diff --git a/gemini-api/pom.xml b/gemini-api/pom.xml
index 596b85c..6398210 100644
--- a/gemini-api/pom.xml
+++ b/gemini-api/pom.xml
@@ -6,7 +6,7 @@
     <parent>
         <groupId>swiss.ameri</groupId>
         <artifactId>gemini</artifactId>
-        <version>1beta.0.2.4</version>
+        <version>1beta.0.2.6-SNAPSHOT</version>
     </parent>
 
     <artifactId>gemini-api</artifactId>
diff --git a/gemini-api/src/main/java/swiss/ameri/gemini/api/GenAi.java b/gemini-api/src/main/java/swiss/ameri/gemini/api/GenAi.java
index 32c4cb0..0417ac1 100644
--- a/gemini-api/src/main/java/swiss/ameri/gemini/api/GenAi.java
+++ b/gemini-api/src/main/java/swiss/ameri/gemini/api/GenAi.java
@@ -8,10 +8,7 @@
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
-import java.util.UUID;
+import java.util.*;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.stream.Collectors;
@@ -145,7 +142,10 @@ public List<SafetyRating> safetyRatings(UUID id) {
             return emptyList();
         }
         return response.candidates().stream()
-                .flatMap(candidate -> candidate.safetyRatings().stream())
+                // when streaming, we sometimes don't get a safety rating... (with 1.5 pro)
+                .map(ResponseCandidate::safetyRatings)
+                .filter(Objects::nonNull)
+                .flatMap(Collection::stream)
                 .toList();
     }
 
diff --git a/gemini-api/src/main/java/swiss/ameri/gemini/api/GenerationConfig.java b/gemini-api/src/main/java/swiss/ameri/gemini/api/GenerationConfig.java
index 5aa64ff..2142da0 100644
--- a/gemini-api/src/main/java/swiss/ameri/gemini/api/GenerationConfig.java
+++ b/gemini-api/src/main/java/swiss/ameri/gemini/api/GenerationConfig.java
@@ -36,7 +36,7 @@
 public record GenerationConfig(
         List<String> stopSequences,
         String responseMimeType,
-        String responseSchema,
+        Schema responseSchema,
         Integer maxOutputTokens,
         Double temperature,
         Double topP,
@@ -53,7 +53,7 @@ public static GenerationConfigBuilder builder() {
     public static class GenerationConfigBuilder {
         private final List<String> stopSequences = new ArrayList<>();
         private String responseMimeType;
-        private String responseSchema;
+        private Schema responseSchema;
         private Integer maxOutputTokens;
         private Double temperature;
         private Double topP;
@@ -69,7 +69,7 @@ public GenerationConfigBuilder responseMimeType(String responseMimeType) {
             return this;
         }
 
