feat(runtime): native platform backends and UI vessels onto main

ui/examples/native-hello-android/app/build.gradle

@@ -0,0 +1,55 @@
+plugins {
+    id 'com.android.application'
+}
+
+android {
+    namespace 'com.neuron.el'
+    compileSdk 34
+
+    defaultConfig {
+        applicationId "com.neuron.el"
+        minSdk 21
+        targetSdk 34
+        versionCode 1
+        versionName "1.0"
+
+        externalNativeBuild {
+            cmake {
+                cppFlags ""
+                arguments "-DANDROID_STL=c++_shared"
+            }
+        }
+
+        ndk {
+            // Build for the two most relevant ABIs. Add x86/x86_64 for emulator.
+            abiFilters "arm64-v8a", "armeabi-v7a", "x86_64"
+        }
+    }
+
+    externalNativeBuild {
+        cmake {
+            path "src/main/jni/CMakeLists.txt"
+            version "3.22.1"
+        }
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+        debug {
+            jniDebuggable true
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+}
+
+dependencies {
+    // No third-party dependencies — el-native uses only android.* framework classes.
+    implementation 'androidx.appcompat:appcompat:1.6.1'
+}

ui/examples/native-hello-android/app/proguard-rules.pro

@@ -0,0 +1,4 @@
+# Add project specific ProGuard rules here.
+# Keep ElBridge and MainActivity so JNI symbol names stay intact.
+-keep class com.neuron.el.ElBridge { *; }
+-keep class com.neuron.el.MainActivity { *; }

ui/examples/native-hello-android/app/src/main/AndroidManifest.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <application
+        android:name=".ElApp"
+        android:label="el-native"
+        android:theme="@style/Theme.AppCompat.Light.NoActionBar"
+        android:allowBackup="false"
+        android:supportsRtl="true">
+
+        <activity
+            android:name=".MainActivity"
+            android:exported="true"
+            android:configChanges="orientation|screenSize|keyboardHidden">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+
+    </application>
+
+</manifest>

ui/examples/native-hello-android/app/src/main/java/com/neuron/el/ElApp.java

@@ -0,0 +1,18 @@
+package com.neuron.el;
+
+import android.app.Application;
+
+/**
+ * ElApp — Application subclass for native-hello-android.
+ *
+ * Currently minimal: exists as an anchor for future app-level initialisation
+ * (crash reporting, global state, etc.).  Listed in AndroidManifest.xml as
+ * android:name=".ElApp".
+ */
+public class ElApp extends Application {
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+    }
+}

ui/examples/native-hello-android/app/src/main/java/com/neuron/el/ElBridge.java

@@ -0,0 +1,711 @@
+/*
+ * ElBridge.java — Android Java companion to el_android.c.
+ *
+ * All public methods are static. The C JNI layer calls these to create views,
+ * set properties, and manage the widget tree. Views are identified by integer
+ * slot indices matching the C-side handle values.
+ *
+ * Threading: every method that touches a View dispatches to the UI thread
+ * using Activity.runOnUiThread(Runnable) and blocks with a CountDownLatch
+ * until the UI thread completes the operation. This mirrors the AppKit
+ * dispatch_sync(main_queue, ^{}) pattern in el_appkit.m.
+ *
+ * Callbacks: Java sets listeners on views that call back into C via:
+ *   nativeOnClick(int slot)
+ *   nativeOnChange(int slot, String text)
+ *   nativeOnSubmit(int slot, String text)
+ * These are declared native and implemented in el_android.c.
+ *
+ * Usage (in your Activity.onCreate):
+ *   System.loadLibrary("elruntime");
+ *   ElBridge.init(this);
+ *
+ * The native library calls __native_init() which calls nativeRegisterActivity
+ * via the C side; alternatively call ElBridge.init(this) directly from Java.
+ *
+ * Compile requirements:
+ *   Android minSdkVersion 21 (Lollipop) or higher.
+ *   No third-party dependencies — uses only android.* framework classes.
+ *   For image loading from arbitrary file paths, BitmapFactory is used.
+ *   To replace with Glide/Picasso, edit createImageView only.
+ */
+
+package com.neuron.el;
+
+import android.app.Activity;
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.graphics.Color;
+import android.graphics.Typeface;
+import android.graphics.drawable.GradientDrawable;
+import android.os.Handler;
+import android.os.Looper;
+import android.text.Editable;
+import android.text.InputType;
+import android.text.TextWatcher;
+import android.view.Gravity;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.Button;
+import android.widget.EditText;
+import android.widget.FrameLayout;
+import android.widget.ImageView;
+import android.widget.LinearLayout;
+import android.widget.ScrollView;
+import android.widget.TextView;
+
+import java.util.concurrent.CountDownLatch;
+
+public class ElBridge {
+
+    /* ── Native callbacks (implemented in el_android.c) ─────────────────── */
+
+    public static native void nativeOnClick(int slot);
+    public static native void nativeOnChange(int slot, String text);
+    public static native void nativeOnSubmit(int slot, String text);
+    public static native void nativeRegisterActivity(Activity activity);
+
+    /* ── State ───────────────────────────────────────────────────────────── */
+
+    private static final int MAX_SLOTS = 4096;
+
+    private static Activity   sActivity;
+    private static Handler    sUiHandler;
+    private static View[]     sViews    = new View[MAX_SLOTS];
+    private static int        sNextSlot = 1;   /* slot 0 reserved / null */
+
+    /* ── Init ────────────────────────────────────────────────────────────── */
+
+    /**
+     * Must be called from the Activity before any widget operations.
+     * Typically called from Activity.onCreate after System.loadLibrary.
+     */
+    public static void init(Activity activity) {
+        sActivity  = activity;
+        sUiHandler = new Handler(Looper.getMainLooper());
+        nativeRegisterActivity(activity);
+    }
+
+    /* ── Slot management ─────────────────────────────────────────────────── */
+
+    private static int allocSlot(View v) {
+        /* Find a free slot starting from sNextSlot, wrap around. */
+        for (int i = 0; i < MAX_SLOTS - 1; i++) {
+            int idx = ((sNextSlot - 1 + i) % (MAX_SLOTS - 1)) + 1;
+            if (sViews[idx] == null) {
+                sViews[idx] = v;
+                sNextSlot = (idx % (MAX_SLOTS - 1)) + 1;
+                return idx;
+            }
+        }
+        android.util.Log.e("ElBridge", "allocSlot: slot table full");
+        return -1;
+    }
+
+    private static View getView(int slot) {
+        if (slot <= 0 || slot >= MAX_SLOTS) return null;
+        return sViews[slot];
+    }
+
+    /* ── UI-thread dispatch helper ───────────────────────────────────────── */
+
+    /*
+     * Dispatch r on the UI thread and block until it completes.
+     * Safe to call from the UI thread itself (runs inline without posting).
+     */
+    private static void runSync(final Runnable r) {
+        if (Looper.myLooper() == Looper.getMainLooper()) {
+            r.run();
+        } else {
+            final CountDownLatch latch = new CountDownLatch(1);
+            sUiHandler.post(new Runnable() {
+                @Override public void run() {
+                    try { r.run(); } finally { latch.countDown(); }
+                }
+            });
+            try { latch.await(); } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+            }
+        }
+    }
+
+    /* ── Integer slot returning runSync helper ───────────────────────────── */
+
+    private interface IntSupplier { int get(); }
+
+    private static int runSyncInt(final IntSupplier s) {
+        final int[] result = { -1 };
+        runSync(new Runnable() {
+            @Override public void run() { result[0] = s.get(); }
+        });
+        return result[0];
+    }
+
+    /* ── Context accessor ────────────────────────────────────────────────── */
+
+    private static Context ctx() { return sActivity; }
+
+    /* ── View creation ───────────────────────────────────────────────────── */
+
+    /**
+     * Create a LinearLayout.
+     * @param orientation 1=VERTICAL, 0=HORIZONTAL
+     * @param spacing     gap between children in dp; applied as bottom/right margin
+     */
+    public static int createLinearLayout(final int orientation, final int spacing) {
+        return runSyncInt(new IntSupplier() {
+            @Override public int get() {
+                LinearLayout ll = new LinearLayout(ctx());
+                ll.setOrientation(orientation == 1
+                        ? LinearLayout.VERTICAL
+                        : LinearLayout.HORIZONTAL);
+                ll.setLayoutParams(new LinearLayout.LayoutParams(
+                        ViewGroup.LayoutParams.MATCH_PARENT,
+                        ViewGroup.LayoutParams.WRAP_CONTENT));
+                /* Spacing is stored so addChild can apply margins. */
+                ll.setTag(R_TAG_SPACING, spacing);
+                return allocSlot(ll);
+            }
+        });
+    }
+
+    /** Create a FrameLayout (ZStack equivalent). */
+    public static int createFrameLayout() {
+        return runSyncInt(new IntSupplier() {
+            @Override public int get() {
+                FrameLayout fl = new FrameLayout(ctx());
+                fl.setLayoutParams(new FrameLayout.LayoutParams(
+                        ViewGroup.LayoutParams.MATCH_PARENT,
+                        ViewGroup.LayoutParams.WRAP_CONTENT));
+                return allocSlot(fl);
+            }
+        });
+    }
+
+    /** Create a ScrollView. */
+    public static int createScrollView() {
+        return runSyncInt(new IntSupplier() {
+            @Override public int get() {
+                ScrollView sv = new ScrollView(ctx());
+                sv.setLayoutParams(new ScrollView.LayoutParams(
+                        ViewGroup.LayoutParams.MATCH_PARENT,
+                        ViewGroup.LayoutParams.MATCH_PARENT));
+                sv.setFillViewport(true);
+                return allocSlot(sv);
+            }
+        });
+    }
+
+    /** Create a TextView with initial text. */
+    public static int createTextView(final String text) {
+        return runSyncInt(new IntSupplier() {
+            @Override public int get() {
+                TextView tv = new TextView(ctx());
+                tv.setText(text != null ? text : "");
+                tv.setLayoutParams(new LinearLayout.LayoutParams(
+                        ViewGroup.LayoutParams.WRAP_CONTENT,
+                        ViewGroup.LayoutParams.WRAP_CONTENT));
+                return allocSlot(tv);
+            }
+        });
+    }
+
+    /** Create a Button with a label. */
+    public static int createButton(final String label) {
+        return runSyncInt(new IntSupplier() {
+            @Override public int get() {
+                Button btn = new Button(ctx());
+                btn.setText(label != null ? label : "");
+                btn.setLayoutParams(new LinearLayout.LayoutParams(
+                        ViewGroup.LayoutParams.WRAP_CONTENT,
+                        ViewGroup.LayoutParams.WRAP_CONTENT));
+                return allocSlot(btn);
+            }
+        });
+    }
+
+    /**
+     * Create an EditText.
+     * @param placeholder hint text
+     * @param singleLine  true = single-line text field; false = multi-line text area
+     */
+    public static int createEditText(final String placeholder, final boolean singleLine) {
+        return runSyncInt(new IntSupplier() {
+            @Override public int get() {
+                EditText et = new EditText(ctx());
+                et.setHint(placeholder != null ? placeholder : "");
+                if (singleLine) {
+                    et.setInputType(InputType.TYPE_CLASS_TEXT
+                            | InputType.TYPE_TEXT_FLAG_NO_SUGGESTIONS);
+                    et.setMaxLines(1);
+                    et.setSingleLine(true);
+                } else {
+                    et.setInputType(InputType.TYPE_CLASS_TEXT
+                            | InputType.TYPE_TEXT_FLAG_MULTI_LINE);
+                    et.setMinLines(3);
+                    et.setSingleLine(false);
+                    et.setGravity(Gravity.TOP | Gravity.START);
+                }
+                et.setLayoutParams(new LinearLayout.LayoutParams(
+                        ViewGroup.LayoutParams.MATCH_PARENT,
+                        ViewGroup.LayoutParams.WRAP_CONTENT));
+                return allocSlot(et);
+            }
+        });
+    }
+
+    /**
+     * Create an ImageView, loading from a file path via BitmapFactory.
+     * If path is null/empty the ImageView is created with no image.
+     */
+    public static int createImageView(final String path) {
+        return runSyncInt(new IntSupplier() {
+            @Override public int get() {
+                ImageView iv = new ImageView(ctx());
+                iv.setScaleType(ImageView.ScaleType.FIT_CENTER);
+                iv.setAdjustViewBounds(true);
+                if (path != null && !path.isEmpty()) {
+                    Bitmap bmp = BitmapFactory.decodeFile(path);
+                    if (bmp != null) {
+                        iv.setImageBitmap(bmp);
+                    } else {
+                        android.util.Log.w("ElBridge",
+                                "createImageView: failed to decode " + path);
+                    }
+                }
+                iv.setLayoutParams(new LinearLayout.LayoutParams(
+                        ViewGroup.LayoutParams.WRAP_CONTENT,
+                        ViewGroup.LayoutParams.WRAP_CONTENT));
+                return allocSlot(iv);
+            }
+        });
+    }
+
+    /* ── Window operations ───────────────────────────────────────────────── */
+
+    /** Set the Activity's content view to the view at slot. */
+    public static void setContentView(final int slot) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (v != null && sActivity != null) {
+                    sActivity.setContentView(v);
+                }
+            }
+        });
+    }
+
+    /** Set the Activity title. */
+    public static void setTitle(final String title) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                if (sActivity != null) {
+                    sActivity.setTitle(title != null ? title : "");
+                }
+            }
+        });
+    }
+
+    /* ── Tree operations ─────────────────────────────────────────────────── */
+
+    /**
+     * Add child view to parent view.
+     * LinearLayout: child added as arranged child with spacing margin.
+     * ScrollView: child replaces current document view.
+     * FrameLayout / other ViewGroup: plain addView.
+     */
+    public static void addChild(final int parentSlot, final int childSlot) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View parent = getView(parentSlot);
+                View child  = getView(childSlot);
+                if (parent == null || child == null) return;
+
+                /* Remove child from existing parent first. */
+                if (child.getParent() instanceof ViewGroup) {
+                    ((ViewGroup) child.getParent()).removeView(child);
+                }
+
+                if (parent instanceof LinearLayout) {
+                    LinearLayout ll = (LinearLayout) parent;
+                    Object tag = ll.getTag(R_TAG_SPACING);
+                    int spacing = (tag instanceof Integer) ? (Integer) tag : 0;
+                    LinearLayout.LayoutParams lp;
+                    Object existingLp = child.getLayoutParams();
+                    if (existingLp instanceof LinearLayout.LayoutParams) {
+                        lp = (LinearLayout.LayoutParams) existingLp;
+                    } else {
+                        lp = new LinearLayout.LayoutParams(
+                                ViewGroup.LayoutParams.WRAP_CONTENT,
+                                ViewGroup.LayoutParams.WRAP_CONTENT);
+                    }
+                    /* Apply spacing as margin on the leading/top edge (after first child). */
+                    if (ll.getChildCount() > 0 && spacing > 0) {
+                        int px = dpToPx(spacing);
+                        if (ll.getOrientation() == LinearLayout.VERTICAL) {
+                            lp.topMargin = px;
+                        } else {
+                            lp.leftMargin = px;
+                        }
+                    }
+                    child.setLayoutParams(lp);
+                    ll.addView(child);
+                } else if (parent instanceof ScrollView) {
+                    ScrollView sv = (ScrollView) parent;
+                    sv.removeAllViews();
+                    sv.addView(child);
+                } else if (parent instanceof ViewGroup) {
+                    ((ViewGroup) parent).addView(child);
+                }
+            }
+        });
+    }
+
+    /** Remove child from its parent. */
+    public static void removeChild(final int parentSlot, final int childSlot) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View parent = getView(parentSlot);
+                View child  = getView(childSlot);
+                if (parent instanceof ViewGroup && child != null) {
+                    ((ViewGroup) parent).removeView(child);
+                }
+            }
+        });
+    }
+
+    /** Remove the view from its parent and release the slot. */
+    public static void destroyView(final int slot) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (v == null) return;
+                if (v.getParent() instanceof ViewGroup) {
+                    ((ViewGroup) v.getParent()).removeView(v);
+                }
+                sViews[slot] = null;
+            }
+        });
+    }
+
+    /* ── Property setters ────────────────────────────────────────────────── */
+
+    public static void setText(final int slot, final String text) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                String s = text != null ? text : "";
+                if (v instanceof EditText) {
+                    ((EditText) v).setText(s);
+                } else if (v instanceof Button) {
+                    ((Button) v).setText(s);
+                } else if (v instanceof TextView) {
+                    ((TextView) v).setText(s);
+                }
+            }
+        });
+    }
+
+    public static String getText(final int slot) {
+        final String[] result = { "" };
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (v instanceof TextView) {
+                    CharSequence cs = ((TextView) v).getText();
+                    result[0] = cs != null ? cs.toString() : "";
+                }
+            }
+        });
+        return result[0];
+    }
+
+    /** Set foreground text color. Components in [0,1]. */
+    public static void setTextColor(final int slot, final float r, final float g,
+                                     final float b, final float a) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (v instanceof TextView) {
+                    ((TextView) v).setTextColor(floatToArgb(r, g, b, a));
+                }
+            }
+        });
+    }
+
+    /** Set background color using a GradientDrawable so corner radius is preserved. */
+    public static void setBackgroundColor(final int slot, final float r, final float g,
+                                           final float b, final float a) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (v == null) return;
+                ensureGradientBackground(v);
+                GradientDrawable gd = (GradientDrawable) v.getBackground();
+                gd.setColor(floatToArgb(r, g, b, a));
+            }
+        });
+    }
+
+    /**
+     * Set font family and size.
+     * family: "system" or null → system default; otherwise tries to load by name.
+     * bold: if true uses Typeface.BOLD.
+     */
+    public static void setFont(final int slot, final String family,
+                                final int sizeSp, final boolean bold) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (!(v instanceof TextView)) return;
+                TextView tv = (TextView) v;
+                Typeface tf;
+                if (family != null && !family.isEmpty()
+                        && !family.equals("system")) {
+                    Typeface base = Typeface.create(family,
+                            bold ? Typeface.BOLD : Typeface.NORMAL);
+                    tf = (base != null) ? base
+                            : Typeface.defaultFromStyle(bold ? Typeface.BOLD : Typeface.NORMAL);
+                } else {
+                    tf = Typeface.defaultFromStyle(bold ? Typeface.BOLD : Typeface.NORMAL);
+                }
+                tv.setTypeface(tf);
+                tv.setTextSize(android.util.TypedValue.COMPLEX_UNIT_SP, sizeSp);
+            }
+        });
+    }
+
+    /** Set padding in dp. */
+    public static void setPadding(final int slot, final int top, final int right,
+                                   final int bottom, final int left) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (v != null) {
+                    v.setPadding(dpToPx(left), dpToPx(top), dpToPx(right), dpToPx(bottom));
+                }
+            }
+        });
+    }
+
+    /** Set explicit width in dp. Passes MATCH_PARENT for negative values. */
+    public static void setWidth(final int slot, final int widthDp) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (v == null) return;
+                ViewGroup.LayoutParams lp = v.getLayoutParams();
+                if (lp == null) lp = new ViewGroup.LayoutParams(
+                        ViewGroup.LayoutParams.WRAP_CONTENT,
+                        ViewGroup.LayoutParams.WRAP_CONTENT);
+                lp.width = widthDp < 0
+                        ? ViewGroup.LayoutParams.MATCH_PARENT
+                        : dpToPx(widthDp);
+                v.setLayoutParams(lp);
+            }
+        });
+    }
+
+    /** Set explicit height in dp. */
+    public static void setHeight(final int slot, final int heightDp) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (v == null) return;
+                ViewGroup.LayoutParams lp = v.getLayoutParams();
+                if (lp == null) lp = new ViewGroup.LayoutParams(
+                        ViewGroup.LayoutParams.WRAP_CONTENT,
+                        ViewGroup.LayoutParams.WRAP_CONTENT);
+                lp.height = heightDp < 0
+                        ? ViewGroup.LayoutParams.MATCH_PARENT
+                        : dpToPx(heightDp);
+                v.setLayoutParams(lp);
+            }
+        });
+    }
+
+    /**
+     * Set flex weight on a child of a LinearLayout.
+     * flex > 0 → weight = flex, width/height = 0dp (expand).
+     * flex == 0 → weight = 0, wrap_content (shrink to content).
+     */
+    public static void setFlex(final int slot, final int flex) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (v == null) return;
+                ViewGroup.LayoutParams lp = v.getLayoutParams();
+                if (lp instanceof LinearLayout.LayoutParams) {
+                    LinearLayout.LayoutParams llp = (LinearLayout.LayoutParams) lp;
+                    if (flex > 0) {
+                        llp.weight = (float) flex;
+                        /* Determine orientation from parent to set 0dp on the right axis. */
+                        if (v.getParent() instanceof LinearLayout) {
+                            LinearLayout parent = (LinearLayout) v.getParent();
+                            if (parent.getOrientation() == LinearLayout.VERTICAL) {
+                                llp.height = 0;
+                            } else {
+                                llp.width = 0;
+                            }
+                        }
+                    } else {
+                        llp.weight = 0f;
+                    }
+                    v.setLayoutParams(llp);
+                }
+            }
+        });
+    }
+
+    /** Set corner radius in dp using a GradientDrawable background. */
+    public static void setCornerRadius(final int slot, final float radiusDp) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (v == null) return;
+                ensureGradientBackground(v);
+                GradientDrawable gd = (GradientDrawable) v.getBackground();
+                gd.setCornerRadius(dpToPxF(radiusDp));
+            }
+        });
+    }
+
+    public static void setEnabled(final int slot, final boolean enabled) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (v != null) v.setEnabled(enabled);
+            }
+        });
+    }
+
+    /**
+     * Show or hide a view.
+     * @param visible true = VISIBLE, false = GONE (matches AppKit setHidden semantics)
+     */
+    public static void setVisibility(final int slot, final boolean visible) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (v != null) v.setVisibility(visible ? View.VISIBLE : View.GONE);
+            }
+        });
+    }
+
+    /* ── Event listener registration ─────────────────────────────────────── */
+
+    /** Register an OnClickListener that calls back into C nativeOnClick. */
+    public static void setOnClickListener(final int slot) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (v == null) return;
+                final int capturedSlot = slot;
+                v.setOnClickListener(new View.OnClickListener() {
+                    @Override public void onClick(View view) {
+                        nativeOnClick(capturedSlot);
+                    }
+                });
+            }
+        });
+    }
+
+    /**
+     * Register a TextWatcher on an EditText that calls back nativeOnChange
+     * for every text change.
+     */
+    public static void setOnChangeListener(final int slot) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (!(v instanceof EditText)) return;
+                final int capturedSlot = slot;
+                ((EditText) v).addTextChangedListener(new TextWatcher() {
+                    @Override public void beforeTextChanged(CharSequence s, int start,
+                                                             int count, int after) {}
+                    @Override public void onTextChanged(CharSequence s, int start,
+                                                         int before, int count) {}
+                    @Override public void afterTextChanged(Editable s) {
+                        nativeOnChange(capturedSlot, s != null ? s.toString() : "");
+                    }
+                });
+            }
+        });
+    }
+
+    /**
+     * Register an OnEditorActionListener on a single-line EditText that calls
+     * nativeOnSubmit when the user presses the action/enter key.
+     */
+    public static void setOnSubmitListener(final int slot) {
+        runSync(new Runnable() {
+            @Override public void run() {
+                View v = getView(slot);
+                if (!(v instanceof EditText)) return;
+                final int capturedSlot = slot;
+                ((EditText) v).setOnEditorActionListener(
+                        new TextView.OnEditorActionListener() {
+                    @Override
+                    public boolean onEditorAction(TextView tv, int actionId,
+                                                   android.view.KeyEvent event) {
+                        nativeOnSubmit(capturedSlot,
+                                tv.getText() != null ? tv.getText().toString() : "");
+                        return true;
+                    }
+                });
+            }
+        });
+    }
+
+    /* ── Internal helpers ─────────────────────────────────────────────────── */
+
+    /*
+     * Tag key used to stash the spacing value on LinearLayouts so addChild
+     * can apply the correct margin between children.
+     * We use a stable integer resource-id-like value; because we do not have
+     * a resources file here we use View.generateViewId() lazily.
+     */
+    private static int sSpacingTagKey = 0;
+
+    private static int R_TAG_SPACING;
+    static {
+        R_TAG_SPACING = View.generateViewId();
+    }
+
+    /** Convert dp to pixels using the Activity's display metrics. */
+    private static int dpToPx(float dp) {
+        if (sActivity == null) return (int) dp;
+        float density = sActivity.getResources().getDisplayMetrics().density;
+        return Math.round(dp * density);
+    }
+
+    private static float dpToPxF(float dp) {
+        if (sActivity == null) return dp;
+        float density = sActivity.getResources().getDisplayMetrics().density;
+        return dp * density;
+    }
+
+    /** Convert RGBA float components (0–1) to an Android ARGB int. */
+    private static int floatToArgb(float r, float g, float b, float a) {
+        int ai = Math.round(a * 255f);
+        int ri = Math.round(r * 255f);
+        int gi = Math.round(g * 255f);
+        int bi = Math.round(b * 255f);
+        return Color.argb(ai, ri, gi, bi);
+    }
+
+    /**
+     * Ensure the view has a GradientDrawable background so that both color
+     * and corner radius can be set independently.  If the current background
+     * is already a GradientDrawable it is reused; otherwise a new transparent
+     * one is installed.
+     */
+    private static void ensureGradientBackground(View v) {
+        if (!(v.getBackground() instanceof GradientDrawable)) {
+            GradientDrawable gd = new GradientDrawable();
+            gd.setColor(Color.TRANSPARENT);
+            v.setBackground(gd);
+        }
+    }
+}

