model : Apertus model implementation (#15852)

* First attempt

* No permute during convert (fixes qk tensors), proper norm application.

* RoPE = NeoX

* Coherence!

* Migrate xielu params from tensors to hyperparameters

* Simple CUDA kernel

* Revert stupid LLM refactorings

* Chat template support

* configchecker / flake8 errors

* Reorder unary.cu

* I do conclude that LLMs are, in fact, stupid.

* Fix after merge

* Final newline

* Make xIELU an UNARY_OP

* Final newline

* Correctly account for parameter shift

* Argh.

* Update ggml/src/ggml-cpu/unary-ops.cpp

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

* Refactor: remove unused methods, inline and factorize softplus, add const modifiers

* Revert CUDA changes, implement xIELU as a separate OP

* Pesky newline

* Add float2half / half2float for F16 inputs/outputs

* CUDA variants, attempt 2

* Actually, attempt 3

* Update ggml/src/ggml-cuda/unary.cu

Co-authored-by: Johannes Gäßler <johannesg@5d6.de>

* Missing convert header

* Proper formula and reference for xIELU in the comments.

* Modify unary-ops.cpp to add the functor-based logic besides the template system to retain optimizations

* Apply suggestions from code review

Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>

* Add tensor mappings for Apertus to global list instead

* Fix lazy on scalars

* Update ggml/src/ggml-cuda/unary.cu

Co-authored-by: Johannes Gäßler <johannesg@5d6.de>

* Add comment about the constraints on positive/negative alpha

* Change `softplus` to `ggml_softplus`

---------

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
Co-authored-by: Johannes Gäßler <johannesg@5d6.de>
Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>

common/chat-parser.cpp

@@ -75,6 +75,35 @@ bool common_chat_msg_parser::add_tool_calls(const json & arr) {
     }
     return true;
 }
+
+bool common_chat_msg_parser::add_tool_call_short_form(const json & tool_call) {
+    if (!tool_call.is_object() || tool_call.size() != 1) {
+        return false;
+    }
+
+    // Get the tool name (the single key in the object)
+    auto it = tool_call.begin();
+    std::string name = it.key();
+
+    if (name.empty()) {
+        return false;
+    }
+
+    // Get the arguments (the nested object)
+    const json & args_json = it.value();
+    std::string arguments = "";
+
+    if (args_json.is_object()) {
+        arguments = args_json.dump();
+    } else if (args_json.is_string()) {
+        arguments = args_json;
+    } else if (!args_json.is_null()) {
+        // For other types, convert to string representation
+        arguments = args_json.dump();
+    }
+
+    return add_tool_call(name, "", arguments);
+}
 void common_chat_msg_parser::finish() {
     if (!is_partial_ && pos_ != input_.size()) {
         throw std::runtime_error("Unexpected content at end of input");// + input_.substr(pos_));

common/chat-parser.h

@@ -64,6 +64,9 @@ class common_chat_msg_parser {
     // Adds an array of tool calls using their "name", "id" and "arguments" fields.
     bool add_tool_calls(const nlohmann::ordered_json & arr);
 
+    // Adds a tool call using the short form: { "tool_name": { "arg1": val, "arg2": val } }
+    bool add_tool_call_short_form(const nlohmann::ordered_json & tool_call);
+
     void finish();
 
     bool consume_spaces();

common/chat.cpp

@@ -638,6 +638,7 @@ const char * common_chat_format_name(common_chat_format format) {
         case COMMON_CHAT_FORMAT_GPT_OSS: return "GPT-OSS";
         case COMMON_CHAT_FORMAT_SEED_OSS: return "Seed-OSS";
         case COMMON_CHAT_FORMAT_NEMOTRON_V2: return "Nemotron V2";
+        case COMMON_CHAT_FORMAT_APERTUS: return "Apertus";
         default:
             throw std::runtime_error("Unknown chat format");
     }
@@ -801,6 +802,7 @@ static std::string apply(
     }
     tmpl_inputs.add_generation_prompt = inputs.add_generation_prompt;
     tmpl_inputs.extra_context = inputs.extra_context;
+    tmpl_inputs.extra_context["enable_thinking"] = inputs.enable_thinking;
     if (additional_context) {
         tmpl_inputs.extra_context.merge_patch(*additional_context);
     }
@@ -1264,6 +1266,75 @@ static common_chat_params common_chat_params_init_nemotron_v2(const common_chat_
     }
     return data;
 }
+
+static common_chat_params common_chat_params_init_apertus(const common_chat_template & tmpl, const struct templates_params & inputs) {
+    common_chat_params data;
+
+    // Generate the prompt using the apply() function with the template
+    data.prompt = apply(tmpl, inputs);
+    data.format = COMMON_CHAT_FORMAT_APERTUS;
+
+    // Handle thinking tags appropriately based on inputs.enable_thinking
+    if (string_ends_with(data.prompt, "<|inner_prefix|>")) {
+        if (!inputs.enable_thinking) {
+            data.prompt += "<|inner_suffix|>";
+        } else {
+            data.thinking_forced_open = true;
+        }
+    }
+
+    // When tools are present, build grammar for the <|tools_prefix|> format
+    if (!inputs.tools.is_null() && inputs.tools.is_array() && !inputs.tools.empty()) {
+        data.grammar_lazy = true;
+        data.grammar      = build_grammar([&](const common_grammar_builder & builder) {
+            auto schemas = json::array();
+            foreach_function(inputs.tools, [&](const json & tool) {
+                const auto & function = tool.at("function");
+                schemas.push_back({
+                    { "type",       "object"                                                   },
+                    { "properties",
+                        {
+                            { function.at("name"), function.at("parameters") }
+                        }                                                                        },
+                    { "required",   json::array({ function.at("name") }) },
+                });
+            });
+            auto schema = json{
+                        { "type",     "array"                                                         },
+                        { "items",    schemas.size() == 1 ? schemas[0] : json{ { "anyOf", schemas } } },
+                        { "minItems", 1                                                               },
+            };
+            if (!inputs.parallel_tool_calls) {
+                schema["maxItems"] = 1;
+            }
+            builder.add_rule("root",
+                                std::string(data.thinking_forced_open ? "( \"<|inner_suffix|>\" space )? " : "") +
+                                    "\"<|tools_prefix|>\"" + builder.add_schema("tool_calls", schema) + "\"<|tools_suffix|>\"");
+                            });
+        data.grammar_triggers.push_back({ COMMON_GRAMMAR_TRIGGER_TYPE_PATTERN_FULL,
+            // If thinking_forced_open, then we capture the <|inner_suffix|> tag in the grammar,
+            // (important for required tool choice) and in the trigger's first capture (decides what is sent to the grammar)
+            std::string(data.thinking_forced_open ?
+                            "[\\s\\S]*?(<\\|inner_suffix\\|>\\s*)" :
+                            "(?:<\\|inner_prefix\\|>[\\s\\S]*?<\\|inner_suffix\\|>\\s*)?") +
+                "(<\\|tools_prefix\\|>)[\\s\\S]*" });
+        data.preserved_tokens = {
+            "<|system_start|>",
+            "<|system_end|>",
+            "<|developer_start|>",
+            "<|developer_end|>",
+            "<|user_start|>",
+            "<|user_end|>",
+            "<|assistant_start|>",
+            "<|assistant_end|>",
+            "<|inner_prefix|>",
+            "<|inner_suffix|>",
+            "<|tools_prefix|>",
+            "<|tools_suffix|>",
+        };
+    }
+    return data;
+}
 static void common_chat_parse_llama_3_1(common_chat_msg_parser & builder, bool with_builtin_tools = false) {
     if (!builder.syntax().parse_tool_calls) {
         builder.add_content(builder.consume_rest());
@@ -2323,6 +2394,37 @@ static void common_chat_parse_nemotron_v2(common_chat_msg_parser & builder) {
     builder.add_content(builder.consume_rest());
 }
 
+static void common_chat_parse_apertus(common_chat_msg_parser & builder) {
+    // Parse thinking tags
+    builder.try_parse_reasoning("<|inner_prefix|>", "<|inner_suffix|>");
+    if (!builder.syntax().parse_tool_calls) {
+        builder.add_content(builder.consume_rest());
+        return;
+    }
+
+    // Look for tool calls
+    static const common_regex tool_call_regex(regex_escape("<|tools_prefix|>"));
+    if (auto res = builder.try_find_regex(tool_call_regex)) {
+        builder.move_to(res->groups[0].end);
+
+        auto tool_calls_data = builder.consume_json();
+        if (tool_calls_data.json.is_array()) {
+            builder.consume_spaces();
+            if (!builder.try_consume_literal("<|tools_suffix|>")) {
+                throw common_chat_msg_partial_exception("Incomplete tool call");
+            }
+            for (const auto & value : tool_calls_data.json) {
+                if (value.is_object()) {
+                    builder.add_tool_call_short_form(value);
+                }
+            }
+        } else {
+            throw common_chat_msg_partial_exception("Incomplete tool call");
+        }
+    }
+    builder.add_content(builder.consume_rest());
+}
+
 static void common_chat_parse_seed_oss(common_chat_msg_parser & builder) {
     // Parse thinking tags first - this handles the main reasoning content
     builder.try_parse_reasoning("<seed:think>", "</seed:think>");
@@ -2567,6 +2669,11 @@ static common_chat_params common_chat_templates_apply_jinja(
         return common_chat_params_init_nemotron_v2(tmpl, params);
     }
 
