model: add Beam (Reflection)

common/chat.cpp

@@ -1104,6 +1104,13 @@ static common_chat_params_init_fn common_chat_template_detect_params_init(const
         return common_chat_params_init_llm_jp_harmony;
     }
 
+    // Harmony XML tool calls, checked before the GPT-OSS JSON calls
+    if (src.find("<|channel|>") != std::string::npos && src.find("<|constrain|>xml") != std::string::npos &&
+        src.find("rfl:parameter") != std::string::npos) {
+        LOG_DBG("Using specialized template: Harmony XML\n");
+        return common_chat_params_init_harmony_xml;
+    }
+
     // GPT-OSS - has unique channel-based structure that needs dedicated handler
     if (src.find("<|channel|>") != std::string::npos) {
         LOG_DBG("Using specialized template: GPT-OSS\n");

common/jinja/value.cpp

@@ -1299,6 +1299,15 @@ const func_builtins & value_object_t::get_builtins() const {
             }
             return result;
         }},
+        {"list", [](const func_args & args) -> value {
+            args.ensure_vals<value_object>();
+            const auto & obj = args.get_pos(0)->as_ordered_object();
+            auto result = mk_val<value_array>();
+            for (const auto & pair : obj) {
+                result->push_back(pair.first);
+            }
+            return result;
+        }},
         {"values", [](const func_args & args) -> value {
             args.ensure_vals<value_object>();
             const auto & obj = args.get_pos(0)->as_ordered_object();

