add support for flux2 klein (#1193)

* add support for flux2 klein 4b

* add support for flux2 klein 8b

* use attention_mask in Flux.2 klein LLMEmbedder

* update docs

README.md

@@ -43,8 +43,8 @@ API and command-line option may change frequently.***
     - SDXL, [SDXL-Turbo](https://huggingface.co/stabilityai/sdxl-turbo)
     - [Some SD1.x and SDXL distilled models](./docs/distilled_sd.md)
     - [SD3/SD3.5](./docs/sd3.md)
-    - [FlUX.1-dev/FlUX.1-schnell](./docs/flux.md)
-    - [FLUX.2-dev](./docs/flux2.md)
+    - [FLUX.1-dev/FLUX.1-schnell](./docs/flux.md)
+    - [FLUX.2-dev/FLUX.2-klein](./docs/flux2.md)
     - [Chroma](./docs/chroma.md)
     - [Chroma1-Radiance](./docs/chroma_radiance.md)
     - [Qwen Image](./docs/qwen_image.md)
@@ -127,8 +127,8 @@ If you want to improve performance or reduce VRAM/RAM usage, please refer to [pe
 
 - [SD1.x/SD2.x/SDXL](./docs/sd.md)
 - [SD3/SD3.5](./docs/sd3.md)
-- [FlUX.1-dev/FlUX.1-schnell](./docs/flux.md)
-- [FLUX.2-dev](./docs/flux2.md)
+- [FLUX.1-dev/FLUX.1-schnell](./docs/flux.md)
+- [FLUX.2-dev/FLUX.2-klein](./docs/flux2.md)
 - [FLUX.1-Kontext-dev](./docs/kontext.md)
 - [Chroma](./docs/chroma.md)
 - [🔥Qwen Image](./docs/qwen_image.md)

conditioner.hpp

@@ -1614,9 +1614,9 @@ struct LLMEmbedder : public Conditioner {
                 bool enable_vision                             = false)
         : version(version) {
         LLM::LLMArch arch = LLM::LLMArch::QWEN2_5_VL;
-        if (sd_version_is_flux2(version)) {
+        if (version == VERSION_FLUX2) {
             arch = LLM::LLMArch::MISTRAL_SMALL_3_2;
-        } else if (sd_version_is_z_image(version) || version == VERSION_OVIS_IMAGE) {
+        } else if (sd_version_is_z_image(version) || version == VERSION_OVIS_IMAGE || version == VERSION_FLUX2_KLEIN) {
             arch = LLM::LLMArch::QWEN3;
         }
         if (arch == LLM::LLMArch::MISTRAL_SMALL_3_2) {
@@ -1708,6 +1708,9 @@ struct LLMEmbedder : public Conditioner {
         int prompt_template_encode_start_idx = 34;
         int max_length                       = 0;
         std::set<int> out_layers;
+        std::vector<int> tokens;
+        std::vector<float> weights;
+        std::vector<float> mask;
         if (llm->enable_vision && conditioner_params.ref_images.size() > 0) {
             LOG_INFO("QwenImageEditPlusPipeline");
             prompt_template_encode_start_idx = 64;
@@ -1771,7 +1774,7 @@ struct LLMEmbedder : public Conditioner {
             prompt_attn_range.second = static_cast<int>(prompt.size());
 
             prompt += "<|im_end|>\n<|im_start|>assistant\n";
-        } else if (sd_version_is_flux2(version)) {
+        } else if (version == VERSION_FLUX2) {
             prompt_template_encode_start_idx = 0;
             out_layers                       = {10, 20, 30};
 
@@ -1793,17 +1796,28 @@ struct LLMEmbedder : public Conditioner {
             prompt_attn_range.second = static_cast<int>(prompt.size());
 
             prompt += "<|im_end|>\n<|im_start|>assistant\n";
-        } else if (sd_version_is_flux2(version)) {
+        } else if (version == VERSION_FLUX2_KLEIN) {
             prompt_template_encode_start_idx = 0;
-            out_layers                       = {10, 20, 30};
+            max_length                       = 512;
+            out_layers                       = {9, 18, 27};
 
