From e4d8a0b2a8fddb98607dc20cf427d3bc1e051414 Mon Sep 17 00:00:00 2001
From: Lucio Lelii <lucio.lelii@isti.cnr.it>
Date: Fri, 24 Apr 2026 12:17:38 +0200
Subject: [PATCH] Add structured JSON generation support for assistant calls

---
 .../manager/llms/providers/LLMProvider.java   |  4 ++++
 .../ollama/InternalOllamaLLMProvider.java     | 24 +++++++++++++++----
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/src/main/java/it/cnr/isti/workflow/manager/llms/providers/LLMProvider.java b/src/main/java/it/cnr/isti/workflow/manager/llms/providers/LLMProvider.java
index c986e35..45b796f 100644
--- a/src/main/java/it/cnr/isti/workflow/manager/llms/providers/LLMProvider.java
+++ b/src/main/java/it/cnr/isti/workflow/manager/llms/providers/LLMProvider.java
@@ -11,6 +11,10 @@ public interface LLMProvider {
     List<String> getRegisteredModels();
     String generate(String model, String prompt);
 
+    default String generateJson(String model, String prompt) {
+        return generate(model, prompt);
+    }
+
     default String generate(String model, String prompt, String authorization) {
         return generate(model, prompt);
     }
diff --git a/src/main/java/it/cnr/isti/workflow/manager/llms/providers/ollama/InternalOllamaLLMProvider.java b/src/main/java/it/cnr/isti/workflow/manager/llms/providers/ollama/InternalOllamaLLMProvider.java
index aed1151..64f08f4 100644
--- a/src/main/java/it/cnr/isti/workflow/manager/llms/providers/ollama/InternalOllamaLLMProvider.java
+++ b/src/main/java/it/cnr/isti/workflow/manager/llms/providers/ollama/InternalOllamaLLMProvider.java
@@ -1,6 +1,7 @@
 package it.cnr.isti.workflow.manager.llms.providers.ollama;
 
 import java.time.Duration;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -46,13 +47,28 @@ public class InternalOllamaLLMProvider implements LLMProvider {
         }
 
         public String generate(String model, String prompt) {
+                return generate(model, prompt, false);
+        }
+
+        @Override
+        public String generateJson(String model, String prompt) {
+                return generate(model, prompt, true);
+        }
+
+        private String generate(String model, String prompt, boolean jsonResponse) {
                 Objects.requireNonNull(prompt, "prompt cannot be null");
                 Objects.requireNonNull(model, "model cannot be null");
                 ObjectMapper mapper = new ObjectMapper();
-                Map<String, Object> bodyMap = Map.of(
-                                "model", model,
-                                "prompt", prompt,
-                                "stream", false);
+                Map<String, Object> bodyMap = new LinkedHashMap<>();
+                bodyMap.put("model", model);
+                bodyMap.put("prompt", prompt);
+                bodyMap.put("stream", false);
+                if (jsonResponse) {
+                        bodyMap.put("format", "json");
+                        bodyMap.put("options", Map.of(
+                                        "temperature", 0.1,
+                                        "num_predict", 4096));
+                }
 
                 // Implement the logic to call the Ollama API and return the response
                 WebClient webClient = webClientBuilder.baseUrl(this.ollamaURL).build();