server: add --reasoning-budget 0 to disable thinking (incl. qwen3 w/ enable_thinking:false) (#13771)

---------

Co-authored-by: ochafik <ochafik@google.com>
Co-authored-by: Xuan-Son Nguyen <thichthat@gmail.com>

common/arg.cpp

@@ -2848,15 +2848,24 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
     ).set_examples({LLAMA_EXAMPLE_SERVER, LLAMA_EXAMPLE_MAIN}).set_env("LLAMA_ARG_JINJA"));
     add_opt(common_arg(
         {"--reasoning-format"}, "FORMAT",
-        "reasoning format (default: deepseek; allowed values: deepseek, none)\n"
+        "controls whether thought tags are allowed and/or extracted from the response, and in which format they're returned; one of:\n"
-        "controls whether thought tags are extracted from the response, and in which format they're returned. 'none' leaves thoughts unparsed in `message.content`, 'deepseek' puts them in `message.reasoning_content` (for DeepSeek R1 & Command R7B only).\n"
+        "- none: leaves thoughts unparsed in `message.content`\n"
-        "only supported for non-streamed responses",
+        "- deepseek: puts thoughts in `message.reasoning_content` (except in streaming mode, which behaves as `none`)\n"
+        "(default: deepseek)",
         [](common_params & params, const std::string & value) {
             /**/ if (value == "deepseek") { params.reasoning_format = COMMON_REASONING_FORMAT_DEEPSEEK; }
             else if (value == "none") {     params.reasoning_format = COMMON_REASONING_FORMAT_NONE; }
-            else { std::invalid_argument("invalid value"); }
+            else { throw std::invalid_argument("invalid value"); }
         }
     ).set_examples({LLAMA_EXAMPLE_SERVER, LLAMA_EXAMPLE_MAIN}).set_env("LLAMA_ARG_THINK"));
+    add_opt(common_arg(
+        {"--reasoning-budget"}, "N",
+        "controls the amount of thinking allowed; currently only one of: -1 for unrestricted thinking budget, or 0 to disable thinking (default: -1)",
+        [](common_params & params, int value) {
+            if (value != 0 && value != -1) { throw std::invalid_argument("invalid value"); }
+            params.reasoning_budget = value;
+        }
+    ).set_examples({LLAMA_EXAMPLE_SERVER, LLAMA_EXAMPLE_MAIN}).set_env("LLAMA_ARG_THINK_BUDGET"));
     add_opt(common_arg(
         {"--chat-template"}, "JINJA_TEMPLATE",
         string_format(
@@ -2955,7 +2964,7 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
         [](common_params & params, const std::string & value) {
             /**/ if (value == "jsonl") { params.batched_bench_output_jsonl = true; }
             else if (value == "md") { params.batched_bench_output_jsonl = false; }
-            else { std::invalid_argument("invalid value"); }
+            else { throw std::invalid_argument("invalid value"); }
         }
     ).set_examples({LLAMA_EXAMPLE_BENCH}));
     add_opt(common_arg(

common/chat.cpp

@@ -133,6 +133,7 @@ struct templates_params {
     bool stream;
     std::string grammar;
     bool add_generation_prompt = true;
+    bool enable_thinking = true;
     std::chrono::system_clock::time_point now = std::chrono::system_clock::now();
 };
 
@@ -573,7 +574,7 @@ common_chat_templates_ptr common_chat_templates_init(
     return tmpls;
 }
 
-std::string common_chat_format_name(common_chat_format format) {
+const char * common_chat_format_name(common_chat_format format) {
     switch (format) {
         case COMMON_CHAT_FORMAT_CONTENT_ONLY: return "Content-only";
         case COMMON_CHAT_FORMAT_GENERIC: return "Generic";
@@ -591,6 +592,15 @@ std::string common_chat_format_name(common_chat_format format) {
     }
 }
 
