[Pfannkuchensack]

Summary

Installing FLUX.3 Klein (single file) or FLUX.3 Klein Base (single file) from the starter models fails with HTTP 404. On 2026-10-17, black-forest-labs/flux-3-image-klein-comfy deleted its underscore-named diffusion models (commit 94a2e33818) after adding the same files under hyphenated names.

Both starters now download diffusion_models/flux3-image-klein-bf16.safetensors and diffusion_models/flux3-image-klein-base-bf16.safetensors, pinned to revision feef60b0aaf63a4773ace96636ebbcf43b881312, so another rename cannot break them. The files are the same LFS objects as before, and as BFL's own model.safetensors (Klein c3e9813c…, Base 5c921759…), so installed models and their hashes do not change.

The FLUX.3 Klein key fixture's docstring named the old file and a local path; it now names the repository paths.

Related Issues / Discussions

Follow-up to #9883.

QA Instructions

• With a Hugging Face token, curl -I on the old resolve/main/...flux3_image_klein_sd_bf16.safetensors and ...flux3_image_klein_bf16.safetensors returns 404; both new pinned URLs return 302.
• pytest tests/backend/model_manager/test_starter_models.py tests/backend/model_manager/test_starter_models_package.py tests/backend/model_manager/configs/test_flux3_main_config.py: 30 passed.
• ruff check and ruff format --check on the changed files: clean.
• A local copy of the old Klein file hashes to c3e9813cdd049c831c836b2e9db61150e49a93fc1a4c63b256494642fee0bd7c, the LFS oid of the new file.
• Not run: a full starter install (11 GB); the install path for URL sources is unchanged. No test was added, because it could only assert the URL literal.

Review

No material findings. A model installed from the old URL still shows as installed, because the installed check falls back to name, base and type when the source differs.

Checklist

• The PR has a short but descriptive title, suitable for a changelog
• Meaningful regression coverage added / updated where needed; obsolete tests/code removed
• Persisted-state and API changes include required migrations / compatibility validation
• Relevant performance/efficiency opportunities considered; material claims have evidence
• Material review findings resolved and relevant checks rerun
• Documentation added / updated (if applicable)
• Updated What's New copy (if doing a release after this PR)

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[joshistoast]

A nit that I think is worth addressing

[joshistoast]

[P3] Renamed existing installations appear uninstalled.

The URL change and line 58 breaks source matching for previously installed models. If the user also renamed the model, get_is_installed() cannot recognize it through its name fallback, offering a redundant ~11 GB download. Recognizing the previous URLs as source aliases would preserve this behavior. Default-name installations remain recognized.

[Pfannkuchensack]

Fixed in f0be6f6. Starters can now list previous_sources. get_is_installed and the webv2 installed-starter lookup also match an installed model's source against them. Both FLUX.3 single-file starters list their old diffusion_models/ URLs, so an install from the old URL counts as installed even after a rename. Covered by a router test and a vitest case.