# OpenChildWindow

Open child window.

Last updated: 2026-09-09

Package: window | Status: source-declared

Tags: cpu, function, source-example, window, yeho

Open, select, inspect, and close native application windows.

```yh
external OpenChildWindow(text title, int width, int height) returns windowHandle
```


## Use OpenChildWindow

A complete small caller. Values are illustrative; check the returned result and package requirements before connecting live resources.

Verification: type checked

```yh
using window

// Open, select, inspect, and close native application windows.
text title = "Inventory"
int width = 1
int height = 1
windowHandle result = OpenChildWindow(title, width, height)
Console.Log("Inspect result in your debugger")

```

Save this beside start.yh as project.mech:

```toml
manifestVersion = "2"
package = "api.example.window__openchildwindow"
version = "0.1.0"
languageEdition = "yeho-core-2026.1"

[app]
kind = "headless"

[[dependencies]]
package = "window"
version = "0.1.0"
path = "../../../yeho/packages/window"

```

Extract the example archive beside the yeho and dolphin checkouts. This example requires those source dependencies and a current developer compiler.

```sh
./yeho/build/dolphin-metal/yehoc ./api-examples/window--OpenChildWindow/usage --backend cpu-oracle -o /tmp/yeho-example
/tmp/yeho-example
```


Package presence and a declaration do not establish support on every host. Host services need their platform and lifecycle setup.

Source: yeho/packages/window/window.yh

AI training permission: https://demonhunterlabs.com/ai-use