diff --git a/src/open_prompt_extension.cpp b/src/open_prompt_extension.cpp
index 93684e0..7335b05 100644
--- a/src/open_prompt_extension.cpp
+++ b/src/open_prompt_extension.cpp
@@ -14,9 +14,47 @@
 #include <sstream>
 #include <mutex>
 #include <iostream>
+#include <duckdb/planner/expression/bound_function_expression.hpp>
+
 #include "yyjson.hpp"
 
+#include<stdio.h>
+
 namespace duckdb {
+    struct OpenPromptData: FunctionData {
+        idx_t model_idx;
+        idx_t json_schema_idx;
+        unique_ptr<FunctionData> Copy() const {
+            auto res = make_uniq<OpenPromptData>();
+            res->model_idx = model_idx;
+            res->json_schema_idx = json_schema_idx;
+            return res;
+        };
+        bool Equals(const FunctionData &other) const {
+            return model_idx == other.Cast<OpenPromptData>().model_idx &&
+                json_schema_idx == other.Cast<OpenPromptData>().json_schema_idx;
+        };
+        OpenPromptData() {
+            model_idx = 0;
+            json_schema_idx = 0;
+        }
+    };
+
+    unique_ptr<FunctionData> OpenPromptBind(ClientContext &context, ScalarFunction &bound_function,
+                                                           vector<unique_ptr<Expression>> &arguments) {
+        auto res = make_uniq<OpenPromptData>();
+        for (idx_t i = 1; i < arguments.size(); ++i) {
+            const auto &argument = arguments[i];
+            if (i == 1 && argument->alias.empty()) {
+                res->model_idx = i;
+            } else if (argument->alias == "json_schema") {
+                res->json_schema_idx = i;
+            }
+        }
+        return std::move(res);
+    }
+
+
 
 static std::pair<duckdb_httplib_openssl::Client, std::string> SetupHttpClient(const std::string &url) {
     std::string scheme, domain, path;
@@ -135,25 +173,36 @@ static void OpenPromptRequestFunction(DataChunk &args, ExpressionState &state, V
 
     UnaryExecutor::Execute<string_t, string_t>(args.data[0], result, args.size(),
         [&](string_t user_prompt) {
+            auto &func_expr = state.expr.Cast<BoundFunctionExpression>();
+            auto &info = func_expr.bind_info->Cast<OpenPromptData>();
             auto &context = state.GetContext();
-            
             // Get configuration with defaults
             std::string api_url = GetConfigValue(context, "openprompt_api_url", 
                                                "http://localhost:11434/v1/chat/completions");
             std::string api_token = GetConfigValue(context, "openprompt_api_token", "");
             std::string model_name = GetConfigValue(context, "openprompt_model_name", "qwen2.5:0.5b");
+            std::string json_schema;
 
-            // Override model if provided as second argument
-            if (args.data.size() > 1 && !args.data[1].GetValue(0).IsNull()) {
-                model_name = args.data[1].GetValue(0).ToString();
+            if (info.model_idx != 0) {
+                model_name = args.data[info.model_idx].GetValue(0).ToString();
+            }
+            if (info.json_schema_idx != 0) {
+                json_schema = args.data[info.json_schema_idx].GetValue(0).ToString();
             }
 
             std::string request_body = "{";
             request_body += "\"model\":\"" + model_name + "\",";
+            if (!json_schema.empty()) {
+                request_body += "\"response_format\":{\"type\":\"json_object\", \"schema\":";
+                request_body += json_schema;
+                request_body += "},";
+            }
             request_body += "\"messages\":[";
             request_body += "{\"role\":\"system\",\"content\":\"You are a helpful assistant.\"},";
             request_body += "{\"role\":\"user\",\"content\":\"" + user_prompt.GetString() + "\"}";
             request_body += "]}";
+            printf("%s\n", request_body.c_str());
+
 
             try {
                 auto client_and_path = SetupHttpClient(api_url);
@@ -233,9 +282,15 @@ static void LoadInternal(DatabaseInstance &instance) {
     
     // Register with both single and two-argument variants
     open_prompt.AddFunction(ScalarFunction(
-        {LogicalType::VARCHAR}, LogicalType::VARCHAR, OpenPromptRequestFunction));
+        {LogicalType::VARCHAR}, LogicalType::VARCHAR, OpenPromptRequestFunction,
+        OpenPromptBind));
     open_prompt.AddFunction(ScalarFunction(
-        {LogicalType::VARCHAR, LogicalType::VARCHAR}, LogicalType::VARCHAR, OpenPromptRequestFunction));
+        {LogicalType::VARCHAR, LogicalType::VARCHAR}, LogicalType::VARCHAR, OpenPromptRequestFunction,
+        OpenPromptBind));
+        open_prompt.AddFunction(ScalarFunction(
+        {LogicalType::VARCHAR, LogicalType::VARCHAR, LogicalType::VARCHAR},
+        LogicalType::VARCHAR, OpenPromptRequestFunction,
+        OpenPromptBind));
     
     ExtensionUtil::RegisterFunction(instance, open_prompt);