ui/examples/native-hello-android/app/src/main/java/com/neuron/el/MainActivity.java

@@ -0,0 +1,38 @@
+package com.neuron.el;
+
+import android.app.Activity;
+import android.os.Bundle;
+
+/**
+ * MainActivity — entry point for native-hello-android.
+ *
+ * Loads the el native shared library, initialises ElBridge with the Activity
+ * reference (required before any widget operations), then hands control to the
+ * compiled el program via nativeMain().
+ *
+ * The el boot sequence (native_init → window_from_manifest → app_build →
+ * window_show) runs inside nativeMain. __native_run_loop is a no-op on Android;
+ * the Activity lifecycle owns the UI thread after onCreate returns.
+ */
+public class MainActivity extends Activity {
+
+    static {
+        System.loadLibrary("elnative");
+    }
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        // Register this Activity with the bridge BEFORE nativeMain so that
+        // el_android_init can look up ElBridge methods and __native_init works.
+        ElBridge.init(this);
+        // Run the compiled el program.
+        nativeMain();
+    }
+
+    /**
+     * Implemented in el_android.c as Java_com_neuron_el_MainActivity_nativeMain.
+     * Calls the el program's main(), which runs the full boot sequence.
+     */
+    private native void nativeMain();
+}

ui/examples/native-hello-android/app/src/main/jni/CMakeLists.txt

@@ -0,0 +1,57 @@
+cmake_minimum_required(VERSION 3.22.1)
+project("elnative")
+
+#
+# CMakeLists.txt for native-hello-android
+#
+# Sources:
+#   el_android.c        — Android JNI widget bridge
+#   el_seed.c           — OS-boundary __-prefixed primitives
+#   el_runtime.c        — High-level el builtins (str_len, json_*, etc.)
+#   el_native_vessel.c  — el-native vessel (compiled from vessels/el-native/src/main.el)
+#   native_hello.c      — App entry point (compiled from examples/native-hello/src/main.el)
+#
+# el_runtime.c and el_seed.c both define __-prefixed symbols. On Android the
+# linker accepts duplicate weak symbols; the shared library loads one copy.
+# The EL_TARGET_ANDROID guard in el_android.c ensures only the Android widget
+# backend is compiled in.
+#
+
+add_library(
+    elnative
+    SHARED
+
+    # native_hello.c listed first so its main() takes precedence over the
+    # vessel's main() when --allow-multiple-definition is in effect.
+    native_hello.c
+    el_native_vessel.c
+    el_android.c
+    el_seed.c
+    el_runtime.c
+)
+
+# EL_TARGET_ANDROID activates the Android JNI widget backend in el_android.c
+# and the corresponding guards in el_seed.c / el_native_target.h.
+target_compile_definitions(elnative PRIVATE
+    EL_TARGET_ANDROID
+)
+
+target_include_directories(elnative PRIVATE
+    ${CMAKE_CURRENT_SOURCE_DIR}
+)
+
+# el_runtime.c and el_seed.c both define __-prefixed OS-boundary symbols.
+# el_runtime.c's copies are weaker definitions; allow-multiple-definition lets
+# the linker pick one copy silently (el_seed.c listed later = its copy wins
+# in the Android linker's right-to-left resolution order).
+target_link_options(elnative PRIVATE
+    "-Wl,--allow-multiple-definition"
+)
+
+find_library(log-lib log)
+find_library(android-lib android)
+
+target_link_libraries(elnative
+    ${log-lib}
+    ${android-lib}
+)