-            prompt = "[SYSTEM_PROMPT]You are an AI that reasons about image descriptions. You give structured responses focusing on object relationships, object\nattribution and actions without speculation.[/SYSTEM_PROMPT][INST]";
+            prompt = "<|im_start|>user\n";
 
             prompt_attn_range.first = static_cast<int>(prompt.size());
             prompt += conditioner_params.text;
             prompt_attn_range.second = static_cast<int>(prompt.size());
 
-            prompt += "[/INST]";
+            prompt += "<|im_end|>\n<|im_start|>assistant\n<think>\n\n</think>\n\n";
+
+            auto tokens_and_weights = tokenize(prompt, prompt_attn_range, 0, false);
+            tokens                  = std::get<0>(tokens_and_weights);
+            weights                 = std::get<1>(tokens_and_weights);
+
+            mask.insert(mask.end(), tokens.size(), 1.f);
+            if (tokens.size() < max_length) {
+                mask.insert(mask.end(), max_length - tokens.size(), 0.f);
+                tokenizer->pad_tokens(tokens, weights, max_length, true);
+            }
         } else if (version == VERSION_OVIS_IMAGE) {
             prompt_template_encode_start_idx = 28;
             max_length                       = prompt_template_encode_start_idx + 256;
@@ -1827,17 +1841,34 @@ struct LLMEmbedder : public Conditioner {
             prompt += "<|im_end|>\n<|im_start|>assistant\n";
         }
 
+        if (tokens.empty()) {
             auto tokens_and_weights = tokenize(prompt, prompt_attn_range, max_length, max_length > 0);
-        auto& tokens            = std::get<0>(tokens_and_weights);
-        auto& weights           = std::get<1>(tokens_and_weights);
+            tokens                  = std::get<0>(tokens_and_weights);
+            weights                 = std::get<1>(tokens_and_weights);
+        }
 
         int64_t t0                        = ggml_time_ms();
         struct ggml_tensor* hidden_states = nullptr;  // [N, n_token, 3584]
 
         auto input_ids = vector_to_ggml_tensor_i32(work_ctx, tokens);
 
+        ggml_tensor* attention_mask = nullptr;
+        if (!mask.empty()) {
+            attention_mask = ggml_new_tensor_2d(work_ctx, GGML_TYPE_F32, mask.size(), mask.size());
+            ggml_ext_tensor_iter(attention_mask, [&](ggml_tensor* attention_mask, int64_t i0, int64_t i1, int64_t i2, int64_t i3) {
+                float value = 0.f;
+                if (mask[i0] == 0.f) {
+                    value = -INFINITY;
+                } else if (i0 > i1) {
+                    value = -INFINITY;
+                }
+                ggml_ext_tensor_set_f32(attention_mask, value, i0, i1, i2, i3);
+            });
+        }
+
         llm->compute(n_threads,
                      input_ids,
+                     attention_mask,
                      image_embeds,
                      out_layers,
                      &hidden_states,
@@ -1861,7 +1892,7 @@ struct LLMEmbedder : public Conditioner {
         GGML_ASSERT(hidden_states->ne[1] > prompt_template_encode_start_idx);
 
         int64_t min_length = 0;
-        if (sd_version_is_flux2(version)) {
+        if (version == VERSION_FLUX2) {
             min_length = 512;
         }
 

docs/flux2.md

@@ -1,6 +1,8 @@
 # How to Use
 
-## Download weights
+## Flux.2-dev
+
+### Download weights
 
 - Download FLUX.2-dev
     - gguf: https://huggingface.co/city96/FLUX.2-dev-gguf/tree/main
@@ -9,7 +11,7 @@
 - Download Mistral-Small-3.2-24B-Instruct-2506-GGUF
     - gguf: https://huggingface.co/unsloth/Mistral-Small-3.2-24B-Instruct-2506-GGUF/tree/main
 
