●Change8

Migrating to ComfyUI v0.3.66

Version v0.3.66 introduces 2 breaking changes. This guide details how to update your code.

Released: 10/21/2025

2
Breaking Changes
4
Migration Steps
7
Affected Symbols

⚠️ Check Your Code

If you use any of these symbols, you need to read this guide:

api-nodes (dynamic pricing format)comfy_io (renamed to IO)merge_nested_dictsVeo3 nodecast_bias_weightnodes_controlnet.pyEasyCache.apply_cache_diff

Breaking Changes

●Issue #1

gfx942 hardware no longer supports fp8 operations, which may cause issues on specific AMD GPUs.

●Issue #2

The dependency aware caching implementation from PR #10368 was reverted in PR #10422, meaning fixes related to --cache-none with loops/lazy execution are temporarily removed.

Migration Steps

  1. 1
    Review usage of gfx942 hardware if experiencing issues related to fp8 operations.
  2. 2
    If relying on the dependency aware caching fix from PR #10368, note that it has been reverted and may require manual re-implementation or waiting for a subsequent fix.
  3. 3
    Update any workflows using the 'veo2' model in the Veo3 node; it has been removed.
  4. 4
    Review Python installation steps if targeting Python 3.14.

Release Summary

This release focuses heavily on performance improvements, including faster workflow cancelling and optimizations for chroma radiance, alongside addressing several GPU-specific memory and compilation issues. It also introduces Python 3.14 instructions and deprecates older API usage.

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View the full release notes and all changes for ComfyUI v0.3.66.

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