diff --git a/src/main/java/qupath/ext/instanseg/core/InstanSeg.java b/src/main/java/qupath/ext/instanseg/core/InstanSeg.java
index b087961..1238cb3 100644
--- a/src/main/java/qupath/ext/instanseg/core/InstanSeg.java
+++ b/src/main/java/qupath/ext/instanseg/core/InstanSeg.java
@@ -247,6 +247,7 @@ private InstanSegResults runInstanSeg(ImageData<BufferedImage> imageData, Collec
                         .postProcess(postProcessor)
                         .downsample(downsample)
                         .build();
+
                 processor.processObjects(taskRunner, imageData, pathObjects);
                 int nObjects = pathObjects.stream().mapToInt(PathObject::nChildObjects).sum();
                 if (predictionProcessor instanceof TilePredictionProcessor tileProcessor) {
diff --git a/src/main/java/qupath/ext/instanseg/core/InstanSegModel.java b/src/main/java/qupath/ext/instanseg/core/InstanSegModel.java
index 5c9a36c..3b35262 100644
--- a/src/main/java/qupath/ext/instanseg/core/InstanSegModel.java
+++ b/src/main/java/qupath/ext/instanseg/core/InstanSegModel.java
@@ -30,6 +30,7 @@
 public class InstanSegModel {
 
     private static final Logger logger = LoggerFactory.getLogger(InstanSegModel.class);
+    private String version;
     private URL modelURL = null;
 
     /**
@@ -44,11 +45,13 @@ public class InstanSegModel {
     private InstanSegModel(BioimageIoSpec.BioimageIoModel bioimageIoModel) {
         this.model = bioimageIoModel;
         this.path = Paths.get(model.getBaseURI());
+        this.version = model.getVersion();
         this.name = model.getName();
     }
 
-    private InstanSegModel(String name, URL modelURL) {
+    private InstanSegModel(String name, String version, URL modelURL) {
         this.name = name;
+        this.version = version;
         this.modelURL = modelURL;
     }
 
@@ -68,46 +71,38 @@ public static InstanSegModel fromPath(Path path) throws IOException {
      * @param browserDownloadUrl The download URL from eg GitHub
      * @return A handle on the created model
      */
-    public static InstanSegModel fromURL(String name, URL browserDownloadUrl) {
-        return new InstanSegModel(name, browserDownloadUrl);
+    public static InstanSegModel fromURL(String name, String version, URL browserDownloadUrl) {
+        return new InstanSegModel(name, version, browserDownloadUrl);
     }
 
     /**
      * Check if the model has been downloaded already.
-     * @return True if a flag has been set.
+     * @return True if the model has a known path that exists and is valid, or if a suitable directory can be found in the localModelPath
      */
-    public boolean isDownloaded(Path localModelPath) {
+    public boolean isValid() {
         // Check path first - *sometimes* the model might be downloaded, but have a name
         // that doesn't match with the filename (although we'd prefer this didn't happen...)
-        if (path != null && model != null && Files.exists(path))
+        if (path != null && model != null && isValidModel(path))
             return true;
-        // todo: this should also check if the contents are what we expect
-        if (Files.exists(localModelPath.resolve(name))) {
-            try {
-                download(localModelPath);
-            } catch (IOException e) {
-                logger.error("Model directory exists but is not valid", e);
-            }
-        } else {
-            // The model may have been deleted or renamed - we won't be able to load it
-            return false;
-        }
-        return path != null && model != null;
+        // The model may have been deleted or renamed - we won't be able to load it
+        return false;
     }
 
     /**
      * Trigger a download for a model
      * @throws IOException If an error occurs when downloading, unzipping, etc.
      */
-    public void download(Path localModelPath) throws IOException {
-        if (path != null && Files.exists(path) && model != null)
+    public void download(Path downloadedModelDir) throws IOException {
+        if (path != null && isValidModel(path) && model != null) {
             return;
+        }
         var zipFile = downloadZipIfNeeded(
                 this.modelURL,
-                localModelPath,
-                name);
+                downloadedModelDir,
+                getFolderName(name, version));
         this.path = unzipIfNeeded(zipFile);
         this.model = BioimageIoSpec.parseModel(path.toFile());
+        this.version = model.getVersion();
     }
 