ui/examples/native-hello-android/app/src/main/jni/el_android.c

@@ -0,0 +1,964 @@
+/*
+ * el_android.c — Android JNI backend for the el native widget system.
+ *
+ * This file implements the Android widget layer that el_seed.c calls through
+ * to when EL_TARGET_ANDROID is defined.  It is the exact Android counterpart
+ * to el_appkit.m and presents the same C API surface.
+ *
+ * Architecture:
+ *   el program (el code)
+ *       → __widget_* C builtins in el_seed.c
+ *           → el_android_* C-callable functions declared here
+ *               → ElBridge static methods in Java via JNI
+ *                   → android.view.View subclasses on the UI thread
+ *
+ * Widget handles: every widget (window root, view, control) is assigned an
+ * int64_t slot index into view_slots[].  The el program holds these as opaque
+ * Int values.  Slot 0 is never valid (null handle = -1 convention).
+ *
+ * Threading: Android requires all UI operations to run on the main (UI) thread.
+ * Every JNI call that mutates a View is dispatched through
+ * Activity.runOnUiThread(Runnable) if the current thread is not the UI thread.
+ * el_android_run_loop is a no-op — Android lifecycle is driven by the Activity.
+ *
+ * Callback mechanism: when a widget fires an event Java calls
+ *   nativeOnClick / nativeOnChange / nativeOnSubmit
+ * The C side looks up the registered El function name for that slot, then:
+ *   dlsym(RTLD_DEFAULT, fn_name)(widget_handle, event_data_string)
+ * This matches the __thread_create pattern in el_seed.c exactly.
+ *
+ * Compile / link (as part of libelruntime.so):
+ *   Compiled by the Android Gradle NDK build system with -DEL_TARGET_ANDROID.
+ *   Link flags: -landroid -llog -ldl
+ *
+ * Java companion: ElBridge.java in the same directory must be compiled into
+ * the Android application's APK (package com.neuron.el).
+ */
+
+#ifdef EL_TARGET_ANDROID
+
+#include <jni.h>
+#include <android/log.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dlfcn.h>
+#include "el_runtime.h"
+
+/* ── Logging ─────────────────────────────────────────────────────────────── */
+
+#define EL_TAG "ElAndroid"
+#define EL_LOGI(...) __android_log_print(ANDROID_LOG_INFO,  EL_TAG, __VA_ARGS__)
+#define EL_LOGW(...) __android_log_print(ANDROID_LOG_WARN,  EL_TAG, __VA_ARGS__)
+#define EL_LOGE(...) __android_log_print(ANDROID_LOG_ERROR, EL_TAG, __VA_ARGS__)
+
+/* ── JNI global state ────────────────────────────────────────────────────── */
+
+static JavaVM  *g_jvm          = NULL;
+static jobject  g_activity     = NULL;   /* global ref to Activity */
+static jclass   g_bridge_class = NULL;   /* global ref to ElBridge class */
+
+/* Cached method IDs on ElBridge — filled in el_android_init(). */
+static jmethodID g_mid_createLinearLayout  = NULL;
+static jmethodID g_mid_createFrameLayout   = NULL;
+static jmethodID g_mid_createScrollView    = NULL;
+static jmethodID g_mid_createTextView      = NULL;
+static jmethodID g_mid_createButton        = NULL;
+static jmethodID g_mid_createEditText      = NULL;
+static jmethodID g_mid_createImageView     = NULL;
+static jmethodID g_mid_setContentView      = NULL;
+static jmethodID g_mid_setTitle            = NULL;
+static jmethodID g_mid_addChild            = NULL;
+static jmethodID g_mid_removeChild         = NULL;
+static jmethodID g_mid_destroyView         = NULL;
+static jmethodID g_mid_setText             = NULL;
+static jmethodID g_mid_getText             = NULL;
+static jmethodID g_mid_setTextColor        = NULL;
+static jmethodID g_mid_setBackgroundColor  = NULL;
+static jmethodID g_mid_setFont             = NULL;
+static jmethodID g_mid_setPadding          = NULL;
+static jmethodID g_mid_setWidth            = NULL;
+static jmethodID g_mid_setHeight           = NULL;
+static jmethodID g_mid_setFlex             = NULL;
+static jmethodID g_mid_setCornerRadius     = NULL;
+static jmethodID g_mid_setEnabled          = NULL;
+static jmethodID g_mid_setVisibility       = NULL;
+static jmethodID g_mid_setOnClickListener  = NULL;
+static jmethodID g_mid_setOnChangeListener = NULL;
+static jmethodID g_mid_setOnSubmitListener = NULL;
+static jmethodID g_mid_runOnUiThread       = NULL;  /* Activity.runOnUiThread */
+
+/* ── Widget table ─────────────────────────────────────────────────────────── */
+
+#define EL_ANDROID_MAX_WIDGETS 4096
+
+typedef enum {
+    EL_WIDGET_FREE      = 0,
+    EL_WIDGET_WINDOW    = 1,
+    EL_WIDGET_VSTACK    = 2,
+    EL_WIDGET_HSTACK    = 3,
+    EL_WIDGET_ZSTACK    = 4,
+    EL_WIDGET_SCROLL    = 5,
+    EL_WIDGET_LABEL     = 6,
+    EL_WIDGET_BUTTON    = 7,
+    EL_WIDGET_TEXTFIELD = 8,
+    EL_WIDGET_TEXTAREA  = 9,
+    EL_WIDGET_IMAGE     = 10,
+} ElWidgetKind;
+
+typedef struct {
+    ElWidgetKind kind;
+    jint         slot;       /* Java-side slot index (matches C index) */
+    char        *cb_click;   /* El function name for click / submit events */
+    char        *cb_change;  /* El function name for value-change events */
+} ElWidget;
+
+static ElWidget _el_widgets[EL_ANDROID_MAX_WIDGETS];
+
+static int64_t el_widget_alloc(ElWidgetKind kind, jint slot) {
+    for (int i = 1; i < EL_ANDROID_MAX_WIDGETS; i++) {
+        if (_el_widgets[i].kind == EL_WIDGET_FREE) {
+            _el_widgets[i].kind      = kind;
+            _el_widgets[i].slot      = slot;
+            _el_widgets[i].cb_click  = NULL;
+            _el_widgets[i].cb_change = NULL;
+            return (int64_t)i;
+        }
+    }
+    EL_LOGE("el_widget_alloc: slot table full");
+    return -1;
+}
+
+static ElWidget *el_widget_get(int64_t handle) {
+    if (handle <= 0 || handle >= EL_ANDROID_MAX_WIDGETS) return NULL;
+    if (_el_widgets[handle].kind == EL_WIDGET_FREE)       return NULL;
+    return &_el_widgets[handle];
+}
+
+static void el_widget_free(int64_t handle) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    w->kind = EL_WIDGET_FREE;
+    w->slot = -1;
+    free(w->cb_click);  w->cb_click  = NULL;
+    free(w->cb_change); w->cb_change = NULL;
+}
+
+/* ── JNI environment helpers ─────────────────────────────────────────────── */
+
+/*
+ * Obtain a JNIEnv for the calling thread.  Attaches the thread to the JVM if
+ * needed (detaches in el_jni_detach_if_attached — call in pairs).
+ */
+static int g_was_attached = 0;  /* thread-local would be cleaner but this is
+                                   safe for single-threaded el programs */
+
+static JNIEnv *el_jni_env(void) {
+    if (!g_jvm) return NULL;
+    JNIEnv *env = NULL;
+    jint rc = (*g_jvm)->GetEnv(g_jvm, (void **)&env, JNI_VERSION_1_6);
+    if (rc == JNI_OK)      { g_was_attached = 0; return env; }
+    if (rc == JNI_EDETACHED) {
+        if ((*g_jvm)->AttachCurrentThread(g_jvm, &env, NULL) == JNI_OK) {
+            g_was_attached = 1;
+            return env;
+        }
+    }
+    EL_LOGE("el_jni_env: failed to obtain JNIEnv");
+    return NULL;
+}
+
+static void el_jni_detach_if_attached(void) {
+    if (g_was_attached && g_jvm) {
+        (*g_jvm)->DetachCurrentThread(g_jvm);
+        g_was_attached = 0;
+    }
+}
+
+/* ── UI-thread dispatch ──────────────────────────────────────────────────── */
+/*
+ * Most ElBridge static methods already dispatch to the UI thread internally
+ * (they call Activity.runOnUiThread).  The helper below is available for
+ * cases where the caller needs to be sure the call has completed before
+ * returning (ElBridge methods marked "sync" use a CountDownLatch internally).
+ *
+ * For the current implementation we call ElBridge methods directly; ElBridge
+ * itself marshals to the UI thread via Activity.runOnUiThread + latch.
+ * This keeps the C side simple and mirrors the AppKit dispatch_sync pattern.
+ */
+
+/* ── JNI_OnLoad ──────────────────────────────────────────────────────────── */
+
+JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM *vm, void *reserved) {
+    (void)reserved;
+    g_jvm = vm;
+    EL_LOGI("JNI_OnLoad: el Android bridge loaded");
+    return JNI_VERSION_1_6;
+}
+
+/* ── el_android_init ─────────────────────────────────────────────────────── */
+/*
+ * Called from __native_init().  The Activity must have already called
+ * ElBridge.registerActivity(activity) from Java before this runs, which sets
+ * g_activity via the nativeRegisterActivity JNI method below.
+ *
+ * Caches all method IDs used later so individual widget calls avoid repeated
+ * FindClass / GetStaticMethodID lookups.
+ */
+void el_android_init(void) {
+    static int done = 0;
+    if (done) return;
+    done = 1;
+
+    JNIEnv *env = el_jni_env();
+    if (!env) { EL_LOGE("el_android_init: no JNIEnv"); return; }
+
+    jclass cls = (*env)->FindClass(env, "com/neuron/el/ElBridge");
+    if (!cls) { EL_LOGE("el_android_init: ElBridge class not found"); return; }
+    g_bridge_class = (*env)->NewGlobalRef(env, cls);
+    (*env)->DeleteLocalRef(env, cls);
+
+#define CACHE_STATIC(var, name, sig) \
+    var = (*env)->GetStaticMethodID(env, g_bridge_class, name, sig); \
+    if (!var) EL_LOGW("el_android_init: method not found: %s %s", name, sig)
+
+    CACHE_STATIC(g_mid_createLinearLayout,  "createLinearLayout",  "(II)I");
+    CACHE_STATIC(g_mid_createFrameLayout,   "createFrameLayout",   "()I");
+    CACHE_STATIC(g_mid_createScrollView,    "createScrollView",     "()I");
+    CACHE_STATIC(g_mid_createTextView,      "createTextView",       "(Ljava/lang/String;)I");
+    CACHE_STATIC(g_mid_createButton,        "createButton",         "(Ljava/lang/String;)I");
+    CACHE_STATIC(g_mid_createEditText,      "createEditText",       "(Ljava/lang/String;Z)I");
+    CACHE_STATIC(g_mid_createImageView,     "createImageView",      "(Ljava/lang/String;)I");
+    CACHE_STATIC(g_mid_setContentView,      "setContentView",       "(I)V");
+    CACHE_STATIC(g_mid_setTitle,            "setTitle",             "(Ljava/lang/String;)V");
+    CACHE_STATIC(g_mid_addChild,            "addChild",             "(II)V");
+    CACHE_STATIC(g_mid_removeChild,         "removeChild",          "(II)V");
+    CACHE_STATIC(g_mid_destroyView,         "destroyView",          "(I)V");
+    CACHE_STATIC(g_mid_setText,             "setText",              "(ILjava/lang/String;)V");
+    CACHE_STATIC(g_mid_getText,             "getText",              "(I)Ljava/lang/String;");
+    CACHE_STATIC(g_mid_setTextColor,        "setTextColor",         "(IFFFF)V");
+    CACHE_STATIC(g_mid_setBackgroundColor,  "setBackgroundColor",   "(IFFFF)V");
+    CACHE_STATIC(g_mid_setFont,             "setFont",              "(ILjava/lang/String;IZ)V");
+    CACHE_STATIC(g_mid_setPadding,          "setPadding",           "(IIIII)V");
+    CACHE_STATIC(g_mid_setWidth,            "setWidth",             "(II)V");
+    CACHE_STATIC(g_mid_setHeight,           "setHeight",            "(II)V");
+    CACHE_STATIC(g_mid_setFlex,             "setFlex",              "(II)V");
+    CACHE_STATIC(g_mid_setCornerRadius,     "setCornerRadius",      "(IF)V");
+    CACHE_STATIC(g_mid_setEnabled,          "setEnabled",           "(IZ)V");
+    CACHE_STATIC(g_mid_setVisibility,       "setVisibility",        "(IZ)V");
+    CACHE_STATIC(g_mid_setOnClickListener,  "setOnClickListener",   "(I)V");
+    CACHE_STATIC(g_mid_setOnChangeListener, "setOnChangeListener",  "(I)V");
+    CACHE_STATIC(g_mid_setOnSubmitListener, "setOnSubmitListener",  "(I)V");
+#undef CACHE_STATIC
+
+    el_jni_detach_if_attached();
+    EL_LOGI("el_android_init: complete");
+}
+
+/* ── JNI: Activity registration ─────────────────────────────────────────── */
+
+/*
+ * Called from Java: ElBridge.registerActivity(activity) calls back here.
+ * Stores a global reference to the Activity so C code can dispatch to it.
+ */
+JNIEXPORT void JNICALL
+Java_com_neuron_el_ElBridge_nativeRegisterActivity(JNIEnv *env, jclass cls,
+                                                    jobject activity) {
+    (void)cls;
+    if (g_activity) {
+        (*env)->DeleteGlobalRef(env, g_activity);
+        g_activity = NULL;
+    }
+    if (activity) {
+        g_activity = (*env)->NewGlobalRef(env, activity);
+        EL_LOGI("nativeRegisterActivity: activity registered");
+    }
+}
+
+/* ── El callback invocation ──────────────────────────────────────────────── */
+/*
+ * Invoke an El callback by symbol name.
+ * Signature matches AppKit: fn(handle: Int, data: String) -> Void
+ *   compiled to: void fn(el_val_t handle, el_val_t data)
+ */
+typedef void (*ElCb2)(int64_t handle, int64_t data);
+
+static void el_android_invoke_cb(const char *fn_name, int64_t handle,
+                                  const char *data) {
+    if (!fn_name || !*fn_name) return;
+    void *sym = dlsym(RTLD_DEFAULT, fn_name);
+    if (!sym) { EL_LOGW("invoke_cb: symbol not found: %s", fn_name); return; }
+    ElCb2 fn = (ElCb2)sym;
+    fn(handle, (int64_t)(uintptr_t)(data ? data : ""));
+}
+
+/* ── JNI: callbacks from Java → C ───────────────────────────────────────── */
+
+JNIEXPORT void JNICALL
+Java_com_neuron_el_ElBridge_nativeOnClick(JNIEnv *env, jclass cls, jint slot) {
+    (void)env; (void)cls;
+    int64_t handle = (int64_t)slot;
+    ElWidget *w = el_widget_get(handle);
+    if (w && w->cb_click) {
+        el_android_invoke_cb(w->cb_click, handle, "");
+    }
+}
+
+JNIEXPORT void JNICALL
+Java_com_neuron_el_ElBridge_nativeOnChange(JNIEnv *env, jclass cls,
+                                            jint slot, jstring text) {
+    (void)cls;
+    int64_t handle = (int64_t)slot;
+    ElWidget *w = el_widget_get(handle);
+    if (w && w->cb_change) {
+        const char *ctext = text ? (*env)->GetStringUTFChars(env, text, NULL) : "";
+        el_android_invoke_cb(w->cb_change, handle, ctext);
+        if (text) (*env)->ReleaseStringUTFChars(env, text, ctext);
+    }
+}
+
+JNIEXPORT void JNICALL
+Java_com_neuron_el_ElBridge_nativeOnSubmit(JNIEnv *env, jclass cls,
+                                            jint slot, jstring text) {
+    (void)cls;
+    int64_t handle = (int64_t)slot;
+    ElWidget *w = el_widget_get(handle);
+    if (w && w->cb_click) {   /* submit stored in cb_click, same as AppKit */
+        const char *ctext = text ? (*env)->GetStringUTFChars(env, text, NULL) : "";
+        el_android_invoke_cb(w->cb_click, handle, ctext);
+        if (text) (*env)->ReleaseStringUTFChars(env, text, ctext);
+    }
+}
+
+/* ── Helper: jstring from C string ──────────────────────────────────────── */
+
+static jstring el_jstr(JNIEnv *env, const char *s) {
+    return (*env)->NewStringUTF(env, s ? s : "");
+}
+
+/* ── Window ──────────────────────────────────────────────────────────────── */
+
+/*
+ * el_android_window_create — on Android a "window" is the root LinearLayout
+ * set as the Activity's content view.  We create a vertical LinearLayout and
+ * store it.  el_android_window_show calls setContentView on the Activity.
+ */
+int64_t el_android_window_create(const char *title, int width, int height,
+                                  int min_width, int min_height) {
+    (void)width; (void)height; (void)min_width; (void)min_height;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return -1;
+
+    /* VERTICAL LinearLayout with no spacing (spacing added via margins in Java) */
+    jint slot = (*env)->CallStaticIntMethod(env, g_bridge_class,
+                                            g_mid_createLinearLayout,
+                                            (jint)1 /* VERTICAL */, (jint)0);
+    if ((*env)->ExceptionCheck(env)) {
+        (*env)->ExceptionClear(env); el_jni_detach_if_attached(); return -1;
+    }
+
+    /* Set activity title */
+    if (g_mid_setTitle && title) {
+        jstring jtitle = el_jstr(env, title);
+        (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setTitle, jtitle);
+        (*env)->DeleteLocalRef(env, jtitle);
+    }
+
+    int64_t handle = el_widget_alloc(EL_WIDGET_WINDOW, (int)slot);
+    el_jni_detach_if_attached();
+    return handle;
+}
+
+void el_android_window_show(int64_t handle) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w || w->kind != EL_WIDGET_WINDOW) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setContentView,
+                                 (jint)w->slot);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+void el_android_window_set_title(int64_t handle, const char *title) {
+    (void)handle;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    jstring jtitle = el_jstr(env, title);
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setTitle, jtitle);
+    (*env)->DeleteLocalRef(env, jtitle);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+/* ── Layout containers ───────────────────────────────────────────────────── */
+
+int64_t el_android_vstack_create(int spacing) {
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return -1;
+    jint slot = (*env)->CallStaticIntMethod(env, g_bridge_class,
+                                            g_mid_createLinearLayout,
+                                            (jint)1 /* VERTICAL */, (jint)spacing);
+    if ((*env)->ExceptionCheck(env)) { (*env)->ExceptionClear(env); el_jni_detach_if_attached(); return -1; }
+    int64_t h = el_widget_alloc(EL_WIDGET_VSTACK, (int)slot);
+    el_jni_detach_if_attached();
+    return h;
+}
+
+int64_t el_android_hstack_create(int spacing) {
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return -1;
+    jint slot = (*env)->CallStaticIntMethod(env, g_bridge_class,
+                                            g_mid_createLinearLayout,
+                                            (jint)0 /* HORIZONTAL */, (jint)spacing);
+    if ((*env)->ExceptionCheck(env)) { (*env)->ExceptionClear(env); el_jni_detach_if_attached(); return -1; }
+    int64_t h = el_widget_alloc(EL_WIDGET_HSTACK, (int)slot);
+    el_jni_detach_if_attached();
+    return h;
+}
+
+int64_t el_android_zstack_create(void) {
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return -1;
+    jint slot = (*env)->CallStaticIntMethod(env, g_bridge_class,
+                                            g_mid_createFrameLayout);
+    if ((*env)->ExceptionCheck(env)) { (*env)->ExceptionClear(env); el_jni_detach_if_attached(); return -1; }
+    int64_t h = el_widget_alloc(EL_WIDGET_ZSTACK, (int)slot);
+    el_jni_detach_if_attached();
+    return h;
+}
+
+int64_t el_android_scroll_create(void) {
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return -1;
+    jint slot = (*env)->CallStaticIntMethod(env, g_bridge_class,
+                                            g_mid_createScrollView);
+    if ((*env)->ExceptionCheck(env)) { (*env)->ExceptionClear(env); el_jni_detach_if_attached(); return -1; }
+    int64_t h = el_widget_alloc(EL_WIDGET_SCROLL, (int)slot);
+    el_jni_detach_if_attached();
+    return h;
+}
+
+/* ── Widget factories ─────────────────────────────────────────────────────── */
+
+int64_t el_android_label_create(const char *text) {
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return -1;
+    jstring jt = el_jstr(env, text);
+    jint slot = (*env)->CallStaticIntMethod(env, g_bridge_class,
+                                            g_mid_createTextView, jt);
+    (*env)->DeleteLocalRef(env, jt);
+    if ((*env)->ExceptionCheck(env)) { (*env)->ExceptionClear(env); el_jni_detach_if_attached(); return -1; }
+    int64_t h = el_widget_alloc(EL_WIDGET_LABEL, (int)slot);
+    el_jni_detach_if_attached();
+    return h;
+}
+
+int64_t el_android_button_create(const char *label) {
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return -1;
+    jstring jl = el_jstr(env, label);
+    jint slot = (*env)->CallStaticIntMethod(env, g_bridge_class,
+                                            g_mid_createButton, jl);
+    (*env)->DeleteLocalRef(env, jl);
+    if ((*env)->ExceptionCheck(env)) { (*env)->ExceptionClear(env); el_jni_detach_if_attached(); return -1; }
+    int64_t h = el_widget_alloc(EL_WIDGET_BUTTON, (int)slot);
+    el_jni_detach_if_attached();
+    return h;
+}
+
+int64_t el_android_text_field_create(const char *placeholder) {
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return -1;
+    jstring jp = el_jstr(env, placeholder);
+    /* singleLine = true */
+    jint slot = (*env)->CallStaticIntMethod(env, g_bridge_class,
+                                            g_mid_createEditText, jp, (jboolean)JNI_TRUE);
+    (*env)->DeleteLocalRef(env, jp);
+    if ((*env)->ExceptionCheck(env)) { (*env)->ExceptionClear(env); el_jni_detach_if_attached(); return -1; }
+    int64_t h = el_widget_alloc(EL_WIDGET_TEXTFIELD, (int)slot);
+    el_jni_detach_if_attached();
+    return h;
+}
+
+int64_t el_android_text_area_create(const char *placeholder) {
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return -1;
+    jstring jp = el_jstr(env, placeholder);
+    /* singleLine = false → multiline EditText */
+    jint slot = (*env)->CallStaticIntMethod(env, g_bridge_class,
+                                            g_mid_createEditText, jp, (jboolean)JNI_FALSE);
+    (*env)->DeleteLocalRef(env, jp);
+    if ((*env)->ExceptionCheck(env)) { (*env)->ExceptionClear(env); el_jni_detach_if_attached(); return -1; }
+    int64_t h = el_widget_alloc(EL_WIDGET_TEXTAREA, (int)slot);
+    el_jni_detach_if_attached();
+    return h;
+}
+
+int64_t el_android_image_create(const char *path) {
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return -1;
+    jstring jp = el_jstr(env, path);
+    jint slot = (*env)->CallStaticIntMethod(env, g_bridge_class,
+                                            g_mid_createImageView, jp);
+    (*env)->DeleteLocalRef(env, jp);
+    if ((*env)->ExceptionCheck(env)) { (*env)->ExceptionClear(env); el_jni_detach_if_attached(); return -1; }
+    int64_t h = el_widget_alloc(EL_WIDGET_IMAGE, (int)slot);
+    el_jni_detach_if_attached();
+    return h;
+}
+
+/* ── Widget property setters ─────────────────────────────────────────────── */
+
+void el_android_widget_set_text(int64_t handle, const char *text) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    jstring jt = el_jstr(env, text);
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setText,
+                                 (jint)w->slot, jt);
+    (*env)->DeleteLocalRef(env, jt);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+const char *el_android_widget_get_text(int64_t handle) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return "";
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return "";
+    jstring js = (jstring)(*env)->CallStaticObjectMethod(env, g_bridge_class,
+                                                          g_mid_getText,
+                                                          (jint)w->slot);
+    if ((*env)->ExceptionCheck(env)) { (*env)->ExceptionClear(env); el_jni_detach_if_attached(); return ""; }
+    const char *result = "";
+    if (js) {
+        const char *cstr = (*env)->GetStringUTFChars(env, js, NULL);
+        result = cstr ? strdup(cstr) : "";
+        if (cstr) (*env)->ReleaseStringUTFChars(env, js, cstr);
+        (*env)->DeleteLocalRef(env, js);
+    }
+    el_jni_detach_if_attached();
+    return result;
+}
+
+void el_android_widget_set_color(int64_t handle, float r, float g, float b, float a) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setTextColor,
+                                 (jint)w->slot, (jfloat)r, (jfloat)g,
+                                 (jfloat)b, (jfloat)a);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+void el_android_widget_set_bg_color(int64_t handle, float r, float g, float b, float a) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setBackgroundColor,
+                                 (jint)w->slot, (jfloat)r, (jfloat)g,
+                                 (jfloat)b, (jfloat)a);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+void el_android_widget_set_font(int64_t handle, const char *family, int size, int bold) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    jstring jfam = el_jstr(env, family);
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setFont,
+                                 (jint)w->slot, jfam, (jint)size,
+                                 (jboolean)(bold ? JNI_TRUE : JNI_FALSE));
+    (*env)->DeleteLocalRef(env, jfam);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+void el_android_widget_set_padding(int64_t handle, int top, int right, int bottom, int left) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setPadding,
+                                 (jint)w->slot, (jint)top, (jint)right,
+                                 (jint)bottom, (jint)left);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+void el_android_widget_set_width(int64_t handle, int width) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setWidth,
+                                 (jint)w->slot, (jint)width);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+void el_android_widget_set_height(int64_t handle, int height) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setHeight,
+                                 (jint)w->slot, (jint)height);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+void el_android_widget_set_flex(int64_t handle, int flex) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setFlex,
+                                 (jint)w->slot, (jint)flex);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+void el_android_widget_set_corner_radius(int64_t handle, int radius) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setCornerRadius,
+                                 (jint)w->slot, (jfloat)radius);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+void el_android_widget_set_disabled(int64_t handle, int disabled) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setEnabled,
+                                 (jint)w->slot,
+                                 (jboolean)(disabled ? JNI_FALSE : JNI_TRUE));
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+void el_android_widget_set_hidden(int64_t handle, int hidden) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    /* visible=true means NOT hidden */
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setVisibility,
+                                 (jint)w->slot,
+                                 (jboolean)(hidden ? JNI_FALSE : JNI_TRUE));
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+/* ── Child management ─────────────────────────────────────────────────────── */
+
+void el_android_widget_add_child(int64_t parent, int64_t child) {
+    ElWidget *pw = el_widget_get(parent);
+    ElWidget *cw = el_widget_get(child);
+    if (!pw || !cw) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_addChild,
+                                 (jint)pw->slot, (jint)cw->slot);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+void el_android_widget_remove_child(int64_t parent, int64_t child) {
+    ElWidget *pw = el_widget_get(parent);
+    ElWidget *cw = el_widget_get(child);
+    if (!pw || !cw) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_removeChild,
+                                 (jint)pw->slot, (jint)cw->slot);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+/* ── Event registration ───────────────────────────────────────────────────── */
+
+void el_android_widget_on_click(int64_t handle, const char *fn_name) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    free(w->cb_click);
+    w->cb_click = (fn_name && *fn_name) ? strdup(fn_name) : NULL;
+    if (!w->cb_click) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setOnClickListener,
+                                 (jint)w->slot);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+void el_android_widget_on_change(int64_t handle, const char *fn_name) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    free(w->cb_change);
+    w->cb_change = (fn_name && *fn_name) ? strdup(fn_name) : NULL;
+    if (!w->cb_change) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setOnChangeListener,
+                                 (jint)w->slot);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+void el_android_widget_on_submit(int64_t handle, const char *fn_name) {
+    /* Submit stored in cb_click, same as AppKit. */
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    free(w->cb_click);
+    w->cb_click = (fn_name && *fn_name) ? strdup(fn_name) : NULL;
+    if (!w->cb_click) return;
+    JNIEnv *env = el_jni_env();
+    if (!env || !g_bridge_class) return;
+    (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_setOnSubmitListener,
+                                 (jint)w->slot);
+    if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    el_jni_detach_if_attached();
+}
+
+/* ── Widget destroy ───────────────────────────────────────────────────────── */
+
+void el_android_widget_destroy(int64_t handle) {
+    ElWidget *w = el_widget_get(handle);
+    if (!w) return;
+    JNIEnv *env = el_jni_env();
+    if (env && g_bridge_class) {
+        (*env)->CallStaticVoidMethod(env, g_bridge_class, g_mid_destroyView,
+                                     (jint)w->slot);
+        if ((*env)->ExceptionCheck(env)) (*env)->ExceptionClear(env);
+    }
+    el_widget_free(handle);
+    el_jni_detach_if_attached();
+}
+
+/* ── Manifest reader ─────────────────────────────────────────────────────── */
+/*
+ * __manifest_read: parse the app{} block from a manifest file.
+ * Returns the raw file contents as an el_val_t (const char* cast).
+ * The caller (el program) parses the returned string.
+ * Reads from the filesystem; for APK assets use the AssetManager path instead.
+ */
+static char *el_read_file(const char *path) {
+    if (!path || !*path) return NULL;
+    FILE *f = fopen(path, "rb");
+    if (!f) return NULL;
+    fseek(f, 0, SEEK_END);
+    long len = ftell(f);
+    fseek(f, 0, SEEK_SET);
+    if (len <= 0) { fclose(f); return NULL; }
+    char *buf = (char *)malloc((size_t)len + 1);
+    if (!buf) { fclose(f); return NULL; }
+    fread(buf, 1, (size_t)len, f);
+    buf[len] = '\0';
+    fclose(f);
+    return buf;
+}
+
+el_val_t el_android_manifest_read(const char *path) {
+    char *contents = el_read_file(path);
+    if (!contents) return (el_val_t)(uintptr_t)"";
+    return (el_val_t)(uintptr_t)contents;  /* caller owns allocation */
+}
+
+/* ── __widget_* C API (called from el_seed.c) ────────────────────────────── */
+/*
+ * These are the functions declared in el_native_target.h under EL_TARGET_ANDROID.
+ * They forward to the el_android_* internal functions above.
+ *
+ * The el_val_t / int64_t ABI matches the AppKit functions exactly:
+ *   - Integer params passed as int64_t, extracted with (int)
+ *   - String params passed as int64_t, extracted with (const char*)(uintptr_t)
+ *   - Float params (r,g,b,a) passed as int64_t bit-cast from double; extracted
+ *     with el_to_float / bit-cast union
+ */
+
+static inline float el_val_to_float(el_val_t v) {
+    union { double d; int64_t i; } u;
+    u.i = v;
+    return (float)u.d;
+}
+
+void __native_init(void) {
+    el_android_init();
+}
+
+void __native_run_loop(void) {
+    /* No-op on Android — lifecycle is driven by the Activity. */
+}
+
+el_val_t __window_create(el_val_t title, el_val_t width, el_val_t height,
+                          el_val_t min_width, el_val_t min_height) {
+    return (el_val_t)el_android_window_create(
+        (const char *)(uintptr_t)title,
+        (int)width, (int)height, (int)min_width, (int)min_height);
+}
+
+void __window_show(el_val_t handle) {
+    el_android_window_show((int64_t)handle);
+}
+
+void __window_set_title(el_val_t handle, el_val_t title) {
+    el_android_window_set_title((int64_t)handle,
+                                (const char *)(uintptr_t)title);
+}
+
+el_val_t __vstack_create(el_val_t spacing) {
+    return (el_val_t)el_android_vstack_create((int)spacing);
+}
+
+el_val_t __hstack_create(el_val_t spacing) {
+    return (el_val_t)el_android_hstack_create((int)spacing);
+}
+
+el_val_t __zstack_create(void) {
+    return (el_val_t)el_android_zstack_create();
+}
+
+el_val_t __scroll_create(void) {
+    return (el_val_t)el_android_scroll_create();
+}
+
+el_val_t __label_create(el_val_t text) {
+    return (el_val_t)el_android_label_create((const char *)(uintptr_t)text);
+}
+
+el_val_t __button_create(el_val_t label) {
+    return (el_val_t)el_android_button_create((const char *)(uintptr_t)label);
+}
+
+el_val_t __text_field_create(el_val_t placeholder) {
+    return (el_val_t)el_android_text_field_create((const char *)(uintptr_t)placeholder);
+}
+
+el_val_t __text_area_create(el_val_t placeholder) {
+    return (el_val_t)el_android_text_area_create((const char *)(uintptr_t)placeholder);
+}
+
+el_val_t __image_create(el_val_t path_or_name) {
+    return (el_val_t)el_android_image_create((const char *)(uintptr_t)path_or_name);
+}
+
+void __widget_set_text(el_val_t handle, el_val_t text) {
+    el_android_widget_set_text((int64_t)handle,
+                               (const char *)(uintptr_t)text);
+}
+
+el_val_t __widget_get_text(el_val_t handle) {
+    return (el_val_t)(uintptr_t)el_android_widget_get_text((int64_t)handle);
+}
+
+void __widget_set_color(el_val_t handle, el_val_t r, el_val_t g,
+                         el_val_t b, el_val_t a) {
+    el_android_widget_set_color((int64_t)handle,
+                                el_val_to_float(r), el_val_to_float(g),
+                                el_val_to_float(b), el_val_to_float(a));
+}
+
+void __widget_set_bg_color(el_val_t handle, el_val_t r, el_val_t g,
+                            el_val_t b, el_val_t a) {
+    el_android_widget_set_bg_color((int64_t)handle,
+                                   el_val_to_float(r), el_val_to_float(g),
+                                   el_val_to_float(b), el_val_to_float(a));
+}
+
+void __widget_set_font(el_val_t handle, el_val_t family,
+                        el_val_t size, el_val_t bold) {
+    el_android_widget_set_font((int64_t)handle,
+                               (const char *)(uintptr_t)family,
+                               (int)size, (int)bold);
+}
+
+void __widget_set_padding(el_val_t handle, el_val_t top, el_val_t right,
+                           el_val_t bottom, el_val_t left) {
+    el_android_widget_set_padding((int64_t)handle,
+                                  (int)top, (int)right, (int)bottom, (int)left);
+}
+
+void __widget_set_width(el_val_t handle, el_val_t width) {
+    el_android_widget_set_width((int64_t)handle, (int)width);
+}
+
+void __widget_set_height(el_val_t handle, el_val_t height) {
+    el_android_widget_set_height((int64_t)handle, (int)height);
+}
+
+void __widget_set_flex(el_val_t handle, el_val_t flex) {
+    el_android_widget_set_flex((int64_t)handle, (int)flex);
+}
+
+void __widget_set_corner_radius(el_val_t handle, el_val_t radius) {
+    el_android_widget_set_corner_radius((int64_t)handle, (int)radius);
+}
+
+void __widget_set_disabled(el_val_t handle, el_val_t disabled) {
+    el_android_widget_set_disabled((int64_t)handle, (int)disabled);
+}
+
+void __widget_set_hidden(el_val_t handle, el_val_t hidden) {
+    el_android_widget_set_hidden((int64_t)handle, (int)hidden);
+}
+
+void __widget_add_child(el_val_t parent, el_val_t child) {
+    el_android_widget_add_child((int64_t)parent, (int64_t)child);
+}
+
+void __widget_remove_child(el_val_t parent, el_val_t child) {
+    el_android_widget_remove_child((int64_t)parent, (int64_t)child);
+}
+
+void __widget_destroy(el_val_t handle) {
+    el_android_widget_destroy((int64_t)handle);
+}
+
+void __widget_on_click(el_val_t handle, el_val_t fn_name) {
+    el_android_widget_on_click((int64_t)handle,
+                               (const char *)(uintptr_t)fn_name);
+}
+
+void __widget_on_change(el_val_t handle, el_val_t fn_name) {
+    el_android_widget_on_change((int64_t)handle,
+                                (const char *)(uintptr_t)fn_name);
+}
+
+void __widget_on_submit(el_val_t handle, el_val_t fn_name) {
+    el_android_widget_on_submit((int64_t)handle,
+                                (const char *)(uintptr_t)fn_name);
+}
+
+el_val_t __manifest_read(el_val_t path) {
+    return el_android_manifest_read((const char *)(uintptr_t)path);
+}
+
+/* ── MainActivity JNI entry point ─────────────────────────────────────────── */
+/*
+ * Java_com_neuron_el_MainActivity_nativeMain — invoked from MainActivity.onCreate
+ * after ElBridge.init(this).  Calls the el program's compiled main() which runs
+ * the boot sequence: native_init → window_from_manifest → app_build → window_show.
+ * __native_run_loop is a no-op on Android; the Activity lifecycle drives the UI.
+ */
+JNIEXPORT void JNICALL
+Java_com_neuron_el_MainActivity_nativeMain(JNIEnv *env, jobject obj) {
+    (void)env; (void)obj;
+    extern int main(int argc, char **argv);
+    char *argv[] = {"el-app", NULL};
+    main(1, argv);
+}
+
+#endif /* EL_TARGET_ANDROID */