common/parsers/harmony-xml.cpp

@@ -0,0 +1,207 @@
+#include "parsers.h"
+
+// Harmony with XML tool calls: <|start|>assistant to=NAME<|channel|>analysis <|constrain|>xml<|message|><rfl:parameter name="KEY">\nVALUE\n</rfl:parameter>
+common_chat_params common_chat_params_init_harmony_xml(const common_chat_template &          tmpl,
+                                                       const autoparser::generation_params & inputs) {
+    common_chat_params data;
+
+    data.prompt            = common_chat_template_direct_apply_impl(tmpl, inputs);
+    data.generation_prompt = common_chat_template_generation_prompt_impl(tmpl, inputs);
+    data.message_delimiters = {
+        { COMMON_CHAT_ROLE_ASSISTANT, "<|start|>assistant" },
+        { COMMON_CHAT_ROLE_USER,      "<|start|>user"      },
+        { COMMON_CHAT_ROLE_SYSTEM,    "<|start|>developer" },
+        { COMMON_CHAT_ROLE_SYSTEM,    "<|start|>system"    },
+    };
+
+    data.format            = COMMON_CHAT_FORMAT_PEG_NATIVE;
+    data.supports_thinking = true;
+
+    data.thinking_start_tag = "<|channel|>analysis<|message|>";
+    data.thinking_end_tags  = {"<|end|>"};
+
+    // EOG text must reach the parser: an XML call has no closing tag of its own
+    static const std::vector<std::string> EOG = {
+        "<|call|>", "<|return|>", "<|endoftext|>", "<|im_end|>", "<|fim_pad|>", "<|repo_name|>", "<|file_sep|>",
+    };
+
+    data.preserved_tokens = {
+        "<|channel|>", "<|constrain|>", "<|message|>", "<|start|>", "<|end|>",
+    };
+    data.preserved_tokens.insert(data.preserved_tokens.end(), EOG.begin(), EOG.end());
+
+    if (inputs.has_continuation()) {
+        const auto & msg = inputs.continue_msg;
+
+        data.generation_prompt = "<|start|>assistant<|channel|>analysis<|message|>" + msg.reasoning_content;
+        if (inputs.continue_final_message == COMMON_CHAT_CONTINUATION_CONTENT) {
+            data.generation_prompt += "<|end|><|start|>assistant<|channel|>final<|message|>" + msg.render_content();
+        }
+
+        data.prompt.append(data.generation_prompt);
+    }
+
+    auto has_tools           = inputs.tools.is_array() && !inputs.tools.empty();
+    auto has_response_format = !inputs.json_schema.is_null() && inputs.json_schema.is_object();
+    auto include_grammar     = has_response_format || (has_tools && inputs.tool_choice != COMMON_CHAT_TOOL_CHOICE_NONE);
+    auto extract_reasoning   = inputs.reasoning_format != COMMON_REASONING_FORMAT_NONE;
+
+    static const std::string PARAM_OPEN  = "<rfl:parameter name=\"";
+    static const std::string PARAM_CLOSE = "\n</rfl:parameter>";
+
+    data.parser = build_chat_peg_parser([&](common_chat_peg_builder & p) {
+        auto start = p.rule("start", p.literal("<|start|>assistant"));
+
+        auto eog = p.choice();
+        for (const auto & tok : EOG) {
+            eog |= p.literal(tok);
+        }
+        auto with_eog = [&](std::vector<std::string> delims) {
+            delims.insert(delims.end(), EOG.begin(), EOG.end());
+            return delims;
+        };
+
+        auto analysis_open  = p.literal("<|channel|>analysis<|message|>");
+        auto analysis_body  = p.until_one_of(with_eog({ "<|end|>", "<|constrain|><|start|>assistant", "<|start|>assistant" }));
+        auto analysis_close = p.optional(p.literal("<|end|>") | p.literal("<|constrain|>") | eog);
+        if (extract_reasoning) {
+            p.rule("analysis", analysis_open + p.reasoning(analysis_body) + analysis_close);
+        } else {
+            p.rule("analysis", p.atomic(p.content(analysis_open)) + p.content(analysis_body + analysis_close));
+        }
+        auto analysis = p.ref("analysis");
+
+        auto final_msg = p.rule("final",
+            p.literal("<|channel|>final<|message|>") +
+            p.content(p.until_one_of(with_eog({ "<|end|>" }))) +
+            p.optional(p.literal("<|end|>") | eog));
+
+        if (has_response_format) {
+            auto constrain_type = p.chars("[A-Za-z0-9_-]", 1, -1);
+            auto constraint     = p.optional(p.space() + p.optional(p.literal("<|constrain|>")) + constrain_type);
+            auto response_format = p.rule("response-format",
+                p.literal("<|channel|>final") + constraint + p.literal("<|message|>") +
+                p.content(p.schema(p.json(), "response-format-schema", inputs.json_schema)) +
+                p.optional(p.literal("<|end|>") | eog));
+
+            return start + p.zero_or_more(analysis + start) + response_format;
+        }
+
+        if (has_tools && inputs.tool_choice != COMMON_CHAT_TOOL_CHOICE_NONE) {
+            // tolerate a missing closing tag
+            std::vector<std::string> value_ends = with_eog({ PARAM_OPEN, "<|end|>" });
+            std::vector<std::string> string_ends = { PARAM_CLOSE };
+            auto next_open = p.choice();
+            for (const auto & e : value_ends) {
+                string_ends.push_back("\n" + e);
+                next_open |= p.literal(e);
+            }
+            auto arg_close = p.tool_arg_close(p.gbnf(
+                p.literal(PARAM_CLOSE) | (p.literal("\n") + p.peek(p.optional(p.literal("\n")) + next_open)),
+                gbnf_format_literal("\n") + " " + gbnf_format_literal(PARAM_CLOSE.substr(1)) + "?"));
+            auto arg_string = p.rule("rfl-arg-string",
+                p.ac(p.tool_arg_string_value(p.until_one_of(string_ends)) + arg_close, PARAM_CLOSE));
+            auto arg_sep = p.optional(p.literal("\n"));
+
+            std::string call_close_gbnf = gbnf_format_literal("<|end|>");
+            for (const auto & tok : EOG) {
+                call_close_gbnf += " | " + gbnf_format_literal(tok);
+            }
+            auto call_close = p.gbnf(p.literal("<|end|>") | eog | p.peek(p.literal("<|start|>assistant")),
+                "(" + call_close_gbnf + ")?");
+
+            auto tool_choice = p.choice();
+            foreach_function(inputs.tools, [&](size_t tool_index, const json & tool) {
+                const auto & function = tool.at("function");
+                std::string  name     = function.at("name");
+
+                std::vector<common_peg_parser> arg_rules;
+                foreach_parameter(function, [&](size_t param_index, const common_chat_schema_property & param, const common_chat_schema_document_ptr & doc) {
+                    auto rule_name = "tool-" + std::to_string(tool_index) + "-arg-" + std::to_string(param_index);
+                    auto arg_open  = p.tool_arg_open(p.literal(PARAM_OPEN) + p.tool_arg_name(p.literal(param.name)) + p.literal("\">\n"));
+
+                    auto types     = param.schema->value_types();
+                    auto arg_value = p.eps();
+                    if (!types.has(common_chat_schema::TYPE_STRING) &&
+                        (types.has(common_chat_schema::TYPE_OBJECT) || types.has(common_chat_schema::TYPE_ARRAY))) {
+                        // the schema grammar fixes the key order, and the model writes keys in its own order
+                        arg_value = p.tool_arg_json_value(p.json()) + arg_close;
+                    } else if (!types.has(common_chat_schema::TYPE_STRING)) {
+                        arg_value = p.tool_arg_json_value(p.schema(p.json(), rule_name + "-schema", doc, *param.schema)) + arg_close;
+                    } else if (types.is_only(common_chat_schema::TYPE_STRING)) {
+                        arg_value = arg_string;
+                    } else {
+                        // grammar keeps only the string rule; the parser tries JSON first to type the value
+                        auto json_value = p.choice();
+                        if (types.has(common_chat_schema::TYPE_OBJECT)) {
+                            json_value |= p.json_object();
+                        }
+                        if (types.has(common_chat_schema::TYPE_ARRAY)) {
+                            json_value |= p.json_array();
+                        }
+                        if (types.has(common_chat_schema::TYPE_NUMBER) || types.has(common_chat_schema::TYPE_INTEGER)) {
+                            json_value |= p.json_number();
+                        }
+                        if (types.has(common_chat_schema::TYPE_BOOLEAN)) {
+                            json_value |= p.json_bool();
+                        }
+                        if (types.has(common_chat_schema::TYPE_NULL)) {
+                            json_value |= p.json_null();
+                        }
+                        arg_value = p.gbnf(p.atomic(p.tool_arg_json_value(json_value) + arg_close) | arg_string, "rfl-arg-string");
+                    }
+
+                    arg_rules.push_back(p.rule(rule_name, p.tool_arg(arg_open + arg_value)));
+                });
+
+                if (arg_rules.empty()) {
+                    auto any_name = p.chars("[^\"\\n<]", 1, -1);
+                    arg_rules.push_back(p.rule("tool-" + std::to_string(tool_index) + "-arg-any",
+                        p.tool_arg(p.tool_arg_open(p.literal(PARAM_OPEN) + p.tool_arg_name(any_name) + p.literal("\">\n")) + arg_string)));
+                }
+
+                auto args = p.zero_or_more(p.choice(arg_rules) + arg_sep);
+
+                auto call = p.tool(
+                    p.tool_open(p.literal(" to=") + p.tool_name(p.literal(name)) +
+                                p.literal("<|channel|>analysis <|constrain|>xml<|message|>")) +
+                    p.tool_args(args) +
+                    p.tool_close(call_close));
+
+                tool_choice |= p.rule("tool-" + std::to_string(tool_index), call);
+            });
+
+            auto tool_calls = inputs.parallel_tool_calls
+                ? tool_choice + p.zero_or_more(start + tool_choice)
+                : tool_choice;
+            auto tool_call = p.trigger_rule("tool-call", tool_calls);
+
+            if (inputs.tool_choice == COMMON_CHAT_TOOL_CHOICE_REQUIRED) {
+                return start + p.zero_or_more(analysis + start) + tool_call;
+            }
+
+            return start + p.zero_or_more(analysis + start) + (tool_call | final_msg | p.content(p.rest()));
+        }
+
+        auto unsolicited = p.rule("unsolicited", p.atomic(p.literal(" to=") + p.rest()));
+
+        // output without a channel header is returned as content instead of failing the request
+        return start + p.zero_or_more(analysis + start) + (final_msg | unsolicited | p.content(p.rest()));
+    });
+
+    if (include_grammar) {
+        data.grammar_lazy = !(has_response_format || (has_tools && inputs.tool_choice == COMMON_CHAT_TOOL_CHOICE_REQUIRED));
+        data.grammar      = build_grammar([&](const common_grammar_builder & builder) {
+            data.parser.build_grammar(builder, data.grammar_lazy);
+        });
+
+        if (data.grammar_lazy) {
+            data.grammar_triggers = {
+                { COMMON_GRAMMAR_TRIGGER_TYPE_PATTERN, "^\\s+to$" },
+                { COMMON_GRAMMAR_TRIGGER_TYPE_PATTERN, "<\\|start\\|>assistant(\\s+to)" },
+            };
+        }
+    }
+
+    return data;
+}