     /**
@@ -213,8 +208,8 @@ public Optional<Path> getPath() {
     @Override
     public String toString() {
         String name = getName();
-        String parent = getPath().map(Path::getFileName).map(Path::toString).orElse(null);
-        String version = getModel().map(BioimageIoSpec.BioimageIoModel::getVersion).orElse(null);
+        String parent = getPath().map(Path::getParent).map(Path::getFileName).map(Path::toString).orElse(null);
+        String version = getModel().map(BioimageIoSpec.BioimageIoModel::getVersion).orElse(this.version);
         if (parent != null && !parent.equals(name)) {
             name = parent + "/" + name;
         }
@@ -271,8 +266,9 @@ private Optional<BioimageIoSpec.BioimageIoModel> getModel() {
         return Optional.ofNullable(model);
     }
 
-    private static Path downloadZipIfNeeded(URL url, Path localDirectory, String filename) throws IOException {
-        var zipFile = localDirectory.resolve(Path.of(filename + ".zip"));
+    private static Path downloadZipIfNeeded(URL url, Path downloadDirectory, String filename) throws IOException {
+        Files.createDirectories(downloadDirectory);
+        var zipFile = downloadDirectory.resolve(filename + ".zip");
         if (!isDownloadedAlready(zipFile)) {
             try (InputStream stream = url.openStream()) {
                 try (ReadableByteChannel readableByteChannel = Channels.newChannel(stream)) {
@@ -286,32 +282,51 @@ private static Path downloadZipIfNeeded(URL url, Path localDirectory, String fil
     }
 
     private static boolean isDownloadedAlready(Path zipFile) {
-        // todo: validate contents somehow
-        return Files.exists(zipFile);
+        if (!Files.exists(zipFile)) {
+            return false;
+        }
+        try {
+            BioimageIoSpec.parseModel(zipFile.toFile());
+        } catch (IOException e) {
+            logger.warn("Invalid zip file", e);
+            return false;
+        }
+        return true;
     }
 
-    private static Path unzipIfNeeded(Path zipFile) throws IOException {
-        var outdir = zipFile.resolveSibling(zipFile.getFileName().toString().replace(".zip", ""));
+    private Path unzipIfNeeded(Path zipFile) throws IOException {
+        var zipSpec = BioimageIoSpec.parseModel(zipFile);
+        String version = zipSpec.getVersion();
+        var outdir = zipFile.resolveSibling(getFolderName(zipSpec.getName(), version));
         if (!isUnpackedAlready(outdir)) {
             try {
-                unzip(zipFile, zipFile.getParent());
+                unzip(zipFile, outdir);
                 // Files.delete(zipFile);
             } catch (IOException e) {
+                logger.error("Error unzipping model", e);
                 // clean up files just in case!
-                Files.deleteIfExists(zipFile);
                 Files.deleteIfExists(outdir);
+            } finally {
+                Files.deleteIfExists(zipFile);
             }
         }
         return outdir;
     }
 
+    private String getFolderName(String name, String version) {
+        if (version == null) {
+            return name;
+        }
+        return name + "-" + version;
+    }
+
     private static boolean isUnpackedAlready(Path outdir) {
         return Files.exists(outdir) && isValidModel(outdir);
     }
 