ui/examples/native-hello-android/app/src/main/jni/el_native_target.h

@@ -0,0 +1,573 @@
+/*
+ * el_native_target.h — Native widget declarations for el programs targeting
+ * native desktop UI (AppKit / GTK4 / Win32).
+ *
+ * This header is designed to be included AFTER el_runtime.h without conflict:
+ *   - It does NOT redefine el_to_float, el_from_float, or any el_runtime.h
+ *     static inlines.
+ *   - It does NOT redeclare __println, __print, or other functions whose
+ *     return types differ between el_seed.h and el_runtime.h.
+ *   - It adds: native widget builtins + float arithmetic helpers that the
+ *     current el_runtime.h omits but elc still emits calls to.
+ *
+ * Usage:
+ *   Inject via -include at compile time, OR #include it after el_runtime.h.
+ *
+ *   clang -DEL_TARGET_MACOS -include el_native_target.h -c my_app.c ...
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <stdlib.h>
+
+/* el_val_t must already be defined by el_runtime.h or el_seed.h. */
+#ifndef EL_VAL_T_DEFINED
+typedef int64_t el_val_t;
+#endif
+
+/* ── Float arithmetic helpers ───────────────────────────────────────────────
+ * elc emits calls to float_div / float_mul etc. for Float-typed expressions.
+ * These were in el_runtime.c through v1.0.0-20260501 but are missing from the
+ * current el_runtime.h. Redeclared here as static inline to avoid link deps.
+ * Only defined if not already declared (old runtimes that still have them). */
+
+#ifndef EL_FLOAT_OPS_DEFINED
+#define EL_FLOAT_OPS_DEFINED
+
+/* el_to_float / el_from_float — bit-cast between el_val_t and double.
+ * Defined as static inline in both el_runtime.h and el_seed.h; we do NOT
+ * redefine them here. We rely on one of those headers being included first. */
+
+static inline el_val_t float_div(el_val_t a, el_val_t b) {
+    union { double d; int64_t i; } ua, ub, ur;
+    ua.i = a; ub.i = b;
+    ur.d = (ub.d != 0.0) ? (ua.d / ub.d) : 0.0;
+    return ur.i;
+}
+
+static inline el_val_t float_mul(el_val_t a, el_val_t b) {
+    union { double d; int64_t i; } ua, ub, ur;
+    ua.i = a; ub.i = b; ur.d = ua.d * ub.d;
+    return ur.i;
+}
+
+static inline el_val_t float_add(el_val_t a, el_val_t b) {
+    union { double d; int64_t i; } ua, ub, ur;
+    ua.i = a; ub.i = b; ur.d = ua.d + ub.d;
+    return ur.i;
+}
+
+static inline el_val_t float_sub(el_val_t a, el_val_t b) {
+    union { double d; int64_t i; } ua, ub, ur;
+    ua.i = a; ub.i = b; ur.d = ua.d - ub.d;
+    return ur.i;
+}
+
+static inline el_val_t float_lt(el_val_t a, el_val_t b) {
+    union { double d; int64_t i; } ua, ub;
+    ua.i = a; ub.i = b;
+    return (el_val_t)(ua.d < ub.d);
+}
+
+static inline el_val_t float_gt(el_val_t a, el_val_t b) {
+    union { double d; int64_t i; } ua, ub;
+    ua.i = a; ub.i = b;
+    return (el_val_t)(ua.d > ub.d);
+}
+
+static inline el_val_t float_lte(el_val_t a, el_val_t b) {
+    union { double d; int64_t i; } ua, ub;
+    ua.i = a; ub.i = b;
+    return (el_val_t)(ua.d <= ub.d);
+}
+
+static inline el_val_t float_gte(el_val_t a, el_val_t b) {
+    union { double d; int64_t i; } ua, ub;
+    ua.i = a; ub.i = b;
+    return (el_val_t)(ua.d >= ub.d);
+}
+
+static inline el_val_t float_eq(el_val_t a, el_val_t b) {
+    union { double d; int64_t i; } ua, ub;
+    ua.i = a; ub.i = b;
+    return (el_val_t)(ua.d == ub.d);
+}
+
+#endif /* EL_FLOAT_OPS_DEFINED */
+
+/* ── Native widget system (macOS AppKit) ────────────────────────────────────
+ * Available when compiled with -DEL_TARGET_MACOS and linked with el_appkit.m.
+ * Widget handles are opaque int64_t slot indices; -1 = invalid. */
+
+#ifdef EL_TARGET_MACOS
+
+/* Initialisation */
+void      __native_init(void);
+void      __native_run_loop(void);
+
+/* Window */
+el_val_t  __window_create(el_val_t title, el_val_t width, el_val_t height,
+                           el_val_t min_width, el_val_t min_height);
+void      __window_show(el_val_t handle);
+void      __window_set_title(el_val_t handle, el_val_t title);
+
+/* Layout containers */
+el_val_t  __vstack_create(el_val_t spacing);
+el_val_t  __hstack_create(el_val_t spacing);
+el_val_t  __zstack_create(void);
+el_val_t  __scroll_create(void);
+
+/* Widgets */
+el_val_t  __label_create(el_val_t text);
+el_val_t  __button_create(el_val_t label);
+el_val_t  __text_field_create(el_val_t placeholder);
+el_val_t  __text_area_create(el_val_t placeholder);
+el_val_t  __image_create(el_val_t path_or_name);
+
+/* Widget properties */
+void      __widget_set_text(el_val_t handle, el_val_t text);
+el_val_t  __widget_get_text(el_val_t handle);
+void      __widget_set_color(el_val_t handle, el_val_t r, el_val_t g,
+                              el_val_t b, el_val_t a);
+void      __widget_set_bg_color(el_val_t handle, el_val_t r, el_val_t g,
+                                 el_val_t b, el_val_t a);
+void      __widget_set_font(el_val_t handle, el_val_t family,
+                             el_val_t size, el_val_t bold);
+void      __widget_set_padding(el_val_t handle, el_val_t top, el_val_t right,
+                                el_val_t bottom, el_val_t left);
+void      __widget_set_width(el_val_t handle, el_val_t width);
+void      __widget_set_height(el_val_t handle, el_val_t height);
+void      __widget_set_flex(el_val_t handle, el_val_t flex);
+void      __widget_set_corner_radius(el_val_t handle, el_val_t radius);
+void      __widget_set_disabled(el_val_t handle, el_val_t disabled);
+void      __widget_set_hidden(el_val_t handle, el_val_t hidden);
+
+/* Layout / tree */
+void      __widget_add_child(el_val_t parent, el_val_t child);
+void      __widget_remove_child(el_val_t parent, el_val_t child);
+void      __widget_destroy(el_val_t handle);
+
+/* Events */
+void      __widget_on_click(el_val_t handle, el_val_t fn_name);
+void      __widget_on_change(el_val_t handle, el_val_t fn_name);
+void      __widget_on_submit(el_val_t handle, el_val_t fn_name);
+
+/* Manifest reader */
+el_val_t  __manifest_read(el_val_t path);
+
+#endif /* EL_TARGET_MACOS */
+
+/* ── Native widget system (Linux GTK4) ──────────────────────────────────────
+ * Available when compiled with -DEL_TARGET_LINUX and linked with el_gtk4.c.
+ * Widget handles are opaque int64_t slot indices; -1 = invalid.
+ * All functions have the same signatures as EL_TARGET_MACOS above. */
+
+#ifdef EL_TARGET_LINUX
+
+/* Initialisation */
+void      __native_init(void);
+void      __native_run_loop(void);
+
+/* Window */
+el_val_t  __window_create(el_val_t title, el_val_t width, el_val_t height,
+                           el_val_t min_width, el_val_t min_height);
+void      __window_show(el_val_t handle);
+void      __window_set_title(el_val_t handle, el_val_t title);
+
+/* Layout containers */
+el_val_t  __vstack_create(el_val_t spacing);
+el_val_t  __hstack_create(el_val_t spacing);
+el_val_t  __zstack_create(void);
+el_val_t  __scroll_create(void);
+
+/* Widgets */
+el_val_t  __label_create(el_val_t text);
+el_val_t  __button_create(el_val_t label);
+el_val_t  __text_field_create(el_val_t placeholder);
+el_val_t  __text_area_create(el_val_t placeholder);
+el_val_t  __image_create(el_val_t path_or_name);
+
+/* Widget properties */
+void      __widget_set_text(el_val_t handle, el_val_t text);
+el_val_t  __widget_get_text(el_val_t handle);
+void      __widget_set_color(el_val_t handle, el_val_t r, el_val_t g,
+                              el_val_t b, el_val_t a);
+void      __widget_set_bg_color(el_val_t handle, el_val_t r, el_val_t g,
+                                 el_val_t b, el_val_t a);
+void      __widget_set_font(el_val_t handle, el_val_t family,
+                             el_val_t size, el_val_t bold);
+void      __widget_set_padding(el_val_t handle, el_val_t top, el_val_t right,
+                                el_val_t bottom, el_val_t left);
+void      __widget_set_width(el_val_t handle, el_val_t width);
+void      __widget_set_height(el_val_t handle, el_val_t height);
+void      __widget_set_flex(el_val_t handle, el_val_t flex);
+void      __widget_set_corner_radius(el_val_t handle, el_val_t radius);
+void      __widget_set_disabled(el_val_t handle, el_val_t disabled);
+void      __widget_set_hidden(el_val_t handle, el_val_t hidden);
+
+/* Layout / tree */
+void      __widget_add_child(el_val_t parent, el_val_t child);
+void      __widget_remove_child(el_val_t parent, el_val_t child);
+void      __widget_destroy(el_val_t handle);
+
+/* Events */
+void      __widget_on_click(el_val_t handle, el_val_t fn_name);
+void      __widget_on_change(el_val_t handle, el_val_t fn_name);
+void      __widget_on_submit(el_val_t handle, el_val_t fn_name);
+
+/* Manifest reader — same JSON output as EL_TARGET_MACOS */
+el_val_t  __manifest_read(el_val_t path);
+
+#endif /* EL_TARGET_LINUX */
+
+/* ── Native widget system (Windows Win32) ───────────────────────────────────
+ * Available when compiled with -DEL_TARGET_WIN32 and linked with el_win32.c.
+ * Widget handles are opaque int64_t slot indices; -1 = invalid.
+ * Link: el_win32.obj comctl32.lib user32.lib gdi32.lib */
+
+#ifdef EL_TARGET_WIN32
+
+/* Initialisation */
+void      __native_init(void);
+void      __native_run_loop(void);
+
+/* Window */
+el_val_t  __window_create(el_val_t title, el_val_t width, el_val_t height,
+                           el_val_t min_width, el_val_t min_height);
+void      __window_show(el_val_t handle);
+void      __window_set_title(el_val_t handle, el_val_t title);
+
+/* Layout containers */
+el_val_t  __vstack_create(el_val_t spacing);
+el_val_t  __hstack_create(el_val_t spacing);
+el_val_t  __zstack_create(void);
+el_val_t  __scroll_create(void);
+
+/* Widgets */
+el_val_t  __label_create(el_val_t text);
+el_val_t  __button_create(el_val_t label);
+el_val_t  __text_field_create(el_val_t placeholder);
+el_val_t  __text_area_create(el_val_t placeholder);
+el_val_t  __image_create(el_val_t path_or_name);
+
+/* Widget properties */
+void      __widget_set_text(el_val_t handle, el_val_t text);
+el_val_t  __widget_get_text(el_val_t handle);
+void      __widget_set_color(el_val_t handle, el_val_t r, el_val_t g,
+                              el_val_t b, el_val_t a);
+void      __widget_set_bg_color(el_val_t handle, el_val_t r, el_val_t g,
+                                 el_val_t b, el_val_t a);
+void      __widget_set_font(el_val_t handle, el_val_t family,
+                             el_val_t size, el_val_t bold);
+void      __widget_set_padding(el_val_t handle, el_val_t top, el_val_t right,
+                                el_val_t bottom, el_val_t left);
+void      __widget_set_width(el_val_t handle, el_val_t width);
+void      __widget_set_height(el_val_t handle, el_val_t height);
+void      __widget_set_flex(el_val_t handle, el_val_t flex);
+void      __widget_set_corner_radius(el_val_t handle, el_val_t radius);
+void      __widget_set_disabled(el_val_t handle, el_val_t disabled);
+void      __widget_set_hidden(el_val_t handle, el_val_t hidden);
+
+/* Layout / tree */
+void      __widget_add_child(el_val_t parent, el_val_t child);
+void      __widget_remove_child(el_val_t parent, el_val_t child);
+void      __widget_destroy(el_val_t handle);
+
+/* Events */
+void      __widget_on_click(el_val_t handle, el_val_t fn_name);
+void      __widget_on_change(el_val_t handle, el_val_t fn_name);
+void      __widget_on_submit(el_val_t handle, el_val_t fn_name);
+
+/* Manifest reader */
+el_val_t  __manifest_read(el_val_t path);
+
+#endif /* EL_TARGET_WIN32 */
+
+/* ── Native widget system (iOS UIKit) ───────────────────────────────────────
+ * Available when compiled with -DEL_TARGET_IOS and linked with el_uikit.m.
+ * Widget handles are opaque int64_t slot indices; -1 = invalid.
+ *
+ * iOS lifecycle note: UIApplicationMain never returns. The el program must
+ * store its UI-build logic in a void(*)(void) function pointer, assign it to
+ * el_main_entry_fn, then call __native_run_loop. ElAppDelegate invokes
+ * el_main_entry_fn inside didFinishLaunchingWithOptions.
+ * Call el_uikit_set_args(argc, argv) from main() before __native_run_loop. */
+
+#ifdef EL_TARGET_IOS
+
+/* Lifecycle entry-function hook — set before calling __native_run_loop. */
+extern void (*el_main_entry_fn)(void);
+
+/* Forward argc/argv from main() to UIApplicationMain. */
+void      el_uikit_set_args(int argc, char** argv);
+
+/* Initialisation */
+void      __native_init(void);
+void      __native_run_loop(void);
+
+/* Window */
+el_val_t  __window_create(el_val_t title, el_val_t width, el_val_t height,
+                           el_val_t min_width, el_val_t min_height);
+void      __window_show(el_val_t handle);
+void      __window_set_title(el_val_t handle, el_val_t title);
+
+/* Layout containers */
+el_val_t  __vstack_create(el_val_t spacing);
+el_val_t  __hstack_create(el_val_t spacing);
+el_val_t  __zstack_create(void);
+el_val_t  __scroll_create(void);
+
+/* Widgets */
+el_val_t  __label_create(el_val_t text);
+el_val_t  __button_create(el_val_t label);
+el_val_t  __text_field_create(el_val_t placeholder);
+el_val_t  __text_area_create(el_val_t placeholder);
+el_val_t  __image_create(el_val_t path_or_name);
+
+/* Widget properties */
+void      __widget_set_text(el_val_t handle, el_val_t text);
+el_val_t  __widget_get_text(el_val_t handle);
+void      __widget_set_color(el_val_t handle, el_val_t r, el_val_t g,
+                              el_val_t b, el_val_t a);
+void      __widget_set_bg_color(el_val_t handle, el_val_t r, el_val_t g,
+                                 el_val_t b, el_val_t a);
+void      __widget_set_font(el_val_t handle, el_val_t family,
+                             el_val_t size, el_val_t bold);
+void      __widget_set_padding(el_val_t handle, el_val_t top, el_val_t right,
+                                el_val_t bottom, el_val_t left);
+void      __widget_set_width(el_val_t handle, el_val_t width);
+void      __widget_set_height(el_val_t handle, el_val_t height);
+void      __widget_set_flex(el_val_t handle, el_val_t flex);
+void      __widget_set_corner_radius(el_val_t handle, el_val_t radius);
+void      __widget_set_disabled(el_val_t handle, el_val_t disabled);
+void      __widget_set_hidden(el_val_t handle, el_val_t hidden);
+
+/* Layout / tree */
+void      __widget_add_child(el_val_t parent, el_val_t child);
+void      __widget_remove_child(el_val_t parent, el_val_t child);
+void      __widget_destroy(el_val_t handle);
+
+/* Events */
+void      __widget_on_click(el_val_t handle, el_val_t fn_name);
+void      __widget_on_change(el_val_t handle, el_val_t fn_name);
+void      __widget_on_submit(el_val_t handle, el_val_t fn_name);
+
+/* Manifest reader */
+el_val_t  __manifest_read(el_val_t path);
+
+#endif /* EL_TARGET_IOS */
+
+/* ── Native widget system (Android JNI) ─────────────────────────────────────
+ * Available when compiled with -DEL_TARGET_ANDROID and linked with
+ * libelruntime.so (which includes el_android.c compiled by the NDK build).
+ * Widget handles are opaque int64_t slot indices; -1 = invalid.
+ *
+ * Java companion: ElBridge.java (package com.neuron.el) must be compiled into
+ * the APK. The Activity must call ElBridge.init(this) before any widget ops.
+ *
+ * Link flags (in Android.mk or CMakeLists.txt):
+ *   -landroid -llog -ldl */
+
+#ifdef EL_TARGET_ANDROID
+
+/* Initialisation */
+void      __native_init(void);
+void      __native_run_loop(void);   /* no-op on Android */
+
+/* Window */
+el_val_t  __window_create(el_val_t title, el_val_t width, el_val_t height,
+                           el_val_t min_width, el_val_t min_height);
+void      __window_show(el_val_t handle);
+void      __window_set_title(el_val_t handle, el_val_t title);
+
+/* Layout containers */
+el_val_t  __vstack_create(el_val_t spacing);
+el_val_t  __hstack_create(el_val_t spacing);
+el_val_t  __zstack_create(void);
+el_val_t  __scroll_create(void);
+
+/* Widgets */
+el_val_t  __label_create(el_val_t text);
+el_val_t  __button_create(el_val_t label);
+el_val_t  __text_field_create(el_val_t placeholder);
+el_val_t  __text_area_create(el_val_t placeholder);
+el_val_t  __image_create(el_val_t path_or_name);
+
+/* Widget properties */
+void      __widget_set_text(el_val_t handle, el_val_t text);
+el_val_t  __widget_get_text(el_val_t handle);
+void      __widget_set_color(el_val_t handle, el_val_t r, el_val_t g,
+                              el_val_t b, el_val_t a);
+void      __widget_set_bg_color(el_val_t handle, el_val_t r, el_val_t g,
+                                 el_val_t b, el_val_t a);
+void      __widget_set_font(el_val_t handle, el_val_t family,
+                             el_val_t size, el_val_t bold);
+void      __widget_set_padding(el_val_t handle, el_val_t top, el_val_t right,
+                                el_val_t bottom, el_val_t left);
+void      __widget_set_width(el_val_t handle, el_val_t width);
+void      __widget_set_height(el_val_t handle, el_val_t height);
+void      __widget_set_flex(el_val_t handle, el_val_t flex);
+void      __widget_set_corner_radius(el_val_t handle, el_val_t radius);
+void      __widget_set_disabled(el_val_t handle, el_val_t disabled);
+void      __widget_set_hidden(el_val_t handle, el_val_t hidden);
+
+/* Layout / tree */
+void      __widget_add_child(el_val_t parent, el_val_t child);
+void      __widget_remove_child(el_val_t parent, el_val_t child);
+void      __widget_destroy(el_val_t handle);
+
+/* Events */
+void      __widget_on_click(el_val_t handle, el_val_t fn_name);
+void      __widget_on_change(el_val_t handle, el_val_t fn_name);
+void      __widget_on_submit(el_val_t handle, el_val_t fn_name);
+
+/* Manifest reader */
+el_val_t  __manifest_read(el_val_t path);
+
+#endif /* EL_TARGET_ANDROID */
+
+/* ── Native widget system (LVGL v9 — embedded / microcontroller) ─────────────
+ * Available when compiled with -DEL_TARGET_LVGL and linked with el_lvgl.c
+ * and the LVGL library (lvgl.a or lvgl source tree).
+ *
+ * Target platforms: ESP32, STM32, industrial panels. Any system with 256KB+
+ * RAM and an LVGL-compatible display driver. No OS required.
+ *
+ * Widget handles are opaque int64_t slot indices; -1 = invalid.
+ *
+ * Bare-metal / no dynamic linker:
+ *   Compile with -DEL_LVGL_NO_DLSYM and provide:
+ *     el_val_t el_lvgl_dispatch(const char *fn, el_val_t a, el_val_t b);
+ *
+ * Compile:
+ *   gcc -DEL_TARGET_LVGL -I./lvgl el_lvgl.c -c -o el_lvgl.o
+ *   # Then link with lvgl.a. */
+
+#ifdef EL_TARGET_LVGL
+
+/* Initialisation */
+void      __native_init(void);
+void      __native_run_loop(void);
+
+/* Window */
+el_val_t  __window_create(el_val_t title, el_val_t width, el_val_t height,
+                           el_val_t min_width, el_val_t min_height);
+void      __window_show(el_val_t handle);
+void      __window_set_title(el_val_t handle, el_val_t title);
+
+/* Layout containers */
+el_val_t  __vstack_create(el_val_t spacing);
+el_val_t  __hstack_create(el_val_t spacing);
+el_val_t  __zstack_create(void);
+el_val_t  __scroll_create(void);
+
+/* Widgets */
+el_val_t  __label_create(el_val_t text);
+el_val_t  __button_create(el_val_t label);
+el_val_t  __text_field_create(el_val_t placeholder);
+el_val_t  __text_area_create(el_val_t placeholder);
+el_val_t  __image_create(el_val_t path_or_name);
+
+/* Widget properties */
+void      __widget_set_text(el_val_t handle, el_val_t text);
+el_val_t  __widget_get_text(el_val_t handle);
+void      __widget_set_color(el_val_t handle, el_val_t r, el_val_t g,
+                              el_val_t b, el_val_t a);
+void      __widget_set_bg_color(el_val_t handle, el_val_t r, el_val_t g,
+                                 el_val_t b, el_val_t a);
+void      __widget_set_font(el_val_t handle, el_val_t family,
+                             el_val_t size, el_val_t bold);
+void      __widget_set_padding(el_val_t handle, el_val_t top, el_val_t right,
+                                el_val_t bottom, el_val_t left);
+void      __widget_set_width(el_val_t handle, el_val_t width);
+void      __widget_set_height(el_val_t handle, el_val_t height);
+void      __widget_set_flex(el_val_t handle, el_val_t flex);
+void      __widget_set_corner_radius(el_val_t handle, el_val_t radius);
+void      __widget_set_disabled(el_val_t handle, el_val_t disabled);
+void      __widget_set_hidden(el_val_t handle, el_val_t hidden);
+
+/* Layout / tree */
+void      __widget_add_child(el_val_t parent, el_val_t child);
+void      __widget_remove_child(el_val_t parent, el_val_t child);
+void      __widget_destroy(el_val_t handle);
+
+/* Events */
+void      __widget_on_click(el_val_t handle, el_val_t fn_name);
+void      __widget_on_change(el_val_t handle, el_val_t fn_name);
+void      __widget_on_submit(el_val_t handle, el_val_t fn_name);
+
+/* Manifest reader — same JSON output as all other native targets */
+el_val_t  __manifest_read(el_val_t path);
+
+#endif /* EL_TARGET_LVGL */
+
+/* ── Native widget system (SDL2 — embedded / Pi) ────────────────────────────
+ * Available when compiled with -DEL_TARGET_SDL2 and linked with el_sdl2.c.
+ * Widget handles are opaque int64_t slot indices; -1 = invalid.
+ *
+ * Target: Raspberry Pi Zero, embedded Linux, any system with a framebuffer
+ * and SDL2 available. No GTK, no desktop environment required.
+ *
+ * Compile:
+ *   gcc -DEL_TARGET_SDL2 $(sdl2-config --cflags) -c el_sdl2.c -o el_sdl2.o
+ * Link:
+ *   $(sdl2-config --libs) -lSDL2_ttf -lSDL2_image -ldl */
+
+#ifdef EL_TARGET_SDL2
+
+/* Initialisation */
+void      __native_init(void);
+void      __native_run_loop(void);
+
+/* Window */
+el_val_t  __window_create(el_val_t title, el_val_t width, el_val_t height,
+                           el_val_t min_width, el_val_t min_height);
+void      __window_show(el_val_t handle);
+void      __window_set_title(el_val_t handle, el_val_t title);
+
+/* Layout containers */
+el_val_t  __vstack_create(el_val_t spacing);
+el_val_t  __hstack_create(el_val_t spacing);
+el_val_t  __zstack_create(void);
+el_val_t  __scroll_create(void);
+
+/* Widgets */
+el_val_t  __label_create(el_val_t text);
+el_val_t  __button_create(el_val_t label);
+el_val_t  __text_field_create(el_val_t placeholder);
+el_val_t  __text_area_create(el_val_t placeholder);
+el_val_t  __image_create(el_val_t path_or_name);
+
+/* Widget properties */
+void      __widget_set_text(el_val_t handle, el_val_t text);
+el_val_t  __widget_get_text(el_val_t handle);
+void      __widget_set_color(el_val_t handle, el_val_t r, el_val_t g,
+                              el_val_t b, el_val_t a);
+void      __widget_set_bg_color(el_val_t handle, el_val_t r, el_val_t g,
+                                 el_val_t b, el_val_t a);
+void      __widget_set_font(el_val_t handle, el_val_t family,
+                             el_val_t size, el_val_t bold);
+void      __widget_set_padding(el_val_t handle, el_val_t top, el_val_t right,
+                                el_val_t bottom, el_val_t left);
+void      __widget_set_width(el_val_t handle, el_val_t width);
+void      __widget_set_height(el_val_t handle, el_val_t height);
+void      __widget_set_flex(el_val_t handle, el_val_t flex);
+void      __widget_set_corner_radius(el_val_t handle, el_val_t radius);
+void      __widget_set_disabled(el_val_t handle, el_val_t disabled);
+void      __widget_set_hidden(el_val_t handle, el_val_t hidden);
+
+/* Layout / tree */
+void      __widget_add_child(el_val_t parent, el_val_t child);
+void      __widget_remove_child(el_val_t parent, el_val_t child);
+void      __widget_destroy(el_val_t handle);
+
+/* Events */
+void      __widget_on_click(el_val_t handle, el_val_t fn_name);
+void      __widget_on_change(el_val_t handle, el_val_t fn_name);
+void      __widget_on_submit(el_val_t handle, el_val_t fn_name);
+
+/* Manifest reader */
+el_val_t  __manifest_read(el_val_t path);
+
+#endif /* EL_TARGET_SDL2 */

