@@ -709,3 +709,28 @@ task refreshKiwixCatalog {
 tasks.matching { it.name == 'assembleRelease' || it.name == 'bundleRelease' }.configureEach {
     dependsOn refreshKiwixCatalog
 }
+
+// ---- Kolibri channel catalog refresh (release-only) ---------------------------
+// Regenerates src/main/assets/kolibri_catalog.jsonl from Kolibri Studio's public API via
+// tools/build_kolibri_catalog.py. Bundled rather than fetched on-device because Studio's
+// channel endpoint is 97% base64 thumbnails with no way to opt out — 4.1 MB to use 119 KB
+// (ADR-4954 D1). Release-only, like the Kiwix catalog above, and never fails the build:
+// on any error the committed JSONL (last known) is kept.
+// Manual run: ./gradlew refreshKolibriCatalog
+task refreshKolibriCatalog {
+    group = 'build setup'
+    description = 'Regenerate assets/kolibri_catalog.jsonl from Kolibri Studio (release / manual)'
+    doLast {
+        try {
+            def proc = ['python3', 'tools/build_kolibri_catalog.py'].execute(null, projectDir)
+            proc.consumeProcessOutput(System.out, System.err)
+            proc.waitFor()
+            if (proc.exitValue() != 0) logger.warn(">> [kolibri catalog] generator exit ${proc.exitValue()}; kept existing JSONL.")
+        } catch (Exception e) {
+            logger.warn(">> [kolibri catalog] skipped (${e.message}); kept existing JSONL.")
+        }
+    }
+}
+tasks.matching { it.name == 'assembleRelease' || it.name == 'bundleRelease' }.configureEach {
+    dependsOn refreshKolibriCatalog
+}
@@ -0,0 +1,127 @@
+/*
+ * ============================================================================
+ * Name        : BundledCatalogSource.java
+ * Author      : AppDevForAll
+ * Copyright   : Copyright (c) 2026 AppDevForAll
+ * Description : Reads the Kolibri channel catalog shipped in the APK.
+ *               Blocking; call from an IO thread (ADFA-4954).
+ * ============================================================================
+ */
+package org.iiab.controller.kolibri.data;
+
+import android.content.Context;
+import android.util.Log;
+
+import org.iiab.controller.kolibri.domain.Channel;
+import org.json.JSONObject;
+
+import java.io.BufferedReader;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * The channel catalog bundled with the app.
+ *
+ * <p>Format is JSON Lines, one object per line, for the reason ADR-4853 gave for
+ * the Books catalog: channel names and descriptions carry commas, quotes and
+ * accents in every script Kolibri publishes in, and a naive CSV split corrupts
+ * rows. JSONL is delimiter-safe and streams line by line, so a malformed line
+ * costs that line rather than the file.
+ *
+ * <p>The first line is a header object carrying {@code generated}; every
+ * subsequent line is a channel. Parsed once and cached for the process, like
+ * {@code KiwixCatalog}: the file does not change while the app runs.
+ *
+ * <p>Blocking. Never throws — a missing or unreadable asset yields an empty
+ * catalog, because a picker with no rows is recoverable and a crash is not.