     private static void unzip(Path zipFile, Path destination) throws IOException {
         if (!Files.exists(destination)) {
-            Files.createDirectory(destination);
+            Files.createDirectories(destination);
         }
         ZipInputStream zipIn = new ZipInputStream(new BufferedInputStream(new FileInputStream(zipFile.toFile())));
         ZipEntry entry = zipIn.getNextEntry();
diff --git a/src/main/java/qupath/ext/instanseg/ui/GitHubUtils.java b/src/main/java/qupath/ext/instanseg/ui/GitHubUtils.java
deleted file mode 100644
index 31aee16..0000000
--- a/src/main/java/qupath/ext/instanseg/ui/GitHubUtils.java
+++ /dev/null
@@ -1,147 +0,0 @@
-package qupath.ext.instanseg.ui;
-
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-import com.google.gson.JsonElement;
-import com.google.gson.JsonParser;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import java.io.IOException;
-import java.net.URI;
-import java.net.URL;
-import java.net.http.HttpClient;
-import java.net.http.HttpRequest;
-import java.net.http.HttpResponse;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.util.Arrays;
-import java.util.Date;
-import java.util.List;
-
-public class GitHubUtils {
-
-    private static final Logger logger = LoggerFactory.getLogger(GitHubUtils.class);
-
-    static class GitHubRelease {
-
-        private String tag_name;
-        private String name;
-        private Date published_at;
-        private GitHubAsset[] assets;
-        private String body;
-
-        String getName() {
-            return name;
-        }
-        String getBody() {
-            return body;
-        }
-        Date getDate() {
-            return published_at;
-        }
-        String getTag() {
-            return tag_name;
-        }
-
-        @Override
-        public String toString() {
-            return name + " with assets:" + Arrays.toString(assets);
-        }
-    }
-
-    static class GitHubAsset {
-
-        private String name;
-        private String content_type;
-        private URL browser_download_url;
-
-        String getType() {
-            return content_type;
-        }
-
-        URL getUrl() {
-            return browser_download_url;
-        }
-
-        String getName() {
-            return name;
-        }
-
-        @Override
-        public String toString() {
-            return name;
-        }
-
-    }
-
-    /**
-     * Get the list of models from the latest GitHub release, downloading if
-     * necessary.
-     * @return A list of GitHub releases, possibly empty.
-     */
-    static List<GitHubRelease> getReleases(Path modelDir) {
-        Path cachedReleases = modelDir == null ? null : modelDir.resolve("releases.json");
-
-        String uString = "https://api.github.com/repos/instanseg/InstanSeg/releases";
-        HttpRequest request = HttpRequest.newBuilder()
-                .uri(URI.create(uString))
-                .GET()
-                .build();
-        HttpResponse<String> response;
-        String json;
-        Gson gson = new GsonBuilder().setPrettyPrinting().create();
-        // check GitHub api for releases
-        try (HttpClient client = HttpClient.newHttpClient()) {
-            response = client.send(request, HttpResponse.BodyHandlers.ofString());
-            // if response is okay, then cache it
-            if (response.statusCode() == 200) {
-                json = response.body();
-                if (cachedReleases != null && Files.exists(cachedReleases.getParent())) {
-                    JsonElement jsonElement = JsonParser.parseString(json);
-                    Files.writeString(cachedReleases, gson.toJson(jsonElement));
-                } else {
-                    logger.debug("Unable to cache release information - no model directory specified");
-                }
-            } else {
-                // otherwise problems
-                throw new IOException("Unable to fetch GitHub release information, status " + response.statusCode());
-            }
-        } catch (IOException | InterruptedException e) {
-            // if not, try to fall back on a cached version
-            if (cachedReleases != null && Files.exists(cachedReleases)) {
-                try {
-                    json = Files.readString(cachedReleases);
-                } catch (IOException ex) {
-                    logger.warn("Unable to read cached release information");
-                    return List.of();
-                }
-            } else {
-                logger.info("Unable to fetch release information from GitHub and no cached version available.");
-                return List.of();
-            }
-        }
-
-        GitHubRelease[] releases = gson.fromJson(json, GitHubRelease[].class);
-        if (!(releases.length > 0)) {
-            logger.info("No releases found in JSON string");
-            return List.of();
-        }
-        return List.of(releases);
-    }
-
-
-    static List<GitHubAsset> getAssets(GitHubRelease release) {
-        var assets = Arrays.stream(release.assets)
-                .filter(a -> a.getType().equals("application/zip"))
-                .toList();
-        if (assets.isEmpty()) {
-            logger.info("No valid assets identified for {}", release.name);
-        } else if (assets.size() > 1) {
-            logger.info("More than one matching model: {}", release.name);
-        }
-        return assets;
-    }
-
-
-}
diff --git a/src/main/java/qupath/ext/instanseg/ui/InstanSegController.java b/src/main/java/qupath/ext/instanseg/ui/InstanSegController.java
index ad91d8d..09220ca 100644
--- a/src/main/java/qupath/ext/instanseg/ui/InstanSegController.java
+++ b/src/main/java/qupath/ext/instanseg/ui/InstanSegController.java
@@ -1,5 +1,6 @@
 package qupath.ext.instanseg.ui;
 
