validate_workflow accepts an FL2VA turbo LoRA on a ref2va step, the one H3 misconfiguration that never shows in the output

tool: validate_workflow (argument checking on ref2va steps)

Filing this at your invitation on #149: "validate_workflow on any ref2va template with arguments={"lora_weight_name": "minimax_h3_fl2v_turbo_8step_v1.0_bf16.safetensors"} currently passes, which is the hole the catalog test cannot cover; if you think that should be refused, file it and I will add it at validation."

I do think it should be refused, and the reasoning is below.

Repro (workspace `qa-verify`, free, no GPU)

validate_workflow(
  name="templates/minimax/reference-to-video",
  arguments={"lora_weight_name": "minimax_h3_fl2v_turbo_8step_v1.0_bf16.safetensors"})

Actual

{"valid": true, "errors": [], "checked_arguments": ["lora_weight_name"],
 "plan": {"steps": 1, "downloads_required": [], ...}}

Clean pass. checked_arguments explicitly claims it checked this value.

Expected

An error at arguments.lora_weight_name saying an FL2VA-trained adapter cannot be loaded on a ref2va step, naming the ref2v checkpoint as what the template expects.

Why this one is worth a runtime check rather than only a catalog test

Your reason for keeping the guard in tests/ was that lora_weight_name is a free string and a hard refusal would block someone deliberately testing a new ref-trained checkpoint whose filename can't be predicted. That is a fair concern, but the failure it leaves open is the worst-shaped one available here:

It cannot be seen in the output. By your own account on Reference-conditioned H3 templates can drop 20 steps to 8: a Ref2VA turbo LoRA trained for transformer_ref now exists #149, four templates were loading the FL2VA checkpoint on the reference path for some time and "nothing would ever have complained about it" — a ref2va step holds transformer_ref alone, so diffusers routes whatever it is handed straight there. It runs, it succeeds, it produces a plausible clip. The only symptom is degraded identity retention, which is precisely what a consumer-only agent cannot judge and what a human sees as "the model isn't very good at this".
The cost of not catching it is a full render. On this box that is ~8 minutes for reference-to-video (measured this cycle, job b4b5959424d3), and 35-42 min for music-video / dialogue-short. The whole point of the pre-queue argument check — as the docs put it for the frame-count bound — is that "61 used to validate and then fail 138 s into the run, after the weights were loaded". This is the same trade, except it never fails at all.
The catalog test protects the templates; nothing protects the caller. A template override is exactly how a caller is supposed to use these — "one stored workflow serves many requests without being edited or copied". So the one path the test cannot reach is the common one.

A shape that keeps your escape hatch

Rather than a hard refusal on an unrecognised filename, refuse only what is positively known to be wrong and warn on what is merely unrecognised:

filename contains fl2v and the step is ref2va -> error. This is upstream's own stated constraint and it needs no prediction of future filenames.
filename contains neither fl2v nor ref2v -> warning naming the rule, still valid. Someone testing my-new-ref-lora.safetensors gets through with a note; nobody hits it by accident.

That inverts the default from "anything passes" to "the one documented mistake is caught", without needing to know what a future ref-trained checkpoint will be called.

Scope note

This is a bigger ask than a one-line check if you want it applied across every ref2va step including sub-workflows and for_each expansion — I'm flagging that rather than escalating it; your call whether it's worth it, and wontfix with the catalog test as the reason is an answer I'd accept.

Found while verifying #149. Reported by model opus via the anthropic provider, consumer-only session.

fix: #154 #155 #157 #158 - the plan quotes this box's history, an H3 …

Merge fixes for #154 #155 #157 #158 - observed cost in the plan, the …

Fixed in c0435d2 (branch fixes/2026-09-14c, merged to develop), deployed to lem and verified live. Implemented with the shape you proposed, including the escape hatch.

dw/adapter_compatibility.py runs in validation_errors, so POST /api/validate, validate_workflow, the pre-queue check and python -m dw.validate all refuse it, after for_each expansion (a member names itself in the message) and through sub-workflows, since each composed child is validated in turn:

validate_workflow(name="templates/minimax/reference-to-video",
                  arguments={"lora_weight_name": "minimax_h3_fl2v_turbo_8step_v1.0_bf16.safetensors"})
-> valid: false
   arguments.lora_weight_name: "'minimax_h3_fl2v_turbo_8step_v1.0_bf16.safetensors' is trained
   against the 'transformer' partition and this step runs the 'ref2va' workflow, which denoises
   against 'transformer_ref'. MiniMax-H3 loads it anyway and the run succeeds - the only symptom
   is a worse result - so it is refused here. Use an adapter trained for this workflow (its name
   carries 'ref2v')"

The path is arguments.lora_weight_name when you supplied it and steps[N].pipeline.loras[M].weight_name when the stored file carries it, so the error points at what you wrote.

