feat!: switch default hub model to FLUX.2 klein 9B (Q5_K_M GGUF)

BREAKING CHANGE: The default hub deployment now uses FLUX.2 klein 9B
instead of FLUX.1-dev-fp8. Existing workflows using CheckpointLoaderSimple
with flux1-dev-fp8.safetensors will not work with the new default image.
Use the flux1-dev-fp8 image tag for backward compatibility.

- Install ComfyUI-GGUF custom node in Dockerfile base stage
- Add flux2-klein-9b model download block (GGUF + text encoder + VAE)
- Change default MODEL_TYPE from flux1-dev-fp8 to flux2-klein-9b
- Add docker-bake.hcl target and CI/CD workflow entries
- Update hub config (description + 25GB container disk)
- Add new workflow files for FLUX.2 klein 9B GGUF
- Update documentation across README, hub README, and deployment guide
- Add diffusion_models + text_encoders to extra_model_paths.yaml

Closes #217

Author: TimPietrusky

.changeset/flux2-klein-default.md

@@ -0,0 +1,9 @@
+---
+"worker-comfyui": major
+---
+
+feat!: switch default hub model from FLUX.1-dev-fp8 to FLUX.2 klein 9B (Q5_K_M GGUF)
+
+BREAKING CHANGE: The default hub deployment now uses FLUX.2 klein 9B instead of FLUX.1-dev-fp8.
+Existing workflows using CheckpointLoaderSimple with flux1-dev-fp8.safetensors will not work
+with the new default image. Use the flux1-dev-fp8 image tag for backward compatibility.

.github/workflows/manual-build-all.yml

@@ -366,6 +366,57 @@ jobs:
             *.args.RELEASE_VERSION=${{ env.RELEASE_VERSION }}
             *.args.HUGGINGFACE_ACCESS_TOKEN=${{ env.HUGGINGFACE_ACCESS_TOKEN }}
 
+  build-flux2-klein-9b:
+    runs-on: [blacksmith-8vcpu-ubuntu-2204, linux]
+    permissions:
+      contents: read
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Clear space to remove unused folders
+        run: |
+          rm -rf /usr/share/dotnet
+          rm -rf /opt/ghc
+          rm -rf "/usr/local/share/boost"
+          rm -rf "$AGENT_TOOLSDIRECTORY"
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: blacksmith docker layer cache
+        uses: useblacksmith/build-push-action@v1
+        with:
+          setup-only: true
+
+      - name: Set environment variables
+        run: |
+          echo "DOCKERHUB_REPO=${{ vars.DOCKERHUB_REPO }}" >> $GITHUB_ENV
+          echo "DOCKERHUB_IMG=${{ vars.DOCKERHUB_IMG }}" >> $GITHUB_ENV
+          echo "HUGGINGFACE_ACCESS_TOKEN=${{ secrets.HUGGINGFACE_ACCESS_TOKEN }}" >> $GITHUB_ENV
+          echo "RELEASE_VERSION=${{ github.event.inputs.version }}" >> $GITHUB_ENV
+
+      - name: Build and push flux2-klein-9b image
+        uses: docker/bake-action@v2
+        with:
+          push: true
+          targets: flux2-klein-9b
+          set: |
+            *.args.DOCKERHUB_REPO=${{ env.DOCKERHUB_REPO }}
+            *.args.DOCKERHUB_IMG=${{ env.DOCKERHUB_IMG }}
+            *.args.RELEASE_VERSION=${{ env.RELEASE_VERSION }}
+            *.args.HUGGINGFACE_ACCESS_TOKEN=${{ env.HUGGINGFACE_ACCESS_TOKEN }}
+
   build-z-image-turbo:
     runs-on: [blacksmith-8vcpu-ubuntu-2204, linux]
     permissions:
@@ -428,6 +479,7 @@ jobs:
         build-flux1-schnell,
         build-flux1-dev,
         build-flux1-dev-fp8,
+        build-flux2-klein-9b,
         build-z-image-turbo,
       ]
     permissions:

.github/workflows/release.yml

@@ -84,6 +84,7 @@ jobs:
           - flux1-schnell
           - flux1-dev
           - flux1-dev-fp8
+          - flux2-klein-9b
           - z-image-turbo
           - base-cuda12-8-1
 

.runpod/README.md

@@ -12,11 +12,11 @@ Run [ComfyUI](https://github.com/comfyanonymous/ComfyUI) workflows as a serverle
 
 ## What is included?
 
-This worker comes with the **FLUX.1-dev-fp8** (`flux1-dev-fp8.safetensors`) model pre-installed and **works only with this specific model** when deployed from the hub.
+This worker comes with the **FLUX.2 klein 9B** (`flux-2-klein-9b-Q5_K_M.gguf`) model pre-installed and **works only with this specific model** when deployed from the hub.
 
 ## Want to use a different model?
 
-**The hub deployment only supports FLUX.1-dev-fp8.** If you need any other model, custom nodes, or LoRAs, you have two options:
+**The hub deployment only supports FLUX.2 klein 9B (Q5_K_M GGUF).** If you need any other model, custom nodes, or LoRAs, you have two options:
 
 ### Option 1: ComfyUI-to-API (Easiest & Recommended)
 
@@ -60,104 +60,94 @@ This example uses a simplified workflow (replace with your actual workflow JSON)
 {
   "input": {
     "workflow": {
-      "6": {
+      "1": {
         "inputs": {
-          "text": "anime cat with massive fluffy fennec ears and a big fluffy tail blonde messy long hair blue eyes wearing a construction outfit placing a fancy black forest cake with candles on top of a dinner table of an old dark Victorian mansion lit by candlelight with a bright window to the foggy forest and very expensive stuff everywhere there are paintings on the walls",
-          "clip": ["30", 1]
+          "unet_name": "flux-2-klein-9b-Q5_K_M.gguf"
         },
-        "class_type": "CLIPTextEncode",
+        "class_type": "UnetLoaderGGUF",
         "_meta": {
-          "title": "CLIP Text Encode (Positive Prompt)"
+          "title": "Load GGUF Model"
         }
       },
-      "8": {
+      "2": {
         "inputs": {
-          "samples": ["31", 0],
-          "vae": ["30", 2]
+          "clip_name": "qwen_3_8b_fp8mixed.safetensors",
+          "type": "flux2"
         },
-        "class_type": "VAEDecode",
+        "class_type": "CLIPLoader",
         "_meta": {
-          "title": "VAE Decode"
+          "title": "Load Text Encoder"
         }
       },
-      "9": {
+      "3": {
         "inputs": {
-          "filename_prefix": "ComfyUI",
-          "images": ["8", 0]
+          "vae_name": "flux2-vae.safetensors"
         },
-        "class_type": "SaveImage",
+        "class_type": "VAELoader",
         "_meta": {
-          "title": "Save Image"
+          "title": "Load VAE"
         }
       },
-      "27": {
+      "4": {
         "inputs": {
-          "width": 512,
-          "height": 512,
-          "batch_size": 1
+          "text": "anime cat with massive fluffy fennec ears and a big fluffy tail blonde messy long hair blue eyes wearing a construction outfit placing a fancy black forest cake with candles on top of a dinner table of an old dark Victorian mansion lit by candlelight with a bright window to the foggy forest and very expensive stuff everywhere there are paintings on the walls",
+          "clip": ["2", 0]
+        },
+        "class_type": "CLIPTextEncode",
+        "_meta": {
+          "title": "CLIP Text Encode (Positive Prompt)"
+        }
+      },
+      "5": {
+        "inputs": {
+          "text": "",
+          "clip": ["2", 0]
         },
-        "class_type": "EmptySD3LatentImage",
+        "class_type": "CLIPTextEncode",
         "_meta": {
-          "title": "EmptySD3LatentImage"
+          "title": "CLIP Text Encode (Negative Prompt)"
         }
       },
-      "30": {
+      "6": {
         "inputs": {
-          "ckpt_name": "flux1-dev-fp8.safetensors"
+          "width": 1024,
+          "height": 1024,
+          "batch_size": 1
         },
-        "class_type": "CheckpointLoaderSimple",
+        "class_type": "EmptyLatentImage",
         "_meta": {
-          "title": "Load Checkpoint"
+          "title": "Empty Latent Image"
         }
       },
-      "31": {
+      "7": {
         "inputs": {
           "seed": 243057879077961,
-          "steps": 10,
+          "steps": 4,
           "cfg": 1,
           "sampler_name": "euler",
           "scheduler": "simple",
           "denoise": 1,
-          "model": ["30", 0],
-          "positive": ["35", 0],
-          "negative": ["33", 0],
-          "latent_image": ["27", 0]
+          "model": ["1", 0],
+          "positive": ["4", 0],
+          "negative": ["5", 0],
+          "latent_image": ["6", 0]
         },
         "class_type": "KSampler",
         "_meta": {
           "title": "KSampler"
         }
       },
-      "33": {
-        "inputs": {
-          "text": "",
-          "clip": ["30", 1]
-        },
-        "class_type": "CLIPTextEncode",
-        "_meta": {
-          "title": "CLIP Text Encode (Negative Prompt)"
-        }
-      },
-      "35": {
-        "inputs": {
-          "guidance": 3.5,
-          "conditioning": ["6", 0]
-        },
-        "class_type": "FluxGuidance",
-        "_meta": {
-          "title": "FluxGuidance"
-        }
-      },
-      "38": {
+      "8": {
         "inputs": {
-          "images": ["8", 0]
+          "samples": ["7", 0],
+          "vae": ["3", 0]
         },
-        "class_type": "PreviewImage",
+        "class_type": "VAEDecode",
         "_meta": {
-          "title": "Preview Image"
+          "title": "VAE Decode"
         }
       },
-      "40": {
+      "9": {
         "inputs": {
           "filename_prefix": "ComfyUI",
           "images": ["8", 0]

.runpod/hub.json

@@ -1,12 +1,12 @@
 {
   "title": "ComfyUI",
-  "description": "Generate images with ComfyUI using FLUX.1-dev (fp8)",
+  "description": "Generate images with ComfyUI using FLUX.2 klein 9B (Q5_K_M GGUF)",
   "type": "serverless",
   "category": "image",
   "iconUrl": "https://cpjrphpz3t5wbwfe.public.blob.vercel-storage.com/comfy-ui.png",
   "config": {
     "runsOn": "GPU",
-    "containerDiskInGb": 20,
+    "containerDiskInGb": 25,
     "gpuIds": "ADA_24",
     "gpuCount": 1,
     "allowedCudaVersions": ["12.7", "12.6"],