+import com.google.gson.Gson;
 import javafx.application.Platform;
 import javafx.beans.binding.Bindings;
 import javafx.beans.binding.BooleanBinding;
@@ -50,8 +51,11 @@
 import java.awt.image.BufferedImage;
 import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
+import java.io.BufferedReader;
 import java.io.File;
 import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
@@ -68,6 +72,7 @@
 import java.util.concurrent.Executors;
 import java.util.concurrent.ForkJoinPool;
 import java.util.concurrent.FutureTask;
+import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
 /**
@@ -211,7 +216,6 @@ private void refreshAvailableModels() {
             }
         }
         var remoteAndNotLocal = remoteModels.stream()
-                .filter(m -> !localModelNames.containsKey(m.getName()))
                 .sorted(comparator)
                 .toList();
         list.addAll(localModels);
@@ -369,8 +373,7 @@ private void updateInputChannels(ImageData<BufferedImage> imageData) {
         // if brightfield, then check R, G, and B
         comboInputChannels.getCheckModel().checkIndices(IntStream.range(0, 3).toArray());
         var modelDir = InstanSegUtils.getModelDirectory().orElse(null);
-        // todo: not clear why this is needed. is this handling the checkcombobox weirdness on clearing checks, or?
-        if (model != null && modelDir != null && model.isDownloaded(modelDir)) {
+        if (model != null && modelDir != null && model.isValid()) {
             var modelChannels = model.getNumChannels();
             if (modelChannels.isPresent()) {
                 int nModelChannels = modelChannels.get();
@@ -459,7 +462,7 @@ private void configureRunning() {
                                 return true;
                             }
                             var modelDir = InstanSegUtils.getModelDirectory().orElse(null);
-                            if (modelDir != null && !model.isDownloaded(modelDir)) {
+                            if (modelDir != null && !model.isValid()) {
                                 return false; // to enable "download and run"
                             }
                             return false;
@@ -483,7 +486,7 @@ private void refreshModelChoice() {
             return;
 
         var modelDir = InstanSegUtils.getModelDirectory().orElse(null);
-        boolean isDownloaded = modelDir != null && model.isDownloaded(modelDir);
+        boolean isDownloaded = modelDir != null && model.isValid();
         if (!isDownloaded || qupath.getImageData() == null) {
             return;
         }
@@ -540,7 +543,7 @@ private InstanSegModel downloadModel(InstanSegModel model, Path modelDir) {
         try {
             Dialogs.showInfoNotification(resources.getString("title"),
                     String.format(resources.getString("ui.popup.fetching"), model.getName()));
-            model.download(modelDir);
+            model.download(modelDir.resolve("downloaded"));
             Dialogs.showInfoNotification(resources.getString("title"),
                     String.format(resources.getString("ui.popup.available"), model.getName()));
             FXUtils.runOnApplicationThread(() -> {
@@ -549,6 +552,7 @@ private InstanSegModel downloadModel(InstanSegModel model, Path modelDir) {
             });
         } catch (IOException ex) {
             Dialogs.showErrorNotification(resources.getString("title"), resources.getString("error.downloading"));
+            logger.error("Error download model", ex);
         }
         return model;
     }
@@ -613,19 +617,21 @@ private static List<InstanSegModel> getRemoteModels() {
                 return List.of();
             }
         }
-        var releases = GitHubUtils.getReleases(InstanSegUtils.getModelDirectory().orElse(null));
-        if (releases.isEmpty()) {
-            logger.info("No releases found.");
-            return List.of();
-        }
-        var release = releases.getFirst();
-        var assets = GitHubUtils.getAssets(release);
+        InputStream in = InstanSegController.class.getResourceAsStream("model-index.json");
+        String cont = new BufferedReader(new InputStreamReader(in))
+                .lines()
+                .collect(Collectors.joining("\n"));
+        var gson = new Gson();
+        var remoteModels = gson.fromJson(cont, RemoteModel[].class);
+
         List<InstanSegModel> models = new ArrayList<>();
-        for (var asset : assets) {
+        for (var remoteModel: remoteModels) {
             models.add(
                     InstanSegModel.fromURL(
-                            asset.getName().replace(".zip", ""),
-                            asset.getUrl())
+                            remoteModel.getName(),
+                            remoteModel.getVersion(),
+                            remoteModel.getUrl()
+                    )
             );
         }
         return List.copyOf(models);
@@ -759,12 +765,12 @@ private void runInstanSeg(InstanSegModel model) {
             return;
         }
 