-## Examples
+### Examples
 
 ```
 .\bin\Release\sd-cli.exe --diffusion-model  ..\..\ComfyUI\models\diffusion_models\flux2-dev-Q4_K_S.gguf --vae ..\..\ComfyUI\models\vae\flux2_ae.safetensors  --llm ..\..\ComfyUI\models\text_encoders\Mistral-Small-3.2-24B-Instruct-2506-Q4_K_M.gguf -r .\kontext_input.png -p "change 'flux.cpp' to 'flux2-dev.cpp'" --cfg-scale 1.0 --sampling-method euler -v --diffusion-fa --offload-to-cpu
@@ -17,5 +19,74 @@
 
 <img alt="flux2 example" src="../assets/flux2/example.png" />
 
+## Flux.2 klein 4B / Flux.2 klein base 4B
 
+### Download weights
 
+- Download FLUX.2-klein-4B
+    - safetensors: https://huggingface.co/black-forest-labs/FLUX.2-klein-4B
+    - gguf: https://huggingface.co/leejet/FLUX.2-klein-4B-GGUF/tree/main
+- Download FLUX.2-klein-base-4B
+    - safetensors: https://huggingface.co/black-forest-labs/FLUX.2-klein-base-4B
+    - gguf: https://huggingface.co/leejet/FLUX.2-klein-base-4B-GGUF/tree/main
+- Download vae
+    - safetensors: https://huggingface.co/black-forest-labs/FLUX.2-dev/tree/main
+- Download Qwen3 4b
+    - safetensors: https://huggingface.co/Comfy-Org/flux2-klein-4B/tree/main/split_files/text_encoders
+    - gguf: https://huggingface.co/unsloth/Qwen3-4B-GGUF/tree/main
+
+### Examples
+
+```
+.\bin\Release\sd-cli.exe --diffusion-model  ..\..\ComfyUI\models\diffusion_models\flux-2-klein-4b.safetensors --vae ..\..\ComfyUI\models\vae\flux2_ae.safetensors  --llm ..\..\ComfyUI\models\text_encoders\qwen_3_4b.safetensors -p "a lovely cat" --cfg-scale 1.0 --steps 4 -v --offload-to-cpu --diffusion-fa
+```
+
+<img alt="flux2-klein-4b" src="../assets/flux2/flux2-klein-4b.png" />
+
+```
+.\bin\Release\sd-cli.exe --diffusion-model  ..\..\ComfyUI\models\diffusion_models\flux-2-klein-4b.safetensors --vae ..\..\ComfyUI\models\vae\flux2_ae.safetensors  --llm ..\..\ComfyUI\models\text_encoders\qwen_3_4b.safetensors -r .\kontext_input.png -p "change 'flux.cpp' to 'klein.cpp'" --cfg-scale 1.0 --sampling-method euler -v --diffusion-fa --offload-to-cpu --steps 4
+```
+
+<img alt="flux2-klein-4b-edit" src="../assets/flux2/flux2-klein-4b-edit.png" />
+
+```
+.\bin\Release\sd-cli.exe --diffusion-model  ..\..\ComfyUI\models\diffusion_models\flux-2-klein-base-4b.safetensors --vae ..\..\ComfyUI\models\vae\flux2_ae.safetensors  --llm ..\..\ComfyUI\models\text_encoders\qwen_3_4b.safetensors -p "a lovely cat" --cfg-scale 4.0 --steps 20 -v --offload-to-cpu --diffusion-fa
+```
+
+<img alt="flux2-klein-base-4b" src="../assets/flux2/flux2-klein-base-4b.png" />
+
+## Flux.2 klein 9B / Flux.2 klein base 9B
+
+### Download weights
+
+- Download FLUX.2-klein-9B
+    - safetensors: https://huggingface.co/black-forest-labs/FLUX.2-klein-9B
+    - gguf: https://huggingface.co/leejet/FLUX.2-klein-9B-GGUF/tree/main
+- Download FLUX.2-klein-base-9B
+    - safetensors: https://huggingface.co/black-forest-labs/FLUX.2-klein-base-9B
+    - gguf: https://huggingface.co/leejet/FLUX.2-klein-base-9B-GGUF/tree/main
+- Download vae
+    - safetensors: https://huggingface.co/black-forest-labs/FLUX.2-dev/tree/main
+- Download Qwen3 8B
+    - safetensors: https://huggingface.co/Comfy-Org/flux2-klein-9B/tree/main/split_files/text_encoders
+    - gguf: https://huggingface.co/unsloth/Qwen3-8B-GGUF/tree/main
+
+### Examples
+
+```
+.\bin\Release\sd-cli.exe --diffusion-model  ..\..\ComfyUI\models\diffusion_models\flux-2-klein-9b.safetensors --vae ..\..\ComfyUI\models\vae\flux2_ae.safetensors  --llm ..\..\ComfyUI\models\text_encoders\qwen_3_8b.safetensors -p "a lovely cat" --cfg-scale 1.0 --steps 4 -v --offload-to-cpu --diffusion-fa
+```
+
+<img alt="flux2-klein-9b" src="../assets/flux2/flux2-klein-9b.png" />
+
+```
+.\bin\Release\sd-cli.exe --diffusion-model  ..\..\ComfyUI\models\diffusion_models\flux-2-klein-9b.safetensors --vae ..\..\ComfyUI\models\vae\flux2_ae.safetensors  --llm ..\..\ComfyUI\models\text_encoders\qwen_3_8b.safetensors -r .\kontext_input.png -p "change 'flux.cpp' to 'klein.cpp'" --cfg-scale 1.0 --sampling-method euler -v --diffusion-fa --offload-to-cpu --steps 4