ui/examples/native-hello-android/app/src/main/jni/el_native_vessel.c

@@ -0,0 +1,459 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include "el_runtime.h"
+
+el_val_t native_init(void);
+el_val_t native_run_loop(void);
+el_val_t manifest_read(el_val_t path);
+el_val_t manifest_title(el_val_t m);
+el_val_t manifest_width(el_val_t m);
+el_val_t manifest_height(el_val_t m);
+el_val_t manifest_min_width(el_val_t m);
+el_val_t manifest_min_height(el_val_t m);
+el_val_t window_create(el_val_t title, el_val_t width, el_val_t height, el_val_t min_width, el_val_t min_height);
+el_val_t window_from_manifest(el_val_t manifest_path);
+el_val_t window_show(el_val_t handle);
+el_val_t window_set_title(el_val_t handle, el_val_t title);
+el_val_t vstack(el_val_t spacing);
+el_val_t vstack_tight(void);
+el_val_t hstack(el_val_t spacing);
+el_val_t zstack(void);
+el_val_t scroll(void);
+el_val_t label(el_val_t text);
+el_val_t button(el_val_t label);
+el_val_t text_field(el_val_t placeholder);
+el_val_t text_area(el_val_t placeholder);
+el_val_t image(el_val_t path_or_name);
+el_val_t widget_set_text(el_val_t handle, el_val_t text);
+el_val_t widget_get_text(el_val_t handle);
+el_val_t widget_set_color(el_val_t handle, el_val_t r, el_val_t g, el_val_t b, el_val_t a);
+el_val_t widget_set_bg_color(el_val_t handle, el_val_t r, el_val_t g, el_val_t b, el_val_t a);
+el_val_t widget_set_font(el_val_t handle, el_val_t family, el_val_t size, el_val_t bold);
+el_val_t widget_set_padding(el_val_t handle, el_val_t top, el_val_t right, el_val_t bottom, el_val_t left);
+el_val_t widget_set_padding_all(el_val_t handle, el_val_t p);
+el_val_t widget_set_padding_xy(el_val_t handle, el_val_t px, el_val_t py);
+el_val_t widget_set_width(el_val_t handle, el_val_t width);
+el_val_t widget_set_height(el_val_t handle, el_val_t height);
+el_val_t widget_set_flex(el_val_t handle, el_val_t flex);
+el_val_t widget_set_corner_radius(el_val_t handle, el_val_t radius);
+el_val_t widget_set_disabled(el_val_t handle, el_val_t disabled);
+el_val_t widget_set_hidden(el_val_t handle, el_val_t hidden);
+el_val_t widget_add_child(el_val_t parent, el_val_t child);
+el_val_t widget_remove_child(el_val_t parent, el_val_t child);
+el_val_t widget_destroy(el_val_t handle);
+el_val_t widget_on_click(el_val_t handle, el_val_t fn_name);
+el_val_t widget_on_change(el_val_t handle, el_val_t fn_name);
+el_val_t widget_on_submit(el_val_t handle, el_val_t fn_name);
+el_val_t hex_channel(el_val_t s, el_val_t offset);
+el_val_t hex_nibble(el_val_t c);
+el_val_t color_hex_r(el_val_t hex);
+el_val_t color_hex_g(el_val_t hex);
+el_val_t color_hex_b(el_val_t hex);
+el_val_t color_hex_a(el_val_t hex);
+el_val_t widget_set_color_hex(el_val_t handle, el_val_t hex);
+el_val_t widget_set_bg_color_hex(el_val_t handle, el_val_t hex);
+el_val_t style_surface(el_val_t handle);
+el_val_t style_button_primary(el_val_t handle);
+el_val_t style_label_body(el_val_t handle);
+el_val_t style_label_heading(el_val_t handle);
+el_val_t style_label_muted(el_val_t handle);
+
+el_val_t TOKEN_PRIMARY;
+el_val_t TOKEN_ON_PRIMARY;
+el_val_t TOKEN_BACKGROUND;
+el_val_t TOKEN_ON_BG;
+el_val_t TOKEN_SURFACE;
+el_val_t TOKEN_ON_SURFACE;
+el_val_t TOKEN_OUTLINE;
+el_val_t TOKEN_ERROR;
+
+el_val_t native_init(void) {
+  __native_init();
+  return 0;
+}
+
+el_val_t native_run_loop(void) {
+  __native_run_loop();
+  return 0;
+}
+
+el_val_t manifest_read(el_val_t path) {
+  return __manifest_read(path);
+  return 0;
+}
+
+el_val_t manifest_title(el_val_t m) {
+  return json_get_string(m, EL_STR("title"));
+  return 0;
+}
+
+el_val_t manifest_width(el_val_t m) {
+  return json_get_int(m, EL_STR("width"));
+  return 0;
+}
+
+el_val_t manifest_height(el_val_t m) {
+  return json_get_int(m, EL_STR("height"));
+  return 0;
+}
+
+el_val_t manifest_min_width(el_val_t m) {
+  return json_get_int(m, EL_STR("min_width"));
+  return 0;
+}
+
+el_val_t manifest_min_height(el_val_t m) {
+  return json_get_int(m, EL_STR("min_height"));
+  return 0;
+}
+
+el_val_t window_create(el_val_t title, el_val_t width, el_val_t height, el_val_t min_width, el_val_t min_height) {
+  return __window_create(title, width, height, min_width, min_height);
+  return 0;
+}
+
+el_val_t window_from_manifest(el_val_t manifest_path) {
+  el_val_t m = manifest_read(manifest_path);
+  el_val_t title = manifest_title(m);
+  el_val_t w = manifest_width(m);
+  el_val_t h = manifest_height(m);
+  el_val_t mw = manifest_min_width(m);
+  el_val_t mh = manifest_min_height(m);
+  el_val_t safe_w = ({ el_val_t _if_result_1 = 0; if ((w > 0)) { _if_result_1 = (w); } else { _if_result_1 = (1200); } _if_result_1; });
+  el_val_t safe_h = ({ el_val_t _if_result_2 = 0; if ((h > 0)) { _if_result_2 = (h); } else { _if_result_2 = (800); } _if_result_2; });
+  el_val_t safe_mw = ({ el_val_t _if_result_3 = 0; if ((mw > 0)) { _if_result_3 = (mw); } else { _if_result_3 = (600); } _if_result_3; });
+  el_val_t safe_mh = ({ el_val_t _if_result_4 = 0; if ((mh > 0)) { _if_result_4 = (mh); } else { _if_result_4 = (400); } _if_result_4; });
+  el_val_t safe_t = ({ el_val_t _if_result_5 = 0; if ((str_len(title) > 0)) { _if_result_5 = (title); } else { _if_result_5 = (EL_STR("App")); } _if_result_5; });
+  return window_create(safe_t, safe_w, safe_h, safe_mw, safe_mh);
+  return 0;
+}
+
+el_val_t window_show(el_val_t handle) {
+  __window_show(handle);
+  return 0;
+}
+
+el_val_t window_set_title(el_val_t handle, el_val_t title) {
+  __window_set_title(handle, title);
+  return 0;
+}
+
+el_val_t vstack(el_val_t spacing) {
+  return __vstack_create(spacing);
+  return 0;
+}
+
+el_val_t vstack_tight(void) {
+  return __vstack_create(0);
+  return 0;
+}
+
+el_val_t hstack(el_val_t spacing) {
+  return __hstack_create(spacing);
+  return 0;
+}
+
+el_val_t zstack(void) {
+  return __zstack_create();
+  return 0;
+}
+
+el_val_t scroll(void) {
+  return __scroll_create();
+  return 0;
+}
+
+el_val_t label(el_val_t text) {
+  return __label_create(text);
+  return 0;
+}
+
+el_val_t button(el_val_t label) {
+  return __button_create(label);
+  return 0;
+}
+
+el_val_t text_field(el_val_t placeholder) {
+  return __text_field_create(placeholder);
+  return 0;
+}
+
+el_val_t text_area(el_val_t placeholder) {
+  return __text_area_create(placeholder);
+  return 0;
+}
+
+el_val_t image(el_val_t path_or_name) {
+  return __image_create(path_or_name);
+  return 0;
+}
+
+el_val_t widget_set_text(el_val_t handle, el_val_t text) {
+  __widget_set_text(handle, text);
+  return 0;
+}
+
+el_val_t widget_get_text(el_val_t handle) {
+  return __widget_get_text(handle);
+  return 0;
+}
+
+el_val_t widget_set_color(el_val_t handle, el_val_t r, el_val_t g, el_val_t b, el_val_t a) {
+  __widget_set_color(handle, r, g, b, a);
+  return 0;
+}
+
+el_val_t widget_set_bg_color(el_val_t handle, el_val_t r, el_val_t g, el_val_t b, el_val_t a) {
+  __widget_set_bg_color(handle, r, g, b, a);
+  return 0;
+}
+
+el_val_t widget_set_font(el_val_t handle, el_val_t family, el_val_t size, el_val_t bold) {
+  el_val_t bold_int = ({ el_val_t _if_result_6 = 0; if (bold) { _if_result_6 = (1); } else { _if_result_6 = (0); } _if_result_6; });
+  __widget_set_font(handle, family, size, bold_int);
+  return 0;
+}
+
+el_val_t widget_set_padding(el_val_t handle, el_val_t top, el_val_t right, el_val_t bottom, el_val_t left) {
+  __widget_set_padding(handle, top, right, bottom, left);
+  return 0;
+}
+
+el_val_t widget_set_padding_all(el_val_t handle, el_val_t p) {
+  __widget_set_padding(handle, p, p, p, p);
+  return 0;
+}
+
+el_val_t widget_set_padding_xy(el_val_t handle, el_val_t px, el_val_t py) {
+  __widget_set_padding(handle, py, px, py, px);
+  return 0;
+}
+
+el_val_t widget_set_width(el_val_t handle, el_val_t width) {
+  __widget_set_width(handle, width);
+  return 0;
+}
+
+el_val_t widget_set_height(el_val_t handle, el_val_t height) {
+  __widget_set_height(handle, height);
+  return 0;
+}
+
+el_val_t widget_set_flex(el_val_t handle, el_val_t flex) {
+  __widget_set_flex(handle, flex);
+  return 0;
+}
+
+el_val_t widget_set_corner_radius(el_val_t handle, el_val_t radius) {
+  __widget_set_corner_radius(handle, radius);
+  return 0;
+}
+
+el_val_t widget_set_disabled(el_val_t handle, el_val_t disabled) {
+  el_val_t d = ({ el_val_t _if_result_7 = 0; if (disabled) { _if_result_7 = (1); } else { _if_result_7 = (0); } _if_result_7; });
+  __widget_set_disabled(handle, d);
+  return 0;
+}
+
+el_val_t widget_set_hidden(el_val_t handle, el_val_t hidden) {
+  el_val_t h = ({ el_val_t _if_result_8 = 0; if (hidden) { _if_result_8 = (1); } else { _if_result_8 = (0); } _if_result_8; });
+  __widget_set_hidden(handle, h);
+  return 0;
+}
+
+el_val_t widget_add_child(el_val_t parent, el_val_t child) {
+  __widget_add_child(parent, child);
+  return 0;
+}
+
+el_val_t widget_remove_child(el_val_t parent, el_val_t child) {
+  __widget_remove_child(parent, child);
+  return 0;
+}
+
+el_val_t widget_destroy(el_val_t handle) {
+  __widget_destroy(handle);
+  return 0;
+}
+
+el_val_t widget_on_click(el_val_t handle, el_val_t fn_name) {
+  __widget_on_click(handle, fn_name);
+  return 0;
+}
+
+el_val_t widget_on_change(el_val_t handle, el_val_t fn_name) {
+  __widget_on_change(handle, fn_name);
+  return 0;
+}
+
+el_val_t widget_on_submit(el_val_t handle, el_val_t fn_name) {
+  __widget_on_submit(handle, fn_name);
+  return 0;
+}
+
+el_val_t hex_channel(el_val_t s, el_val_t offset) {
+  el_val_t hi = str_slice(s, offset, (offset + 1));
+  el_val_t lo = str_slice(s, (offset + 1), (offset + 2));
+  el_val_t h = hex_nibble(hi);
+  el_val_t l = hex_nibble(lo);
+  return ((h * 16) + l);
+  return 0;
+}
+
+el_val_t hex_nibble(el_val_t c) {
+  if (str_eq(c, EL_STR("0"))) {
+    return 0;
+  }
+  if (str_eq(c, EL_STR("1"))) {
+    return 1;
+  }
+  if (str_eq(c, EL_STR("2"))) {
+    return 2;
+  }
+  if (str_eq(c, EL_STR("3"))) {
+    return 3;
+  }
+  if (str_eq(c, EL_STR("4"))) {
+    return 4;
+  }
+  if (str_eq(c, EL_STR("5"))) {
+    return 5;
+  }
+  if (str_eq(c, EL_STR("6"))) {
+    return 6;
+  }
+  if (str_eq(c, EL_STR("7"))) {
+    return 7;
+  }
+  if (str_eq(c, EL_STR("8"))) {
+    return 8;
+  }
+  if (str_eq(c, EL_STR("9"))) {
+    return 9;
+  }
+  if (str_eq(c, EL_STR("a"))) {
+    return 10;
+  }
+  if (str_eq(c, EL_STR("b"))) {
+    return 11;
+  }
+  if (str_eq(c, EL_STR("c"))) {
+    return 12;
+  }
+  if (str_eq(c, EL_STR("d"))) {
+    return 13;
+  }
+  if (str_eq(c, EL_STR("e"))) {
+    return 14;
+  }
+  if (str_eq(c, EL_STR("f"))) {
+    return 15;
+  }
+  if (str_eq(c, EL_STR("A"))) {
+    return 10;
+  }
+  if (str_eq(c, EL_STR("B"))) {
+    return 11;
+  }
+  if (str_eq(c, EL_STR("C"))) {
+    return 12;
+  }
+  if (str_eq(c, EL_STR("D"))) {
+    return 13;
+  }
+  if (str_eq(c, EL_STR("E"))) {
+    return 14;
+  }
+  if (str_eq(c, EL_STR("F"))) {
+    return 15;
+  }
+  return 0;
+  return 0;
+}
+
+el_val_t color_hex_r(el_val_t hex) {
+  el_val_t s = ({ el_val_t _if_result_9 = 0; if (str_starts_with(hex, EL_STR("#"))) { _if_result_9 = (str_slice(hex, 1, str_len(hex))); } else { _if_result_9 = (hex); } _if_result_9; });
+  el_val_t v = hex_channel(s, 0);
+  return float_div(int_to_float(v), el_from_float(255.0));
+  return 0;
+}
+
+el_val_t color_hex_g(el_val_t hex) {
+  el_val_t s = ({ el_val_t _if_result_10 = 0; if (str_starts_with(hex, EL_STR("#"))) { _if_result_10 = (str_slice(hex, 1, str_len(hex))); } else { _if_result_10 = (hex); } _if_result_10; });
+  el_val_t v = hex_channel(s, 2);
+  return float_div(int_to_float(v), el_from_float(255.0));
+  return 0;
+}
+
+el_val_t color_hex_b(el_val_t hex) {
+  el_val_t s = ({ el_val_t _if_result_11 = 0; if (str_starts_with(hex, EL_STR("#"))) { _if_result_11 = (str_slice(hex, 1, str_len(hex))); } else { _if_result_11 = (hex); } _if_result_11; });
+  el_val_t v = hex_channel(s, 4);
+  return float_div(int_to_float(v), el_from_float(255.0));
+  return 0;
+}
+
+el_val_t color_hex_a(el_val_t hex) {
+  el_val_t s = ({ el_val_t _if_result_12 = 0; if (str_starts_with(hex, EL_STR("#"))) { _if_result_12 = (str_slice(hex, 1, str_len(hex))); } else { _if_result_12 = (hex); } _if_result_12; });
+  if (str_len(s) < 8) {
+    return el_from_float(1.0);
+  }
+  el_val_t v = hex_channel(s, 6);
+  return float_div(int_to_float(v), el_from_float(255.0));
+  return 0;
+}
+
+el_val_t widget_set_color_hex(el_val_t handle, el_val_t hex) {
+  widget_set_color(handle, color_hex_r(hex), color_hex_g(hex), color_hex_b(hex), color_hex_a(hex));
+  return 0;
+}
+
+el_val_t widget_set_bg_color_hex(el_val_t handle, el_val_t hex) {
+  widget_set_bg_color(handle, color_hex_r(hex), color_hex_g(hex), color_hex_b(hex), color_hex_a(hex));
+  return 0;
+}
+
+el_val_t style_surface(el_val_t handle) {
+  widget_set_bg_color_hex(handle, TOKEN_SURFACE);
+  widget_set_corner_radius(handle, 8);
+  return 0;
+}
+
+el_val_t style_button_primary(el_val_t handle) {
+  widget_set_bg_color_hex(handle, TOKEN_PRIMARY);
+  widget_set_color_hex(handle, TOKEN_ON_PRIMARY);
+  widget_set_corner_radius(handle, 8);
+  widget_set_padding_xy(handle, 16, 8);
+  return 0;
+}
+
+el_val_t style_label_body(el_val_t handle) {
+  widget_set_color_hex(handle, TOKEN_ON_BG);
+  widget_set_font(handle, EL_STR("system"), 14, 0);
+  return 0;
+}
+
+el_val_t style_label_heading(el_val_t handle) {
+  widget_set_color_hex(handle, TOKEN_ON_BG);
+  widget_set_font(handle, EL_STR("system"), 20, 1);
+  return 0;
+}
+
+el_val_t style_label_muted(el_val_t handle) {
+  widget_set_color_hex(handle, TOKEN_OUTLINE);
+  widget_set_font(handle, EL_STR("system"), 12, 0);
+  return 0;
+}
+
+int el_vessel_main(int _argc, char** _argv) {
+  el_runtime_init_args(_argc, _argv);
+  TOKEN_PRIMARY = EL_STR("#60a5fa");
+  TOKEN_ON_PRIMARY = EL_STR("#0f172a");
+  TOKEN_BACKGROUND = EL_STR("#0f172a");
+  TOKEN_ON_BG = EL_STR("#f8fafc");
+  TOKEN_SURFACE = EL_STR("#1e293b");
+  TOKEN_ON_SURFACE = EL_STR("#f8fafc");
+  TOKEN_OUTLINE = EL_STR("#475569");
+  TOKEN_ERROR = EL_STR("#f87171");
+  return 0;
+}
+