+const char * common_reasoning_format_name(common_reasoning_format format) {
+    switch (format) {
+        case COMMON_REASONING_FORMAT_NONE:     return "none";
+        case COMMON_REASONING_FORMAT_DEEPSEEK: return "deepseek";
+        default:
+            throw std::runtime_error("Unknown reasoning format");
+    }
+}
+
 static std::string wrap_code_as_arguments(common_chat_msg_parser & builder, const std::string & code) {
     std::string arguments;
     if (builder.is_partial()) {
@@ -918,8 +928,14 @@ static common_chat_params common_chat_params_init_command_r7b(const common_chat_
     data.prompt = apply(tmpl, adjusted_messages, inputs.tools.empty() ? json() : inputs.tools, inputs.add_generation_prompt, {});
     data.format = COMMON_CHAT_FORMAT_COMMAND_R7B;
     if (string_ends_with(data.prompt, "<|START_THINKING|>")) {
+        if (!inputs.enable_thinking) {
+            data.prompt += "<|END_THINKING|>";
+        } else {
             data.thinking_forced_open = true;
         }
+    } else if (!inputs.enable_thinking && string_ends_with(data.prompt, "<|CHATBOT_TOKEN|>")) {
+        data.prompt += "<|START_THINKING|><|END_THINKING|>";
+    }
 
     data.grammar_lazy = inputs.tool_choice != COMMON_CHAT_TOOL_CHOICE_REQUIRED;
     data.grammar = build_grammar([&](const common_grammar_builder & builder) {
@@ -1186,8 +1202,12 @@ static common_chat_params common_chat_params_init_deepseek_r1(const common_chat_
     data.prompt = prompt;
     data.format = COMMON_CHAT_FORMAT_DEEPSEEK_R1;
     if (string_ends_with(data.prompt, "<think>\n")) {
+        if (!inputs.enable_thinking) {
+            data.prompt += "</think>";
+        } else {
             data.thinking_forced_open = true;
         }
+    }
 
     if (inputs.tools.is_array() && !inputs.tools.empty()) {
         data.grammar_lazy = inputs.tool_choice != COMMON_CHAT_TOOL_CHOICE_REQUIRED && inputs.json_schema.is_null();
@@ -1460,12 +1480,21 @@ static void common_chat_parse_functionary_v3_1_llama_3_1(common_chat_msg_parser
 static common_chat_params common_chat_params_init_hermes_2_pro(const common_chat_template & tmpl, const struct templates_params & inputs) {
     common_chat_params data;
 
-    data.prompt = apply(tmpl, inputs.messages, inputs.tools.empty() ? json() : inputs.tools, inputs.add_generation_prompt);
+    json additional_context = {
+        {"enable_thinking", inputs.enable_thinking},
+    };
+
+    data.prompt = apply(tmpl, inputs.messages, inputs.tools.empty() ? json() : inputs.tools, inputs.add_generation_prompt, additional_context);
     data.format = COMMON_CHAT_FORMAT_HERMES_2_PRO;
     if (string_ends_with(data.prompt, "<think>\n")) {
+        if (!inputs.enable_thinking) {
+            data.prompt += "</think>";
+        } else {
             data.thinking_forced_open = true;
         }
+    }
 
+    if (!inputs.tools.is_null()) {
         // (content)?(<tool_call>{"name": "foo", "arguments": {"a": 1}}</tool_call>)*
         data.grammar_lazy = inputs.tool_choice != COMMON_CHAT_TOOL_CHOICE_REQUIRED;
         data.grammar = build_grammar([&](const common_grammar_builder & builder) {
@@ -1558,6 +1587,7 @@ static common_chat_params common_chat_params_init_hermes_2_pro(const common_chat
                 "```xml",
             };
         });
+    }
 
     return data;
 }
@@ -1669,6 +1699,7 @@ static common_chat_params common_chat_templates_apply_jinja(
     params.messages = common_chat_msgs_to_json_oaicompat<json>(inputs.messages, /* concat_text= */ !tmpl.original_caps().requires_typed_content);
     params.add_generation_prompt = inputs.add_generation_prompt;
     params.tool_choice = inputs.tool_choice;
+    params.enable_thinking = inputs.enable_thinking;
     params.grammar = inputs.grammar;
     params.now = inputs.now;
     if (!inputs.json_schema.empty()) {
@@ -1702,7 +1733,7 @@ static common_chat_params common_chat_templates_apply_jinja(
     }
 