+```
+
+<img alt="flux2-klein-9b-edit" src="../assets/flux2/flux2-klein-9b-edit.png" />
+
+```
+.\bin\Release\sd-cli.exe --diffusion-model  ..\..\ComfyUI\models\diffusion_models\flux-2-klein-base-9b.safetensors --vae ..\..\ComfyUI\models\vae\flux2_ae.safetensors  --llm ..\..\ComfyUI\models\text_encoders\qwen_3_8b.safetensors -p "a lovely cat" --cfg-scale 4.0 --steps 20 -v --offload-to-cpu --diffusion-fa
+```
+
+<img alt="flux2-klein-base-9b" src="../assets/flux2/flux2-klein-base-9b.png" />

flux.hpp

@@ -1288,13 +1288,9 @@ namespace Flux {
             } else if (version == VERSION_OVIS_IMAGE) {
                 flux_params.semantic_txt_norm = true;
                 flux_params.use_yak_mlp       = true;
-                flux_params.context_in_dim    = 2048;
                 flux_params.vec_in_dim        = 0;
             } else if (sd_version_is_flux2(version)) {
-                flux_params.context_in_dim   = 15360;
                 flux_params.in_channels      = 128;
-                flux_params.hidden_size      = 6144;
-                flux_params.num_heads        = 48;
                 flux_params.patch_size       = 1;
                 flux_params.out_channels     = 128;
                 flux_params.mlp_ratio        = 3.f;
@@ -1307,12 +1303,12 @@ namespace Flux {
                 flux_params.ref_index_scale  = 10.f;
                 flux_params.use_mlp_silu_act = true;
             }
+            int64_t head_dim = 0;
             for (auto pair : tensor_storage_map) {
                 std::string tensor_name = pair.first;
                 if (!starts_with(tensor_name, prefix))
                     continue;
                 if (tensor_name.find("guidance_in.in_layer.weight") != std::string::npos) {
-                    // not schnell
                     flux_params.guidance_embed = true;
                 }
                 if (tensor_name.find("__x0__") != std::string::npos) {
@@ -1344,13 +1340,30 @@ namespace Flux {
                         flux_params.depth_single_blocks = block_depth + 1;
                     }
                 }
+                if (ends_with(tensor_name, "txt_in.weight")) {
+                    flux_params.context_in_dim = pair.second.ne[0];
+                    flux_params.hidden_size    = pair.second.ne[1];
+                }
+                if (ends_with(tensor_name, "single_blocks.0.norm.key_norm.scale")) {
+                    head_dim = pair.second.ne[0];
+                }
+                if (ends_with(tensor_name, "double_blocks.0.txt_attn.norm.key_norm.scale")) {
+                    head_dim = pair.second.ne[0];
+                }
             }
 
-            LOG_INFO("Flux blocks: %d double, %d single", flux_params.depth, flux_params.depth_single_blocks);
+            flux_params.num_heads = static_cast<int>(flux_params.hidden_size / head_dim);
+
+            LOG_INFO("flux: depth = %d, depth_single_blocks = %d, guidance_embed = %s, context_in_dim = %" PRId64
+                     ", hidden_size = %" PRId64 ", num_heads = %d",
+                     flux_params.depth,
+                     flux_params.depth_single_blocks,
+                     flux_params.guidance_embed ? "true" : "false",
+                     flux_params.context_in_dim,
+                     flux_params.hidden_size,
+                     flux_params.num_heads);
             if (flux_params.is_chroma) {
                 LOG_INFO("Using pruned modulation (Chroma)");
-            } else if (!flux_params.guidance_embed) {
-                LOG_INFO("Flux guidance is disabled (Schnell mode)");
             }
 
             flux = Flux(flux_params);

ggml_extend.hpp

@@ -1348,6 +1348,7 @@ __STATIC_INLINE__ struct ggml_tensor* ggml_ext_attention_ext(struct ggml_context
         v = ggml_reshape_3d(ctx, v, L_k, d_head, n_kv_head * N);   // [N * n_kv_head, d_head, L_k]
 