+    // Apertus format detection
+    if (src.find("<|system_start|>") != std::string::npos && src.find("<|tools_prefix|>") != std::string::npos) {
+        return common_chat_params_init_apertus(tmpl, params);
+    }
+
     // Use generic handler when mixing tools + JSON schema.
     // TODO: support that mix in handlers below.
     if ((params.tools.is_array() && params.json_schema.is_object())) {
@@ -2734,6 +2841,9 @@ static void common_chat_parse(common_chat_msg_parser & builder) {
         case COMMON_CHAT_FORMAT_NEMOTRON_V2:
             common_chat_parse_nemotron_v2(builder);
             break;
+        case COMMON_CHAT_FORMAT_APERTUS:
+            common_chat_parse_apertus(builder);
+            break;
         default:
             throw std::runtime_error(std::string("Unsupported format: ") + common_chat_format_name(builder.syntax().format));
     }

common/chat.h

@@ -114,6 +114,7 @@ enum common_chat_format {
     COMMON_CHAT_FORMAT_GPT_OSS,
     COMMON_CHAT_FORMAT_SEED_OSS,
     COMMON_CHAT_FORMAT_NEMOTRON_V2,
+    COMMON_CHAT_FORMAT_APERTUS,
 
     COMMON_CHAT_FORMAT_COUNT, // Not a format, just the # formats
 };

convert_hf_to_gguf.py

@@ -8945,6 +8945,43 @@ class SmallThinkerModel(TextModel):
                 raise ValueError(f"Unprocessed experts: {experts}")
 
 
+@ModelBase.register("ApertusForCausalLM")
+class ApertusModel(LlamaModel):
+    model_arch = gguf.MODEL_ARCH.APERTUS
+    undo_permute = False
+
+    _alpha_n = {}
+    _alpha_p = {}
+    _beta = {}
+    _eps = {}
+
+    def modify_tensors(self, data_torch, name, bid):
+        # Handle xIELU activation parameters
+        n_layers = self.hparams["num_hidden_layers"]
+        if name.endswith(".act_fn.alpha_n"):
+            self._alpha_n[bid] = data_torch.to("cpu").float().item()
+            if (len(self._alpha_n) == n_layers):
+                self.gguf_writer.add_xielu_alpha_n([self._alpha_n[k] for k in sorted(self._alpha_n)])
+            return []
+        if name.endswith(".act_fn.alpha_p"):
+            self._alpha_p[bid] = data_torch.to("cpu").float().item()
+            if (len(self._alpha_p) == n_layers):
+                self.gguf_writer.add_xielu_alpha_p([self._alpha_p[k] for k in sorted(self._alpha_p)])
+            return []
+        if name.endswith(".act_fn.beta"):
+            self._beta[bid] = data_torch.to("cpu").float().item()
+            if (len(self._beta) == n_layers):
+                self.gguf_writer.add_xielu_beta([self._beta[k] for k in sorted(self._beta)])
+            return []
+        if name.endswith(".act_fn.eps"):
+            self._eps[bid] = data_torch.to("cpu").float().item()
+            if (len(self._eps) == n_layers):
+                self.gguf_writer.add_xielu_eps([self._eps[k] for k in sorted(self._eps)])
+            return []
+
+        return super().modify_tensors(data_torch, name, bid)
+
+
 class MistralModel(LlamaModel):
     model_arch = gguf.MODEL_ARCH.LLAMA
     model_name = "Mistral"
@@ -9112,7 +9149,7 @@ class LazyTorchTensor(gguf.LazyBase):
     def from_safetensors_slice(cls, st_slice: Any) -> Tensor:
         dtype = cls._dtype_str_map[st_slice.get_dtype()]
         shape: tuple[int, ...] = tuple(st_slice.get_shape())
-        lazy = cls(meta=cls.meta_with_dtype_and_shape(dtype, shape), args=(st_slice,), func=lambda s: s[:])
+        lazy = cls(meta=cls.meta_with_dtype_and_shape(dtype, shape), args=(st_slice,), func=lambda s: s[...] if len(s.get_shape()) == 0 else s[:])
         return cast(torch.Tensor, lazy)
 
     @classmethod

ggml/include/ggml.h

@@ -576,6 +576,7 @@ extern "C" {
         GGML_UNARY_OP_HARDSIGMOID,
         GGML_UNARY_OP_EXP,
         GGML_UNARY_OP_GELU_ERF,
+        GGML_UNARY_OP_XIELU,
 
         GGML_UNARY_OP_COUNT,
     };
@@ -1150,6 +1151,18 @@ extern "C" {
             struct ggml_context * ctx,
             struct ggml_tensor  * a);
 
+    // xIELU activation function
+    // x = x * (c_a(alpha_n) + c_b(alpha_p, beta) * sigmoid(beta * x)) + eps * (x > 0)
+    // where c_a = softplus and c_b(a, b) = softplus(a) + b are constraining functions
+    // that constrain the positive and negative source alpha values respectively
+    GGML_API struct ggml_tensor * ggml_xielu(
+            struct ggml_context * ctx,
+            struct ggml_tensor  * a,
+            float alpha_n,
+            float alpha_p,
+            float beta,
+            float eps);
+
     // gated linear unit ops
     // A: n columns, r rows,
     // result is n / 2 columns, r rows,

ggml/src/ggml-cpu/ggml-cpu.c

@@ -2187,6 +2187,7 @@ static int ggml_get_n_tasks(struct ggml_tensor * node, int n_threads) {
                 case GGML_UNARY_OP_GELU_ERF:
                 case GGML_UNARY_OP_GELU_QUICK:
                 case GGML_UNARY_OP_SILU:
+                case GGML_UNARY_OP_XIELU:
                     {
                         n_tasks = n_threads;
                     } break;

ggml/src/ggml-cpu/ops.cpp

@@ -8637,7 +8637,7 @@ static void ggml_compute_forward_ssm_scan_f32(
                 // n_head
                 for (int h = ih0; h < ih1; ++h) {
                     // ref: https://github.com/state-spaces/mamba/blob/62db608da60f6fc790b8ed9f4b3225e95ca15fde/mamba_ssm/ops/triton/softplus.py#L16
-                    const float dt_soft_plus = dt[h] <= 20.0f ? log1pf(expf(dt[h])) : dt[h];
+                    const float dt_soft_plus = ggml_softplus(dt[h]);
                     const float dA = expf(dt_soft_plus * A[h]);
                     const int g = h / (nh / ng); // repeat_interleave
 
@@ -8734,7 +8734,7 @@ static void ggml_compute_forward_ssm_scan_f32(
                 // n_head
                 for (int h = ih0; h < ih1; ++h) {
                     // ref: https://github.com/state-spaces/mamba/blob/62db608da60f6fc790b8ed9f4b3225e95ca15fde/mamba_ssm/ops/triton/softplus.py#L16
-                    const float dt_soft_plus = dt[h] <= 20.0f ? log1pf(expf(dt[h])) : dt[h];
+                    const float dt_soft_plus = ggml_softplus(dt[h]);
                     const int g = h / (nh / ng); // repeat_interleave
 
                     // dim
@@ -8997,6 +8997,10 @@ void ggml_compute_forward_unary(
             {
                 ggml_compute_forward_exp(params, dst);
             } break;
+        case GGML_UNARY_OP_XIELU:
+            {
+                ggml_compute_forward_xielu(params, dst);
+            } break;
         default:
             {
                 GGML_ABORT("fatal error");

ggml/src/ggml-cpu/unary-ops.cpp

@@ -52,6 +52,15 @@ static inline float op_sqrt(float x) {
     return sqrtf(x);
 }
 
+static inline float op_xielu(float x, float alpha_n, float alpha_p, float beta, float eps) {
+    if (x > 0.0f) {
+        return alpha_p * x * x + beta * x;
+    } else {
+        const float min_x_eps = fminf(x, eps);
+        return (expm1f(min_x_eps) - x) * alpha_n + beta * x;
+    }
+}
+
 static inline float op_sin(float x) {
     return sinf(x);
 }
@@ -121,6 +130,86 @@ static void unary_op(const ggml_compute_params * params, ggml_tensor * dst) {
     }
 }
 