-        public GenerationConfigBuilder responseSchema(String responseSchema) {
+        public GenerationConfigBuilder responseSchema(Schema responseSchema) {
             this.responseSchema = responseSchema;
             return this;
         }
diff --git a/gemini-api/src/main/java/swiss/ameri/gemini/api/Schema.java b/gemini-api/src/main/java/swiss/ameri/gemini/api/Schema.java
new file mode 100644
index 0000000..0f29b0c
--- /dev/null
+++ b/gemini-api/src/main/java/swiss/ameri/gemini/api/Schema.java
@@ -0,0 +1,178 @@
+package swiss.ameri.gemini.api;
+
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * The Schema object allows the definition of input and output data types.
+ * These types can be objects, but also primitives and arrays.
+ * Represents a select subset of an OpenAPI 3.0 schema object.
+ *
+ * @param type             Required. Data type.
+ * @param format           Optional. The format of the data. This is used only for primitive datatypes.
+ *                         Supported formats:
+ *                         for NUMBER type: float, double
+ *                         for INTEGER type: int32, int64
+ *                         for STRING type: enum
+ * @param description      Optional. A brief description of the parameter. This could contain examples of use.
+ *                         Parameter description may be formatted as Markdown.
+ * @param nullable         Optional. Indicates if the value may be null.
+ * @param ameri_swiss_enum Optional. <b>Note: the ameri_swiss prefix must be removed by the {@link swiss.ameri.gemini.spi.JsonParser}</b>.
+ *                         Possible values of the element of Type.STRING with enum format.
+ *                         For example we can define an Enum Direction as :
+ *                         <code>{type:STRING, format:enum, enum:["EAST", NORTH", "SOUTH", "WEST"]}</code>
+ * @param maxItems         Optional. Maximum number of the elements for Type.ARRAY.
+ * @param minItems         Optional. Minimum number of the elements for Type.ARRAY.
+ * @param properties       Optional. Properties of Type.OBJECT.
+ *                         An object containing a list of "key": value pairs. Example:
+ *                         <code>{ "name": "wrench", "mass": "1.3kg", "count": "3" }</code>.
+ * @param required         Optional. Required properties of Type.OBJECT.
+ * @param items            Optional. Schema of the elements of Type.ARRAY.
+ * @see <a href="https://ai.google.dev/api/caching#Schema">Schema</a> for further information.
+ */
+public record Schema(
+        Type type,
+        String format,
+        String description,
+        Boolean nullable,
+        List<String> ameri_swiss_enum,
+        String maxItems,
+        String minItems,
+        Map<String, Schema> properties,
+        List<String> required,
+        Schema items
+) {
+
+
+    /**
+     * Create a {@link SchemaBuilder}.
+     *
+     * @return an empty {@link SchemaBuilder}
+     */
+    public static SchemaBuilder builder() {
+        return new SchemaBuilder();
+    }
+
+    /**
+     * A builder for {@link Schema}. Currently, does not validate the fields when building the model. Not thread-safe.
+     */
+    public static class SchemaBuilder {
+        private Type type;
+        private String format;
+        private String description;
+        private Boolean nullable;
+        private List<String> ameri_swiss_enum;
+        private String maxItems;
+        private String minItems;
+        private Map<String, Schema> properties;
+        private List<String> required;
+        private Schema items;
+
+
+        private SchemaBuilder() {
+        }
+
+        public Schema build() {
+            return new Schema(
+                    this.type,
+                    this.format,
+                    this.description,
+                    this.nullable,
+                    this.ameri_swiss_enum,
+                    this.maxItems,
+                    this.minItems,
+                    this.properties,
+                    this.required,
+                    this.items
+            );
+        }
+
+        public SchemaBuilder type(Type type) {
+            this.type = type;
+            return this;
+        }
+
+        public SchemaBuilder format(String format) {
+            this.format = format;
+            return this;
+        }
+
+        public SchemaBuilder description(String description) {
+            this.description = description;
+            return this;
+        }
+
+        public SchemaBuilder nullable(Boolean nullable) {
+            this.nullable = nullable;
+            return this;
+        }
+
+        public SchemaBuilder ameri_swiss_enum(List<String> ameri_swiss_enum) {
+            this.ameri_swiss_enum = ameri_swiss_enum;
+            return this;
+        }
+
+        public SchemaBuilder maxItems(String maxItems) {
+            this.maxItems = maxItems;
+            return this;
+        }
+
+        public SchemaBuilder minItems(String minItems) {
+            this.minItems = minItems;
+            return this;
+        }
+
+        public SchemaBuilder properties(Map<String, Schema> properties) {
+            this.properties = properties;
+            return this;
+        }
+
+        public SchemaBuilder required(List<String> required) {
+            this.required = required;
+            return this;
+        }
+
+        public SchemaBuilder items(Schema items) {
+            this.items = items;
+            return this;
+        }
+    }
+
+    /**
+     * Type contains the list of OpenAPI data types.
+     *
+     * @see <a href="https://ai.google.dev/api/caching#Type">Data types</a>
+     */
+    public enum Type {
+        /**
+         * Not specified, should not be used.
+         */
+        TYPE_UNSPECIFIED,
+        /**
+         * String type.
+         */
+        STRING,
+        /**
+         * Number type.
+         */
+        NUMBER,
+        /**
+         * Integer type.
+         */
+        INTEGER,
+        /**
+         * Boolean type.
+         */
+        BOOLEAN,
+        /**
+         * Array type.
+         */
+        ARRAY,
+        /**
+         * Object type.
+         */
+        OBJECT
+    }
+}
+
diff --git a/gemini-gson/pom.xml b/gemini-gson/pom.xml
index 5766553..7804315 100644
--- a/gemini-gson/pom.xml
+++ b/gemini-gson/pom.xml
@@ -7,7 +7,7 @@
     <parent>
         <groupId>swiss.ameri</groupId>
         <artifactId>gemini</artifactId>
-        <version>1beta.0.2.4</version>
+        <version>1beta.0.2.6-SNAPSHOT</version>
     </parent>
 