         auto kq = ggml_mul_mat(ctx, k, q);  // [N * n_head, L_q, L_k]
+        ggml_mul_mat_set_prec(kq, GGML_PREC_F32);
         kq = ggml_scale_inplace(ctx, kq, scale);
         if (mask) {
             kq = ggml_add_inplace(ctx, kq, mask);

llm.hpp

@@ -837,7 +837,8 @@ namespace LLM {
 
         struct ggml_tensor* forward(GGMLRunnerContext* ctx,
                                     struct ggml_tensor* x,
-                                    struct ggml_tensor* input_pos) {
+                                    struct ggml_tensor* input_pos,
+                                    struct ggml_tensor* attention_mask = nullptr) {
             // x: [N, n_token, hidden_size]
             int64_t n_token = x->ne[1];
             int64_t N       = x->ne[2];
@@ -880,7 +881,7 @@ namespace LLM {
             k = ggml_cont(ctx->ggml_ctx, ggml_ext_torch_permute(ctx->ggml_ctx, k, 0, 2, 1, 3));  // [N, num_kv_heads, n_token, head_dim]
             k = ggml_reshape_3d(ctx->ggml_ctx, k, k->ne[0], k->ne[1], k->ne[2] * k->ne[3]);      // [N*num_kv_heads, n_token, head_dim]
 
-            x = ggml_ext_attention_ext(ctx->ggml_ctx, ctx->backend, q, k, v, num_heads, nullptr, true, true, false);  // [N, n_token, hidden_size]
+            x = ggml_ext_attention_ext(ctx->ggml_ctx, ctx->backend, q, k, v, num_heads, attention_mask, false, true, false);  // [N, n_token, hidden_size]
 
             x = out_proj->forward(ctx, x);  // [N, n_token, hidden_size]
             return x;
@@ -898,7 +899,8 @@ namespace LLM {
 
         struct ggml_tensor* forward(GGMLRunnerContext* ctx,
                                     struct ggml_tensor* x,
-                                    struct ggml_tensor* input_pos) {
+                                    struct ggml_tensor* input_pos,
+                                    struct ggml_tensor* attention_mask = nullptr) {
             // x: [N, n_token, hidden_size]
             auto self_attn                = std::dynamic_pointer_cast<Attention>(blocks["self_attn"]);
             auto mlp                      = std::dynamic_pointer_cast<MLP>(blocks["mlp"]);
@@ -907,7 +909,7 @@ namespace LLM {
 
             auto residual = x;
             x             = input_layernorm->forward(ctx, x);
-            x             = self_attn->forward(ctx, x, input_pos);
+            x             = self_attn->forward(ctx, x, input_pos, attention_mask);
             x             = ggml_add_inplace(ctx->ggml_ctx, x, residual);
 
             residual = x;
@@ -936,6 +938,7 @@ namespace LLM {
         struct ggml_tensor* forward(GGMLRunnerContext* ctx,
                                     struct ggml_tensor* input_ids,
                                     struct ggml_tensor* input_pos,
+                                    struct ggml_tensor* attention_mask,
                                     std::vector<std::pair<int, ggml_tensor*>> image_embeds,
                                     std::set<int> out_layers) {
             // input_ids: [N, n_token]
@@ -990,7 +993,7 @@ namespace LLM {
             for (int i = 0; i < num_layers; i++) {
                 auto block = std::dynamic_pointer_cast<TransformerBlock>(blocks["layers." + std::to_string(i)]);
 
-                x = block->forward(ctx, x, input_pos);
+                x = block->forward(ctx, x, input_pos, attention_mask);
                 if (out_layers.find(i + 1) != out_layers.end()) {
                     intermediate_outputs.push_back(x);
                 }
@@ -1036,12 +1039,13 @@ namespace LLM {
         struct ggml_tensor* forward(GGMLRunnerContext* ctx,
                                     struct ggml_tensor* input_ids,
                                     struct ggml_tensor* input_pos,
+                                    struct ggml_tensor* attention_mask,
                                     std::vector<std::pair<int, ggml_tensor*>> image_embeds,
                                     std::set<int> out_layers) {
             // input_ids: [N, n_token]