ui/examples/native-hello-android/app/src/main/jni/el_runtime.h

@@ -0,0 +1,883 @@
+/*
+ * el_runtime.h — El language C runtime header
+ *
+ * Declares all built-in functions available to compiled El programs.
+ * Include this in every generated .c file.
+ *
+ * Value model:
+ *   All El values are represented as el_val_t (= int64_t).
+ *   On 64-bit systems a pointer fits in int64_t.
+ *   String values are cast: (el_val_t)(uintptr_t)"hello"
+ *   Integer values are stored directly.
+ *   This lets arithmetic work naturally while still passing strings around.
+ *
+ * Type conventions (El -> C):
+ *   String  -> el_val_t  (holds const char* via uintptr_t cast)
+ *   Int     -> el_val_t
+ *   Bool    -> el_val_t  (0 = false, nonzero = true)
+ *   Any     -> el_val_t
+ *   Void    -> void
+ *
+ * Macros for convenience:
+ *   EL_STR(s)    cast string literal to el_val_t
+ *   EL_CSTR(v)   cast el_val_t back to const char*
+ *   EL_INT(v)    identity — el_val_t is already int64_t
+ *   EL_NULL      null / zero value
+ *   EL_FALSE     boolean false (0)
+ *   EL_TRUE      boolean true (1)
+ *
+ * Link requirements:
+ *   -lcurl     — required for the HTTP client (http_get, http_post, llm_*).
+ *   -lpthread  — required for the HTTP server (one detached thread per
+ *                connection, capped at 64 concurrent).
+ *   -loqs      — optional; required only when liboqs is installed and the
+ *                pq_* / sha3_256_hex entry points are needed. Detected at
+ *                compile time via __has_include(<oqs/oqs.h>).
+ *   -lcrypto   — optional; pulled in alongside -loqs. Used for X25519 in
+ *                pq_hybrid_* and HKDF-SHA256 derivation.
+ *
+ * Canonical compile command:
+ *   cc -std=c11 -I el-compiler/runtime -lcurl -lpthread \
+ *      -o <out> <prog>.c el-compiler/runtime/el_runtime.c
+ *
+ * With liboqs (post-quantum stack):
+ *   cc -std=c11 -I el-compiler/runtime -lcurl -lpthread -loqs -lcrypto \
+ *      -o <out> <prog>.c el-compiler/runtime/el_runtime.c
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <stdlib.h>
+
+typedef int64_t el_val_t;
+
+#define EL_STR(s)  ((el_val_t)(uintptr_t)(s))
+#define EL_CSTR(v) ((const char*)(uintptr_t)(v))
+#define EL_INT(v)  (v)
+#define EL_NULL    ((el_val_t)0)
+#define EL_FALSE   ((el_val_t)0)
+#define EL_TRUE    ((el_val_t)1)
+
+/* Float values share the el_val_t (int64) slot via a bit-cast.
+ * The codegen emits Float literals as `el_from_float(<dbl>)` so the
+ * underlying bits represent the IEEE 754 double. Float-aware builtins
+ * (math, format, json) round-trip via these helpers. */
+static inline double el_to_float(el_val_t v) {
+    union { int64_t i; double f; } u;
+    u.i = (int64_t)v;
+    return u.f;
+}
+
+static inline el_val_t el_from_float(double f) {
+    union { double f; int64_t i; } u;
+    u.f = f;
+    return (el_val_t)u.i;
+}
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* ── I/O ──────────────────────────────────────────────────────────────────── */
+
+el_val_t  println(el_val_t s);
+el_val_t  print(el_val_t s);
+el_val_t  readline(void);
+
+/* ── String builtins ─────────────────────────────────────────────────────── */
+
+el_val_t  el_str_concat(el_val_t a, el_val_t b);
+el_val_t  str_eq(el_val_t a, el_val_t b);
+el_val_t  str_starts_with(el_val_t s, el_val_t prefix);
+el_val_t  str_ends_with(el_val_t s, el_val_t suffix);
+el_val_t  str_len(el_val_t s);
+el_val_t  str_concat(el_val_t a, el_val_t b);
+el_val_t  int_to_str(el_val_t n);
+el_val_t  str_to_int(el_val_t s);
+el_val_t  native_str_to_int(el_val_t s);
+el_val_t  str_slice(el_val_t s, el_val_t start, el_val_t end);
+el_val_t  str_contains(el_val_t s, el_val_t sub);
+el_val_t  str_replace(el_val_t s, el_val_t from, el_val_t to);
+el_val_t  str_to_upper(el_val_t s);
+el_val_t  str_to_lower(el_val_t s);
+el_val_t  str_trim(el_val_t s);
+
+/* ── Math ────────────────────────────────────────────────────────────────── */
+
+el_val_t  el_abs(el_val_t n);
+el_val_t  el_max(el_val_t a, el_val_t b);
+el_val_t  el_min(el_val_t a, el_val_t b);
+
+/* ── Refcount (ARC) ──────────────────────────────────────────────────────────
+ * Lists and Maps carry a refcount. Strings and ints do not — el_retain and
+ * el_release are safe no-ops on non-refcounted values (they sniff a magic
+ * header at offset 0 and only act if the magic matches).
+ *
+ * Codegen emits these at let-binding shadowing, function entry (params), and
+ * function exit (locals other than the returned value). The refcount lets
+ * el_list_append and el_map_set mutate in place when uniquely owned (cheap)
+ * and copy-on-write when shared (preserves persistent semantics across
+ * accumulator patterns in the compiler itself).                              */
+
+void      el_retain(el_val_t v);
+void      el_release(el_val_t v);
+
+/* ── Scoped arena (CLI use) ───────────────────────────────────────────────── */
+el_val_t  el_arena_push(void);
+el_val_t  el_arena_pop(el_val_t mark);
+
+/* ── List ────────────────────────────────────────────────────────────────── */
+
+el_val_t  el_list_new(el_val_t count, ...);
+el_val_t  el_list_len(el_val_t list);
+el_val_t  el_list_get(el_val_t list, el_val_t index);
+el_val_t  el_list_append(el_val_t list, el_val_t elem);
+el_val_t  el_list_empty(void);
+el_val_t  el_list_clone(el_val_t list);
+
+/* ── Map ─────────────────────────────────────────────────────────────────── */
+
+el_val_t  el_map_new(el_val_t pair_count, ...);
+el_val_t  el_get_field(el_val_t map, el_val_t key);
+el_val_t  el_map_get(el_val_t map, el_val_t key);
+el_val_t  el_map_set(el_val_t map, el_val_t key, el_val_t value);
+
+/* ── HTTP ─────────────────────────────────────────────────────────────────── */
+
+el_val_t  http_get(el_val_t url);
+el_val_t  http_post(el_val_t url, el_val_t body);
+el_val_t  http_post_json(el_val_t url, el_val_t json_body);
+el_val_t  http_get_with_headers(el_val_t url, el_val_t headers_map);
+el_val_t  http_post_with_headers(el_val_t url, el_val_t body, el_val_t headers_map);
+el_val_t  http_post_json_with_headers(el_val_t url, el_val_t headers_map, el_val_t json_body);
+el_val_t  http_post_form_auth(el_val_t url, el_val_t form_body, el_val_t auth_header);
+el_val_t  http_delete(el_val_t url);
+el_val_t  http_serve(el_val_t port, el_val_t handler);
+el_val_t  http_set_handler(el_val_t name);
+
+/* HTTP server v2 ─────────────────────────────────────────────────────────────
+ * Same dispatch model as http_serve, but the handler signature is widened:
+ *
+ *     el_val_t handler(method, path, headers_map, body)
+ *
+ * `headers_map` is an ElMap from lowercased header name → header value (both
+ * Strings). Repeated headers are joined with ", " per RFC 7230.
+ *
+ * Response value: the handler may return either
+ *   (a) a plain body string — same auto-content-type / 200-OK behaviour as
+ *       http_serve (3-arg) — or
+ *   (b) a response envelope built with `http_response(status, headers_json,
+ *       body)`. The runtime detects the envelope discriminator
+ *       `"el_http_response":1` at the start of the returned string and
+ *       unpacks status / headers / body before sending.
+ *
+ * The 3-arg http_serve(port, handler) remains supported unchanged for
+ * existing handlers (e.g. products/web/server.el): it dispatches with
+ * (method, path, body), hardcodes 200 OK, and auto-detects content type. */
+el_val_t  http_serve_v2(el_val_t port, el_val_t handler);
+el_val_t  http_set_handler_v2(el_val_t name);
+
+/* Build an HTTP response envelope. `headers_json` should be a JSON object
+ * literal like `{"WWW-Authenticate":"Basic"}` (or "" / "{}" for none). The
+ * returned string carries the discriminator `{"el_http_response":1,...}`
+ * which the runtime's send-path detects and unpacks. Detection happens
+ * uniformly inside http_send_response, so a 3-arg handler may also return
+ * an envelope. The 3-arg variant remains documented as a fixed 200-OK
+ * auto-content-type contract for legacy handlers that return plain bodies. */
+el_val_t  http_response(el_val_t status, el_val_t headers_json, el_val_t body);
+
+/* SSE connection fd — set by http_worker_v2 before calling the El handler,
+ * cleared afterwards. Defined in el_seed.c; called from el_runtime.c.
+ * The getter is exposed as __http_conn_fd() to El programs. */
+void      el_seed_set_http_conn_fd(int fd);
+
+/* HTTP timeout — every libcurl request honors EL_HTTP_TIMEOUT_MS (default
+ * 60000ms). Read lazily on first use, so setting the env var any time before
+ * the first http_* call is sufficient.                                    */
+
+/* Streaming variants — write the response body straight to a file via
+ * libcurl's CURLOPT_WRITEFUNCTION = fwrite. These bypass the el_val_t string
+ * wrapper entirely, so binary payloads (audio/mpeg, image/png, etc.) survive
+ * embedded NUL bytes that would truncate a strlen()-based code path.
+ *
+ * Both honor EL_HTTP_TIMEOUT_MS, follow redirects, and accept the same
+ * `headers_map` shape as http_post_with_headers (ElMap of String→String).
+ *
+ * Return value: 1 on success (file fully written), 0 on any failure
+ * (network, file open, partial write). On failure the output file is removed
+ * so callers cannot mistake a partially-written file for a valid one. */
+el_val_t  http_post_to_file(el_val_t url, el_val_t body, el_val_t headers_map, el_val_t output_path);
+el_val_t  http_get_to_file(el_val_t url, el_val_t headers_map, el_val_t output_path);
+
+/* ── URL encoding ────────────────────────────────────────────────────────── */
+
+el_val_t  url_encode(el_val_t s);   /* RFC 3986 unreserved set */
+el_val_t  url_decode(el_val_t s);   /* '+' → space, %XX → byte  */
+
+/* ── HTML allowlist sanitizer ────────────────────────────────────────────────
+ * el_html_sanitize(input_html, allowlist_json) — strict allowlist HTML
+ * cleaner. State-machine parser; tag/attribute names compared case-
+ * insensitively against the allowlist; `<a href>` / `<… src>` URL schemes
+ * validated (http, https, mailto, fragment-only, or relative); whole-
+ * subtree drop for script / style / iframe / object / embed / form; HTML-
+ * escapes free text outside dropped subtrees.
+ *
+ * The allowlist is JSON of the form
+ *     {"p":[],"a":["href","title"],"strong":[],...}
+ * where each value is the array of attribute names allowed for that tag. */
+el_val_t  el_html_sanitize(el_val_t input_html, el_val_t allowlist_json);
+el_val_t  html_raw(el_val_t s);
+el_val_t  html_escape(el_val_t s);
+
+/* ── Filesystem ──────────────────────────────────────────────────────────── */
+
+el_val_t  fs_read(el_val_t path);
+el_val_t  fs_write(el_val_t path, el_val_t content);
+el_val_t  fs_list(el_val_t path);
+el_val_t  fs_list_json(el_val_t path);
+el_val_t  fs_exists(el_val_t path);
+el_val_t  fs_mkdir(el_val_t path);   /* mkdir -p, mode 0755                */
+
+/* Length-explicit binary write. `length` is an Int (el_val_t holding the
+ * byte count). The caller knows the length from context — typically because
+ * `bytes` came from base64_decode (which produces a magic-tagged binary
+ * buffer with embedded NULs possible) and the caller already tracks the
+ * decoded length, OR because the bytes came from a fixed-size source
+ * (sha256_bytes = 32, hmac_sha256_bytes = 32). Bypasses strlen entirely.
+ *
+ * Returns 1 on success, 0 on failure (invalid path, can't open, partial
+ * write, negative length). On partial-write failure, the file is removed
+ * so callers cannot read back a truncated artefact. */
+el_val_t  fs_write_bytes(el_val_t path, el_val_t bytes, el_val_t length);
+
+/* ── JSON ────────────────────────────────────────────────────────────────── */
+
+el_val_t  json_get(el_val_t json, el_val_t key);
+el_val_t  json_parse(el_val_t s);
+el_val_t  json_stringify(el_val_t v);
+el_val_t  json_get_string(el_val_t json_str, el_val_t key);
+el_val_t  json_get_int(el_val_t json_str, el_val_t key);
+el_val_t  json_get_float(el_val_t json_str, el_val_t key);
+el_val_t  json_get_bool(el_val_t json_str, el_val_t key);
+el_val_t  json_get_raw(el_val_t json_str, el_val_t key);
+el_val_t  json_set(el_val_t json_str, el_val_t key, el_val_t value);
+el_val_t  json_array_len(el_val_t json_str);
+el_val_t  json_array_get(el_val_t json_str, el_val_t index);
+el_val_t  json_array_get_string(el_val_t json_str, el_val_t index);
+el_val_t  json_escape_string(el_val_t sv);
+el_val_t  json_build_object(el_val_t kvs);
+el_val_t  json_build_array(el_val_t items);
+
+/* ── Time ────────────────────────────────────────────────────────────────── */
+
+el_val_t  time_now(void);
+el_val_t  time_now_utc(void);
+el_val_t  sleep_secs(el_val_t secs);
+el_val_t  sleep_ms(el_val_t ms);
+el_val_t  time_format(el_val_t ts, el_val_t fmt);
+el_val_t  time_to_parts(el_val_t ts);
+el_val_t  time_from_parts(el_val_t secs, el_val_t ns, el_val_t tz);
+el_val_t  time_add(el_val_t ts, el_val_t n, el_val_t unit);
+el_val_t  time_diff(el_val_t ts1, el_val_t ts2, el_val_t unit);
+el_val_t  now_ns(void);
+
+/* ── Instant + Duration: first-class temporal types ──────────────────────────
+ * Both types share the el_val_t (int64) slot. Instants are nanoseconds
+ * since the Unix epoch; Durations are signed nanoseconds. Type discipline
+ * is enforced at codegen-time: BinOps on names registered as Instant or
+ * Duration route through the typed wrappers below; mismatches like
+ * Instant+Instant become #error at the C compiler.
+ *
+ * Postfix literals — `30.seconds`, `1.hour`, `500.millis`, `30.nanos` — are
+ * recognised by the parser as DurationLit AST nodes and lowered to literal
+ * int64 nanoseconds at codegen time. The runtime never sees the units. */
+
+el_val_t  el_now_instant(void);
+el_val_t  now(void);
+el_val_t  unix_seconds(el_val_t n);
+el_val_t  unix_millis(el_val_t n);
+el_val_t  instant_from_iso8601(el_val_t s);
+
+el_val_t  el_duration_from_nanos(el_val_t ns);
+el_val_t  duration_seconds(el_val_t n);
+el_val_t  duration_millis(el_val_t n);
+el_val_t  duration_nanos(el_val_t n);
+
+el_val_t  el_instant_add_dur(el_val_t inst, el_val_t dur);
+el_val_t  el_instant_sub_dur(el_val_t inst, el_val_t dur);
+el_val_t  el_instant_diff(el_val_t a, el_val_t b);
+el_val_t  el_duration_add(el_val_t a, el_val_t b);
+el_val_t  el_duration_sub(el_val_t a, el_val_t b);
+el_val_t  el_duration_scale(el_val_t dur, el_val_t scalar);
+el_val_t  el_duration_div(el_val_t dur, el_val_t scalar);
+
+el_val_t  el_instant_lt(el_val_t a, el_val_t b);
+el_val_t  el_instant_le(el_val_t a, el_val_t b);
+el_val_t  el_instant_gt(el_val_t a, el_val_t b);
+el_val_t  el_instant_ge(el_val_t a, el_val_t b);
+el_val_t  el_instant_eq(el_val_t a, el_val_t b);
+el_val_t  el_instant_ne(el_val_t a, el_val_t b);
+el_val_t  el_duration_lt(el_val_t a, el_val_t b);
+el_val_t  el_duration_le(el_val_t a, el_val_t b);
+el_val_t  el_duration_gt(el_val_t a, el_val_t b);
+el_val_t  el_duration_ge(el_val_t a, el_val_t b);
+el_val_t  el_duration_eq(el_val_t a, el_val_t b);
+el_val_t  el_duration_ne(el_val_t a, el_val_t b);
+
+el_val_t  instant_to_unix_seconds(el_val_t i);
+el_val_t  instant_to_unix_millis(el_val_t i);
+el_val_t  instant_to_iso8601(el_val_t i);
+el_val_t  duration_to_seconds(el_val_t d);
+el_val_t  duration_to_millis(el_val_t d);
+el_val_t  duration_to_nanos(el_val_t d);
+
+el_val_t  el_sleep_duration(el_val_t dur);
+el_val_t  unix_timestamp(void);
+
+el_val_t  ttl_cache_set(el_val_t key, el_val_t value);
+el_val_t  ttl_cache_get(el_val_t key, el_val_t max_age);
+el_val_t  ttl_cache_age(el_val_t key);
+
+/* ── Calendar + CalendarTime + Rhythm + LocalDate/Time/DateTime ─────────────
+ * Phase 1.5 of the time system. Calendar is pluggable: EarthCalendar (IANA
+ * zones, Gregorian, DST) is the user-facing default; MarsCalendar,
+ * CycleCalendar(period), NoCycleCalendar, RelativeCalendar handle non-Earth
+ * domains.
+ *
+ * A Calendar interprets an Instant under a particular cycle convention and
+ * produces a CalendarTime. CalendarTime carries the underlying Instant and
+ * a back-pointer to its Calendar; arithmetic and formatting consult the
+ * Calendar to convert ns since epoch into year/month/day/hour/minute/second
+ * (or sol/phase, or cycle/phase, depending on kind).
+ *
+ * Storage convention: Calendar / CalendarTime / Rhythm / LocalDate /
+ * LocalDateTime are heap-allocated structs whose pointers are cast into
+ * el_val_t. A 24-bit magic header at offset 0 lets the runtime identify
+ * the kind safely. LocalTime is small enough to live in the int64 slot
+ * directly (nanos since midnight, signed).                                  */
+
+/* Zone — opaque IANA zone or fixed offset, used by EarthCalendar.
+ * `zone_id` is either an IANA name ("America/New_York", "UTC") or a fixed
+ * offset string ("+05:30", "-08:00"). The runtime resolves it via tzset()
+ * on first use of the owning EarthCalendar.                                  */
+el_val_t  zone(el_val_t id);
+el_val_t  zone_utc(void);
+el_val_t  zone_local(void);
+el_val_t  zone_offset(el_val_t hours, el_val_t minutes);
+
+/* Calendar constructors. Each returns an el_val_t pointer to a heap-
+ * allocated, magic-tagged Calendar struct. Calendars are interned by
+ * (kind, zone_id, period_ns, epoch_ns) so identical constructors return
+ * the same pointer — equality is reference equality.                        */
+el_val_t  earth_calendar(el_val_t z);
+el_val_t  earth_calendar_default(void);
+el_val_t  mars_calendar(void);
+el_val_t  cycle_calendar(el_val_t period_dur);
+el_val_t  no_cycle_calendar(void);
+el_val_t  relative_calendar(el_val_t epoch_inst);
+
+/* CalendarTime constructors and methods. Returns a heap-allocated struct
+ * whose pointer fits in el_val_t. */
+el_val_t  now_in(el_val_t cal);
+el_val_t  in_calendar(el_val_t inst, el_val_t cal);
+el_val_t  cal_format(el_val_t ct, el_val_t pattern);
+el_val_t  cal_to_instant(el_val_t ct);
+el_val_t  cal_cycle_phase(el_val_t ct);
+el_val_t  cal_in(el_val_t ct, el_val_t cal);
+
+/* LocalDate / LocalTime / LocalDateTime — calendar-agnostic value types.
+ * LocalTime carries nanoseconds since midnight as a signed int64 directly
+ * in the el_val_t slot (no allocation). LocalDate / LocalDateTime are
+ * heap-allocated structs with magic headers. */
+el_val_t  local_date(el_val_t y, el_val_t m, el_val_t d);
+el_val_t  local_time(el_val_t h, el_val_t m, el_val_t s, el_val_t ns);
+el_val_t  local_datetime(el_val_t date, el_val_t time);
+el_val_t  zoned(el_val_t date, el_val_t time, el_val_t cal);
+
+el_val_t  local_date_year(el_val_t ld);
+el_val_t  local_date_month(el_val_t ld);
+el_val_t  local_date_day(el_val_t ld);
+el_val_t  local_time_hour(el_val_t lt);
+el_val_t  local_time_minute(el_val_t lt);
+el_val_t  local_time_second(el_val_t lt);
+el_val_t  local_time_nanos(el_val_t lt);
+
+el_val_t  el_local_date_add_dur(el_val_t ld, el_val_t dur);
+el_val_t  el_local_time_add_dur(el_val_t lt, el_val_t dur);
+el_val_t  el_local_date_lt(el_val_t a, el_val_t b);
+el_val_t  el_local_date_eq(el_val_t a, el_val_t b);
+
+/* Rhythm — pluggable recurrence AST. Returns a heap-allocated struct
+ * pointer in el_val_t; rhythms are immutable so callers may share them. */
+el_val_t  rhythm_cycle_start(void);
+el_val_t  rhythm_cycle_phase(el_val_t phase);
+el_val_t  rhythm_duration(el_val_t d);
+el_val_t  rhythm_session_start(void);
+el_val_t  rhythm_event(el_val_t name);
+el_val_t  rhythm_and(el_val_t a, el_val_t b);
+el_val_t  rhythm_or(el_val_t a, el_val_t b);
+el_val_t  rhythm_weekday(el_val_t day);
+el_val_t  rhythm_weekly_at(el_val_t day, el_val_t hour, el_val_t minute);
+el_val_t  rhythm_next_after(el_val_t r, el_val_t after, el_val_t cal);
+el_val_t  rhythm_matches(el_val_t r, el_val_t ct);
+
+/* ── UUID ────────────────────────────────────────────────────────────────── */
+
+el_val_t  uuid_new(void);
+el_val_t  uuid_v4(void);
+
+/* ── Environment ─────────────────────────────────────────────────────────── */
+
+el_val_t  env(el_val_t key);
+
+/* ── In-process state K/V ────────────────────────────────────────────────── */
+
+el_val_t  state_set(el_val_t key, el_val_t value);
+el_val_t  state_get(el_val_t key);
+el_val_t  state_del(el_val_t key);
+el_val_t  state_keys(void);
+el_val_t  state_has(el_val_t key);
+el_val_t  state_get_or(el_val_t key, el_val_t default_val);
+
+/* ── Float formatting ────────────────────────────────────────────────────── */
+
+el_val_t  float_to_str(el_val_t f);
+el_val_t  int_to_float(el_val_t n);
+el_val_t  float_to_int(el_val_t f);
+el_val_t  format_float(el_val_t f, el_val_t decimals);
+el_val_t  decimal_round(el_val_t f, el_val_t decimals);
+el_val_t  str_to_float(el_val_t s);
+
+/* ── Math (Float-aware) ──────────────────────────────────────────────────── */
+
+el_val_t  math_sqrt(el_val_t f);
+el_val_t  math_log(el_val_t f);
+el_val_t  math_ln(el_val_t f);
+el_val_t  math_sin(el_val_t f);
+el_val_t  math_cos(el_val_t f);
+el_val_t  math_pi(void);
+
+/* ── String additions ────────────────────────────────────────────────────── */
+
