ComfyUI SDK for Workshop

This SDK provides ComfyUI as a persistent browser-accessible service for node-based diffusion workflows in Workshop. ComfyUI runs with GPU acceleration on NVIDIA, AMD, and Intel GPUs with a CPU fallback when no supported GPU is available. The Python virtual environment, downloaded models, and generated outputs are persisted on the host across workshop updates. Optionally, connect the venv plug to the uv SDK for a uv-managed environment.

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Reference workshop

A minimal workshop:

# workshop.yaml
name: comfy-app
base: [email protected]
sdks:
  - name: system
    plugs:
      comfy-ui:
        interface: tunnel
        endpoint: 127.0.0.1:8188
  - name: comfy
    channel: latest/stable

actions:
  verify: |
    curl -fsS http://127.0.0.1:8188/system_stats

This exposes ComfyUI through the browser tunnel, so the UI is accessible at http://localhost:8188 on the host.

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Using the SDK

Prerequisites, project layout

1. No prerequisite SDKs are required for the default setup. The uv SDK is optional; see Using a uv-managed venv below.
2. No specific project layout is needed. ComfyUI reads and writes its own directories under /home/workshop/comfy/ inside the workshop.
3. The first launch installs PyTorch and ComfyUI dependencies into the virtual environment via the setup-project hook, so it takes longer than subsequent launches. The installed packages are persisted via the venv mount plug and reused across workshop updates.

Access ComfyUI

After workshop launch, open http://localhost:8188 in a browser.

• The default ComfyUI workflow is available in the UI. Custom workflows can be loaded by drag-and-drop; see the ComfyUI repository for workflow examples and upstream documentation.
• Generated images are written to /home/workshop/comfy/output/, which persists across workshop updates via the output mount plug.

Verify from the command line

To confirm the ComfyUI service is running, check the user service from a workshop shell:

workshop shell
systemctl --user status comfy
journalctl --user -u comfy

Using a uv-managed venv

By default, ComfyUI runs inside a Python virtual environment managed by the SDK itself. If you prefer to manage packages with uv, you can connect the comfy:venv plug to the uv SDK's venv slot.

When connected, the uv SDK's virtual environment is mounted at the comfy SDK's venv path. PyTorch and ComfyUI dependencies are still installed into the venv on first launch. This lets you manage packages with uv pip instead of plain pip.

# workshop.yaml
name: comfy-app
base: [email protected]
sdks:
  - name: system
    plugs:
      comfy-ui:
        interface: tunnel
        endpoint: 127.0.0.1:8188
  - name: uv
    channel: latest/stable
  - name: comfy
    channel: latest/stable

connections:
  - plug: comfy:venv
    slot: uv:venv

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Plugs (resources this SDK consumes)

gpu

• Interface: gpu
• Purpose: Grants access to host GPU hardware for accelerated inference.

venv

• Interface: mount
• Workshop target: $SDK/venv
• Purpose: Persists the Python virtual environment (PyTorch and ComfyUI dependencies) across workshop updates.

models

• Interface: mount
• Workshop target: /home/workshop/comfy/models
• Purpose: Persists downloaded model checkpoints, VAEs, LoRAs, and other model files across workshop updates.

output

• Interface: mount
• Workshop target: /home/workshop/comfy/output
• Purpose: Persists generated images and other output files across workshop updates.

Slots (resources this SDK provides)

comfy-ui

• Interface: tunnel
• Endpoint: 127.0.0.1:8188
• Purpose: Exposes the ComfyUI HTTP server to the host for browser access. Connect a matching plug on the system SDK to make ComfyUI accessible at the plug address on the host.

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Documentation and guidance

• ComfyUI repository and documentation
• ComfyUI examples
• Workshop documentation

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Community and support

• ComfyUI community: ComfyUI GitHub
• Workshop forum: Discourse
• Please review our Code of Conduct before participating.

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Contributions

All contributions, including code, documentation updates, and issue reports, are welcome!

• See CONTRIBUTING.md for guidelines.
• Open issues or pull requests on the official repository.

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License and copyright

Copyright 2025-2026 Canonical Ltd.

ComfyUI is licensed under the GNU General Public License v3.0.