             auto model = std::dynamic_pointer_cast<TextModel>(blocks["model"]);
 
-            auto x = model->forward(ctx, input_ids, input_pos, image_embeds, out_layers);
+            auto x = model->forward(ctx, input_ids, input_pos, attention_mask, image_embeds, out_layers);
             return x;
         }
 
@@ -1063,6 +1067,7 @@ namespace LLM {
         LLM model;
 
         std::vector<int> input_pos_vec;
+        std::vector<float> attention_mask_vec;
         std::vector<float> window_mask_vec;
         std::vector<int> window_index_vec;
         std::vector<int> window_inverse_index_vec;
@@ -1157,9 +1162,10 @@ namespace LLM {
         struct ggml_tensor* forward(GGMLRunnerContext* ctx,
                                     struct ggml_tensor* input_ids,
                                     struct ggml_tensor* input_pos,
+                                    struct ggml_tensor* attention_mask,
                                     std::vector<std::pair<int, ggml_tensor*>> image_embeds,
                                     std::set<int> out_layers) {
-            auto hidden_states = model.forward(ctx, input_ids, input_pos, image_embeds, out_layers);  // [N, n_token, hidden_size]
+            auto hidden_states = model.forward(ctx, input_ids, input_pos, attention_mask, image_embeds, out_layers);  // [N, n_token, hidden_size]
             return hidden_states;
         }
 
@@ -1174,6 +1180,7 @@ namespace LLM {
         }
 
         struct ggml_cgraph* build_graph(struct ggml_tensor* input_ids,
+                                        struct ggml_tensor* attention_mask,
                                         std::vector<std::pair<int, ggml_tensor*>> image_embeds,
                                         std::set<int> out_layers) {
             struct ggml_cgraph* gf = ggml_new_graph(compute_ctx);
@@ -1205,9 +1212,26 @@ namespace LLM {
                                                 input_pos_vec.size());
             set_backend_tensor_data(input_pos, input_pos_vec.data());
 
+            if (attention_mask != nullptr) {
+                attention_mask = to_backend(attention_mask);
+            } else {
+                attention_mask_vec.resize(n_tokens * n_tokens);
+                for (int i0 = 0; i0 < n_tokens; i0++) {
+                    for (int i1 = 0; i1 < n_tokens; i1++) {
+                        float value = 0.f;
+                        if (i0 > i1) {
+                            value = -INFINITY;
+                        }
+                        attention_mask_vec[i1 * n_tokens + i0] = value;
+                    }
+                }
+                attention_mask = ggml_new_tensor_2d(compute_ctx, GGML_TYPE_F32, n_tokens, n_tokens);
+                set_backend_tensor_data(attention_mask, attention_mask_vec.data());
+            }
+
             auto runner_ctx = get_context();
 
-            struct ggml_tensor* hidden_states = forward(&runner_ctx, input_ids, input_pos, image_embeds, out_layers);
+            struct ggml_tensor* hidden_states = forward(&runner_ctx, input_ids, input_pos, attention_mask, image_embeds, out_layers);
 
             ggml_build_forward_expand(gf, hidden_states);
 
@@ -1216,12 +1240,13 @@ namespace LLM {
 
         bool compute(const int n_threads,
                      struct ggml_tensor* input_ids,
+                     struct ggml_tensor* attention_mask,
                      std::vector<std::pair<int, ggml_tensor*>> image_embeds,
                      std::set<int> out_layers,
                      ggml_tensor** output,
                      ggml_context* output_ctx = nullptr) {
             auto get_graph = [&]() -> struct ggml_cgraph* {
-                return build_graph(input_ids, image_embeds, out_layers);
+                return build_graph(input_ids, attention_mask, image_embeds, out_layers);
             };
             return GGMLRunner::compute(get_graph, n_threads, true, output, output_ctx);
         }
