Inspector is a network inspector for Compose Multiplatform apps. One capture feeds an in-app overlay, a local web UI with a searchable archive, and an MCP server your coding agent can query. It is debug-only by construction, so none of it can end up in a release build.
A row in the overlay, a row in the browser and a row an agent reads are the same record. A filter you type on the phone is a string you can hand to an agent.
A draggable pill shows the latest call. Tap it and you get the full inspector, from one Compose codebase on Android, iOS and desktop.
Every session is archived, and you can browse it at 127.0.0.1:8099,
live or long after the app has closed.
status:4xx path:/checkout since:marker("pay")POST /checkout returned 409 cart_stale
because the cart was at version 7 while the app sent 6. The retry 212ms later succeeded.Your coding agent reads the same archive you do. It starts with a one-kilobyte summary and pulls only the bodies it needs.
session_summary, list_transactions, get_body, explain, timeline, export_sessionA small JVM daemon that runs on your machine and nowhere else. Sessions are plain folders and
jsonl files you can grep, diff and attach to a bug report.
These are real renders of the overlay at phone width, built from the same Compose code that runs on Android and iOS. Swipe through.
The daemon serves this page at 127.0.0.1:8099. Screenshots are from the bundled sample app.
The path tab draws the route through the app as a line of stations, one per visit, and under it a line per visit: the calls, cache writes, analytics events and taps that happened while that screen was up, in order. It updates live as the user moves, without pulling the view away from what you are reading.
Needs your app to send a screen signal when it navigates. Anything else you send, under any
tag, appears on the screen it happened on. A failed call is always shown, never folded away.
Use export ▾ beside the session picker. Each export is one file, holds the whole session with no filter or page limit, and the person you send it to doesn't need Inspector installed.
The same page, working offline with the session embedded. Open it straight from an email.
A readable timeline and every call, ready for a ticket or a chat.
Everything: calls, markers, signals and bodies, for your own tools.
Just the calls, for DevTools or any HAR viewer.
An export contains whatever was captured, including credentials unless you turned redaction on. Read it before you send it.
Screens, view-model state and cache contents sit on the same timeline as the traffic. You can see which screen made the call and what the app believed before and after it.
Every row below says exactly what has been tested. Since 1.2.0: a physical iPhone, over the cable.
| Target | Status | Notes |
|---|---|---|
| Android emulator | ✓ Supported | Overlay and daemon verified with the sample app. |
| iOS simulator | ✓ Supported | Overlay and daemon verified with the sample app. |
| Desktop (JVM) | ✓ Supported | The reference sample. |
| iPhone, over USB | ✓ Supported | Since 1.2.0. Plug it in and run inspector serve, with no code change. Verified on an iPhone 12 Pro: 188 calls archived, and replay signing works across the cable. Cable only; a phone paired over Wi-Fi is skipped by design. |
| Android phone, over USB | ◐ Early | Connects through adb reverse. The route is verified on an emulator, but no Android build has run on a physical phone yet. Reports welcome. |
Release builds swap every module for a no-op twin with an identical API. A canary check then scans your release artifacts and fails the build if any capture code made it in.
Requires Kotlin 2.3.20, Compose Multiplatform 1.11 and Ktor 3. The integration guide covers the rest.
implementation("io.github.shafichariri:inspector-core:1.3.0")
implementation("io.github.shafichariri:inspector-ui:1.3.0")
val client = HttpClient(engine) {
Inspector.install(this) // add last
}
InspectorOverlay { App() }
inspector serve # then open http://127.0.0.1:8099 inspector mcp # point your agent's MCP config here
These limits are deliberate choices, and they're listed here so you don't find them the hard way.
URLSession.Inspector is free and Apache-2.0 licensed. If it saved you a debugging session, sponsoring pays for what's next: proxy capture for WebViews and native iOS networking.