+el_val_t  str_index_of(el_val_t s, el_val_t sub);
+el_val_t  str_split(el_val_t s, el_val_t sep);
+el_val_t  str_char_at(el_val_t s, el_val_t i);
+el_val_t  str_char_code(el_val_t s, el_val_t i);
+el_val_t  str_pad_left(el_val_t s, el_val_t width, el_val_t pad);
+el_val_t  str_pad_right(el_val_t s, el_val_t width, el_val_t pad);
+el_val_t  str_format(el_val_t fmt, el_val_t data);
+el_val_t  str_lower(el_val_t s);
+el_val_t  str_upper(el_val_t s);
+
+/* ── Text-processing primitives (Phase 1: byte/codepoint, ASCII char classes)
+ * Phase 2 (filed): Unicode-grapheme awareness, NFC/NFD normalization, regex.
+ * is_* predicates: empty input returns false; multi-char requires ALL bytes
+ * to match. ASCII ranges only in Phase 1. */
+
+/* Counting */
+el_val_t  str_count(el_val_t s, el_val_t sub);              /* non-overlapping */
+el_val_t  str_count_chars(el_val_t s);                      /* codepoint count */
+el_val_t  str_count_bytes(el_val_t s);                      /* alias of str_len */
+el_val_t  str_count_lines(el_val_t s);
+el_val_t  str_count_words(el_val_t s);
+el_val_t  str_count_letters(el_val_t s);                    /* ASCII [A-Za-z] */
+el_val_t  str_count_digits(el_val_t s);                     /* ASCII [0-9] */
+
+/* Find / position */
+el_val_t  str_index_of_all(el_val_t s, el_val_t sub);       /* [Int] of byte offsets */
+el_val_t  str_last_index_of(el_val_t s, el_val_t sub);
+el_val_t  str_find_chars(el_val_t s, el_val_t any_of);      /* first idx of any ch */
+
+/* Transform */
+el_val_t  str_repeat(el_val_t s, el_val_t n);
+el_val_t  str_reverse(el_val_t s);                          /* by codepoint */
+el_val_t  str_strip_prefix(el_val_t s, el_val_t prefix);
+el_val_t  str_strip_suffix(el_val_t s, el_val_t suffix);
+el_val_t  str_strip_chars(el_val_t s, el_val_t chars);
+el_val_t  str_lstrip(el_val_t s);
+el_val_t  str_rstrip(el_val_t s);
+
+/* Char classification (Bool) */
+el_val_t  is_letter(el_val_t s);
+el_val_t  is_digit(el_val_t s);
+el_val_t  is_alphanumeric(el_val_t s);
+el_val_t  is_whitespace(el_val_t s);
+el_val_t  is_punctuation(el_val_t s);
+el_val_t  is_uppercase(el_val_t s);
+el_val_t  is_lowercase(el_val_t s);
+
+/* Split / join */
+el_val_t  str_split_lines(el_val_t s);
+el_val_t  str_split_chars(el_val_t s);                      /* alias of native_string_chars */
+el_val_t  str_split_n(el_val_t s, el_val_t sep, el_val_t n);
+el_val_t  str_join(el_val_t list, el_val_t sep);            /* alias of list_join */
+
+/* ── List additions ──────────────────────────────────────────────────────── */
+
+el_val_t  list_push(el_val_t list, el_val_t elem);
+el_val_t  list_push_front(el_val_t list, el_val_t elem);
+el_val_t  list_join(el_val_t list, el_val_t sep);
+el_val_t  list_range(el_val_t start, el_val_t end);
+
+/* ── Bool helpers ────────────────────────────────────────────────────────── */
+
+el_val_t  bool_to_str(el_val_t b);
+
+/* ── Numeric parsing ─────────────────────────────────────────────────────── */
+
+el_val_t  parse_int(el_val_t s, el_val_t default_val);
+
+/* ── Process ─────────────────────────────────────────────────────────────── */
+
+el_val_t  exit_program(el_val_t code);
+el_val_t  getpid_now(void);
+
+/* Self-terminating memory guard. Reads ELC_MAX_MEM_MB (default 512) and
+ * exits with code 1 if resident memory exceeds the limit. Call periodically
+ * during long compilation loops (e.g. after each function is compiled).
+ * Returns 0 when memory is within bounds.                                   */
+el_val_t  el_mem_check(void);
+
+/* ── CGI identity ─────────────────────────────────────────────────────────────
+ * Called at the start of main() in CGI programs (those with a `cgi {}` block).
+ * Records the program's DHARMA identity before any other code executes.      */
+
+void      el_cgi_init(el_val_t name, el_val_t dharma_id, el_val_t principal,
+                      el_val_t network, el_val_t engram);
+
+/* ── DHARMA network builtins ─────────────────────────────────────────────────
+ * Available to CGI programs (declared with a `cgi {}` block).
+ *
+ * Peers are addressed by `dharma_id` of the form
+ *     "<registry-id>@<transport-url>"   e.g. "ntn-genesis@http://localhost:7770"
+ * If the @<url> portion is omitted, transport defaults to
+ * "http://localhost:7770" (the local CGI daemon assumption).
+ *
+ * Wire protocol (all peers expose):
+ *   POST <url>/dharma/recv      { channel, from, content } → response body
+ *   POST <url>/dharma/event     { type, payload, source, timestamp }
+ *   POST <url>/api/activate     { query }                 → list of nodes
+ *
+ * Hosting application's responsibility: an El program with a `cgi {}` block
+ * runs http_serve() with its own request handler; that handler should route
+ * "/dharma/event" requests by calling el_runtime_dharma_event_arrive() so
+ * incoming events feed dharma_field() queues. The runtime itself does not
+ * intercept any /dharma path.                                                */
+
+el_val_t  dharma_connect(el_val_t cgi_id);
+el_val_t  dharma_send(el_val_t channel, el_val_t content);
+el_val_t  dharma_activate(el_val_t query);
+void      dharma_emit(el_val_t event_type, el_val_t payload);
+el_val_t  dharma_field(el_val_t event_type);
+void      dharma_strengthen(el_val_t cgi_id, el_val_t weight);
+el_val_t  dharma_relationship(el_val_t cgi_id);
+el_val_t  dharma_peers(void);
+
+/* Public C API: called by an El program's HTTP handler when a /dharma/event
+ * request arrives. Pushes onto the per-event-type queue and signals any
+ * pending dharma_field() blockers. All three arguments must be NUL-terminated
+ * C strings (or NULL — then treated as empty).                               */
+void      el_runtime_dharma_event_arrive(const char* event_type,
+                                         const char* payload,
+                                         const char* source);
+
+/* ── Engram local graph primitives ───────────────────────────────────────────
+ * Operate on the CGI's local Engram knowledge graph.
+ * `engram_activate` queries the local graph only; `dharma_activate` is
+ * network-wide across all connected CGI graphs.                              */
+
+el_val_t  engram_node(el_val_t content, el_val_t node_type, el_val_t salience);
+el_val_t  engram_node_full(el_val_t content, el_val_t node_type, el_val_t label,
+                           el_val_t salience, el_val_t importance, el_val_t confidence,
+                           el_val_t tier, el_val_t tags);
+/* Layered consciousness — see el_runtime.c for the layered architecture
+ * design notes (search "Layered consciousness architecture"). The five
+ * canonical layers (safety / core-identity / domain-knowledge / imprint /
+ * suit) are seeded automatically; engram_add_layer extends the registry
+ * with imprint or suit overlays at runtime. Nodes default to layer 1
+ * (core-identity) when created via engram_node / engram_node_full. */
+el_val_t  engram_node_layered(el_val_t content, el_val_t node_type, el_val_t label,
+                              el_val_t salience, el_val_t certainty, el_val_t confidence,
+                              el_val_t status, el_val_t tags, el_val_t layer_id);
+el_val_t  engram_add_layer(el_val_t name, el_val_t priority, el_val_t suppressible,
+                           el_val_t transparent, el_val_t injectable);
+el_val_t  engram_remove_layer(el_val_t layer_id);
+el_val_t  engram_list_layers(void);
+el_val_t  engram_get_node(el_val_t id);
+void      engram_strengthen(el_val_t node_id);
+void      engram_forget(el_val_t node_id);
+el_val_t  engram_node_count(void);
+el_val_t  engram_search(el_val_t query, el_val_t limit);
+el_val_t  engram_scan_nodes(el_val_t limit, el_val_t offset);
+void      engram_connect(el_val_t from_id, el_val_t to_id, el_val_t weight, el_val_t relation);
+el_val_t  engram_edge_between(el_val_t from_id, el_val_t to_id);
+el_val_t  engram_neighbors(el_val_t node_id);
+el_val_t  engram_neighbors_filtered(el_val_t node_id, el_val_t max_depth, el_val_t direction);
+el_val_t  engram_edge_count(void);
+/* Three-pass activation: background fan-out → working-memory promotion →
+ * Layer 0 override. See "Three-pass activation" in el_runtime.c. */
+el_val_t  engram_activate(el_val_t query, el_val_t depth);
+el_val_t  engram_save(el_val_t path);
+el_val_t  engram_load(el_val_t path);
+
+/* JSON-string accessors — return pre-serialized JSON so HTTP handlers
+ * can pass results straight through without round-tripping ElList/ElMap
+ * through json_stringify. */
+el_val_t  engram_get_node_json(el_val_t id);
+el_val_t  engram_search_json(el_val_t query, el_val_t limit);
+el_val_t  engram_scan_nodes_json(el_val_t limit, el_val_t offset);
+el_val_t  engram_scan_nodes_by_type_json(el_val_t node_type, el_val_t limit, el_val_t offset);
+el_val_t  engram_neighbors_json(el_val_t node_id, el_val_t max_depth, el_val_t direction);
+el_val_t  engram_activate_json(el_val_t query, el_val_t depth);
+el_val_t  engram_stats_json(void);
+el_val_t  engram_list_layers_json(void);
+/* engram_compile_layered_json — produce a prompt-ready text block split
+ * into "[LAYER 0 — STRUCTURAL]" (non-suppressible layers, sacred fire)
+ * and "[ENGRAM CONTEXT]" (standard suppressible layers). Returns "" if
+ * no nodes promoted to working memory. */
+el_val_t  engram_compile_layered_json(el_val_t intent, el_val_t depth);
+
+/* ── LLM (Anthropic API client) ─────────────────────────────────────────────
+ * All functions call https://api.anthropic.com/v1/messages with the API key
+ * from env ANTHROPIC_API_KEY. Default model when empty: claude-sonnet-4-5. */
+
+el_val_t  llm_call(el_val_t model, el_val_t prompt);
+el_val_t  llm_call_system(el_val_t model, el_val_t system_prompt, el_val_t user_prompt);
+el_val_t  llm_call_agentic(el_val_t model, el_val_t system, el_val_t user, el_val_t tools);
+el_val_t  llm_vision(el_val_t model, el_val_t system, el_val_t prompt, el_val_t image_url_or_b64);
+el_val_t  llm_models(void);
+
+/* Register a tool handler by name. The handler is looked up via dlsym
+ * (mirroring http_set_handler), so any El `fn <name>(input)` compiles to
+ * a global C symbol that this function can locate at runtime.
+ * Handler signature: `el_val_t handler(el_val_t input_json)` — receives
+ * the tool input as a JSON-string el_val_t and returns a JSON-string
+ * el_val_t result. Used by llm_call_agentic.                                 */
+void      llm_register_tool(el_val_t name, el_val_t handler_fn_name);
+
+/* ── args() ─────────────────────────────────────────────────────────────────
+ * Provides access to command-line arguments passed to the program.
+ * Populated by el_runtime_init_args() before main() runs.           */
+
+el_val_t  args(void);
+void      el_runtime_init_args(int argc, char** argv);
+
+/* ── Crypto primitives ─────────────────────────────────────────────────────
+ * SHA-256, HMAC-SHA-256, and base64 (standard + URL-safe).
+ * Self-contained — no OpenSSL/libcrypto dependency. The implementations are
+ * adapted from public-domain reference code (Brad Conte / RFC 4648).
+ *
+ * Bytes-returning variants (sha256_bytes, hmac_sha256_bytes) return a string
+ * value whose contents are raw binary; callers usually feed these into
+ * base64_encode. Note that el_val_t strings are NUL-terminated by convention,
+ * so the binary payload may contain embedded NULs — pass it directly into
+ * base64_encode (which uses an explicit length) rather than treating it as
+ * a printable C string.
+ *
+ * The "base64" variants emit/accept RFC 4648 standard alphabet with padding.
+ * The "base64url" variants use URL-safe alphabet (`-`/`_`) with no padding,
+ * as used in JWTs.                                                           */
+
+el_val_t  sha256_hex(el_val_t input);
+el_val_t  sha256_bytes(el_val_t input);
+el_val_t  hmac_sha256_hex(el_val_t key, el_val_t message);
+el_val_t  hmac_sha256_bytes(el_val_t key, el_val_t message);
+el_val_t  base64_encode(el_val_t input);
+el_val_t  base64_decode(el_val_t input);
+el_val_t  base64url_encode(el_val_t input);
+el_val_t  base64url_decode(el_val_t input);
+
+/* Length-aware variants (internal — exposed for the rare caller that already
+ * has a known-length binary buffer and doesn't want to round-trip through
+ * a NUL-terminated el_val_t string). Sha256_bytes and hmac_sha256_bytes feed
+ * these implicitly. */
+el_val_t  el_sha256_bytes_n(const unsigned char* data, size_t len);
+el_val_t  el_base64_encode_n(const unsigned char* data, size_t len, int url_safe);
+
+/* ── Post-quantum primitives (liboqs-backed) ────────────────────────────────
+ * All inputs/outputs hex-encoded. Algorithm choices:
+ *   Signature: CRYSTALS-Dilithium-3   (NIST level 3, balanced)
+ *   KEM:       CRYSTALS-Kyber-768     (NIST level 3)
+ *   Hash:      SHA3-256 (Keccak)      (PQ-aware protocols favour SHA3 over SHA2)
+ *
+ * If liboqs is not linked (detected via __has_include(<oqs/oqs.h>) at compile
+ * time), the pq_* entry points return a JSON-shaped error string so callers
+ * fail loudly rather than silently fall back to classical schemes:
+ *   {"error":"liboqs not linked, post-quantum primitives unavailable"}
+ *
+ * The hybrid handshake pairs X25519 with Kyber-768 per NIST PQ guidance and
+ * CNSA 2.0. Combined shared secret is HKDF-SHA256(x25519_ss || kyber_ss).
+ * Even if Kyber falls, X25519 holds; if X25519 falls under quantum attack,
+ * Kyber holds. SHA3-256 also remains usable independent of liboqs (the
+ * Keccak permutation is PQ-OK as a primitive). */
+
+el_val_t  pq_keygen_signature(void);
+el_val_t  pq_sign(el_val_t secret_key_hex, el_val_t message);
+el_val_t  pq_verify(el_val_t public_key_hex, el_val_t message, el_val_t signature_hex);
+
+el_val_t  pq_kem_keygen(void);
+el_val_t  pq_kem_encaps(el_val_t public_key_hex);
+el_val_t  pq_kem_decaps(el_val_t secret_key_hex, el_val_t ciphertext_hex);
+
+el_val_t  pq_hybrid_keygen(void);
+el_val_t  pq_hybrid_handshake(el_val_t remote_pub_combined);
+
+el_val_t  sha3_256_hex(el_val_t input);
+
+/* ── AEAD: AES-256-GCM (libcrypto-backed) ───────────────────────────────────
+ * Symmetric authenticated encryption used to wrap envelopes after a KEM
+ * handshake. Caller MUST supply a 32-byte key (64 hex chars) — typically the
+ * Kyber-768 / hybrid shared_secret, optionally normalized via SHA3-256.
+ *
+ * aead_encrypt returns a JSON map {"nonce":"...","ciphertext":"..."} where
+ * ciphertext is the AES-256-GCM output with the 16-byte auth tag appended.
+ * Nonce is a fresh 12-byte CSPRNG draw — callers never pick the nonce, which
+ * structurally rules out the GCM nonce-reuse footgun.
+ *
+ * aead_decrypt returns the plaintext String, or "" on any failure (including
+ * auth-tag mismatch). Callers MUST check for "" before trusting the result. */
+el_val_t  aead_encrypt(el_val_t key_hex, el_val_t plaintext);
+el_val_t  aead_decrypt(el_val_t key_hex, el_val_t nonce_hex, el_val_t ciphertext_hex);
+
+/* ── Native VM builtin aliases (for compiled El source) ─────────────────────
+ * These match the El VM's native_* builtins so that El source compiled
+ * to C can call the same names without modification.                */
+
+el_val_t  native_list_get(el_val_t list, el_val_t index);
+el_val_t  native_list_len(el_val_t list);
+el_val_t  native_list_append(el_val_t list, el_val_t elem);
+el_val_t  native_list_empty(void);
+el_val_t  native_list_clone(el_val_t list);
+el_val_t  native_string_chars(el_val_t s);
+el_val_t  native_int_to_str(el_val_t n);
+
+/* ── Method-call shorthand aliases ──────────────────────────────────────────
+ * The El method-call convention `obj.method(args)` compiles to
+ * `method(obj, args)`.  These aliases expose the runtime functions under
+ * the short names that result from method calls in El source.
+ *
+ * Example: `myList.append(x)` → `append(myList, x)` (calls this alias)
+ *          `myList.len()`     → `len(myList)`         (calls this alias)  */
+
+el_val_t  append(el_val_t list, el_val_t elem);   /* el_list_append */
+el_val_t  len(el_val_t list);                      /* el_list_len    */
+el_val_t  get(el_val_t list, el_val_t index);      /* el_list_get    */
+el_val_t  map_get(el_val_t map, el_val_t key);     /* el_map_get     */
+el_val_t  map_set(el_val_t map, el_val_t key, el_val_t value); /* el_map_set */
+
+/* ── OTLP/HTTP Observability ─────────────────────────────────────────────── */
+/* See bottom of el_runtime.c for the implementation.
+ * Configured by env vars OTLP_ENDPOINT, OTEL_SERVICE_NAME, OTEL_SERVICE_VERSION.
+ * No-op when OTLP_ENDPOINT is unset. Drop-on-failure semantics. */
+/* ── Subprocess execution ────────────────────────────────────────────────── */
+el_val_t exec_command(el_val_t cmd);   /* run shell command, return exit code */
+el_val_t exec_capture(el_val_t cmd);   /* run shell command, capture stdout   */
+el_val_t exec(el_val_t cmd);           /* exec(cmd) → stdout String (30s timeout) */
+el_val_t exec_bg(el_val_t cmd);        /* exec_bg(cmd) → PID String (non-blocking) */
+
+/* ── Stdout redirection (used by compiler JS pipeline) ───────────────────── */
+el_val_t stdout_to_file(el_val_t path); /* redirect process stdout to a file  */
+el_val_t stdout_restore(void);          /* restore process stdout to terminal  */
+
+el_val_t emit_log(el_val_t level, el_val_t msg, el_val_t fields_json);
+el_val_t emit_metric(el_val_t name, el_val_t value, el_val_t tags_json);
+el_val_t trace_span_start(el_val_t name);
+el_val_t trace_span_end(el_val_t span_handle);
+el_val_t emit_event(el_val_t name, el_val_t duration_ms);
+
+el_val_t __thread_create(el_val_t fn_name_v, el_val_t arg_v);
+el_val_t __thread_join(el_val_t tid_v);
+
+/* ── __ prefixed aliases (self-hosting compiler ABI) ─────────────────────────
+ * The El self-hosting compiler emits calls to __-prefixed names. These are
+ * forwarding wrappers around the existing el_runtime functions above.        */
+
+/* I/O */
+el_val_t  __println(el_val_t s);
+el_val_t  __print(el_val_t s);
+el_val_t  __readline(void);
+
+/* String */
+el_val_t  __int_to_str(el_val_t n);
+el_val_t  __str_to_int(el_val_t s);
+el_val_t  __float_to_str(el_val_t f);
+el_val_t  __str_to_float(el_val_t s);
+el_val_t  __str_len(el_val_t s);
+el_val_t  __str_char_at(el_val_t s, el_val_t i);
+el_val_t  __str_cmp(el_val_t a, el_val_t b);
+el_val_t  __str_ncmp(el_val_t a, el_val_t b, el_val_t n);
+el_val_t  __str_concat_raw(el_val_t a, el_val_t b);
+el_val_t  __str_slice_raw(el_val_t s, el_val_t start, el_val_t end);
+el_val_t  __str_alloc(el_val_t n);
+el_val_t  __str_set_char(el_val_t s, el_val_t i, el_val_t c);
+
+/* URL encoding */
+el_val_t  __url_encode(el_val_t s);
+el_val_t  __url_decode(el_val_t s);
+
+/* Environment */
+el_val_t  __env_get(el_val_t key);
+
+/* Subprocess */
+el_val_t  __exec(el_val_t cmd);
+el_val_t  __exec_bg(el_val_t cmd);
+
+/* Process */
+el_val_t  __exit_program(el_val_t code);
+
+/* Filesystem */
+el_val_t  __fs_exists(el_val_t path);
+el_val_t  __fs_mkdir(el_val_t path);
+el_val_t  __fs_read(el_val_t path);
+el_val_t  __fs_write(el_val_t path, el_val_t content);
+el_val_t  __fs_write_bytes(el_val_t path, el_val_t bytes, el_val_t n);
+el_val_t  __fs_list_raw(el_val_t path);
+
+/* HTTP server */
+el_val_t  __http_response(el_val_t status, el_val_t headers_json, el_val_t body);
+el_val_t  __http_serve(el_val_t port, el_val_t handler);
+el_val_t  __http_serve_v2(el_val_t port, el_val_t handler);
+
+/* HTTP conn fd / SSE (weak; overridden by el_seed.c when linked together) */
+el_val_t  __http_conn_fd(void);
+el_val_t  __http_sse_open(el_val_t conn_id);
+el_val_t  __http_sse_send(el_val_t conn_id, el_val_t data);
+el_val_t  __http_sse_close(el_val_t conn_id);
+
+/* HTTP client (requires HAVE_CURL; stubs provided for no-curl builds) */
+el_val_t  __http_do(el_val_t method, el_val_t url, el_val_t body,
+                    el_val_t headers_map, el_val_t timeout_ms);
+el_val_t  __http_do_map(el_val_t method, el_val_t url, el_val_t body,
+                        el_val_t headers_json, el_val_t timeout_ms);
+el_val_t  __http_do_map_to_file(el_val_t method, el_val_t url, el_val_t body,
+                                el_val_t headers_json, el_val_t output_path);
+
+/* JSON */
+el_val_t  __json_array_get(el_val_t json, el_val_t index);
+el_val_t  __json_array_get_string(el_val_t json, el_val_t index);
+el_val_t  __json_array_len(el_val_t json);
+el_val_t  __json_get(el_val_t json, el_val_t key);
+el_val_t  __json_get_raw(el_val_t json, el_val_t key);
+el_val_t  __json_set(el_val_t json, el_val_t key, el_val_t value);
+el_val_t  __json_parse_map(el_val_t json_str);
+el_val_t  __json_stringify_val(el_val_t val);
+
+/* Hashing */
+el_val_t  __sha256_hex(el_val_t s);
+
+/* State K/V */
+el_val_t  __state_del(el_val_t key);
+el_val_t  __state_get(el_val_t key);
+el_val_t  __state_keys(void);
+el_val_t  __state_set(el_val_t key, el_val_t val);
+
+/* UUID */
+el_val_t  __uuid_v4(void);
+
+/* Args */
+el_val_t  __args_json(void);
+
+#ifdef __cplusplus
+}
+#endif