common/parsers/parsers.h

@@ -59,6 +59,8 @@ common_chat_params common_chat_params_init_gigachat_v3(const common_chat_templat
 
 common_chat_params common_chat_params_init_gpt_oss(const common_chat_template & tmpl, const autoparser::generation_params & inputs);
 
+common_chat_params common_chat_params_init_harmony_xml(const common_chat_template & tmpl, const autoparser::generation_params & inputs);
+
 common_chat_params common_chat_params_init_k2_horizon(const common_chat_template & tmpl, const autoparser::generation_params & inputs);
 
 common_chat_params common_chat_params_init_kimi_k2(const common_chat_template & tmpl, const autoparser::generation_params & inputs);

common/parsers/sources.cmake

@@ -9,6 +9,7 @@ set(LLAMA_CHAT_PARSERS_SOURCES
     ${CMAKE_CURRENT_LIST_DIR}/gemma4.cpp
     ${CMAKE_CURRENT_LIST_DIR}/gigachat-v3.cpp
     ${CMAKE_CURRENT_LIST_DIR}/gpt-oss.cpp
+    ${CMAKE_CURRENT_LIST_DIR}/harmony-xml.cpp
     ${CMAKE_CURRENT_LIST_DIR}/k2-horizon.cpp
     ${CMAKE_CURRENT_LIST_DIR}/kimi-k2.cpp
     ${CMAKE_CURRENT_LIST_DIR}/kimi-k3.cpp

conversion/__init__.py

@@ -24,6 +24,7 @@
     "ArcticForCausalLM": "arctic",
     "AudioFlamingo3ForConditionalGeneration": "qwen",
     "BaiChuanForCausalLM": "baichuan",
+    "BeamForCausalLM": "beam",
     "BaichuanForCausalLM": "baichuan",
     "BailingMoeForCausalLM": "bailingmoe",
     "BailingMoeV2ForCausalLM": "bailingmoe",