+template <float (*op)(float, ggml_tensor *)>
+static void unary_op_params(const ggml_compute_params * params, ggml_tensor * dst) {
+    const ggml_tensor * src0 = dst->src[0];
+
+    /*  */ if (src0->type == GGML_TYPE_F32  && dst->type == GGML_TYPE_F32) { // all f32
+        apply_unary_op<op, float, float>(params, dst);
+    } else if (src0->type == GGML_TYPE_F16  && dst->type == GGML_TYPE_F16) { // all f16
+        apply_unary_op<op, ggml_fp16_t, ggml_fp16_t>(params, dst);
+    } else if (src0->type == GGML_TYPE_BF16 && dst->type == GGML_TYPE_BF16) { // all bf16
+        apply_unary_op<op, ggml_bf16_t, ggml_bf16_t>(params, dst);
+    } else if (src0->type == GGML_TYPE_BF16 && dst->type == GGML_TYPE_F32) {
+        apply_unary_op<op, ggml_bf16_t, float>(params, dst);
+    } else if (src0->type == GGML_TYPE_F16  && dst->type == GGML_TYPE_F32) {
+        apply_unary_op<op, ggml_fp16_t, float>(params, dst);
+    } else {
+        fprintf(stderr, "%s: unsupported types: dst: %s, src0: %s\n", __func__,
+            ggml_type_name(dst->type), ggml_type_name(src0->type));
+        GGML_ABORT("fatal error");
+    }
+}
+
+// Extend vec_unary_op to support functors
+template <typename Op, typename src0_t, typename dst_t>
+static inline void vec_unary_op_functor(int64_t n, dst_t * y, const src0_t * x, Op op) {
+    constexpr auto src0_to_f32 = type_conversion_table<src0_t>::to_f32;
+    constexpr auto f32_to_dst  = type_conversion_table<dst_t >::from_f32;
+
+    for (int i = 0; i < n; i++) {
+        y[i] = f32_to_dst(op(src0_to_f32(x[i])));
+    }
+}
+
+// Extend apply_unary_op to support functors
+template <typename Op, typename src0_t, typename dst_t>
+static void apply_unary_op_functor(const ggml_compute_params * params, ggml_tensor * dst, Op op) {
+    const ggml_tensor * src0 = dst->src[0];
+
+    GGML_ASSERT(ggml_is_contiguous_1(src0) && ggml_is_contiguous_1(dst) && ggml_are_same_shape(src0, dst));
+
+    GGML_TENSOR_UNARY_OP_LOCALS
+
+    GGML_ASSERT( nb0 == sizeof(dst_t));
+    GGML_ASSERT(nb00 == sizeof(src0_t));
+
+    const auto [ir0, ir1] = get_thread_range(params, src0);
+
+    for (int64_t ir = ir0; ir < ir1; ++ir) {
+        const int64_t i03 = ir/(ne02*ne01);
+        const int64_t i02 = (ir - i03*ne02*ne01)/ne01;
+        const int64_t i01 = (ir - i03*ne02*ne01 - i02*ne01);
+
+        dst_t        * dst_ptr  = (dst_t  *)       ((char *)       dst->data  + i03*nb3  + i02*nb2  + i01*nb1 );
+        const src0_t * src0_ptr = (const src0_t *) ((const char *) src0->data + i03*nb03 + i02*nb02 + i01*nb01);
+
+        vec_unary_op_functor(ne0, dst_ptr, src0_ptr, op);
+    }
+}
+
+// Generic dispatcher for functors
+template <typename Op>
+static void unary_op_functor(const ggml_compute_params * params, ggml_tensor * dst, Op op) {
+    const ggml_tensor * src0 = dst->src[0];
+
+    /*  */ if (src0->type == GGML_TYPE_F32  && dst->type == GGML_TYPE_F32) { // all f32
+        apply_unary_op_functor<Op, float, float>(params, dst, op);
+    } else if (src0->type == GGML_TYPE_F16  && dst->type == GGML_TYPE_F16) { // all f16
+        apply_unary_op_functor<Op, ggml_fp16_t, ggml_fp16_t>(params, dst, op);
+    } else if (src0->type == GGML_TYPE_BF16 && dst->type == GGML_TYPE_BF16) { // all bf16
+        apply_unary_op_functor<Op, ggml_bf16_t, ggml_bf16_t>(params, dst, op);
+    } else if (src0->type == GGML_TYPE_BF16 && dst->type == GGML_TYPE_F32) {
+        apply_unary_op_functor<Op, ggml_bf16_t, float>(params, dst, op);
+    } else if (src0->type == GGML_TYPE_F16  && dst->type == GGML_TYPE_F32) {
+        apply_unary_op_functor<Op, ggml_fp16_t, float>(params, dst, op);
+    } else {
+        fprintf(stderr, "%s: unsupported types: dst: %s, src0: %s\n", __func__,
+            ggml_type_name(dst->type), ggml_type_name(src0->type));
+        GGML_ABORT("fatal error");
+    }
+}
+
 void ggml_compute_forward_abs(const ggml_compute_params * params, ggml_tensor * dst) {
     unary_op<op_abs>(params, dst);
 }
@@ -184,3 +273,17 @@ void ggml_compute_forward_cos(const ggml_compute_params * params, ggml_tensor *
 void ggml_compute_forward_log(const ggml_compute_params * params, ggml_tensor * dst) {
     unary_op<op_log>(params, dst);
 }
+
+void ggml_compute_forward_xielu(const ggml_compute_params * params, ggml_tensor * dst) {
+    const float alpha_n = ggml_get_op_params_f32(dst, 1);
+    const float alpha_p = ggml_get_op_params_f32(dst, 2);
+    const float beta = ggml_get_op_params_f32(dst, 3);
+    const float eps = ggml_get_op_params_f32(dst, 4);
+
+    const auto xielu_op_params = [alpha_n, alpha_p, beta, eps](float f) {
+        return op_xielu(f, alpha_n, alpha_p, beta, eps);
+    };
+
+    unary_op_functor(params, dst, xielu_op_params);
+}
+

ggml/src/ggml-cpu/unary-ops.h

@@ -22,6 +22,7 @@ void ggml_compute_forward_sqrt(const struct ggml_compute_params * params, struct
 void ggml_compute_forward_sin(const struct ggml_compute_params * params, struct ggml_tensor * dst);
 void ggml_compute_forward_cos(const struct ggml_compute_params * params, struct ggml_tensor * dst);
 void ggml_compute_forward_log(const struct ggml_compute_params * params, struct ggml_tensor * dst);
+void ggml_compute_forward_xielu(const struct ggml_compute_params * params, struct ggml_tensor * dst);
 
 #ifdef __cplusplus
 }

ggml/src/ggml-cuda/ggml-cuda.cu

@@ -2334,6 +2334,9 @@ static bool ggml_cuda_compute_forward(ggml_backend_cuda_context & ctx, struct gg
                 case GGML_UNARY_OP_ELU:
                     ggml_cuda_op_elu(ctx, dst);
                     break;
+                case GGML_UNARY_OP_XIELU:
+                    ggml_cuda_op_xielu(ctx, dst);
+                    break;
                 default:
                     return false;
             }

ggml/src/ggml-cuda/unary.cu

@@ -1,4 +1,5 @@
 #include "unary.cuh"
+#include "convert.cuh"
 
 static __device__ __forceinline__ float op_abs(float x) {
     return fabsf(x);
@@ -375,6 +376,59 @@ void ggml_cuda_op_swiglu_oai(ggml_backend_cuda_context & ctx, ggml_tensor * dst)
     swiglu_oai_cuda(src0_p, src1_p, (float *)dst_d, ggml_nelements(dst), nc, src0_o / sizeof(float), src1_o / sizeof(float), alpha, limit, stream);
 }
 
+/* CUDA kernel + launcher for xIELU */
+
+template <typename T>
+static __global__ void xielu_kernel(const T * x, T * dst, const int k, float alpha_n, float alpha_p, float beta, float eps) {
+    const int i = blockDim.x*blockIdx.x + threadIdx.x;
+
+    if (i >= k) {
+        return;
+    }
+
+    const float xi = ggml_cuda_cast<float>(x[i]);
+
+    const float gate_pos = (xi > 0.0f);
+    const float y_pos = alpha_p * xi * xi + beta * xi;
+    const float min_v_eps = fminf(xi, eps);
+    const float y_neg = (expm1f(min_v_eps) - xi) * alpha_n + beta * xi;
+    const float out = gate_pos * y_pos + (1.0f - gate_pos) * y_neg;
+
+    dst[i] = ggml_cuda_cast<T>(out);
+}
+
+template <typename T>
+static void xielu_cuda(const T * x, T * dst, const int k, float alpha_n, float alpha_p, float beta, float eps, cudaStream_t stream) {
+    const int num_blocks = (k + CUDA_XIELU_BLOCK_SIZE) / CUDA_XIELU_BLOCK_SIZE;
+    xielu_kernel<<<num_blocks, CUDA_XIELU_BLOCK_SIZE, 0, stream>>>(x, dst, k, alpha_n, alpha_p, beta, eps);
+}
+
+void ggml_cuda_op_xielu(ggml_backend_cuda_context & ctx, ggml_tensor * dst) {
+    const ggml_tensor * src0 = dst->src[0];
+    const void * src0_d = src0->data;
+    void * dst_d = dst->data;
+    cudaStream_t stream = ctx.stream();
+
+    GGML_ASSERT(ggml_is_contiguous(src0));
+
+    GGML_ASSERT(src0->type == GGML_TYPE_F32 || src0->type == GGML_TYPE_F16);
+    GGML_ASSERT( dst->type == GGML_TYPE_F32 ||  dst->type == GGML_TYPE_F16);
+    GGML_ASSERT(src0->type == dst->type);
+
+    const float alpha_n = ggml_get_op_params_f32(dst, 1);
+    const float alpha_p = ggml_get_op_params_f32(dst, 2);
+    const float beta    = ggml_get_op_params_f32(dst, 3);
+    const float eps     = ggml_get_op_params_f32(dst, 4);
+
+    if (src0->type == GGML_TYPE_F16) {
+        xielu_cuda((const half *)src0_d, (half *)dst_d, ggml_nelements(src0), alpha_n, alpha_p, beta, eps, stream);
+    } else {
+        xielu_cuda((const float *)src0_d, (float *)dst_d, ggml_nelements(src0), alpha_n, alpha_p, beta, eps, stream);
+    }
+}
+
+
+
 /* silu_back */
 
 static __device__ __forceinline__ float op_silu_back(float grad, float x) {

ggml/src/ggml-cuda/unary.cuh

@@ -16,6 +16,7 @@
 #define CUDA_SIN_BLOCK_SIZE 256
 #define CUDA_COS_BLOCK_SIZE 256
 #define CUDA_GLU_BLOCK_SIZE 256
+#define CUDA_XIELU_BLOCK_SIZE 256
 
 void ggml_cuda_op_abs(ggml_backend_cuda_context & ctx, ggml_tensor * dst);
 
