Dynamic UI & Parameters

Every model in modelBridge gets a purpose-built interface — sliders, dropdowns, checkboxes, text inputs, media uploads — all generated automatically from the model’s OpenAPI specification. No hardcoded forms, no simplified interfaces. The full model, as its creators intended.

How It Works

When you select a model, the plugin reads its parsed schema and renders a form tailored to that model’s inputs. A model with 4 parameters gets 4 controls. A model with 20 parameters gets 20 controls, organized into main and advanced sections. Switch models, and the entire form regenerates.

This is the core differentiator of modelBridge — a single engine that supports every fal.ai model without model-specific code.

Parameter Types

Every parameter a model exposes becomes an appropriate input in the panel. Sliders for ranges, dropdowns for options, toggles for on/off settings, media upload cards for image and video inputs, and tag inputs for lists. You interact with the model in plain editorial terms — not raw API parameters.

Each control shows the field’s label, current value, and default value. Required fields are marked visually.

Main vs Advanced Settings

The form is split into two tiers automatically:

Always Visible (Main Settings)

Parameters you adjust on every generation:

• Prompt — the text description field
• Duration — video length
• Aspect ratio — output dimensions
• Resolution — output quality
• Number of images — for multi-image models

Advanced Settings (Expandable)

Power user controls behind a toggle:

• Negative prompt — what to avoid in generation
• CFG scale — how closely to follow the prompt
• Seed — for reproducible results
• Width / Height — explicit pixel dimensions
• FPS — frames per second
• Inference steps — quality vs speed tradeoff
• Model-specific parameters — any other fields the model exposes

The separation is driven by field semantics and schema metadata — not hardcoded per model. A model the plugin has never seen before still gets the right layout.

Live Cost Updates

As you change parameters, the cost estimate updates in real time. Fields that affect cost include:

• Duration (longer = more expensive)
• Resolution (higher = more expensive)
• Audio toggle (adds a surcharge on some models)
• Number of images (multiplies the cost)
• Quality tier (some models charge more for higher quality)

The cost badge above the Generate button reflects your current parameter values at all times.

Prompt Persistence

Your prompt text carries over when you switch models. Write a prompt, switch from one model to another, and the text is already there. Model-specific settings (duration, aspect ratio, resolution) reset to the new model’s defaults.

Media Input Cards

Models that require media input show a media card at the top of the form. The card type depends on what the model needs:

• Single media card — one image or video input (image-to-video, video-to-video)
• Dual-frame card — start and end frame columns (interpolation models)
• No card — text-only models (text-to-video, text-to-image)

Media cards show real-time validation status — green for valid, red with a specific error message when the selected media does not meet the model’s requirements.

Extract a Frame from a Video Clip

When a model wants an image but you have a video selected on your timeline, modelBridge adds an Extract frame button to the media card.

The button shows the exact timecode of your current playhead — Extract frame (00:03:87) — and updates live as you move the playhead. Scrub to the frame you want, click once, and that frame becomes the model’s image input. No exporting, no Photoshop roundtrip, no JPG sitting in your Downloads folder.

This is what unlocks one of modelBridge’s most powerful workflows: any video frame on your timeline can feed any image-to-image or image-to-video model. Pick a hero frame from your own footage, animate it, restyle it, upscale it — without leaving Premiere.

Workflow

Scrub on the timeline → the timecode in the button updates → click when you find the frame → the extracted image is loaded as input. See Video frame to AI for full workflow recipes.

Field Validation

Every field is validated against the schema before generation:

• Required fields — Generate is disabled until all required fields are filled
• Range constraints — sliders enforce min/max from the schema
• Enum values — dropdowns only show valid options
• Media type — media cards check format, dimensions, file size, and duration

Invalid fields show inline error messages. The Generate button tooltip tells you exactly what is missing or wrong.

Hybrid URL Fields

Some models accept media either from your timeline selection or from a pasted URL. These appear in Advanced Settings as tabbed inputs — “From Selection” vs “Paste URL”. Labels update in real time to reflect your current selection state:

• “Using selected video” / “Using selected image” — when a clip is selected
• “No media selected” — when nothing is selected
• “This model requires a video clip” — when the wrong media type is selected (red error state)

Use the Paste URL field for any public image URL — Midjourney, DALL-E, Stable Diffusion galleries, or any direct CDN link. See Midjourney to Premiere Pro for the full workflow.