diff --git a/.gitmodules b/.gitmodules
index 1a5fb675..b3625f46 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -70,3 +70,7 @@
 	url = https://github.com/1bit-MONSTER/ROCmFPX.git
 	shallow = true
 	branch = 1bit/vulkan-rocmi4
+[submodule "third_party/comfyui.cpp"]
+	path = third_party/comfyui.cpp
+	url = https://github.com/1bit-MONSTER/comfyui.cpp.git
+	branch = master
diff --git a/CMakeLists.txt b/CMakeLists.txt
index e05e2cec..ba645538 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -144,6 +144,24 @@ if(ONEBIT_ZINC)
     endif()
 endif()
 
+# ── ComfyUI.cpp (docs/comfyui.md) ──────────────────────────────────────────
+# Off by default: it needs LibTorch. Builds third_party/comfyui.cpp (GPL-3.0) with
+# scripts/build-comfyui.sh as its own program; `1bit comfy <workflow.json>` runs it as a
+# child process. The engine never links it, so the engine itself stays Apache-2.0.
+option(ONEBIT_COMFYUI "Build ComfyUI.cpp (third_party/comfyui.cpp) for 1bit comfy" OFF)
+if(ONEBIT_COMFYUI)
+    if(NOT EXISTS "${CMAKE_SOURCE_DIR}/third_party/comfyui.cpp/CMakeLists.txt")
+        message(FATAL_ERROR "ONEBIT_COMFYUI needs third_party/comfyui.cpp: git submodule update --init third_party/comfyui.cpp")
+    endif()
+    set(ONEBIT_COMFYUI_BIN "${CMAKE_BINARY_DIR}/comfyui/comfyui_cpp")
+    add_custom_target(comfyui
+        COMMAND ${CMAKE_SOURCE_DIR}/scripts/build-comfyui.sh ${CMAKE_BINARY_DIR}/comfyui
+        BYPRODUCTS ${ONEBIT_COMFYUI_BIN}
+        USES_TERMINAL)
+    add_dependencies(onebit comfyui)
+    target_compile_definitions(onebit PRIVATE ONEBIT_COMFYUI_BIN="${ONEBIT_COMFYUI_BIN}")
+endif()
+
 # ── Hugging Face tokenizers (docs/tokenizers.md) ───────────────────────────
 # Off by default: it needs cargo. Any model's tokenizer.json, through our C ABI
 # over third_party/tokenizers (the same release as the tokenizers npm/PyPI
diff --git a/NOTICE b/NOTICE
index 4a3f5397..736f55a4 100644
--- a/NOTICE
+++ b/NOTICE
@@ -68,6 +68,16 @@ ZINC (third_party/zinc)
   Copyright (c) 2025 ZINC Contributors
   License: MIT
 
+ComfyUI.cpp (third_party/comfyui.cpp)
+  https://github.com/1bit-MONSTER/comfyui.cpp
+  A C++ port of ComfyUI (https://github.com/Comfy-Org/ComfyUI, Copyright (C)
+  Comfy Org and ComfyUI contributors, GPL-3.0).
+  License: GPL-3.0. ComfyUI.cpp is built as a separate program
+  (scripts/build-comfyui.sh) that `1bit comfy` runs as a child process; none of
+  its code is linked into this product. It links LibTorch (BSD-3-Clause) and
+  vendors stb (MIT / public domain), nlohmann/json (MIT) and the CLIP BPE
+  vocabulary (MIT).
+
 OpenFlowLM-Next open kernels (third_party/OpenFlowLM-Next; only open_kernels/ is built)
   https://github.com/bong-water-water-bong/OpenFlowLM-Next
   (a fork of https://github.com/Atomic-Germ/OpenFlowLM-Next)
diff --git a/README.md b/README.md
index e40ffa74..9f20c18e 100644
--- a/README.md
+++ b/README.md
@@ -30,6 +30,7 @@ serves each model behind an OpenAI-compatible API (`1bit serve`), whatever devic
 - ZINC, which also reaches NVIDIA GPUs (CUDA) and Apple GPUs (Metal)
 - MLX on Apple Silicon, through lemon-mlx-engine
 - Laya, which decides where each request runs
+- ComfyUI.cpp: ComfyUI workflows (Stable Diffusion 1.5 text-to-image and image-to-image) in C++, matching ComfyUI's output to 50 dB ([docs/comfyui.md](docs/comfyui.md))
 - every Hugging Face model architecture, kept current by a daily census
 