ui/examples/native-hello-android/app/src/main/jni/native_hello.c

@@ -0,0 +1,123 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include "el_runtime.h"
+
+el_val_t on_greet_click(el_val_t widget, el_val_t data);
+el_val_t on_counter_click(el_val_t widget, el_val_t data);
+el_val_t on_name_change(el_val_t widget, el_val_t data);
+el_val_t app_build(el_val_t window);
+
+el_val_t g_window;
+el_val_t g_label;
+el_val_t g_input;
+el_val_t g_button;
+el_val_t g_counter;
+el_val_t g_counter_lbl;
+el_val_t manifest_env;
+el_val_t manifest_path;
+el_val_t win;
+el_val_t g_window;
+
+el_val_t on_greet_click(el_val_t widget, el_val_t data) {
+  el_val_t name = widget_get_text(g_input);
+  el_val_t greeting = ({ el_val_t _if_result_1 = 0; if ((str_len(name) > 0)) { _if_result_1 = (el_str_concat(el_str_concat(EL_STR("Hello, "), name), EL_STR("!"))); } else { _if_result_1 = (EL_STR("Hello, World!")); } _if_result_1; });
+  widget_set_text(g_label, greeting);
+  return 0;
+}
+
+el_val_t on_counter_click(el_val_t widget, el_val_t data) {
+  el_val_t g_counter = (g_counter + 1);
+  widget_set_text(g_counter_lbl, el_str_concat(EL_STR("Clicks: "), int_to_str(g_counter)));
+  return 0;
+}
+
+el_val_t on_name_change(el_val_t widget, el_val_t data) {
+  el_val_t has_text = (str_len(data) > 0);
+  widget_set_disabled(g_button, !has_text);
+  return 0;
+}
+
+el_val_t app_build(el_val_t window) {
+  el_val_t root = vstack(0);
+  widget_set_padding_all(root, 24);
+  widget_set_bg_color_hex(root, EL_STR("#0f172a"));
+  widget_set_flex(root, 1);
+  el_val_t title = label(EL_STR("el-native \xe2\x80\x94 native widget demo"));
+  style_label_heading(title);
+  widget_add_child(root, title);
+  el_val_t gap1 = label(EL_STR(""));
+  widget_set_height(gap1, 16);
+  widget_add_child(root, gap1);
+  el_val_t subtitle = label(EL_STR("AppKit controls from el code, no ObjC in the app layer."));
+  style_label_muted(subtitle);
+  widget_add_child(root, subtitle);
+  el_val_t gap2 = label(EL_STR(""));
+  widget_set_height(gap2, 24);
+  widget_add_child(root, gap2);
+  el_val_t input_row = hstack(8);
+  el_val_t name_label = label(EL_STR("Name:"));
+  style_label_body(name_label);
+  widget_set_width(name_label, 60);
+  el_val_t input = text_field(EL_STR("Enter your name\xe2\x80\xa6"));
+  style_label_body(input);
+  widget_set_flex(input, 1);
+  widget_on_change(input, EL_STR("on_name_change"));
+  el_val_t g_input = input;
+  el_val_t greet_btn = button(EL_STR("Greet"));
+  style_button_primary(greet_btn);
+  widget_set_disabled(greet_btn, 1);
+  widget_on_click(greet_btn, EL_STR("on_greet_click"));
+  el_val_t g_button = greet_btn;
+  widget_add_child(input_row, name_label);
+  widget_add_child(input_row, input);
+  widget_add_child(input_row, greet_btn);
+  widget_add_child(root, input_row);
+  el_val_t gap3 = label(EL_STR(""));
+  widget_set_height(gap3, 12);
+  widget_add_child(root, gap3);
+  el_val_t greeting = label(EL_STR("Waiting for name\xe2\x80\xa6"));
+  style_label_body(greeting);
+  widget_set_color_hex(greeting, EL_STR("#60a5fa"));
+  widget_set_font(greeting, EL_STR("system"), 16, 1);
+  el_val_t g_label = greeting;
+  widget_add_child(root, greeting);
+  el_val_t gap4 = label(EL_STR(""));
+  widget_set_height(gap4, 24);
+  widget_add_child(root, gap4);
+  el_val_t counter_row = hstack(12);
+  el_val_t counter_lbl = label(EL_STR("Clicks: 0"));
+  style_label_body(counter_lbl);
+  el_val_t g_counter_lbl = counter_lbl;
+  el_val_t counter_btn = button(EL_STR("Click me"));
+  style_button_primary(counter_btn);
+  widget_on_click(counter_btn, EL_STR("on_counter_click"));
+  widget_add_child(counter_row, counter_lbl);
+  widget_add_child(counter_row, counter_btn);
+  widget_add_child(root, counter_row);
+  widget_add_child(window, root);
+  return 0;
+}
+
+int main(int _argc, char** _argv) {
+  el_runtime_init_args(_argc, _argv);
+  g_window = (-1);
+  g_label = (-1);
+  g_input = (-1);
+  g_button = (-1);
+  g_counter = 0;
+  g_counter_lbl = (-1);
+  native_init();
+  manifest_env = env(EL_STR("EL_MANIFEST"));
+  manifest_path = ({ el_val_t _if_result_2 = 0; if ((str_len(manifest_env) > 0)) { _if_result_2 = (manifest_env); } else { _if_result_2 = (EL_STR("manifest.el")); } _if_result_2; });
+  win = window_from_manifest(manifest_path);
+  g_window = win;
+  if (win < 0) {
+    println(EL_STR("Error: failed to create window. Is EL_TARGET_MACOS defined?"));
+    exit_program(1);
+  }
+  app_build(win);
+  window_show(win);
+  native_run_loop();
+  return 0;
+}
+

ui/examples/native-hello-android/app/src/main/res/layout/activity_main.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  activity_main.xml — placeholder layout.
+
+  The el program sets the content view programmatically via ElBridge.setContentView
+  (called from __window_show → el_android_window_show). This layout is not used
+  at runtime but satisfies Gradle's res/ validation checks.
+-->
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical" />

ui/examples/native-hello-android/app/src/main/res/values/strings.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="app_name">el-native</string>
+</resources>