diff --git a/common/arg.cpp b/common/arg.cpp
index 152f671ab..ba3074350 100644
--- a/common/arg.cpp
+++ b/common/arg.cpp
@@ -2006,6 +2006,23 @@ 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",
+        "set to JSON array of tool definitions used for assistant function-calling (requires --jinja)",
+        [](common_params &params, const std::string & value) {
+            params.jinja_tools.tools(value);
+
+        }).set_examples({LLAMA_EXAMPLE_MAIN}));
+
+    add_opt(common_arg(
+        {"--tool-choice"}, "JINJA_TOOL_CHOICE",
+        "set to \"auto\", \"required\", \"none\" or a JSON object specifying a tool function (default: \"auto\")",
+        [](common_params &params, const std::string & value) {
+            params.jinja_tools.choice(value);
+
+        }).set_examples({LLAMA_EXAMPLE_MAIN}));
+
     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 8661e164a..13e03e88f 100644
--- a/common/common.cpp
+++ b/common/common.cpp
@@ -7,9 +7,6 @@
 
 #include "common.h"
 #include "log.h"
-// Change JSON_ASSERT from assert() to GGML_ASSERT:
-#define JSON_ASSERT GGML_ASSERT
-#include "json.hpp"
 #include "json-schema-to-grammar.h"
 #include "llama.h"
 #include "chat.hpp"
@@ -1772,6 +1769,46 @@ std::string common_detokenize(const struct llama_vocab * vocab, const std::vecto
 // Chat template utils
 //
 
+common_params_tools::common_params_tools(std::string tools, std::string choice) {
+    this->tools(tools);
+    this->choice(choice);
+}
+
+void common_params_tools::tools(std::string tools) {
+    if (tools.empty()) {
+        tools_.reset();
+        return;
+    }
+    try {
+        tools_ = std::make_shared<json>(json::parse(tools));
+        if (! tools_->is_array()) {
+            throw std::invalid_argument("tools must be a valid JSON array");
+        }
+
+    } catch (const json::exception & err) {
+        throw std::invalid_argument(err.what());
+    }
+}
+
+void common_params_tools::choice(std::string choice) {
+    try {
+        if (choice == "auto" || choice == "required" || choice == "none") {
+            tool_choice_ = std::move(choice);
+
+        } else {
+            auto choice_ptr = std::make_shared<json>(json::parse(choice));
+            tool_choice_ = choice_ptr;
+            if (! choice_ptr->is_object()) {
+                throw std::invalid_argument(
+                    "tool choice must be a valid JSON object, \"auto\", \"required\", or \"none\"");
+            }
+        }
+
+    } catch (const json::exception & err) {
+        throw std::invalid_argument(err.what());
+    }
+}
+
 bool common_chat_verify_template(const std::string & tmpl, bool use_jinja) {
     if (use_jinja) {
         try {
@@ -1793,20 +1830,85 @@ bool common_chat_verify_template(const std::string & tmpl, bool use_jinja) {
     return res >= 0;
 }
 