@@ -1525,7 +1550,7 @@ namespace LLM {
                 struct ggml_tensor* out = nullptr;
 
                 int64_t t0 = ggml_time_ms();
-                model.compute(8, input_ids, image_embeds, {}, &out, work_ctx);
+                model.compute(8, input_ids, nullptr, image_embeds, {}, &out, work_ctx);
                 int64_t t1 = ggml_time_ms();
 
                 print_ggml_tensor(out);
@@ -1565,7 +1590,7 @@ namespace LLM {
                 struct ggml_tensor* out = nullptr;
 
                 int64_t t0 = ggml_time_ms();
-                model.compute(8, input_ids, {}, {10, 20, 30}, &out, work_ctx);
+                model.compute(8, input_ids, nullptr, {}, {10, 20, 30}, &out, work_ctx);
                 int64_t t1 = ggml_time_ms();
 
                 print_ggml_tensor(out);
@@ -1588,7 +1613,7 @@ namespace LLM {
                 struct ggml_tensor* out = nullptr;
 
                 int64_t t0 = ggml_time_ms();
-                model.compute(8, input_ids, {}, {35}, &out, work_ctx);
+                model.compute(8, input_ids, nullptr, {}, {35}, &out, work_ctx);
                 int64_t t1 = ggml_time_ms();
 
                 print_ggml_tensor(out);
@@ -1611,7 +1636,7 @@ namespace LLM {
                 struct ggml_tensor* out = nullptr;
 
                 int64_t t0 = ggml_time_ms();
-                model.compute(8, input_ids, {}, {}, &out, work_ctx);
+                model.compute(8, input_ids, nullptr, {}, {}, &out, work_ctx);
                 int64_t t1 = ggml_time_ms();
 
                 print_ggml_tensor(out);

model.cpp

@@ -1034,6 +1034,8 @@ SDVersion ModelLoader::get_sd_version() {
 
     bool is_xl                       = false;
     bool is_flux                     = false;
+    bool is_flux2                    = false;
+    bool has_single_block_47         = false;
     bool is_wan                      = false;
     int64_t patch_embedding_channels = 0;
     bool has_img_emb                 = false;
@@ -1055,7 +1057,10 @@ SDVersion ModelLoader::get_sd_version() {
                 return VERSION_QWEN_IMAGE;
             }
             if (tensor_storage.name.find("model.diffusion_model.double_stream_modulation_img.lin.weight") != std::string::npos) {
-                return VERSION_FLUX2;
+                is_flux2 = true;
+            }
+            if (tensor_storage.name.find("single_blocks.47.linear1.weight") != std::string::npos) {
+                has_single_block_47 = true;
             }
             if (tensor_storage.name.find("model.diffusion_model.double_blocks.0.img_mlp.gate_proj.weight") != std::string::npos) {
                 return VERSION_OVIS_IMAGE;
@@ -1138,7 +1143,7 @@ SDVersion ModelLoader::get_sd_version() {
         return VERSION_SDXL;
     }
 
-    if (is_flux) {
+    if (is_flux && !is_flux2) {
         if (input_block_weight.ne[0] == 384) {
             return VERSION_FLUX_FILL;
         }
@@ -1151,6 +1156,13 @@ SDVersion ModelLoader::get_sd_version() {
         return VERSION_FLUX;
     }
 
+    if (is_flux2) {
+        if (has_single_block_47) {
+            return VERSION_FLUX2;
+        }
+        return VERSION_FLUX2_KLEIN;
+    }
+
     if (token_embedding_weight.ne[0] == 768) {
         if (is_inpaint) {
             return VERSION_SD1_INPAINT;

model.h

@@ -45,6 +45,7 @@ enum SDVersion {
     VERSION_WAN2_2_TI2V,
     VERSION_QWEN_IMAGE,
     VERSION_FLUX2,
+    VERSION_FLUX2_KLEIN,
     VERSION_Z_IMAGE,
     VERSION_OVIS_IMAGE,
     VERSION_COUNT,
@@ -100,7 +101,7 @@ static inline bool sd_version_is_flux(SDVersion version) {
 }
 
 static inline bool sd_version_is_flux2(SDVersion version) {
-    if (version == VERSION_FLUX2) {
+    if (version == VERSION_FLUX2 || version == VERSION_FLUX2_KLEIN) {
         return true;
     }
     return false;

stable-diffusion.cpp

@@ -48,6 +48,7 @@ const char* model_version_to_str[] = {
     "Wan 2.2 TI2V",
     "Qwen Image",
     "Flux.2",
+    "Flux.2 klein",
     "Z-Image",
     "Ovis Image",
 };