@@ -72,3 +73,5 @@ void ggml_cuda_op_swiglu_oai(ggml_backend_cuda_context & ctx, ggml_tensor * dst)
 void ggml_cuda_op_geglu_erf(ggml_backend_cuda_context & ctx, ggml_tensor * dst);
 
 void ggml_cuda_op_geglu_quick(ggml_backend_cuda_context & ctx, ggml_tensor * dst);
+
+void ggml_cuda_op_xielu(ggml_backend_cuda_context & ctx, ggml_tensor * dst);

ggml/src/ggml-impl.h

@@ -102,6 +102,9 @@ static bool ggml_op_is_empty(enum ggml_op op) {
     }
 }
 
+static inline float ggml_softplus(float input) {
+    return (input > 20.0f) ? input : logf(1 + expf(input));
+}
 //
 // logging
 //

ggml/src/ggml.c

@@ -1143,10 +1143,10 @@ static const char * GGML_UNARY_OP_NAME[GGML_UNARY_OP_COUNT] = {
     "HARDSIGMOID",
     "EXP",
     "GELU_ERF",
+    "XIELU",
 };
 
-static_assert(GGML_UNARY_OP_COUNT == 15, "GGML_UNARY_OP_COUNT != 15");
-
+static_assert(GGML_UNARY_OP_COUNT == 16, "GGML_UNARY_OP_COUNT != 16");
 
 static const char * GGML_GLU_OP_NAME[GGML_GLU_OP_COUNT] = {
     "REGLU",
@@ -2652,6 +2652,29 @@ struct ggml_tensor * ggml_silu_inplace(
     return ggml_unary_inplace(ctx, a, GGML_UNARY_OP_SILU);
 }
 
+// ggml_xielu
+
+struct ggml_tensor * ggml_xielu(
+        struct ggml_context * ctx,
+        struct ggml_tensor  * a,
+        float alpha_n,
+        float alpha_p,
+        float beta,
+        float eps) {
+    struct ggml_tensor * result = ggml_dup_tensor(ctx, a);
+
+    ggml_set_op_params_i32(result, 0, (int32_t) GGML_UNARY_OP_XIELU);
+    ggml_set_op_params_f32(result, 1, beta + ggml_softplus(alpha_n));
+    ggml_set_op_params_f32(result, 2, ggml_softplus(alpha_p));
+    ggml_set_op_params_f32(result, 3, beta);
+    ggml_set_op_params_f32(result, 4, eps);
+
+    result->op     = GGML_OP_UNARY;
+    result->src[0] = a;
+
+    return result;
+}
+
 // ggml_silu_back
 
 struct ggml_tensor * ggml_silu_back(

gguf-py/gguf/constants.py

@@ -297,6 +297,13 @@ class Keys:
     class Diffusion:
         SHIFT_LOGITS        = "diffusion.shift_logits"
 
+    class xIELU:
+        ALPHA_P             = "xielu.alpha_p"
+        ALPHA_N             = "xielu.alpha_n"
+        BETA                = "xielu.beta"
+        EPS                 = "xielu.eps"
+
+
 #
 # recommended mapping of model tensor names for storage in gguf
 #
@@ -405,6 +412,7 @@ class MODEL_ARCH(IntEnum):
     LLADA_MOE        = auto()
     SEED_OSS         = auto()
     GROVEMOE         = auto()
+    APERTUS          = auto()
 
 
 class VISION_PROJECTOR_TYPE(IntEnum):
@@ -746,6 +754,7 @@ MODEL_ARCH_NAMES: dict[MODEL_ARCH, str] = {
     MODEL_ARCH.LLADA_MOE:        "llada-moe",
     MODEL_ARCH.SEED_OSS:         "seed_oss",
     MODEL_ARCH.GROVEMOE:         "grovemoe",
+    MODEL_ARCH.APERTUS:          "apertus",
 }
 
 VISION_PROJECTOR_TYPE_NAMES: dict[VISION_PROJECTOR_TYPE, str] = {
@@ -2706,6 +2715,24 @@ MODEL_TENSORS: dict[MODEL_ARCH, list[MODEL_TENSOR]] = {
         MODEL_TENSOR.FFN_DOWN_EXP,
         MODEL_TENSOR.FFN_UP_EXP,
     ],
+    MODEL_ARCH.APERTUS: [
+        MODEL_TENSOR.TOKEN_EMBD,
+        MODEL_TENSOR.OUTPUT_NORM,
+        MODEL_TENSOR.OUTPUT,
+        MODEL_TENSOR.ROPE_FREQS,
+        MODEL_TENSOR.ATTN_NORM,
+        MODEL_TENSOR.ATTN_Q,
+        MODEL_TENSOR.ATTN_K,
+        MODEL_TENSOR.ATTN_V,
+        MODEL_TENSOR.ATTN_OUT,
+        MODEL_TENSOR.ATTN_ROT_EMBD,
+        MODEL_TENSOR.ATTN_Q_NORM,
+        MODEL_TENSOR.ATTN_K_NORM,
+        MODEL_TENSOR.FFN_NORM,
+        MODEL_TENSOR.FFN_GATE,
+        MODEL_TENSOR.FFN_DOWN,
+        MODEL_TENSOR.FFN_UP,
+    ],
     MODEL_ARCH.LLADA_MOE: [
         MODEL_TENSOR.TOKEN_EMBD,
         MODEL_TENSOR.OUTPUT_NORM,

gguf-py/gguf/gguf_writer.py

@@ -1084,6 +1084,18 @@ class GGUFWriter:
     def add_audio_stack_factor(self, value: int) -> None:
         self.add_uint32(Keys.ClipAudio.Projector.STACK_FACTOR, value)
 
+    def add_xielu_alpha_p(self, values: Sequence[float]):
+        self.add_array(Keys.xIELU.ALPHA_P, values)
+
+    def add_xielu_alpha_n(self, values: Sequence[float]):
+        self.add_array(Keys.xIELU.ALPHA_N, values)
+
+    def add_xielu_beta(self, values: Sequence[float]):
+        self.add_array(Keys.xIELU.BETA, values)
+
+    def add_xielu_eps(self, values: Sequence[float]):
+        self.add_array(Keys.xIELU.EPS, values)
+
     # diffusion models
 
     def add_diffusion_shift_logits(self, value: bool) -> None:

gguf-py/gguf/tensor_mapping.py

@@ -148,6 +148,7 @@ class TensorNameMap:
             "model.layers.{bid}.operator_norm",                     # lfm2
             "model.transformer.blocks.{bid}.attn_norm",             # llada
             "layers.{bid}.input_layernorm",                         # qwen3-embedding
+            "model.layers.{bid}.attention_layernorm"                # apertus
         ),
 
         # Attention norm 2
@@ -325,6 +326,7 @@ class TensorNameMap:
             "model.layers.layers.{bid}.pre_mlp_norm",                        # plamo2
             "model.transformer.blocks.{bid}.ff_norm",                        # llada
             "layers.{bid}.post_attention_layernorm",                         # qwen3-embedding
+            "model.layers.{bid}.feedforward_layernorm",                      # apertus
         ),
 
         # Post feed-forward norm
@@ -547,6 +549,7 @@ class TensorNameMap:
             "transformer.layers.{bid}.attn.q_norm",                           # openelm
             "model.layers.layers.{bid}.mixer.q",                              # plamo2
             "layers.{bid}.self_attn.q_norm",                                  # qwen3-embedding
+            "model.layers.{bid}.attention.query_layernorm",                   # apertus
         ),
 
         MODEL_TENSOR.ATTN_K_NORM: (
@@ -560,6 +563,7 @@ class TensorNameMap:
             "transformer.layers.{bid}.attn.k_norm",                           # openelm
             "model.layers.layers.{bid}.mixer.k",                              # plamo2
             "layers.{bid}.self_attn.k_norm",                                  # qwen3-embedding
+            "model.layers.{bid}.attention.key_layernorm",                     # apertus
         ),
 