+static void copy_chat_params(const common_chat_params & src, common_chat_sampling_updater * update_sparams)
+{
+    GGML_ASSERT(update_sparams && update_sparams->sparams && update_sparams->vocab);
+
+    auto & dst = *update_sparams->sparams;
+    auto vocab = update_sparams->vocab;
+
+    dst.grammar      = src.grammar;
+    dst.grammar_lazy = src.grammar_lazy;
+
+    for (const auto & trigger : src.grammar_triggers) {
+        auto ids = common_tokenize(vocab, trigger.word, false, true);
+
+        if (ids.size() == 1) {
+            LOG_DBG("Grammar trigger token: %d (`%s`)\n", ids[0], trigger.word.c_str());
+            dst.grammar_trigger_tokens.push_back(ids[0]);
+            dst.preserved_tokens.insert(ids[0]);
+            continue;
+        }
+        LOG_DBG("Grammar trigger word: `%s`\n", trigger.word.c_str());
+        dst.grammar_trigger_words.push_back(trigger);
+    }
+
+    for (const auto & preserved : src.preserved_tokens) {
+        auto ids = common_tokenize(vocab, preserved, false, true);
+        if (ids.size() == 1) {
+            LOG_DBG("Preserved token: %d\n", ids[0]);
+            dst.preserved_tokens.insert(ids[0]);
+
+        } else {
+            // This may happen when using a tool call style meant for a model
+            // with special tokens to preserve on a model without said tokens.
+            LOG_WRN("Not preserved because more than 1 token (wrong chat template override?): %s\n",
+                    preserved.c_str());
+        }
+    }
+}
+
 std::string common_chat_apply_template(
-        const common_chat_template & tmpl,
+        const common_chat_templates & tmpl,
         const std::vector<common_chat_msg> & msgs,
         bool add_ass,
-        bool use_jinja) {
+        bool use_jinja,
+        const common_params_tools & tools,
+        common_chat_sampling_updater * update_sparams)
+{
+    const auto & tmpl_selected =
+        tools.tools() && tmpl.template_tool_use ? *tmpl.template_tool_use : *tmpl.template_default;
+
     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.tools() != nullptr) {
+            inputs.tools = *tools.tools();
+        }
+
+        auto choice = tools.choice();
+        if (std::holds_alternative<std::string>(choice)) {
+            inputs.tool_choice = std::get<std::string>(choice);
+
+        } else {
+            auto choice_ptr = std::get<common_params_tools::json_ptr>(choice);
+            if (choice_ptr != nullptr) {
+                inputs.tool_choice = *choice_ptr;
+            }
+        }
+
         inputs.messages = messages;
         inputs.add_generation_prompt = add_ass;
-        return common_chat_params_init(tmpl, inputs).prompt;
+        auto chat_params = common_chat_params_init(tmpl_selected, inputs);
+        if (update_sparams) {
+            copy_chat_params(chat_params, update_sparams);
+        }
+        return chat_params.prompt;
     }
 
     int alloc_size = 0;
@@ -1819,7 +1921,7 @@ std::string common_chat_apply_template(
     std::vector<char> buf(alloc_size);
 
     // run the first time to get the total output length
-    int32_t res = llama_chat_apply_template(tmpl.source().c_str(), chat.data(), chat.size(), add_ass, buf.data(), buf.size());
+    int32_t res = llama_chat_apply_template(tmpl_selected.source().c_str(), chat.data(), chat.size(), add_ass, buf.data(), buf.size());
 
     // error: chat template is not supported
     if (res < 0) {
@@ -1831,7 +1933,7 @@ std::string common_chat_apply_template(
     // if it turns out that our buffer is too small, we resize it
     if ((size_t) res > buf.size()) {
         buf.resize(res);
-        res = llama_chat_apply_template(tmpl.source().c_str(), chat.data(), chat.size(), add_ass, buf.data(), buf.size());
+        res = llama_chat_apply_template(tmpl_selected.source().c_str(), chat.data(), chat.size(), add_ass, buf.data(), buf.size());
     }
 
     std::string formatted_chat(buf.data(), res);
@@ -1839,13 +1941,18 @@ std::string common_chat_apply_template(
 }
 
 std::string common_chat_format_single(
-        const common_chat_template & tmpl,
+        const common_chat_templates & tmpl,
         const std::vector<common_chat_msg> & past_msg,
         const common_chat_msg & new_msg,
         bool add_ass,
-        bool use_jinja) {
+        bool use_jinja,
+        const common_params_tools & tools,
+        common_chat_sampling_updater * update_sparams)
+{
     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, update_sparams);
+
     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') {
@@ -1853,13 +1960,13 @@ std::string common_chat_format_single(
     };
     // format chat with new_msg
     chat_new.push_back(new_msg);
-    auto fmt_new_msg = common_chat_apply_template(tmpl, chat_new, add_ass, use_jinja);
+    auto fmt_new_msg = common_chat_apply_template(tmpl, chat_new, add_ass, use_jinja, tools, update_sparams);
     // get the diff part
     ss << fmt_new_msg.substr(fmt_past_msg.size(), fmt_new_msg.size() - fmt_past_msg.size());
     return ss.str();
 }
 
