diff --git a/common/arg.cpp b/common/arg.cpp
index f5e9b294f..b916dcfcc 100644
--- a/common/arg.cpp
+++ b/common/arg.cpp
@@ -1993,6 +1993,15 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
                 std::back_inserter(params.chat_template));
         }
     ).set_examples({LLAMA_EXAMPLE_MAIN, LLAMA_EXAMPLE_SERVER}).set_env("LLAMA_ARG_CHAT_TEMPLATE_FILE"));
+    add_opt(common_arg(
+        {"--tools"}, "JINJA_TOOLS",
+        string_format(
+            "set to a JSON array of tool definitions used for assistant function-calling "
+            "(requires --jinja)"),
+        [](common_params &params, const std::string & value) {
+            params.jinja_tools = value;
+        }
+    ).set_examples({LLAMA_EXAMPLE_MAIN}).set_env("LLAMA_ARG_JINJA_TOOLS"));
     add_opt(common_arg(
         {"-sps", "--slot-prompt-similarity"}, "SIMILARITY",
         string_format("how much the prompt of a request must match the prompt of a slot in order to use that slot (default: %.2f, 0.0 = disabled)\n", params.slot_prompt_similarity),
diff --git a/common/common.cpp b/common/common.cpp
index 6c81d18f9..de4a52905 100644
--- a/common/common.cpp
+++ b/common/common.cpp
@@ -1797,13 +1797,27 @@ std::string common_chat_apply_template(
         const common_chat_template & tmpl,
         const std::vector<common_chat_msg> & msgs,
         bool add_ass,
-        bool use_jinja) {
+        bool use_jinja,
+        std::string tools_json_arr)
+{
     if (use_jinja) {
+        common_chat_inputs inputs;
+
         auto messages = json::array();
         for (const auto & msg : msgs) {
             messages.push_back({{"role", msg.role}, {"content", msg.content}});
         }
-        common_chat_inputs inputs;
+
+        if (! tools_json_arr.empty()) {
+            try {
+                inputs.tools = tools_json_arr;
+
+            } catch (const json::exception & err) {
+                LOG_WRN("Failed to parse tools JSON array \"%s\": \"%s\". Ignoring tools...\n",
+                        tools_json_arr.c_str(), err.what());
+            }
+        }
+
         inputs.messages = messages;
         inputs.add_generation_prompt = add_ass;
         return common_chat_params_init(tmpl, inputs).prompt;
@@ -1843,9 +1857,13 @@ std::string common_chat_format_single(
         const std::vector<common_chat_msg> & past_msg,
         const common_chat_msg & new_msg,
         bool add_ass,
-        bool use_jinja) {
+        bool use_jinja,
+        std::string tools_json_arr)
+{
     std::ostringstream ss;
-    auto fmt_past_msg = past_msg.empty() ? "" : common_chat_apply_template(tmpl, past_msg, false, use_jinja);
+    auto fmt_past_msg = past_msg.empty() ? ""
+        : common_chat_apply_template(tmpl, past_msg, false, use_jinja, tools_json_arr);
+
     std::vector<common_chat_msg> chat_new(past_msg);
     // if the past_msg ends with a newline, we must preserve it in the formatted version
     if (add_ass && !fmt_past_msg.empty() && fmt_past_msg.back() == '\n') {
@@ -2182,4 +2200,3 @@ common_control_vector_data common_control_vector_load(const std::vector<common_c
 
     return result;
 }
-
diff --git a/common/common.h b/common/common.h
index 6c1809277..3ad209ee7 100644
--- a/common/common.h
+++ b/common/common.h
@@ -344,7 +344,7 @@ struct common_params {
     std::string chat_template = "";                                                                         // NOLINT
     bool use_jinja = false;                                                                                 // NOLINT
     bool enable_chat_template = true;
-
+    std::string jinja_tools   = "";
     std::vector<std::string> api_keys;
 
     std::string ssl_file_key  = "";                                                                         // NOLINT
@@ -645,7 +645,8 @@ std::string common_chat_apply_template(
         const common_chat_template & tmpl,
         const std::vector<common_chat_msg> & chat,
         bool add_ass,
-        bool use_jinja);
+        bool use_jinja,
+        std::string tools_json_arr = std::string());
 
 // Format single message, while taking into account the position of that message in chat history
 std::string common_chat_format_single(
@@ -653,7 +654,8 @@ std::string common_chat_format_single(
         const std::vector<common_chat_msg> & past_msg,
         const common_chat_msg & new_msg,
         bool add_ass,
-        bool use_jinja);
+        bool use_jinja,
+        std::string tools_json_arr = std::string());
 
 // Returns an example of formatted chat
 std::string common_chat_format_example(
diff --git a/examples/main/main.cpp b/examples/main/main.cpp
index e654d3542..dd0f65bfe 100644
--- a/examples/main/main.cpp
+++ b/examples/main/main.cpp
@@ -263,20 +263,27 @@ int main(int argc, char ** argv) {
 
     std::vector<llama_token> embd_inp;
 
-    auto chat_add_and_format = [&chat_msgs, &chat_templates](const std::string & role, const std::string & content) {
+    auto chat_add_and_format = [&chat_msgs, &chat_templates](const std::string & role,
+                                                             const std::string & content,
+                                                             const std::string & tools = std::string()) {
         common_chat_msg new_msg{role, content, {}};
-        auto formatted = common_chat_format_single(*chat_templates.template_default, chat_msgs, new_msg, role == "user", g_params->use_jinja);
+        auto formatted = common_chat_format_single(*chat_templates.template_default,
+                                                   chat_msgs, new_msg,
+                                                   role == "user",
+                                                   g_params->use_jinja, tools);
+
         chat_msgs.push_back({role, content, {}});
         LOG_DBG("formatted: '%s'\n", formatted.c_str());
         return formatted;
     };
 
     {
-        auto prompt = (params.conversation_mode && params.enable_chat_template)
-            // format the system prompt in conversation mode (fallback to default if empty)
-            ? chat_add_and_format("system", params.prompt.empty() ? DEFAULT_SYSTEM_MESSAGE : params.prompt)
-            // otherwise use the prompt as is
+        std::string system_prompt (params.prompt.empty() ? DEFAULT_SYSTEM_MESSAGE : params.prompt);
+        bool use_conversation_prompt (params.conversation_mode && params.enable_chat_template);
+        auto prompt = use_conversation_prompt ?
+            chat_add_and_format("system", system_prompt, params.jinja_tools)
             : params.prompt;
+
         if (params.interactive_first || !params.prompt.empty() || session_tokens.empty()) {
             LOG_DBG("tokenize the prompt\n");
             embd_inp = common_tokenize(ctx, prompt, true, true);