         MODEL_TENSOR.ROPE_FREQS: (

models/templates/Apertus-8B-Instruct.jinja

@@ -0,0 +1,327 @@
+{%- macro render_typescript_type(param_spec, required_params, is_nullable=false) -%}
+    {%- if param_spec.type == "array" -%}
+        {%- if param_spec['items'] -%}
+            {%- if param_spec['items']['type'] == "string" -%}
+                {{- "string[]" }}
+            {%- elif param_spec['items']['type'] == "number" -%}
+                {{- "number[]" }}
+            {%- elif param_spec['items']['type'] == "integer" -%}
+                {{- "number[]" }}
+            {%- elif param_spec['items']['type'] == "boolean" -%}
+                {{- "boolean[]" }}
+            {%- else -%}
+                {%- set inner_type = render_typescript_type(param_spec['items'], required_params) -%}
+                {%- if inner_type == "object | object" or inner_type|length > 50 -%}
+                    {{- "any[]" }}
+                {%- else -%}
+                    {{- inner_type + "[]" }}
+                {%- endif -%}
+            {%- endif -%}
+            {%- if param_spec.nullable -%}
+                {{- " | null" }}
+            {%- endif -%}
+        {%- else -%}
+            {{- "any[]" }}
+            {%- if param_spec.nullable -%}
+                {{- " | null" }}
+            {%- endif -%}
+        {%- endif -%}
+    {%- elif param_spec.type is defined and param_spec.type is iterable and param_spec.type is not string and param_spec.type is not mapping and param_spec.type[0] is defined -%}
+        {#- Handle array of types like ["object", "object"] from Union[dict, list] #}
+        {%- if param_spec.type | length > 1 -%}
+            {{- param_spec.type | join(" | ") }}
+        {%- else -%}
+            {{- param_spec.type[0] }}
+        {%- endif -%}
+    {%- elif param_spec.oneOf -%}
+        {#- Handle oneOf schemas - check for complex unions and fallback to any #}
+        {%- set has_object_variants = false -%}
+        {%- for variant in param_spec.oneOf -%}
+            {%- if variant.type == "object" -%}
+                {%- set has_object_variants = true -%}
+            {%- endif -%}
+        {%- endfor -%}
+        {%- if has_object_variants and param_spec.oneOf|length > 1 -%}
+            {{- "any" }}
+        {%- else -%}
+            {%- for variant in param_spec.oneOf -%}
+                {{- render_typescript_type(variant, required_params) -}}
+                {%- if variant.description %}
+                    {{- "// " + variant.description }}
+                {%- endif -%}
+                {%- if variant.default is defined %}
+                    {{ "// default: " + variant.default|tojson }}
+                {%- endif -%}
+                {%- if not loop.last %}
+                    {{- " | " }}
+                {% endif -%}
+            {%- endfor -%}
+        {%- endif -%}
+    {%- elif param_spec.type == "string" -%}
+        {%- if param_spec.enum -%}
+            {{- '"' + param_spec.enum|join('" | "') + '"' -}}
+        {%- else -%}
+            {{- "string" }}
+            {%- if param_spec.nullable %}
+                {{- " | null" }}
+            {%- endif -%}
+        {%- endif -%}
+    {%- elif param_spec.type == "number" -%}
+        {{- "number" }}
+    {%- elif param_spec.type == "integer" -%}
+        {{- "number" }}
+    {%- elif param_spec.type == "boolean" -%}
+        {{- "boolean" }}
+    {%- elif param_spec.type == "object" -%}
+        {%- if param_spec.properties -%}
+            {{- "{\n" }}
+            {%- for prop_name, prop_spec in param_spec.properties.items() -%}
+                {{- prop_name -}}
+                {%- if prop_name not in (param_spec.required or []) -%}
+                    {{- "?" }}
+                {%- endif -%}
+                {{- ": " }}
+                {{ render_typescript_type(prop_spec, param_spec.required or []) }}
+                {%- if not loop.last -%}
+                    {{-", " }}
+                {%- endif -%}
+            {%- endfor -%}
+            {{- "}" }}
+        {%- else -%}
+            {{- "object" }}
+        {%- endif -%}
+    {%- else -%}
+        {{- "any" }}
+    {%- endif -%}
+{%- endmacro -%}
+
+{%- macro render_tools(tools) -%}
+    {%- for tool in tools %}
+        {{- "// " + tool.description + "\n" }}
+        {{- "type "+ tool.name + " = " }}
+        {%- if tool.parameters and tool.parameters.properties %}
+            {{- "(_: {\n" }}
+            {%- for param_name, param_spec in tool.parameters.properties.items() %}
+                {%- if param_spec.description %}
+                    {{- "// " + param_spec.description + "\n" }}
+                {%- endif %}
+                {{- param_name }}
+                {%- if param_name not in (tool.parameters.required or []) -%}
+                    {{- "?" }}
+                {%- endif -%}
+                {{- ": " }}
+                {{- render_typescript_type(param_spec, tool.parameters.required or []) }}
+                {%- if param_spec.default is defined -%}
+                    {%- if param_spec.enum %}
+                        {{- ", // default: " + param_spec.default }}
+                    {%- elif param_spec.oneOf %}
+                        {{- "// default: " + param_spec.default }}
+                    {%- else %}
+                        {{- ", // default: " + param_spec.default|tojson }}
+                    {%- endif -%}
+                {%- endif -%}
+                {%- if not loop.last %}
+                    {{- ",\n" }}
+                {%- else %}
+                    {{- "\n" }}
+                {%- endif -%}
+            {%- endfor %}
+            {{- "}) => any;" }}
+        {%- else -%}
+            {{- "() => any;" }}
+        {%- endif -%}
+        {%- if not loop.last -%}
+            {{- "\n" }}
+        {%- endif -%}
+    {%- endfor %}
+{%- endmacro -%}
+
+{{ bos_token }}
+
+{%- set system_token = '<|system_start|>' -%}
+{%- set end_system_token = '<|system_end|>' -%}
+{%- set developer_token = '<|developer_start|>' -%}
+{%- set end_developer_token = '<|developer_end|>' -%}
+{%- set user_token = '<|user_start|>' -%}
+{%- set end_user_token = '<|user_end|>' -%}
+{%- set assistant_token = '<|assistant_start|>' -%}
+{%- set end_assistant_token = '<|assistant_end|>' -%}
+{%- set inner_token = '<|inner_prefix|>' -%}
+{%- set outer_token = '<|inner_suffix|>' -%}
+{%- set tool_calls_token = '<|tools_prefix|>' -%}
+{%- set end_tool_calls_token = '<|tools_suffix|>' -%}
+
+{%- set ns = namespace(in_assistant=false, in_tool=false, in_inner=false, assistant_format=none) -%}
+
+{%- if messages and messages[0].role == 'system' -%}
+    {%- if "content" in messages[0] -%}
+        {%- if messages[0].content is string -%}
+            {{ system_token + messages[0].content + end_system_token }}
+        {%- elif messages[0].content is mapping and "text" in messages[0].content -%}
+            {{ system_token + messages[0].content.text + end_system_token }}
+        {%- else -%}
+            {{- raise_exception("Invalid system message") -}}
+        {%- endif -%}
+    {%- else -%}
+        {{- raise_exception("Invalid system message") -}}
+    {%- endif -%}
+    {%- set loop_messages = messages[1:] -%}
+{%- else -%}
+    {{ system_token + 'You are Apertus, a helpful assistant created by the SwissAI initiative.\nKnowledge cutoff: 2024-04\nCurrent date: ' + strftime_now('%Y-%m-%d') + end_system_token }}
+    {%- set loop_messages = messages -%}
+{%- endif -%}
+
+{{ developer_token + 'Deliberation: ' }}
+{%- if enable_thinking is defined and enable_thinking -%}
+    {{ 'enabled\n' }}
+{%- else -%}
+    {{ 'disabled\n' }}
+{%- endif -%}
+{%- if tools is defined and tools -%}
+    {{ 'Tool Capabilities:\n' + render_tools(tools) }}
+{%- else -%}
+    {{ 'Tool Capabilities: disabled' }}
+{%- endif -%}
+{{ end_developer_token }}
+
+{%- for message in loop_messages -%}
+    {%- if message.role == 'user' -%}
+        {%- set ns.in_inner = false -%}
+        {%- if ns.in_tool -%}
+            {{ ']' }}
+            {%- set ns.in_tool = false -%}
+        {%- endif -%}
+        {%- if ns.in_assistant -%}
+            {{ end_assistant_token }}
+            {%- set ns.in_assistant = false -%}
+        {%- endif -%}
+        {%- if "content" in message -%}
+            {{ user_token }}
+            {%- if message.content is string -%}
+                {{ message.content }}
+            {%- elif message.content is mapping and "parts" in message.content -%}
+                {%- set parts = message.content.parts -%}
+                {%- for part in parts -%}
+                    {%- if part.type == "text" -%}
+                        {{ part.text }}
+                    {%- else -%}
+                        {{- raise_exception("Invalid user part: " + part.type) -}}
+                    {%- endif -%}
+                {%- endfor -%}
+            {%- else -%}
+                {{- raise_exception("Invalid user message: " + message.role) -}}
+            {%- endif -%}
+            {{ end_user_token }}
+        {%- endif -%}
+    {%- elif message.role == 'assistant' -%}
+        {%- if not ns.in_assistant -%}
+            {{ assistant_token }}
+            {%- set ns.in_assistant = true -%}
+        {%- endif -%}
+        {%- if "content" in message and message.content is not none -%}
+            {%- if message.content is string and (ns.assistant_format is none or ns.assistant_format == "string") -%}
+                {%- if ns.in_tool -%}
+                    {{ ']' }}
+                    {%- set ns.in_tool = false -%}
+                {%- endif -%}
+                {%- set ns.assistant_format = "string" -%}
+                {{ message.content }}
+            {%- elif message.content is mapping and "blocks" in message.content and (ns.assistant_format is none or ns.assistant_format == "mapping") -%}
+                {%- set ns.assistant_format = "mapping" -%}
+                {%- set blocks = message.content.blocks -%}
+                {%- for block in blocks -%}
+                    {%- if block.type == 'thoughts' -%}
+                        {%- if ns.in_tool -%}
+                            {{ ']' }}
+                            {%- set ns.in_tool = false -%}
+                        {%- endif -%}
+                        {%- if not ns.in_inner -%}
+                            {%- set ns.in_inner = true -%}
+                            {{ inner_token }}
+                        {%- endif -%}
+                        {{ block.text }}
+                    {%- elif block.type == 'tool_calls' -%}
+                        {%- if ns.in_tool -%}
+                            {{ ']' }}
+                            {%- set ns.in_tool = false -%}
+                        {%- endif -%}
+                        {%- if ns.in_inner and not loop.first and block.calls|length == 1 and block.calls[0].name == 'display_answers' -%}
+                            {%- set ns.in_inner = false -%}
+                            {{ outer_token }}
+                        {%- endif -%}
+                        {{ tool_calls_token + '[' }}
+                        {%- for tool_call in block.calls -%}
+                            {{- '{"' + tool_call.name + '": ' + tool_call.arguments + '}' }}
+                            {%- if not loop.last -%}
+                                {{- ", " }}
+                            {%- endif -%}
+                        {%- endfor -%}
+                        {{ ']' + end_tool_calls_token }}
+                    {%- elif block.type == 'tool_outputs' -%}
+                        {%- if ns.in_tool -%}
+                            {{- raise_exception("Cannot have both tool outputs as separate messages and tool outputs as blocks") -}}
+                        {%- endif -%}
+                        {{ '[' }}
+                        {%- for tool_output in block.outputs -%}
+                            {{- tool_output.output }}
+                            {%- if not loop.last -%}
+                                {{- ", " }}
+                            {%- endif -%}
+                        {%- endfor -%}
+                        {{- ']' }}
+                    {%- elif block.type == 'response' -%}
+                        {%- if ns.in_tool -%}
+                            {{ ']' }}
+                            {%- set ns.in_tool = false -%}
+                        {%- endif -%}
+                        {%- if (not loop.first and ns.in_inner) or (ns.in_assistant and ns.in_inner) -%}
+                            {%- set ns.in_inner = false -%}
+                            {{ outer_token }}
+                        {%- endif -%}
+                        {{ block.text }}
+                    {%- else -%}
+                        {{- raise_exception("Invalid assistant block type: " + block.type) -}}
+                    {%- endif -%}
+                {%- endfor -%}
+            {%- else -%}
+                {{- raise_exception("Invalid assistant content '" + message.content + "', expected " + ns.assistant_format) -}}
+            {%- endif -%}
+        {%- elif "tool_calls" not in message -%}
+            {{- raise_exception("Invalid assistant message " + message) -}}
+        {%- endif -%}
+        {%- if "tool_calls" in message and message.tool_calls -%}
+            {{ tool_calls_token + '[' }}
+            {%- for tool_call in message.tool_calls -%}
+                {%- if tool_call.type == 'function' -%}
+                    {%- set function = tool_call.function -%}
+                    {{- '{"' + function.name + '": ' + function.arguments + '}' }}
+                    {%- if not loop.last -%}
+                        {{- ", " }}
+                    {%- endif -%}
+                {%- else -%}
+                    {{- raise_exception("Invalid tool call type: " + tool_call.type) -}}
+                {%- endif -%}
+            {%- endfor -%}
+            {{ ']' + end_tool_calls_token }}
+        {%- endif -%}
+    {%- elif message.role == 'tool' -%}
+        {%- if not ns.in_assistant -%}
+            {{- raise_exception("Tool message outside of assistant") -}}
+        {%- endif -%}
+        {%- if not ns.in_tool -%}
+            {{ '[' }}
+            {%- set ns.in_tool = true -%}
+        {%- else -%}
+            {{ ", "}}
+        {%- endif -%}
+        {{ message.content }}
+    {%- else -%}
+        {{- raise_exception("Invalid message role") -}}
+    {%- endif -%}
+{%- endfor -%}
+{%- if ns.in_tool -%}
+    {{ ']' }}
+{%- endif -%}
+{%- if add_generation_prompt -%}
+    {{ assistant_token }}
+{%- endif -%}