-        if (!model.isDownloaded(modelPath)) {
+        if (!model.isValid()) {
             if (!Dialogs.showYesNoDialog(resources.getString("title"), resources.getString("ui.model-popup")))
                 return;
             downloadModelAsync(model)
                     .thenAccept((InstanSegModel suppliedModel) -> {
-                        if (suppliedModel == null || !suppliedModel.isDownloaded(modelPath)) {
+                        if (suppliedModel == null || !suppliedModel.isValid()) {
                             Dialogs.showErrorNotification(resources.getString("title"), String.format(resources.getString("error.localModel")));
                         } else {
                             runInstanSeg(suppliedModel);
diff --git a/src/main/java/qupath/ext/instanseg/ui/InstanSegUtils.java b/src/main/java/qupath/ext/instanseg/ui/InstanSegUtils.java
index 2535b5d..e057abd 100644
--- a/src/main/java/qupath/ext/instanseg/ui/InstanSegUtils.java
+++ b/src/main/java/qupath/ext/instanseg/ui/InstanSegUtils.java
@@ -70,7 +70,7 @@ public static BooleanBinding createModelDownloadedBinding(ObservableValue<Instan
                         return false;
                     }
                     var modelDir = getModelDirectory().orElse(null);
-                    return modelDir != null && model.isDownloaded(modelDir);
+                    return modelDir != null && model.isValid();
                 },
                 selectedModel, needsUpdating,
                 InstanSegPreferences.modelDirectoryProperty());
diff --git a/src/main/java/qupath/ext/instanseg/ui/MessageTextHelper.java b/src/main/java/qupath/ext/instanseg/ui/MessageTextHelper.java
index 915742f..8274991 100644
--- a/src/main/java/qupath/ext/instanseg/ui/MessageTextHelper.java
+++ b/src/main/java/qupath/ext/instanseg/ui/MessageTextHelper.java
@@ -130,7 +130,7 @@ private String getWarningText() {
         if (deviceChoiceBox.getSelectionModel().isEmpty())
             return resources.getString("ui.error.no-device");
         var modelDir = InstanSegUtils.getModelDirectory().orElse(null);
-        if (modelDir != null && modelChoiceBox.getSelectionModel().getSelectedItem().isDownloaded(modelDir)) {
+        if (modelDir != null && modelChoiceBox.getSelectionModel().getSelectedItem().isValid()) {
             // shouldn't happen if downloaded anyway!
             var modelChannels = modelChoiceBox.getSelectionModel().getSelectedItem().getNumChannels();
             if (modelChannels.isPresent()) {
diff --git a/src/main/java/qupath/ext/instanseg/ui/ModelListCell.java b/src/main/java/qupath/ext/instanseg/ui/ModelListCell.java
index d7e27e1..bb253f4 100644
--- a/src/main/java/qupath/ext/instanseg/ui/ModelListCell.java
+++ b/src/main/java/qupath/ext/instanseg/ui/ModelListCell.java
@@ -1,6 +1,5 @@
 package qupath.ext.instanseg.ui;
 