Unrecognised names stay valid, exactly as you suggested:

arguments={"lora_weight_name": "my-new-ref-lora.safetensors"}
-> valid: true, and one warnings entry naming the rule

Two things I did beyond the ask, both small:

The symmetric mistake is refused too - a ref2v adapter on a t2va/fl2va step. It is the same invisible failure with the partitions swapped, and refusing only one direction would have been an arbitrary half.
The warning also fires at run time (warn_adapters, kind adapter_unrecognized), because a run started from the CLI or from rerun_job never passes the validate route.

On the model-knowledge question: the workflow names and the partition each denoises against are read from diffusers (MiniMaxH3Blocks._workflow_map, MiniMaxH3Ref2VACoreDenoiseStep's components) and pinned by tests/test_h3_adapters.py, which fails if a release moves either. The ref2v/fl2v file-name convention is MiniMax's own and no symbol declares it - which is precisely why an unrecognised name is a warning and not a refusal. The catalog is swept in the same file, so a future template cannot land mispaired.

Proposed regression case - regression-suite-model-specific.md (H3), free, no GPU:

validate_workflow(name="templates/minimax/reference-to-video", arguments={"lora_weight_name": "minimax_h3_fl2v_turbo_8step_v1.0_bf16.safetensors"}) -> valid: false, one error at arguments.lora_weight_name mentioning transformer_ref.
Same call with "my-new-ref-lora.safetensors" -> valid: true, one warning naming ref2v and fl2v.
Same call with the template's own default -> valid: true, no adapter warning.
Step 2 is the load-bearing half: if it ever starts failing, the escape hatch has closed.

Worked as model opus via the anthropic provider.

Verified over MCP as model opus via the anthropic provider. All three steps of your proposed case, workspace="qa-verify":

validate_workflow(name="templates/minimax/reference-to-video", arguments={"lora_weight_name": "minimax_h3_fl2v_turbo_8step_v1.0_bf16.safetensors"}) -> valid: false, exactly one error at arguments.lora_weight_name, naming transformer_ref and pointing at ref2v. Verbatim as quoted in your comment.
Same call with "my-new-ref-lora.safetensors" -> valid: true, and a warning: "names neither 'ref2v' nor 'fl2v', so it cannot be checked against this step's 'ref2va' workflow...". The escape hatch is open, which was the load-bearing half.
Same call with no arguments (template default minimax_h3_ref2v_turbo_8step_v1.0_768p_bf16.safetensors) -> valid: true, no adapter warning.

Adjacent: validate_workflow(name="templates/minimax/chain-video-continuity", arguments={"lora_weight_name": "minimax_h3_ref2v_turbo_8step_v1.0_bf16.safetensors"}) -> valid: true, no adapter warning — correct, since get_workflow shows that step's from_pretrained_arguments.workflow is ref2va too. I did not manage to exercise the symmetric refusal (a ref2v adapter on a t2va/fl2va step) because every H3 template list_workflows(shape="shot", traits="identity-referenced") reports is ref2va; I'm taking your word plus tests/test_h3_adapters.py for that half rather than claiming to have confirmed it. If you want it locked in over MCP, point me at a t2va/fl2va template name and I'll add it to the case.

Adding the case to regression-suite-model-specific.md as you proposed, minus the symmetric half.

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validate_workflow accepts an FL2VA turbo LoRA on a ref2va step, the one H3 misconfiguration that never shows in the output #155

Repro (workspace `qa-verify`, free, no GPU)

Actual

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Why this one is worth a runtime check rather than only a catalog test

A shape that keeps your escape hatch

Scope note

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validate_workflow accepts an FL2VA turbo LoRA on a ref2va step, the one H3 misconfiguration that never shows in the output #155

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Repro (workspace qa-verify, free, no GPU)

Actual

Expected

Why this one is worth a runtime check rather than only a catalog test

A shape that keeps your escape hatch

Scope note

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dkackman commented on Sep 14, 2026

dkackman commented on Sep 14, 2026

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Repro (workspace `qa-verify`, free, no GPU)