src/llama-arch.cpp

@@ -99,6 +99,7 @@ static const std::map<llm_arch, const char *> LLM_ARCH_NAMES = {
     { LLM_ARCH_LLADA_MOE,        "llada-moe"        },
     { LLM_ARCH_SEED_OSS,         "seed_oss"         },
     { LLM_ARCH_GROVEMOE,         "grovemoe"         },
+    { LLM_ARCH_APERTUS,          "apertus"          },
     { LLM_ARCH_UNKNOWN,          "(unknown)"        },
 };
 
@@ -256,6 +257,11 @@ static const std::map<llm_kv, const char *> LLM_KV_NAMES = {
     { LLM_KV_ADAPTER_LORA_PROMPT_PREFIX,      "adapter.lora.prompt_prefix" },
     { LLM_KV_ADAPTER_ALORA_INVOCATION_TOKENS, "adapter.alora.invocation_tokens" },
 
+    { LLM_KV_XIELU_ALPHA_N,         "xielu.alpha_n"         },
+    { LLM_KV_XIELU_ALPHA_P,         "xielu.alpha_p"         },
+    { LLM_KV_XIELU_BETA,            "xielu.beta"            },
+    { LLM_KV_XIELU_EPS,             "xielu.eps"             },
+
     // deprecated
     { LLM_KV_TOKENIZER_PREFIX_ID, "tokenizer.ggml.prefix_token_id" },
     { LLM_KV_TOKENIZER_SUFFIX_ID, "tokenizer.ggml.suffix_token_id" },
@@ -2119,6 +2125,25 @@ static const std::map<llm_arch, std::map<llm_tensor, const char *>> LLM_TENSOR_N
             { LLM_TENSOR_FFN_UP_EXPS,        "blk.%d.ffn_up_exps" }
         },
     },
+    {
+        LLM_ARCH_APERTUS,
+        {
+            { LLM_TENSOR_TOKEN_EMBD,      "token_embd" },
+            { LLM_TENSOR_OUTPUT_NORM,     "output_norm" },
+            { LLM_TENSOR_OUTPUT,          "output" },
+            { LLM_TENSOR_ROPE_FREQS,      "rope_freqs" },
+            { LLM_TENSOR_ATTN_NORM,       "blk.%d.attn_norm" },
+            { LLM_TENSOR_ATTN_Q,          "blk.%d.attn_q" },
+            { LLM_TENSOR_ATTN_K,          "blk.%d.attn_k" },
+            { LLM_TENSOR_ATTN_V,          "blk.%d.attn_v" },
+            { LLM_TENSOR_ATTN_OUT,        "blk.%d.attn_output" },
+            { LLM_TENSOR_ATTN_Q_NORM,     "blk.%d.attn_q_norm" },
+            { LLM_TENSOR_ATTN_K_NORM,     "blk.%d.attn_k_norm" },
+            { LLM_TENSOR_FFN_NORM,        "blk.%d.ffn_norm" },
+            { LLM_TENSOR_FFN_DOWN,        "blk.%d.ffn_down" },
+            { LLM_TENSOR_FFN_UP,          "blk.%d.ffn_up" },
+        },
+    },
     {
         LLM_ARCH_DREAM,
         {

src/llama-arch.h

@@ -103,6 +103,7 @@ enum llm_arch {
     LLM_ARCH_LLADA_MOE,
     LLM_ARCH_SEED_OSS,
     LLM_ARCH_GROVEMOE,
+    LLM_ARCH_APERTUS,
     LLM_ARCH_UNKNOWN,
 };
 
@@ -260,6 +261,11 @@ enum llm_kv {
 
     LLM_KV_SHORTCONV_L_CACHE,
 
+    LLM_KV_XIELU_ALPHA_N,
+    LLM_KV_XIELU_ALPHA_P,
+    LLM_KV_XIELU_BETA,
+    LLM_KV_XIELU_EPS,
+
     // deprecated:
     LLM_KV_TOKENIZER_PREFIX_ID,
     LLM_KV_TOKENIZER_SUFFIX_ID,

src/llama-hparams.h

@@ -169,6 +169,12 @@ struct llama_hparams {
     uint32_t laurel_rank  = 64;
     uint32_t n_embd_altup = 256;
 
+    // xIELU
+    std::array<float, LLAMA_MAX_LAYERS> xielu_alpha_n;
+    std::array<float, LLAMA_MAX_LAYERS> xielu_alpha_p;
+    std::array<float, LLAMA_MAX_LAYERS> xielu_beta;
+    std::array<float, LLAMA_MAX_LAYERS> xielu_eps;
+
     // needed by encoder-decoder models (e.g. T5, FLAN-T5)
     // ref: https://github.com/ggerganov/llama.cpp/pull/8141
     llama_token dec_start_token_id = LLAMA_TOKEN_NULL;

src/llama-model-loader.cpp

@@ -465,6 +465,8 @@ namespace GGUFMeta {
     // TODO: this is not very clever - figure out something better
     template bool llama_model_loader::get_key_or_arr<std::array<int, 4>>(enum llm_kv kid, std::array<int, 4> & result, uint32_t n, bool required);
     template bool llama_model_loader::get_key_or_arr<std::array<uint32_t, 512>>(enum llm_kv kid, std::array<uint32_t, 512> & result, uint32_t n, bool required);
+    template bool llama_model_loader::get_key_or_arr<std::array<float, 512>>(enum llm_kv kid, std::array<float, 512> & result, uint32_t n, bool required);
+
 
 llama_model_loader::llama_model_loader(
         const std::string & fname,

src/llama-model.cpp

@@ -512,9 +512,13 @@ void llama_model::load_hparams(llama_model_loader & ml) {
         llm_arch_is_recurrent(ml.get_arch()));
 
     std::fill(hparams.rope_sections.begin(), hparams.rope_sections.end(), 0);
-
     std::fill(hparams.swa_layers.begin(), hparams.swa_layers.end(), 0);
 