     // Hermes 2/3 Pro, Qwen 2.5 Instruct (w/ tools)
-    if (src.find("<tool_call>") != std::string::npos && params.json_schema.is_null() && params.tools.is_array() && params.json_schema.is_null()) {
+    if (src.find("<tool_call>") != std::string::npos && params.json_schema.is_null()) {
         return common_chat_params_init_hermes_2_pro(tmpl, params);
     }
 
@@ -1821,7 +1852,7 @@ static void common_chat_parse_content_only(common_chat_msg_parser & builder) {
 }
 
 static void common_chat_parse(common_chat_msg_parser & builder, common_chat_format format) {
-    LOG_DBG("Parsing input with format %s: %s\n", common_chat_format_name(format).c_str(), builder.input().c_str());
+    LOG_DBG("Parsing input with format %s: %s\n", common_chat_format_name(format), builder.input().c_str());
 
     switch (format) {
         case COMMON_CHAT_FORMAT_CONTENT_ONLY:
@@ -1858,7 +1889,7 @@ static void common_chat_parse(common_chat_msg_parser & builder, common_chat_form
             common_chat_parse_command_r7b(builder);
             break;
         default:
-            throw std::runtime_error("Unsupported format: " + common_chat_format_name(format));
+            throw std::runtime_error(std::string("Unsupported format: ") + common_chat_format_name(format));
     }
     builder.finish();
 }

common/chat.h

@@ -123,6 +123,7 @@ struct common_chat_templates_inputs {
     common_chat_tool_choice tool_choice = COMMON_CHAT_TOOL_CHOICE_AUTO;
     bool parallel_tool_calls = false;
     common_reasoning_format reasoning_format = COMMON_REASONING_FORMAT_NONE;
+    bool enable_thinking = true;
     std::chrono::system_clock::time_point now = std::chrono::system_clock::now();
 };
 
@@ -181,7 +182,8 @@ std::string common_chat_format_example(
     const struct common_chat_templates * tmpls,
     bool use_jinja);
 
-std::string               common_chat_format_name(common_chat_format format);
+const char*               common_chat_format_name(common_chat_format format);
+const char*               common_reasoning_format_name(common_reasoning_format format);
 common_chat_msg           common_chat_parse(const std::string & input, bool is_partial, const common_chat_syntax & syntax);
 
 common_chat_tool_choice common_chat_tool_choice_parse_oaicompat(const std::string & tool_choice);

common/common.h

@@ -368,6 +368,7 @@ struct common_params {
     bool use_jinja = false;                                                                                 // NOLINT
     bool enable_chat_template = true;
     common_reasoning_format reasoning_format = COMMON_REASONING_FORMAT_DEEPSEEK;
+    int reasoning_budget = -1;
     bool prefill_assistant = true;                                                                          // if true, any trailing assistant message will be prefilled into the response
 
     std::vector<std::string> api_keys;