-std::string common_chat_format_example(const common_chat_template & tmpl, bool use_jinja) {
+std::string common_chat_format_example(const common_chat_templates & tmpl, bool use_jinja) {
     std::vector<common_chat_msg> msgs = {
         {"system",    "You are a helpful assistant", {}},
         {"user",      "Hello", {}},
@@ -2195,4 +2302,3 @@ 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 b208d0c7e..f7bdb4e69 100644
--- a/common/common.h
+++ b/common/common.h
@@ -8,6 +8,10 @@
 #include <string>
 #include <vector>
 #include <sstream>
+#include <variant>
+// Change JSON_ASSERT from assert() to GGML_ASSERT:
+#define JSON_ASSERT GGML_ASSERT
+#include "json.hpp"
 
 #ifdef _WIN32
 #define DIRECTORY_SEPARATOR '\\'
@@ -202,6 +206,31 @@ struct common_params_vocoder {
     bool use_guide_tokens = false; // enable guide tokens to improve TTS accuracy            // NOLINT
 };
 
+class common_params_tools {
+public:
+    using json = nlohmann::ordered_json;
+    using json_ptr = std::shared_ptr<json>;
+    using tool_choice_t = std::variant<std::string, json_ptr>;
+
+    common_params_tools(std::string tools  = "",
+                        std::string choice = "auto");
+
+    common_params_tools(const common_params_tools & other) = default;
+    common_params_tools(common_params_tools && other) noexcept = default;
+    common_params_tools & operator=(const common_params_tools & other) = default;
+    common_params_tools & operator=(common_params_tools && other) noexcept = default;
+
+    void tools(std::string tools);
+    const json * tools() const { return tools_.get(); }
+
+    void choice(std::string choice);
+    const tool_choice_t & choice() const { return tool_choice_; }
+
+private:
+    json_ptr tools_;
+    tool_choice_t tool_choice_;
+};
+
 struct common_params {
     int32_t n_predict             =    -1; // new tokens to predict
     int32_t n_ctx                 =  4096; // context size
@@ -346,6 +375,7 @@ struct common_params {
     std::string chat_template = "";                                                                         // NOLINT
     bool use_jinja = false;                                                                                 // NOLINT
     bool enable_chat_template = true;
+    common_params_tools jinja_tools;
 
     std::vector<std::string> api_keys;
 
@@ -641,26 +671,35 @@ struct common_chat_templates {
     std::unique_ptr<common_chat_template> template_tool_use;
 };
 
+struct common_chat_sampling_updater {
+    common_params_sampling * sparams;
+    const llama_vocab      * vocab;
+};
+
 // CPP wrapper for llama_chat_apply_template
 // If the built-in template is not supported, we default to chatml
 // If the custom "tmpl" is not supported, we throw an error
 std::string common_chat_apply_template(
-        const common_chat_template & tmpl,
+        const common_chat_templates & tmpl,
         const std::vector<common_chat_msg> & chat,
         bool add_ass,
-        bool use_jinja);
+        bool use_jinja,
+        const common_params_tools & tools = common_params_tools(),
+        common_chat_sampling_updater * update_sparams = nullptr);
 
 // Format single message, while taking into account the position of that message in chat history
 std::string common_chat_format_single(
-        const common_chat_template & tmpl,
+        const common_chat_templates & tmpl,
         const std::vector<common_chat_msg> & past_msg,
         const common_chat_msg & new_msg,
         bool add_ass,
-        bool use_jinja);
+        bool use_jinja,
+        const common_params_tools & tools = common_params_tools(),
+        common_chat_sampling_updater * update_sparams = nullptr);
 
 // Returns an example of formatted chat
 std::string common_chat_format_example(
-    const common_chat_template & tmpl, bool use_jinja);
+    const common_chat_templates & tmpl, bool use_jinja);
 
 common_chat_templates common_chat_templates_from_model(const struct llama_model * model, const std::string & chat_template_override);
 
diff --git a/examples/main/main.cpp b/examples/main/main.cpp
index e654d3542..0ea614bcd 100644
--- a/examples/main/main.cpp
+++ b/examples/main/main.cpp
@@ -219,7 +219,7 @@ int main(int argc, char ** argv) {
     // print chat template example in conversation mode
     if (params.conversation_mode) {
         if (params.enable_chat_template) {
-            LOG_INF("%s: chat template example:\n%s\n", __func__, common_chat_format_example(*chat_templates.template_default, params.use_jinja).c_str());
+            LOG_INF("%s: chat template example:\n%s\n", __func__, common_chat_format_example(chat_templates, params.use_jinja).c_str());
         } else {
             LOG_INF("%s: in-suffix/prefix is specified, chat template will be disabled\n", __func__);
         }
@@ -263,20 +263,31 @@ 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, &sparams, vocab](
+        const std::string & role, const std::string & content,
+        const common_params_tools & tools = common_params_tools())
+    {
+        bool add_ass = (role == "user");
+
         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);
+
+        common_chat_sampling_updater updater{&sparams, vocab};
+        auto formatted =
+            common_chat_format_single(chat_templates, chat_msgs, new_msg, add_ass, g_params->use_jinja,
+                                      tools, &updater);
+
         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);
diff --git a/examples/server/server.cpp b/examples/server/server.cpp
index 0718806c8..1f6230c4c 100644
--- a/examples/server/server.cpp
+++ b/examples/server/server.cpp
@@ -4479,7 +4479,7 @@ int main(int argc, char ** argv) {
     // print sample chat example to make it clear which template is used
     LOG_INF("%s: chat template, chat_template: %s, example_format: '%s'\n", __func__,
         ctx_server.chat_templates.template_default->source().c_str(),
-        common_chat_format_example(*ctx_server.chat_templates.template_default, ctx_server.params_base.use_jinja).c_str());
+        common_chat_format_example(ctx_server.chat_templates, ctx_server.params_base.use_jinja).c_str());
 
     ctx_server.queue_tasks.on_new_task([&ctx_server](const server_task & task) {
         ctx_server.process_single_task(task);
diff --git a/examples/server/utils.hpp b/examples/server/utils.hpp
index 5f97df5fd..f1b4ee5b5 100644
--- a/examples/server/utils.hpp
+++ b/examples/server/utils.hpp
@@ -348,7 +348,7 @@ static llama_tokens format_infill(
 }
 
 // Format given chat. If tmpl is empty, we take the template from model metadata
-inline std::string format_chat(const common_chat_template & tmpl, const std::vector<json> & messages) {
+inline std::string format_chat(const common_chat_templates & tmpl, const std::vector<json> & messages) {
     std::vector<common_chat_msg> chat;
 
     for (size_t i = 0; i < messages.size(); ++i) {
@@ -663,7 +663,7 @@ static json oaicompat_completion_params_parse(
             llama_params["stop"].push_back(stop);
         }
     } else {
-        llama_params["prompt"] = format_chat(tmpl, body.at("messages"));
+        llama_params["prompt"] = format_chat(chat_templates, body.at("messages"));
     }
 
     // Handle "n" field
diff --git a/tests/test-chat-template.cpp b/tests/test-chat-template.cpp
index e0314ae1d..022205b7b 100644
--- a/tests/test-chat-template.cpp
+++ b/tests/test-chat-template.cpp
@@ -339,7 +339,8 @@ int main(void) {
     common_chat_msg sys_msg{"system", "You are a helpful assistant", {}};
 
     auto fmt_sys = [&](std::string tmpl_str) {
-        minja::chat_template tmpl(tmpl_str, "", "");
+        common_chat_templates tmpl;
+        tmpl.template_default.reset(new common_chat_template(tmpl_str, "", ""));
         auto output = common_chat_format_single(tmpl, chat2, sys_msg, false, /* use_jinja= */ false);
         printf("fmt_sys(%s) : %s\n", tmpl_str.c_str(), output.c_str());
         printf("-------------------------\n");
@@ -366,7 +367,8 @@ int main(void) {
     common_chat_msg new_msg{"user", "How are you", {}};
 
     auto fmt_single = [&](std::string tmpl_str) {
-        minja::chat_template tmpl(tmpl_str, "", "");
+        common_chat_templates tmpl;
+        tmpl.template_default.reset(new common_chat_template(tmpl_str, "", ""));
         auto output = common_chat_format_single(tmpl, chat2, new_msg, true, /* use_jinja= */ false);
         printf("fmt_single(%s) : %s\n", tmpl_str.c_str(), output.c_str());
         printf("-------------------------\n");