Add Model Port Generic

Goal

Prototype or parity-debug one scheduler, conditioner, upsampler, vocoder, adapter, preprocessor, or unknown component in FastVideo-native code.

Inputs

Follow ../add-model/shared/component_skill_common.md and require the complete packet from ../add-model/contracts/component_context.md.

Generic-component packet fields:

• component: component name.
• component_type: scheduler, conditioner, upsampler, vocoder, adapter, preprocessor, or unknown.
• parity_test: tests/local_tests/<bucket>/test_<family>_<component>_parity.py.
• weights: converted component dir, HF subfolder, or none.
• target_files: matching fastvideo/models/ and fastvideo/configs/models/ bucket files when applicable.

Modes

Use the common prototype and parity-debug modes from ../add-model/shared/component_skill_common.md.

Generic-component prototype concerns include stateless/stateful ambiguity, missing loader buckets, source prefixes, mutable scheduler state, and output container shape.

Reuse Proof

Apply the shared reuse proof. Generic-component comparison must include mutable state, scaling constants, scheduler/conditioner semantics, output containers, and whether the component owns state or is stateless.

Existing FastVideo Patterns

• Schedulers live under fastvideo/models/schedulers/ and expose EntryClass.
• Upsamplers use fastvideo/models/upsamplers/ plus configs under fastvideo/configs/models/upsamplers/; see hunyuan15.py.
• Vocoders and audio-specific modules can live under fastvideo/models/audio/ with configs under fastvideo/configs/models/audio/; see ltx2_audio_vae.py.
• Compound conditioners may fit the encoder bucket when the pipeline loader uses ConditionerLoader; see stable_audio_conditioner.py.
• Registry discovery uses EntryClass; config bucket exports are required when pipeline configs import them by bucket.
• Use the narrowest matching config bucket. Wrong bucket inheritance can typecheck but fail during pipeline wiring.
• Layer guidance: fastvideo/layers/AGENTS.md.

Bucket Decision

• If the component is a transformer/DiT, stop and use add-model-03-port-dit.
• If the component is a VAE/autoencoder, stop and use add-model-04-port-vae.
• If the component is a text/image/audio encoder or encoder-like conditioner, stop and use add-model-05-port-encoder unless the loader requires a different bucket.
• Otherwise choose the narrowest existing bucket. Add a new bucket only when no existing loader/config shape can represent the component without misleading names or unsafe runtime behavior.

Implementation Rules

• Match official behavior, not just shapes: constructor args, default values, runtime flags, RNG use, dtype/autocast, scaling constants, masks, and output containers all matter.
• Keep the implementation minimal and native. Do not keep a runtime import of the official implementation as the production component.
• For schedulers, compare timesteps, sigmas/noise levels, step outputs, shift handling, prediction type, and any mutable internal state.
• For upsamplers, compare resize mode, align_corners, residual branches, causal padding, normalization, and exact target-shape behavior.
• For vocoders/audio components, compare waveform shape, sample-rate contract, channel order, hop length, normalization, and dtype.
• If private upstream deps are required only for tests, keep stubs under tests/local_tests/helpers/ and do not import them from production code.

Prototype Checks

Follow the shared prototype success criteria.

Parity-Debug Loop

Run the shared parity-debug loop. The component test command is:

pytest <parity_test> -v -s

For numerical drift, add targeted intermediate comparisons in the test to identify the first divergent operation.

Escape Hatches

Follow ../add-model/shared/common_rules.md and the component-specific guidance in ../add-model/shared/component_skill_common.md. Generic-component ask cases include creating a new loader bucket, accepting an unsupported private op, choosing between incompatible official definitions, or dropping a required component.

Handoff

Return ../add-model/contracts/component_skill_handoff.md following the common handoff rules in ../add-model/shared/component_skill_common.md.