     <artifactId>gemini-gson</artifactId>
diff --git a/gemini-gson/src/main/java/swiss/ameri/gemini/gson/GsonJsonParser.java b/gemini-gson/src/main/java/swiss/ameri/gemini/gson/GsonJsonParser.java
index 09a13aa..6c0dc87 100644
--- a/gemini-gson/src/main/java/swiss/ameri/gemini/gson/GsonJsonParser.java
+++ b/gemini-gson/src/main/java/swiss/ameri/gemini/gson/GsonJsonParser.java
@@ -1,6 +1,9 @@
 package swiss.ameri.gemini.gson;
 
+import com.google.gson.FieldNamingStrategy;
 import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import swiss.ameri.gemini.api.Schema;
 import swiss.ameri.gemini.spi.JsonParser;
 
 /**
@@ -8,6 +11,17 @@
  */
 public class GsonJsonParser implements JsonParser {
 
+    /**
+     * Field naming strategy to avoid usage of illegal field names in java.
+     * See e.g. {@link Schema#ameri_swiss_enum()}, which cannot be named {@code enum}.
+     */
+    public static final FieldNamingStrategy FIELD_NAMING_STRATEGY = field -> {
+        if (field.getName().startsWith("ameri_swiss_")) {
+            return field.getName().substring("ameri_swiss_".length());
+        }
+        return field.getName();
+    };
+
     private final Gson gson;
 
     /**
@@ -23,7 +37,7 @@ public GsonJsonParser(Gson gson) {
      * Create a default {@link JsonParser} instance.
      */
     public GsonJsonParser() {
-        this(new Gson());
+        this(new GsonBuilder().setFieldNamingStrategy(FIELD_NAMING_STRATEGY).create());
     }
 
     @Override
diff --git a/gemini-tester/pom.xml b/gemini-tester/pom.xml
index 90285d5..c505e3e 100644
--- a/gemini-tester/pom.xml
+++ b/gemini-tester/pom.xml
@@ -7,7 +7,7 @@
     <parent>
         <groupId>swiss.ameri</groupId>
         <artifactId>gemini</artifactId>
-        <version>1beta.0.2.4</version>
+        <version>1beta.0.2.6-SNAPSHOT</version>
     </parent>
     <artifactId>gemini-tester</artifactId>
 
diff --git a/gemini-tester/src/main/java/swiss/ameri/gemini/tester/GeminiTester.java b/gemini-tester/src/main/java/swiss/ameri/gemini/tester/GeminiTester.java
index 3895b96..0b81e42 100644
--- a/gemini-tester/src/main/java/swiss/ameri/gemini/tester/GeminiTester.java
+++ b/gemini-tester/src/main/java/swiss/ameri/gemini/tester/GeminiTester.java
@@ -8,6 +8,7 @@
 import java.io.InputStream;
 import java.util.Base64;
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
@@ -38,6 +39,8 @@ public static void main(String[] args) throws Exception {
             countTokens(genAi);
             generateContent(genAi);
             generateContentStream(genAi);
+            generateWithResponseSchema(genAi);
+            generateContentStreamWithResponseSchema(genAi);
             multiChatTurn(genAi);
             textAndImage(genAi);
             embedContents(genAi);
@@ -90,7 +93,7 @@ private static void countTokens(GenAi genAi) {
     private static void multiChatTurn(GenAi genAi) {
         System.out.println("----- multi turn chat");
         GenerativeModel chatModel = GenerativeModel.builder()
-                .modelName(ModelVariant.GEMINI_1_0_PRO)
+                .modelName(ModelVariant.GEMINI_1_5_PRO)
                 .addContent(new Content.TextContent(
                         Content.Role.USER.roleName(),
                         "Write the first line of a story about a magic backpack."
@@ -133,9 +136,68 @@ private static void generateContent(GenAi genAi) throws InterruptedException, Ex
                 .get(20, TimeUnit.SECONDS);
     }
 