-import javafx.scene.control.ContentDisplay;
 import javafx.scene.control.ListCell;
 import javafx.scene.control.Tooltip;
 import org.controlsfx.glyphfont.FontAwesome;
@@ -32,7 +31,7 @@ public void updateItem(InstanSegModel model, boolean empty) {
         } else {
             setText(model.toString());
             var dir = InstanSegUtils.getLocalModelDirectory().orElse(null);
-            if (dir != null && !model.isDownloaded(dir)) {
+            if (dir != null && !model.isValid()) {
                 setGraphic(web);
                 tooltip.setText(resources.getString("ui.model-not-downloaded.tooltip"));
                 setTooltip(tooltip);
diff --git a/src/main/java/qupath/ext/instanseg/ui/RemoteModel.java b/src/main/java/qupath/ext/instanseg/ui/RemoteModel.java
new file mode 100644
index 0000000..4ca947a
--- /dev/null
+++ b/src/main/java/qupath/ext/instanseg/ui/RemoteModel.java
@@ -0,0 +1,33 @@
+package qupath.ext.instanseg.ui;
+
+import java.net.URL;
+
+public class RemoteModel {
+    private final String name;
+    private final URL url;
+    private final String version;
+    private final String license;
+
+    RemoteModel(String name, URL url, String version, String license) {
+        this.name = name;
+        this.url = url;
+        this.version = version;
+        this.license = license;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public URL getUrl() {
+        return url;
+    }
+
+    public String getVersion() {
+        return version;
+    }
+
+    public String getLicense() {
+        return license;
+    }
+}
diff --git a/src/main/java/qupath/ext/instanseg/ui/Watcher.java b/src/main/java/qupath/ext/instanseg/ui/Watcher.java
index 8757270..e37f321 100644
--- a/src/main/java/qupath/ext/instanseg/ui/Watcher.java
+++ b/src/main/java/qupath/ext/instanseg/ui/Watcher.java
@@ -54,7 +54,7 @@ class Watcher {
     //Binding to the directory we want to watch for models.
     private final ObjectBinding<Path> modelDirectoryBinding = InstanSegUtils.getModelDirectoryBinding();
 
-    private static Watcher instance = new Watcher();
+    private static final Watcher instance = new Watcher();
 
     private Watcher() {
         modelDirectoryBinding.addListener(this::handleModelDirectoryChange);
@@ -74,11 +74,11 @@ private void handleModelDirectoryChange(ObservableValue<? extends Path> observab
         // Currently, we look *only* in the model directory for models
         // But we could register subdirectories here if we wanted (e.g. 'local', 'downloaded')
         if (oldPath != null) {
-            unregister(oldPath);
+            unregister(oldPath.resolve("local"));
         }
-        if (newPath != null && Files.isDirectory(newPath)) {
+        if (newPath != null && Files.isDirectory(newPath.resolve("local"))) {
             try {
-                register(newPath);
+                register(newPath.resolve("local"));
             } catch (IOException e) {
                 logger.error("Unable to register new model directory", e);
             }
@@ -130,6 +130,7 @@ private void processEvents() {
             if (key.watchable() instanceof Path dir) {
 
                 for (WatchEvent<?> rawEvent : key.pollEvents()) {
+                    @SuppressWarnings("unchecked")
                     WatchEvent<Path> event = (WatchEvent<Path>)rawEvent;
                     WatchEvent.Kind<Path> kind = event.kind();
                     Path fileName = event.context();
diff --git a/src/main/resources/qupath/ext/instanseg/ui/model-index.json b/src/main/resources/qupath/ext/instanseg/ui/model-index.json
new file mode 100644
index 0000000..bcb3547
--- /dev/null
+++ b/src/main/resources/qupath/ext/instanseg/ui/model-index.json
@@ -0,0 +1,14 @@
+[
+  {
+    "name": "brightfield_nuclei",
+    "url": "https://github.com/alanocallaghan/instanseg/releases/download/v0.1.0/brightfield_nuclei.zip",
+    "version": "0.1.0",
+    "license": "Apache-2.0"
+  },
+  {
+    "name": "fluorescence_nuclei_and_cells",
+    "url": "https://github.com/alanocallaghan/instanseg/releases/download/v0.1.0/fluorescence_nuclei_and_cells.zip",
+    "version": "0.1.0",
+    "license": "Apache-2.0"
+  }
+]