+    std::fill(hparams.xielu_alpha_n.begin(), hparams.xielu_alpha_n.end(), 0.0f);
+    std::fill(hparams.xielu_alpha_p.begin(), hparams.xielu_alpha_p.end(), 0.0f);
+    std::fill(hparams.xielu_beta.begin(), hparams.xielu_beta.end(), 0.0f);
+    std::fill(hparams.xielu_eps.begin(), hparams.xielu_eps.end(), 0.0f);
+
     ml.get_key_or_arr(LLM_KV_FEED_FORWARD_LENGTH,  hparams.n_ff_arr,   hparams.n_layer, false);
     ml.get_key_or_arr(LLM_KV_ATTENTION_HEAD_COUNT, hparams.n_head_arr, hparams.n_layer, false);
 
@@ -2033,6 +2037,19 @@ void llama_model::load_hparams(llama_model_loader & ml) {
                     default: type = LLM_TYPE_UNKNOWN;
                 }
             } break;
+        case LLM_ARCH_APERTUS:
+            {
+                ml.get_key(LLM_KV_ATTENTION_LAYERNORM_RMS_EPS, hparams.f_norm_rms_eps);
+                ml.get_key_or_arr(LLM_KV_XIELU_ALPHA_N,        hparams.xielu_alpha_n, hparams.n_layer);
+                ml.get_key_or_arr(LLM_KV_XIELU_ALPHA_P,        hparams.xielu_alpha_p, hparams.n_layer);
+                ml.get_key_or_arr(LLM_KV_XIELU_BETA,           hparams.xielu_beta,    hparams.n_layer);
+                ml.get_key_or_arr(LLM_KV_XIELU_EPS,            hparams.xielu_eps,     hparams.n_layer);
+
+                switch (hparams.n_layer) {
+                    case 32: type = LLM_TYPE_8B; break;
+                    default: type = LLM_TYPE_UNKNOWN;
+                }
+            } break;
         default: throw std::runtime_error("unsupported model architecture");
     }
 
@@ -5915,6 +5932,48 @@ bool llama_model::load_tensors(llama_model_loader & ml) {
                         layer.ffn_up_chexps   = create_tensor(tn(LLM_TENSOR_FFN_UP_CHEXPS,   "weight", i), {  n_embd, n_ff_chexp, n_chunk_expert}, 0);
                     }
                 } break;
+            case LLM_ARCH_APERTUS:
+                {
+                    tok_embd = create_tensor(tn(LLM_TENSOR_TOKEN_EMBD, "weight"), { n_embd, n_vocab }, 0);
+
+                    // output
+                    output_norm = create_tensor(tn(LLM_TENSOR_OUTPUT_NORM, "weight"), { n_embd }, 0);
+                    output      = create_tensor(tn(LLM_TENSOR_OUTPUT,      "weight"), { n_embd, n_vocab }, 0);
+
+                    for (int i = 0; i < n_layer; ++i) {
+                        auto & layer = layers[i];
+
+                        layer.attn_norm = create_tensor(tn(LLM_TENSOR_ATTN_NORM, "weight", i), { n_embd }, 0);
+
+                        if (hparams.rope_scaling_type_train == LLAMA_ROPE_SCALING_TYPE_LONGROPE) {
+                            layer.rope_long  = create_tensor(tn(LLM_TENSOR_ROPE_FACTORS_LONG,  "weight", i), { n_rot/2 }, TENSOR_NOT_REQUIRED | (i != 0 ? TENSOR_DUPLICATED : 0));
+                            layer.rope_short = create_tensor(tn(LLM_TENSOR_ROPE_FACTORS_SHORT, "weight", i), { n_rot/2 }, TENSOR_NOT_REQUIRED | (i != 0 ? TENSOR_DUPLICATED : 0));
+                        } else {
+                            layer.rope_freqs = create_tensor(tn(LLM_TENSOR_ROPE_FREQS, "weight", i), { n_rot/2 }, TENSOR_NOT_REQUIRED | (i != 0 ? TENSOR_DUPLICATED : 0));
+                        }
+
+                        layer.wq = create_tensor(tn(LLM_TENSOR_ATTN_Q,   "weight", i), { n_embd, n_embd_head_k * n_head }, 0);
+                        layer.wk = create_tensor(tn(LLM_TENSOR_ATTN_K,   "weight", i), { n_embd, n_embd_gqa }, 0);
+                        layer.wv = create_tensor(tn(LLM_TENSOR_ATTN_V,   "weight", i), { n_embd, n_embd_gqa }, 0);
+                        layer.wo = create_tensor(tn(LLM_TENSOR_ATTN_OUT, "weight", i), { n_embd_head_k * n_head, n_embd }, 0);
+
+                        // optional bias tensors
+                        layer.bq = create_tensor(tn(LLM_TENSOR_ATTN_Q,   "bias", i), { n_embd },     TENSOR_NOT_REQUIRED);
+                        layer.bk = create_tensor(tn(LLM_TENSOR_ATTN_K,   "bias", i), { n_embd_gqa }, TENSOR_NOT_REQUIRED);
+                        layer.bv = create_tensor(tn(LLM_TENSOR_ATTN_V,   "bias", i), { n_embd_gqa }, TENSOR_NOT_REQUIRED);
+                        layer.bo = create_tensor(tn(LLM_TENSOR_ATTN_OUT, "bias", i), { n_embd },     TENSOR_NOT_REQUIRED);
+
+                        layer.ffn_norm = create_tensor(tn(LLM_TENSOR_FFN_NORM, "weight", i), { n_embd }, 0);
+                        layer.ffn_down = create_tensor(tn(LLM_TENSOR_FFN_DOWN, "weight", i), { n_ff, n_embd }, 0);
+                        layer.ffn_up = create_tensor(tn(LLM_TENSOR_FFN_UP, "weight", i), { n_embd, n_ff }, 0);
+
+                        // Q and K layernorms for Apertus
+                        layer.attn_q_norm   = create_tensor(tn(LLM_TENSOR_ATTN_Q_NORM, "weight", i), { n_embd_head_k }, 0);
+                        layer.attn_q_norm_b = create_tensor(tn(LLM_TENSOR_ATTN_Q_NORM, "bias",   i), { n_embd_head_k }, TENSOR_NOT_REQUIRED);
+                        layer.attn_k_norm   = create_tensor(tn(LLM_TENSOR_ATTN_K_NORM, "weight", i), { n_embd_head_k }, 0);
+                        layer.attn_k_norm_b = create_tensor(tn(LLM_TENSOR_ATTN_K_NORM, "bias",   i), { n_embd_head_k }, TENSOR_NOT_REQUIRED);
+                    }
+                } break;
             default:
                 throw std::runtime_error("unknown architecture");
         }
@@ -19099,6 +19158,141 @@ struct llm_build_grovemoe : public llm_graph_context {
     }
 };
 