models/templates/Qwen-Qwen3-0.6B.jinja

@@ -0,0 +1,85 @@
+{%- if tools %}
+    {{- '<|im_start|>system\n' }}
+    {%- if messages[0].role == 'system' %}
+        {{- messages[0].content + '\n\n' }}
+    {%- endif %}
+    {{- "# Tools\n\nYou may call one or more functions to assist with the user query.\n\nYou are provided with function signatures within <tools></tools> XML tags:\n<tools>" }}
+    {%- for tool in tools %}
+        {{- "\n" }}
+        {{- tool | tojson }}
+    {%- endfor %}
+    {{- "\n</tools>\n\nFor each function call, return a json object with function name and arguments within <tool_call></tool_call> XML tags:\n<tool_call>\n{\"name\": <function-name>, \"arguments\": <args-json-object>}\n</tool_call><|im_end|>\n" }}
+{%- else %}
+    {%- if messages[0].role == 'system' %}
+        {{- '<|im_start|>system\n' + messages[0].content + '<|im_end|>\n' }}
+    {%- endif %}
+{%- endif %}
+{%- set ns = namespace(multi_step_tool=true, last_query_index=messages|length - 1) %}
+{%- for message in messages[::-1] %}
+    {%- set index = (messages|length - 1) - loop.index0 %}
+    {%- if ns.multi_step_tool and message.role == "user" and not(message.content.startswith('<tool_response>') and message.content.endswith('</tool_response>')) %}
+        {%- set ns.multi_step_tool = false %}
+        {%- set ns.last_query_index = index %}
+    {%- endif %}
+{%- endfor %}
+{%- for message in messages %}
+    {%- if (message.role == "user") or (message.role == "system" and not loop.first) %}
+        {{- '<|im_start|>' + message.role + '\n' + message.content + '<|im_end|>' + '\n' }}
+    {%- elif message.role == "assistant" %}
+        {%- set content = message.content %}
+        {%- set reasoning_content = '' %}
+        {%- if message.reasoning_content is defined and message.reasoning_content is not none %}
+            {%- set reasoning_content = message.reasoning_content %}
+        {%- else %}
+            {%- if '</think>' in message.content %}
+                {%- set content = message.content.split('</think>')[-1].lstrip('\n') %}
+                {%- set reasoning_content = message.content.split('</think>')[0].rstrip('\n').split('<think>')[-1].lstrip('\n') %}
+            {%- endif %}
+        {%- endif %}
+        {%- if loop.index0 > ns.last_query_index %}
+            {%- if loop.last or (not loop.last and reasoning_content) %}
+                {{- '<|im_start|>' + message.role + '\n<think>\n' + reasoning_content.strip('\n') + '\n</think>\n\n' + content.lstrip('\n') }}
+            {%- else %}
+                {{- '<|im_start|>' + message.role + '\n' + content }}
+            {%- endif %}
+        {%- else %}
+            {{- '<|im_start|>' + message.role + '\n' + content }}
+        {%- endif %}
+        {%- if message.tool_calls %}
+            {%- for tool_call in message.tool_calls %}
+                {%- if (loop.first and content) or (not loop.first) %}
+                    {{- '\n' }}
+                {%- endif %}
+                {%- if tool_call.function %}
+                    {%- set tool_call = tool_call.function %}
+                {%- endif %}
+                {{- '<tool_call>\n{"name": "' }}
+                {{- tool_call.name }}
+                {{- '", "arguments": ' }}
+                {%- if tool_call.arguments is string %}
+                    {{- tool_call.arguments }}
+                {%- else %}
+                    {{- tool_call.arguments | tojson }}
+                {%- endif %}
+                {{- '}\n</tool_call>' }}
+            {%- endfor %}
+        {%- endif %}
+        {{- '<|im_end|>\n' }}
+    {%- elif message.role == "tool" %}
+        {%- if loop.first or (messages[loop.index0 - 1].role != "tool") %}
+            {{- '<|im_start|>user' }}
+        {%- endif %}
+        {{- '\n<tool_response>\n' }}
+        {{- message.content }}
+        {{- '\n</tool_response>' }}
+        {%- if loop.last or (messages[loop.index0 + 1].role != "tool") %}
+            {{- '<|im_end|>\n' }}
+        {%- endif %}
+    {%- endif %}
+{%- endfor %}
+{%- if add_generation_prompt %}
+    {{- '<|im_start|>assistant\n' }}
+    {%- if enable_thinking is defined and enable_thinking is false %}
+        {{- '<think>\n\n</think>\n\n' }}
+    {%- endif %}
+{%- endif %}

models/templates/README.md

@@ -20,4 +20,5 @@ These templates can be updated with the following commands:
 ./scripts/get_chat_template.py NousResearch/Hermes-3-Llama-3.1-8B tool_use   > models/templates/NousResearch-Hermes-3-Llama-3.1-8B-tool_use.jinja
 ./scripts/get_chat_template.py Qwen/Qwen2.5-7B-Instruct                      > models/templates/Qwen-Qwen2.5-7B-Instruct.jinja
 ./scripts/get_chat_template.py Qwen/QwQ-32B                                  > models/templates/Qwen-QwQ-32B.jinja
+./scripts/get_chat_template.py Qwen/Qwen3-0.6B                               > models/templates/Qwen-Qwen3-0.6B.jinja
 ```

tests/test-chat.cpp

@@ -737,14 +737,14 @@ static void test_template_output_parsers() {
         auto tmpls = read_templates("models/templates/Qwen-QwQ-32B.jinja");
         std::vector<std::string> end_tokens{ "<|im_end|>" };
 
-        assert_equals(COMMON_CHAT_FORMAT_CONTENT_ONLY, common_chat_templates_apply(tmpls.get(), inputs_no_tools).format);
+        assert_equals(COMMON_CHAT_FORMAT_HERMES_2_PRO, common_chat_templates_apply(tmpls.get(), inputs_no_tools).format);
         assert_equals(COMMON_CHAT_FORMAT_HERMES_2_PRO, common_chat_templates_apply(tmpls.get(), inputs_tools).format);
     }
     {
         auto tmpls = read_templates("models/templates/NousResearch-Hermes-2-Pro-Llama-3-8B-tool_use.jinja");
         std::vector<std::string> end_tokens{ "<|im_end|>" };
 
-        assert_equals(COMMON_CHAT_FORMAT_CONTENT_ONLY, common_chat_templates_apply(tmpls.get(), inputs_no_tools).format);
+        assert_equals(COMMON_CHAT_FORMAT_HERMES_2_PRO, common_chat_templates_apply(tmpls.get(), inputs_no_tools).format);
         assert_equals(COMMON_CHAT_FORMAT_HERMES_2_PRO, common_chat_templates_apply(tmpls.get(), inputs_tools).format);
         assert_equals(
             COMMON_CHAT_FORMAT_HERMES_2_PRO,

tools/server/README.md

@@ -173,7 +173,8 @@ The project is under active development, and we are [looking for feedback and co
 | `--no-slots` | disables slots monitoring endpoint<br/>(env: LLAMA_ARG_NO_ENDPOINT_SLOTS) |
 | `--slot-save-path PATH` | path to save slot kv cache (default: disabled) |
 | `--jinja` | use jinja template for chat (default: disabled)<br/>(env: LLAMA_ARG_JINJA) |
-| `--reasoning-format FORMAT` | reasoning format (default: deepseek; allowed values: deepseek, none)<br/>controls whether thought tags are extracted from the response, and in which format they're returned. 'none' leaves thoughts unparsed in `message.content`, 'deepseek' puts them in `message.reasoning_content` (for DeepSeek R1 & Command R7B only).<br/>only supported for non-streamed responses<br/>(env: LLAMA_ARG_THINK) |
+| `--reasoning-format FORMAT` | controls whether thought tags are allowed and/or extracted from the response, and in which format they're returned; one of:<br/>- none: leaves thoughts unparsed in `message.content`<br/>- deepseek: puts thoughts in `message.reasoning_content` (except in streaming mode, which behaves as `none`)<br/>(default: deepseek)<br/>(env: LLAMA_ARG_THINK) |
+| `--reasoning-budget N` | controls the amount of thinking allowed; currently only one of: -1 for unrestricted thinking budget, or 0 to disable thinking (default: -1)<br/>(env: LLAMA_ARG_THINK_BUDGET) |
 | `--chat-template JINJA_TEMPLATE` | set custom jinja chat template (default: template taken from model's metadata)<br/>if suffix/prefix are specified, template will be disabled<br/>only commonly used templates are accepted (unless --jinja is set before this flag):<br/>list of built-in templates:<br/>bailing, chatglm3, chatglm4, chatml, command-r, deepseek, deepseek2, deepseek3, exaone3, falcon3, gemma, gigachat, glmedge, granite, llama2, llama2-sys, llama2-sys-bos, llama2-sys-strip, llama3, llama4, megrez, minicpm, mistral-v1, mistral-v3, mistral-v3-tekken, mistral-v7, mistral-v7-tekken, monarch, openchat, orion, phi3, phi4, rwkv-world, smolvlm, vicuna, vicuna-orca, yandex, zephyr<br/>(env: LLAMA_ARG_CHAT_TEMPLATE) |
 | `--chat-template-file JINJA_TEMPLATE_FILE` | set custom jinja chat template file (default: template taken from model's metadata)<br/>if suffix/prefix are specified, template will be disabled<br/>only commonly used templates are accepted (unless --jinja is set before this flag):<br/>list of built-in templates:<br/>bailing, chatglm3, chatglm4, chatml, command-r, deepseek, deepseek2, deepseek3, exaone3, falcon3, gemma, gigachat, glmedge, granite, llama2, llama2-sys, llama2-sys-bos, llama2-sys-strip, llama3, llama4, megrez, minicpm, mistral-v1, mistral-v3, mistral-v3-tekken, mistral-v7, mistral-v7-tekken, monarch, openchat, orion, phi3, phi4, rwkv-world, smolvlm, vicuna, vicuna-orca, yandex, zephyr<br/>(env: LLAMA_ARG_CHAT_TEMPLATE_FILE) |
 | `--no-prefill-assistant` | whether to prefill the assistant's response if the last message is an assistant message (default: prefill enabled)<br/>when this flag is set, if the last message is an assistant message then it will be treated as a full message and not prefilled<br/>(env: LLAMA_ARG_NO_PREFILL_ASSISTANT) |

tools/server/server.cpp

@@ -178,7 +178,7 @@ struct slot_params {
             {"grammar_triggers",          grammar_triggers},
             {"preserved_tokens",          sampling.preserved_tokens},
             {"chat_format",               common_chat_format_name(oaicompat_chat_syntax.format)},
-            {"reasoning_format",          (oaicompat_chat_syntax.reasoning_format == COMMON_REASONING_FORMAT_DEEPSEEK ? "deepseek" : "none")},
+            {"reasoning_format",          common_reasoning_format_name(oaicompat_chat_syntax.reasoning_format)},
             {"reasoning_in_content",      oaicompat_chat_syntax.reasoning_in_content},
             {"thinking_forced_open",      oaicompat_chat_syntax.thinking_forced_open},
             {"samplers",                  samplers},
@@ -357,7 +357,7 @@ struct server_task {
             auto it = data.find("chat_format");
             if (it != data.end()) {
                 params.oaicompat_chat_syntax.format = static_cast<common_chat_format>(it->get<int>());
-                SRV_INF("Chat format: %s\n", common_chat_format_name(params.oaicompat_chat_syntax.format).c_str());
+                SRV_INF("Chat format: %s\n", common_chat_format_name(params.oaicompat_chat_syntax.format));
             } else {
                 params.oaicompat_chat_syntax.format = defaults.oaicompat_chat_syntax.format;
             }
@@ -2089,6 +2089,7 @@ struct server_context {
             /* common_chat_templates */ chat_templates.get(),
             /* allow_image           */ mctx ? mtmd_support_vision(mctx) : false,
             /* allow_audio           */ mctx ? mtmd_support_audio (mctx) : false,
+            /* enable_thinking       */ params_base.reasoning_budget != 0,
         };
     }
 

tools/server/tests/unit/test_template.py

@@ -25,6 +25,40 @@ def create_server():
     server.n_slots = 1
 
 
+@pytest.mark.parametrize("tools", [None, [], [TEST_TOOL]])