 > **Status:** the engine runs inside Lemonade through `1bit serve` ([docs/lemonade.md](docs/lemonade.md),
diff --git a/app/main.cpp b/app/main.cpp
index 3ec1d9b6..ee96e062 100644
--- a/app/main.cpp
+++ b/app/main.cpp
@@ -46,6 +46,9 @@
 #include <string>
 #include <vector>
 
+#include <cerrno>
+#include <unistd.h>
+
 namespace {
 
 constexpr const char* kVersion = "0.0.1";
@@ -61,6 +64,7 @@ void usage(FILE* out) {
                  "  npu-run [options]           generate on the NPU fast lane (npu-run --help)\n"
                  "  npu-lax [options]           Qwen3.6-35B-A3B on the NPU lax kernels (npu-lax --help)\n"
 #endif
+                 "  comfy <workflow.json>       run a ComfyUI workflow with ComfyUI.cpp (docs/comfyui.md)\n"
                  "  version                     print the version\n"
                  "  help                        show this help\n");
 }
@@ -119,6 +123,29 @@ int run_npu(int argc, char** argv) {
 }
 #endif
 
+// ComfyUI.cpp is GPL-3.0 and a separate program: exec it, never link it (docs/comfyui.md).
+// The binary: $ONEBIT_COMFYUI, then this build's (-DONEBIT_COMFYUI=ON), then comfyui_cpp on PATH.
+int run_comfy(int argc, char** argv) {
+    if (argc < 1 || !std::strcmp(argv[0], "-h") || !std::strcmp(argv[0], "--help")) {
+        std::printf("usage: 1bit comfy <workflow.json>\n"
+                    "  runs a ComfyUI API-format workflow (SD1.5 txt2img/img2img, see docs/comfyui.md)\n");
+        return argc < 1 ? 2 : 0;
+    }
+    std::string bin;
+    if (const char* e = std::getenv("ONEBIT_COMFYUI"); e && *e) bin = e;
+#ifdef ONEBIT_COMFYUI_BIN
+    if (bin.empty() && std::filesystem::exists(ONEBIT_COMFYUI_BIN)) bin = ONEBIT_COMFYUI_BIN;
+#endif
+    if (bin.empty()) bin = "comfyui_cpp";
+    std::vector<char*> args{bin.data()};
+    for (int i = 0; i < argc; ++i) args.push_back(argv[i]);
+    args.push_back(nullptr);
+    ::execvp(args[0], args.data());
+    std::fprintf(stderr, "1bit comfy: cannot run %s: %s (build with -DONEBIT_COMFYUI=ON or set ONEBIT_COMFYUI)\n",
+                 bin.c_str(), std::strerror(errno));
+    return 127;
+}
+
 }  // namespace
 