+
+    private static void generateContentStreamWithResponseSchema(GenAi genAi) {
+        System.out.println("----- Generate content (streaming) with response schema -- with usage meta data");
+        var model = createResponseSchemaModel();
+        genAi.generateContentStream(model)
+                .forEach(x -> {
+                    System.out.println(x);
+                    // note that the usage metadata is updated as it arrives
+                    System.out.println(genAi.usageMetadata(x.id()));
+                    System.out.println(genAi.safetyRatings(x.id()));
+                });
+    }
+
+    private static void generateWithResponseSchema(GenAi genAi) throws InterruptedException, ExecutionException, TimeoutException {
+        var model = createResponseSchemaModel();
+        System.out.println("----- Generate with response schema (blocking)");
+        genAi.generateContent(model)
+                .thenAccept(gcr -> {
+                    System.out.println(gcr);
+                    System.out.println("----- Generate with response schema (blocking) usage meta data & safety ratings");
+                    System.out.println(genAi.usageMetadata(gcr.id()));
+                    System.out.println(genAi.safetyRatings(gcr.id()).stream().map(GenAi.SafetyRating::toTypedSafetyRating).toList());
+                })
+                .get(20, TimeUnit.SECONDS);
+    }
+
+    private static GenerativeModel createResponseSchemaModel() {
+        return GenerativeModel.builder()
+                .modelName(ModelVariant.GEMINI_1_5_FLASH)
+                .addContent(Content.textContent(
+                        Content.Role.USER,
+                        "List 3 popular cookie recipes."
+                ))
+                .addSafetySetting(SafetySetting.of(
+                        SafetySetting.HarmCategory.HARM_CATEGORY_DANGEROUS_CONTENT,
+                        SafetySetting.HarmBlockThreshold.BLOCK_ONLY_HIGH
+                ))
+                .generationConfig(new GenerationConfig(
+                        null,
+                        "application/json",
+                        Schema.builder()
+                                .type(Schema.Type.ARRAY)
+                                .items(Schema.builder()
+                                        .type(Schema.Type.OBJECT)
+                                        .properties(Map.of(
+                                                "recipe_name", Schema.builder()
+                                                        .type(Schema.Type.STRING)
+                                                        .build()
+                                        ))
+                                        .build())
+                                .build(),
+                        null,
+                        null,
+                        null,
+                        null
+                ))
+                .build();
+    }
+
     private static GenerativeModel createStoryModel() {
         return GenerativeModel.builder()
-                .modelName(ModelVariant.GEMINI_1_0_PRO)
+                .modelName(ModelVariant.GEMINI_1_5_PRO)
                 .addContent(Content.textContent(
                         Content.Role.USER,
                         "Write a 50 word story about a magic backpack."
@@ -159,7 +221,7 @@ private static GenerativeModel createStoryModel() {
     private static void getModel(GenAi genAi) {
         System.out.println("----- Get Model");
         System.out.println(
-                genAi.getModel(ModelVariant.GEMINI_1_0_PRO)
+                genAi.getModel(ModelVariant.GEMINI_1_5_PRO)
         );
     }
 
diff --git a/pom.xml b/pom.xml
index 3ef3b06..100c860 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
 
     <groupId>swiss.ameri</groupId>
     <artifactId>gemini</artifactId>
-    <version>1beta.0.2.4</version>
+    <version>1beta.0.2.6-SNAPSHOT</version>
     <packaging>pom</packaging>
 
     <licenses>