+@pytest.mark.parametrize("template_name,reasoning_budget,expected_end", [
+    ("deepseek-ai-DeepSeek-R1-Distill-Qwen-32B", None, "<think>\n"),
+    ("deepseek-ai-DeepSeek-R1-Distill-Qwen-32B",   -1, "<think>\n"),
+    ("deepseek-ai-DeepSeek-R1-Distill-Qwen-32B",    0, "<think>\n</think>"),
+
+    ("Qwen-Qwen3-0.6B", -1, "<|im_start|>assistant\n"),
+    ("Qwen-Qwen3-0.6B",  0, "<|im_start|>assistant\n<think>\n\n</think>\n\n"),
+
+    ("Qwen-QwQ-32B", -1, "<|im_start|>assistant\n<think>\n"),
+    ("Qwen-QwQ-32B",  0, "<|im_start|>assistant\n<think>\n</think>"),
+
+    ("CohereForAI-c4ai-command-r7b-12-2024-tool_use", -1, "<|START_OF_TURN_TOKEN|><|CHATBOT_TOKEN|>"),
+    ("CohereForAI-c4ai-command-r7b-12-2024-tool_use",  0, "<|START_OF_TURN_TOKEN|><|CHATBOT_TOKEN|><|START_THINKING|><|END_THINKING|>"),
+])
+def test_reasoning_budget(template_name: str, reasoning_budget: int | None, expected_end: str, tools: list[dict]):
+    global server
+    server.jinja = True
+    server.reasoning_budget = reasoning_budget
+    server.chat_template_file = f'../../../models/templates/{template_name}.jinja'
+    server.start(timeout_seconds=TIMEOUT_SERVER_START)
+
+    res = server.make_request("POST", "/apply-template", data={
+        "messages": [
+            {"role": "user", "content": "What is today?"},
+        ],
+        "tools": tools,
+    })
+    assert res.status_code == 200
+    prompt = res.body["prompt"]
+
+    assert prompt.endswith(expected_end), f"Expected prompt to end with '{expected_end}', got '{prompt}'"
+
+
 @pytest.mark.parametrize("tools", [None, [], [TEST_TOOL]])
 @pytest.mark.parametrize("template_name,format", [
     ("meta-llama-Llama-3.3-70B-Instruct",    "%d %b %Y"),

tools/server/tests/utils.py

@@ -84,7 +84,8 @@ class ServerProcess:
     draft_max: int | None = None
     no_webui: bool | None = None
     jinja: bool | None = None
-    reasoning_format: Literal['deepseek', 'none'] | None = None
+    reasoning_format: Literal['deepseek', 'none', 'nothink'] | None = None
+    reasoning_budget: int | None = None
     chat_template: str | None = None
     chat_template_file: str | None = None
     server_path: str | None = None
@@ -191,6 +192,8 @@ class ServerProcess:
             server_args.append("--jinja")
         if self.reasoning_format is not None:
             server_args.extend(("--reasoning-format", self.reasoning_format))
+        if self.reasoning_budget is not None:
+            server_args.extend(("--reasoning-budget", self.reasoning_budget))
         if self.chat_template:
             server_args.extend(["--chat-template", self.chat_template])
         if self.chat_template_file:

tools/server/utils.hpp

@@ -568,6 +568,7 @@ struct oaicompat_parser_options {
     common_chat_templates * tmpls;
     bool allow_image;
     bool allow_audio;
+    bool enable_thinking = true;
 };
 
 // used by /chat/completions endpoint
@@ -733,6 +734,7 @@ static json oaicompat_chat_params_parse(
     inputs.parallel_tool_calls   = json_value(body, "parallel_tool_calls", false);
     inputs.add_generation_prompt = json_value(body, "add_generation_prompt", true);
     inputs.reasoning_format      = opt.reasoning_format;
+    inputs.enable_thinking       = opt.enable_thinking;
     if (!inputs.tools.empty() && inputs.tool_choice != COMMON_CHAT_TOOL_CHOICE_NONE && body.contains("grammar")) {
         throw std::runtime_error("Cannot use custom grammar constraints with tools.");
     }