 int main(int argc, char** argv) {
@@ -161,6 +188,7 @@ int main(int argc, char** argv) {
         }
     }
 #endif
+    if (cmd == "comfy") return run_comfy(argc - 2, argv + 2);
     if (cmd == "version" || cmd == "--version") {
         std::printf("1bit %s\n", kVersion);
         return 0;
diff --git a/docs/comfyui.md b/docs/comfyui.md
new file mode 100644
index 00000000..0bca39aa
--- /dev/null
+++ b/docs/comfyui.md
@@ -0,0 +1,72 @@
+<!--
+Copyright 2026 bong-water-water-bong
+SPDX-License-Identifier: Apache-2.0
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
+
+# ComfyUI.cpp
+
+ComfyUI.cpp runs ComfyUI workflows in C++. It is a port of ComfyUI's workflow engine and of
+the Stable Diffusion 1.5 nodes on LibTorch, pinned as the submodule `third_party/comfyui.cpp`
+([1bit-MONSTER/comfyui.cpp](https://github.com/1bit-MONSTER/comfyui.cpp)).
+
+```
+git submodule update --init third_party/comfyui.cpp
+cmake -S . -B build -DONEBIT_COMFYUI=ON
+cmake --build build
+build/1bit comfy workflow.json
+```
+
+`1bit comfy` takes a workflow in ComfyUI's API format (the JSON that ComfyUI's "Save (API)"
+writes) and runs it. SaveImage writes the PNG to the node's `path` input.
+
+## License
+
+ComfyUI is GPL-3.0, and so is ComfyUI.cpp. The engine is Apache-2.0, so it never links
+ComfyUI.cpp. `scripts/build-comfyui.sh` builds it as its own program,
+`build/comfyui/comfyui_cpp`, and `1bit comfy` runs that program in place of itself.
+`1bit comfy` looks for the binary in `$ONEBIT_COMFYUI` first, then this build's, then
+`comfyui_cpp` on `PATH`.
+
+## What runs
+
+Everything a Stable Diffusion 1.5 txt2img or img2img workflow needs:
+- CheckpointLoaderSimple, CLIPTextEncode, EmptyLatentImage
+- KSampler with `euler` / `normal`, including denoise below 1
+- VAEEncode, VAEDecode, LoadImage and SaveImage
+- the conditioning, latent and image nodes
+
+It runs on the CPU for now, through LibTorch; the build takes LibTorch from the Python `torch`
+package.
+
+## Parity with ComfyUI
+
+ComfyUI.cpp pins ComfyUI itself (`third_party/ComfyUI`, Comfy-Org/ComfyUI `1568e6c`).
+`tools/parity_sd15.py` in that repository runs the same workflows through both on CPU fp32 and
+compares the images. Measured on Strix Halo with `v1-5-pruned-emaonly.safetensors`, 512x512,
+20 steps, cfg 7:
+
+| workflow | PSNR vs ComfyUI | max / mean abs diff (0-255) | pixels off by > 2 |
+|---|---|---|---|
+| txt2img, "a cat", seed 0 | 50.6 dB | 15 / 0.515 | 0.286% |
+| img2img, denoise 0.6, seed 7 | 51.2 dB | 1 / 0.498 | 0.000% |
+
+The remaining difference is fp32 rounding: ComfyUI batches the cond and uncond passes and uses
+PyTorch's attention kernel. Through `1bit comfy`, the txt2img workflow takes 48 s and gives the
+same 50.6 dB. ComfyUI takes about 35 s on the same CPU.
+
+## Next
+
+- The GPU: LibTorch on ROCm for gfx1151.
+- More model families and samplers beyond SD1.5 with Euler.
diff --git a/scripts/build-comfyui.sh b/scripts/build-comfyui.sh
new file mode 100755
index 00000000..25afd81b
--- /dev/null
+++ b/scripts/build-comfyui.sh
@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+# Copyright 2026 bong-water-water-bong
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# build-comfyui.sh <prefix>
+#
+# Builds ComfyUI.cpp pinned in third_party/comfyui.cpp (1bit-MONSTER/comfyui.cpp, GPL-3.0)
+# into <prefix>/comfyui_cpp. It is a separate program: the engine runs it as a child
+# process (`1bit comfy`) and never links it (docs/comfyui.md). Needs LibTorch; the
+# build takes torch's CMake config from `python3 -c "import torch"`, or from Torch_DIR.
+set -euo pipefail
+prefix=${1:?usage: build-comfyui.sh <prefix>}
+root=$(cd "$(dirname "$0")/.." && pwd)
+src=$root/third_party/comfyui.cpp
+[ -f "$src/CMakeLists.txt" ] || { echo "third_party/comfyui.cpp is empty: git submodule update --init third_party/comfyui.cpp"; exit 1; }
+mkdir -p "$prefix"
+prefix=$(cd "$prefix" && pwd)
+cmake -S "$src" -B "$prefix/build" -DCMAKE_BUILD_TYPE=Release
+cmake --build "$prefix/build" -j"$(nproc)" --target comfyui_cpp
+cp "$prefix/build/comfyui_cpp" "$prefix/comfyui_cpp"
+echo "built $prefix/comfyui_cpp (comfyui.cpp $(git -C "$src" rev-parse --short=12 HEAD 2>/dev/null || echo unknown))"
diff --git a/third_party/comfyui.cpp b/third_party/comfyui.cpp
new file mode 160000
index 00000000..4a08238c
--- /dev/null
+++ b/third_party/comfyui.cpp
@@ -0,0 +1 @@
+Subproject commit 4a08238cef8bcfc7048d852eefa096651d62785a
diff --git a/tools/site.py b/tools/site.py
index 1586680f..8a9e66a3 100644
--- a/tools/site.py
+++ b/tools/site.py
@@ -77,7 +77,7 @@
     ("Start", [("serve", "1bit serve"), ("lemonade", "Lemonade")]),
     ("Devices", [("npu", "NPU"), ("hrx", "HRX + Vulkan"), ("vulkan", "Vulkan (upstream)"), ("lean", "Lean (ROCmFP4, ROCmI4)"),
                  ("zinc", "ZINC"), ("apple", "Apple Silicon")]),
-    ("Components", [("laya", "Laya router"), ("tokenizers", "Tokenizers"), ("kernel", "Linux kernel")]),
+    ("Components", [("laya", "Laya router"), ("comfyui", "ComfyUI.cpp"), ("tokenizers", "Tokenizers"), ("kernel", "Linux kernel")]),
     ("Project", [("PORTING", "Porting map")]),
 ]