  WebInspectorDataKitTesting/  Ready production-path DataKit test scenarios.
  WebInspectorProxyKit/        Typed protocol proxy product.
  WebInspectorProxyKitTesting/ Production-path raw peer test runtime.
  WebInspectorUI*/             Internal UIKit implementation targets.
Packages/
  WebInspectorNativeBridge/    Local native bridge package for ProxyKit internals.
Docs/
  MIGRATION.md                 Version-by-version migration notes.
  WebKitVersionMapping.md      WebKit runtime/source mapping notes.

License

See LICENSE.