+ */
+public final class BundledCatalogSource {
+
+    private static final String TAG = "K2Go-Kolibri";
+    private static final String ASSET = "kolibri_catalog.jsonl";
+
+    /** Marks the header line, so it is never mistaken for a channel. */
+    private static final String HEADER_KEY = "catalog";
+
+    private static volatile List<Channel> cachedChannels;
+    private static volatile String cachedGeneratedOn = "";
+
+    private final Context appContext;
+
+    public BundledCatalogSource(Context context) {
+        this.appContext = context.getApplicationContext();
+    }
+
+    /** Every channel in the asset, in file order. Never null. */
+    public List<Channel> channels() {
+        load();
+        return cachedChannels;
+    }
+
+    /** ISO-8601 date from the header line, or empty. */
+    public String generatedOn() {
+        load();
+        return cachedGeneratedOn;
+    }
+
+    /** Drops the cache. For tests and for a future in-place catalog refresh. */
+    public static void invalidate() {
+        cachedChannels = null;
+        cachedGeneratedOn = "";
+    }
+
+    private void load() {
+        if (cachedChannels != null) {
+            return;
+        }
+        synchronized (BundledCatalogSource.class) {
+            if (cachedChannels != null) {
+                return;
+            }
+            List<Channel> out = new ArrayList<>();
+            String generated = "";
+            int skipped = 0;
+
+            try (InputStream is = appContext.getAssets().open(ASSET);
+                 BufferedReader r = new BufferedReader(
+                         new InputStreamReader(is, StandardCharsets.UTF_8))) {
+                String line;
+                while ((line = r.readLine()) != null) {
+                    String t = line.trim();
+                    if (t.isEmpty()) {
+                        continue;
+                    }
+                    try {
+                        JSONObject o = new JSONObject(t);
+                        if (o.has(HEADER_KEY)) {
+                            generated = o.optString("generated", "");
+                            continue;
+                        }
+                        Channel c = StudioCatalogMapper.channel(o);
+                        if (c == null) {
+                            skipped++;
+                        } else {
+                            out.add(c);
+                        }
+                    } catch (Exception badLine) {
+                        skipped++;
+                    }
+                }
+            } catch (Exception e) {
+                // A missing asset is a build problem, not a runtime one, but it
+                // must not take the app down: log loudly and show nothing.
+                Log.w(TAG, "bundled catalog unavailable: " + e.getMessage());
+            }
+
+            if (skipped > 0) {
+                Log.w(TAG, "bundled catalog: skipped " + skipped + " unusable line(s)");
+            }
+            cachedGeneratedOn = generated;
+            cachedChannels = Collections.unmodifiableList(out);
+        }
+    }
+}
@@ -0,0 +1,58 @@
+/*
+ * ============================================================================
+ * Name        : CatalogRepositoryImpl.java
+ * Author      : AppDevForAll
+ * Copyright   : Copyright (c) 2026 AppDevForAll
+ * Description : Wires the bundled catalog and the live Studio tree behind the
+ *               domain port (ADFA-4954).
+ * ============================================================================
+ */
+package org.iiab.controller.kolibri.data;
+
+import android.content.Context;
+
+import org.iiab.controller.kolibri.domain.CatalogRepository;
+import org.iiab.controller.kolibri.domain.Channel;
+import org.iiab.controller.kolibri.domain.TopicNode;
+
+import java.util.List;
+
+/**
+ * The Data-layer implementation of {@link CatalogRepository}.
+ *
+ * <p>Two sources with different characters, which is the whole point of putting
+ * them behind one port: channels come from a file in the APK and cannot fail in
+ * any interesting way, trees come from the internet and can.
+ *
+ * <p>Blocking, like its sources. Callers run it on {@code AppExecutors.io()}.
+ */
+public final class CatalogRepositoryImpl implements CatalogRepository {
+
+    private final BundledCatalogSource bundled;
+    private final StudioTreeSource studio;
+
+    public CatalogRepositoryImpl(Context context) {
+        this(new BundledCatalogSource(context), new StudioTreeSource());
+    }
+
+    /** For tests and for pointing the tree source at a mirror. */
+    public CatalogRepositoryImpl(BundledCatalogSource bundled, StudioTreeSource studio) {
+        this.bundled = bundled;
+        this.studio = studio;
+    }
+
+    @Override
+    public List<Channel> channels() {
+        return bundled.channels();
+    }
+
+    @Override
+    public String catalogGeneratedOn() {
+        return bundled.generatedOn();
+    }
+
+    @Override
+    public TopicNode fetchTree(String nodeId) {
+        return studio.fetchTree(nodeId);
+    }
+}