+struct llm_build_apertus : public llm_graph_context {
+    llm_build_apertus(const llama_model & model, const llm_graph_params & params) : llm_graph_context(params) {
+        const int64_t n_embd_head = hparams.n_embd_head_v;
+
+        GGML_ASSERT(n_embd_head == hparams.n_embd_head_k);
+        GGML_ASSERT(n_embd_head == hparams.n_rot);
+
+        ggml_tensor * cur;
+        ggml_tensor * inpL;
+
+        inpL = build_inp_embd(model.tok_embd);
+
+        ggml_tensor * inp_pos = build_inp_pos();
+        auto * inp_attn = build_attn_inp_kv();
+
+        const float kq_scale = hparams.f_attention_scale == 0.0f ? 1.0f / sqrtf(float(n_embd_head)) : hparams.f_attention_scale;
+
+        ggml_tensor * inp_out_ids = build_inp_out_ids();
+
+        for (int il = 0; il < n_layer; ++il) {
+            ggml_tensor * inpSA = inpL;
+
+            cur = build_norm(inpL,
+                    model.layers[il].attn_norm, nullptr,
+                    LLM_NORM_RMS, il);
+            cb(cur, "attn_norm", il);
+
+            // self-attention
+            {
+                ggml_tensor * rope_factors = model.get_rope_factors(cparams, il);
+
+                // compute Q and K and RoPE them
+                ggml_tensor * Qcur = build_lora_mm(model.layers[il].wq, cur);
+                cb(Qcur, "Qcur", il);
+
+                ggml_tensor * Kcur = build_lora_mm(model.layers[il].wk, cur);
+                cb(Kcur, "Kcur", il);
+
+                ggml_tensor * Vcur = build_lora_mm(model.layers[il].wv, cur);
+                cb(Vcur, "Vcur", il);
+
+                Qcur = ggml_reshape_3d(ctx0, Qcur, n_embd_head, n_head,    n_tokens);
+                Qcur = build_norm(Qcur, model.layers[il].attn_q_norm, NULL, LLM_NORM_RMS, il);
+                cb(Qcur, "Qcur_normed", il);
+
+                Kcur = ggml_reshape_3d(ctx0, Kcur, n_embd_head, n_head_kv, n_tokens);
+                Kcur = build_norm(Kcur, model.layers[il].attn_k_norm, NULL, LLM_NORM_RMS, il);
+                cb(Kcur, "Kcur_normed", il);
+
+                Vcur = ggml_reshape_3d(ctx0, Vcur, n_embd_head, n_head_kv, n_tokens);
+
+                Qcur = ggml_rope_ext(
+                        ctx0, Qcur, inp_pos, rope_factors,
+                        n_rot, rope_type, n_ctx_orig, freq_base, freq_scale,
+                        ext_factor, attn_factor, beta_fast, beta_slow
+                        );
+
+                Kcur = ggml_rope_ext(
+                        ctx0, Kcur, inp_pos, rope_factors,
+                        n_rot, rope_type, n_ctx_orig, freq_base, freq_scale,
+                        ext_factor, attn_factor, beta_fast, beta_slow
+                        );
+
+                cb(Qcur, "Qcur_pos", il);
+                cb(Kcur, "Kcur_pos", il);
+                cb(Vcur, "Vcur_pos", il);
+
+                cur = build_attn(inp_attn,
+                        model.layers[il].wo, model.layers[il].bo,
+                        Qcur, Kcur, Vcur, nullptr, nullptr, nullptr, kq_scale, il);
+                cb(cur, "attn_out", il);
+            }
+
+            if (il == n_layer - 1 && inp_out_ids) {
+                cur   = ggml_get_rows(ctx0,   cur, inp_out_ids);
+                inpSA = ggml_get_rows(ctx0, inpSA, inp_out_ids);
+            }
+
+            ggml_tensor * ffn_inp = ggml_add(ctx0, cur, inpSA);
+            cb(ffn_inp, "ffn_inp", il);
+
+            // feed-forward network with xIELU activation
+            {
+                cur = build_norm(ffn_inp,
+                        model.layers[il].ffn_norm, nullptr,
+                        LLM_NORM_RMS, il);
+                cb(cur, "ffn_norm", il);
+
+                // Up projection
+                ggml_tensor * up = build_lora_mm(model.layers[il].ffn_up, cur);
+                cb(up, "ffn_up", il);
+
+                float alpha_n_val = hparams.xielu_alpha_n[il];
+                float alpha_p_val = hparams.xielu_alpha_p[il];
+                float beta_val = hparams.xielu_beta[il];
+                float eps_val = hparams.xielu_eps[il];
+
+                // Apply xIELU activation
+                ggml_tensor * activated = ggml_xielu(ctx0, up, alpha_n_val, alpha_p_val, beta_val, eps_val);
+                cb(activated, "ffn_xielu", il);
+
+                // Down projection
+                cur = build_lora_mm(model.layers[il].ffn_down, activated);
+                cb(cur, "ffn_down", il);
+            }
+
+            cur = ggml_add(ctx0, cur, ffn_inp);
+            cb(cur, "ffn_out", il);
+
+            cur = build_cvec(cur, il);
+            cb(cur, "l_out", il);
+
+            // input for next layer
+            inpL = cur;
+        }
+
+        cur = inpL;
+
+        cur = build_norm(cur,
+                model.output_norm, nullptr,
+                LLM_NORM_RMS, -1);
+
+        cb(cur, "result_norm", -1);
+        res->t_embd = cur;
+
+        // lm_head
+        cur = build_lora_mm(model.output, cur);
+
+        cb(cur, "result_output", -1);
+        res->t_logits = cur;
+
+        ggml_build_forward_expand(gf, cur);
+    }
+};
+
 llama_memory_i * llama_model::create_memory(const llama_memory_params & params, llama_cparams & cparams) const {
     llama_memory_i * res;
 
@@ -19629,6 +19823,10 @@ ggml_cgraph * llama_model::build_graph(const llm_graph_params & params) const {
             {
                 llm = std::make_unique<llm_build_grovemoe>(*this, params);
             } break;
+        case LLM_ARCH_APERTUS:
+            {
+                llm = std::make_unique<llm_build_apertus>(*this, params);
+            } break;
         default:
             GGML_ABORT("fatal error");
     }
@@ -19835,6 +20033,7 @@ llama_rope_type llama_model_rope_type(const llama_model * model) {
         case LLM_ARCH_GLM4_MOE:
         case LLM_ARCH_SEED_OSS:
         case LLM_ARCH_GROVEMOE:
+        case LLM_ARCH_APERTUS:
             return LLAMA_ROPE_TYPE_NEOX;
 
         case LLM_ARCH_QWEN2VL:

src/llama-model.h

@@ -380,6 +380,12 @@ struct llama_layer {
     // openai-moe
     struct ggml_tensor * attn_sinks = nullptr;
 
+    // xIELU activation parameters for Apertus
+    struct ggml_tensor * ffn_act_alpha_n = nullptr;
+    struct ggml_tensor * ffn_act_alpha_p = nullptr;
+    struct ggml_tensor * ffn_act_beta    = nullptr;
+    struct ggml_tensor * ffn_act_eps     = nullptr;
+
     struct llama_layer_posnet posnet;
 
     struct llama_layer_convnext convnext;

tests/test-chat.cpp

@@ -2054,6 +2054,79 @@ static void test_template_output_parsers() {
                     /* .parse_tool_calls = */ true,
                 }));
     }
+    {
+        auto tmpls = read_templates("models/templates/Apertus-8B-Instruct.jinja");
+        std::vector<std::string> end_tokens{ "<|assistant_end|>" };
+
+        assert_equals(COMMON_CHAT_FORMAT_APERTUS, common_chat_templates_apply(tmpls.get(), inputs_no_tools).format);
+        assert_equals(COMMON_CHAT_FORMAT_APERTUS, common_chat_templates_apply(tmpls.get(), inputs_tools).format);
+
+        // Test parsing regular content
+        assert_msg_equals(message_assist,
+            common_chat_parse(
+                "Hello, world!\nWhat's up?",
+                /* is_partial= */ false,
+                {COMMON_CHAT_FORMAT_APERTUS}));
+
+        // Test parsing content with thinking
+        assert_msg_equals(message_assist_thoughts,
+            common_chat_parse(
+                "<|inner_prefix|>I'm\nthinking<|inner_suffix|>Hello, world!\nWhat's up?",
+                /* is_partial= */ false,
+                {
+                    /* .format = */ COMMON_CHAT_FORMAT_APERTUS,
+                    /* .reasoning_format = */ COMMON_REASONING_FORMAT_DEEPSEEK,
+                }));
+
+        // Test parsing tool calls
+        assert_msg_equals(message_assist_call,
+            common_chat_parse(
+                "<|tools_prefix|>[{\"special_function\": {\"arg1\": 1}}]<|tools_suffix|>",
+                /* is_partial= */ false,
+                {COMMON_CHAT_FORMAT_APERTUS}));
+
+        // Test parsing tool calls with thinking
+        assert_msg_equals(message_assist_call_thoughts,
+            common_chat_parse(
+                "<|inner_prefix|>I'm\nthinking<|inner_suffix|><|tools_prefix|>[{\"special_function\": {\"arg1\": 1}}]<|tools_suffix|>",
+                /* is_partial= */ false,
+                {
+                    /* .format = */ COMMON_CHAT_FORMAT_APERTUS,
+                    /* .reasoning_format = */ COMMON_REASONING_FORMAT_DEEPSEEK
+                }));
+
+        // Test tool calls with extra content
+        assert_msg_equals(message_assist_call_content,
+            common_chat_parse(
+                "<|tools_prefix|>[{\"special_function\": {\"arg1\": 1}}]<|tools_suffix|>Hello, world!\nWhat's up?",
+                /* is_partial= */ false,
+                {COMMON_CHAT_FORMAT_APERTUS}
+            ));
+
+        // Test tool calls with extra content AND thinking
+        assert_msg_equals(message_assist_call_thoughts_content,
+            common_chat_parse(
+                "<|inner_prefix|>I'm\nthinking<|inner_suffix|><|tools_prefix|>[{\"special_function\": {\"arg1\": 1}}]<|tools_suffix|>Hello, world!\nWhat's up?",
+                /* is_partial= */ false,
+                {
+                    /* .format = */ COMMON_CHAT_FORMAT_APERTUS,
+                    /* .reasoning_format = */ COMMON_REASONING_FORMAT_DEEPSEEK
+                }));
+
+        // Test template generation for regular content
+        test_templates(tmpls.get(), end_tokens, message_assist, tools,
+                      "Hello, world!\nWhat's up?",
+                      /* expect_grammar_triggered= */ false);
+
+        // Test template generation for tool calls
+        test_templates(tmpls.get(), end_tokens, message_assist_call, tools,
+                      "<|tools_prefix|>[{\"special_function\": {\"arg1\": 1}}]<|tools_suffix|>",
+                      /* expect_grammar_triggered= */ true
+        );
+
+        assert_equals(true, common_chat_templates_support_enable_thinking(tmpls.get()));
+    }
+
 }
 
 static void test_msg_diffs_compute() {

tools/tts/convert_pt_to_hf.py

@@ -12,7 +12,7 @@ import re
 from safetensors.torch import save_file
 
 # default
-model_path = './model.pt';
+model_path = './model.pt'
 
 # read from CLI
 if len(sys.argv) > 1: