Compdown

A natural language for After Effects.

Compdown is an After Effects extension that lets you describe After Effects content (compositions, layers, folders, files, keyframes, effects, etc.) in YAML and create them with a single click.

It also allows you to export existing comps back into YAML.

Why text?

• Readable — Elegant syntax that stays clean when you ship it across teams
• Shareable — Save it, gist it, email it, or drop it in a repo. Text travels well
• Fast — Copy, paste, process. Stay in After Effects and skip binary presets
• AI-friendly — If an AI can read and write the same text you use, it can help draft scenes, explore variations, or build first passes

Supported Features

After Effects

• Project structure: Define folders, files, and compositions in YAML; creation order is folders → files → compositions → layers
• Layer types: Solids, nulls, adjustment layers, text layers, shape layers, camera layers, light layers, audio layers, file-based layers (footage, images), and composition-in-composition nesting via the composition key
• Shape layers: Parametric shapes (rectangle, ellipse, polygon, star) and custom paths with fill and stroke properties
• Masks: Per-layer masks with modes, opacity, feather, expansion, and optional animated paths
• Text animators: Per-character animation via text animators (opacity/position/scale/rotation/etc.)
• Keyframe animation: Transform properties (position, scale, rotation, opacity, anchor point) with static values or arrays of keyframes
• Layer effects: Native effects on layers, with properties supporting static or animated values, by display name or matchName

Extension

• Schema validation: Real-time type and structure validation for all YAML, with detailed, line-numbered errors before anything reaches AE
• Built-in editor: CodeMirror 6 with YAML syntax highlighting, code folding, one-dark theme, and error gutter
• Import/export: Load .yaml/.yml files from disk and export existing AE comps back to YAML with a single click

Installation

1. Build the extension:

   npm install
   npm run build

2. Enable unsigned extensions in After Effects (use aescripts ZXP Installer > Settings > Debug > Enable Debugging, or set the PlayerDebugMode registry/plist flag).

3. Restart After Effects. The panel appears under Window > Extensions > Compdown.

For distribution as a signed ZXP:

npm run zxp

Development

npm run dev        # Dev server with HMR (localhost:3000)
npm run build      # Production build
npm run serve      # Preview production build (localhost:5000)

Type-check the panel side:

npx tsc -p tsconfig-build.json --noEmit

YAML Schema

A Compdown document has three optional top-level keys: folders, files, and compositions. At least one must be present.

Note

Compdown automatically handles some YAML parsing quirks so you don't need extra quotes:

• type: null works as-is (YAML would normally parse this as a null value, not the string "null")
• color: 000000 works as-is (YAML would normally parse all-digit values as numbers)

Minimal example

compositions:
  - name: My Comp
    layers:
      - name: background
        type: solid
        color: 1a1a2e
      - name: title
        type: text
        text: Hello World
        transform:
          position: [960, 540]

Full example

folders:
  - name: Footage
  - name: Renders
  - name: Plates
    parent: Footage

files:
  - id: bg
    path: /path/to/background.png
    folder: Footage
  - id: seq
    path: /path/to/sequence/frame_[0001-0100].png
    sequence: true

compositions:
  - name: Lower Third
    width: 1920
    height: 200
    duration: 5
    layers:
      - name: bar
        type: solid
        color: 1a1a2e
      - name: label
        type: text
        text: Breaking News
        transform:
          opacity:
            - time: 0
              value: 0
            - time: 1
              value: 100

  - name: Main Comp
    width: 1920
    height: 1080
    duration: 10
    framerate: 30
    pixelAspect: 1
    color: "000000"
    folder: Renders
    layers:
      - name: bg plate
        file: bg
        transform:
          position: [960, 540]
          scale: [100, 100]
          opacity: 80
      - name: lower third
        composition: Lower Third
        transform:
          position:
            - time: 2
              value: [960, 1280]
            - time: 3
              value: [960, 980]
      - name: adjustment
        type: adjustment
        blendingMode: softLight
        effectsActive: true
      - name: video clip
        file: seq
        motionBlur: true
        quality: best
        samplingQuality: bicubic
        frameBlendingType: pixelMotion
        label: 4
      - name: guide
        type: null
        threeDLayer: true
        locked: true
        shy: true
        guideLayer: true

Reference

folders

Property	Type	Required	Description
name	string	yes	Folder name
parent	string	no	Parent folder name

files

Property	Type	Required	Description
id	string | number	yes	Unique identifier for the file
path	string	yes	Absolute file path
sequence	boolean	no	Import as image sequence
folder	string	no	Target project folder

compositions

Property	Type	Required	Default	Description
name	string	yes		Composition name
width	int	no	1920	Width in pixels
height	int	no	1080	Height in pixels
duration	number	no	10	Duration in seconds
framerate	number	no	30	Frames per second
pixelAspect	number	no	1	Pixel aspect ratio
color	string	no	"000000"	Background hex color
folder	string	no		Target project folder
layers	array	no		List of layers (below)
markers	array	no		List of markers (below)

layers

Each layer must have exactly one of type, file, or composition.

Core identity and source

Property	Type	Required	Description
name	string	yes	Layer name
type	string	if no file/composition	solid, null, adjustment, text, camera, light, shape, audio
file	string | number	if no type/composition	References a file id
composition	string	if no type/file	References another composition by name
transform	object	no	Transform properties (see below)

Timing and placement

Property	Type	Required	Description
inPoint	number	no	In point (seconds, >= 0)
outPoint	number	no	Out point (seconds, >= 0)
startTime	number	no	Start time offset
label	int	no	Color label index (0-16)

Type-specific (solid and text)

Property	Type	Required	Description
width	int	no	Solid width
height	int	no	Solid height
color	string	yes for solid	6-char hex color (e.g. FF0000)
text	string	yes for text	Text content
fontSize	number	no	Font size
font	string	no	Font family name
fillColor	string	no	Text fill color (6-char hex)
strokeColor	string	no	Text stroke color (6-char hex)
strokeWidth	number	no	Text stroke width
tracking	number	no	Character spacing
leading	number	no	Line spacing
justification	string	no	left, center, right

Type-specific (audio)

Property	Type	Required	Description
file	string | number	yes for audio	References a file id

Layer switches and toggles

Property	Type	Required	Description
enabled	boolean	no	Layer visibility
shy	boolean	no	Shy flag
locked	boolean	no	Lock flag
threeDLayer	boolean	no	Enable 3D
solo	boolean	no	Solo the layer
audioEnabled	boolean	no	Enable/disable audio
motionBlur	boolean	no	Enable motion blur
collapseTransformation	boolean	no	Continuously rasterize / collapse
guideLayer	boolean	no	Mark as guide layer
effectsActive	boolean	no	Global effects toggle
timeRemapEnabled	boolean	no	Enable time remapping

Parenting and render behavior

Property	Type	Required	Description
parent	string	no	Parent layer name
blendingMode	string	no	Blending mode (see list below)
quality	string	no	best, draft, wireframe
samplingQuality	string	no	bicubic, bilinear
autoOrient	string	no	off, alongPath, cameraOrPointOfInterest
frameBlendingType	string	no	none, frameMix, pixelMotion
trackMatteType	string	no	none, alpha, alphaInverted, luma, lumaInverted

Camera-specific

Property	Type	Required	Description
cameraType	string	no	oneNode, twoNode (for camera layers)
zoom	number	no	Camera zoom
depthOfField	boolean	no	Enable depth of field
focusDistance	number	no	Camera focus distance
aperture	number	no	Camera aperture
blurLevel	number	no	Blur level (0-100)

Light-specific

Property	Type	Required	Description
lightType	string	yes for light	parallel, spot, point, ambient
intensity	number	no	Light intensity
lightColor	string	no	Light color (6-char hex)
coneAngle	number	no	Spot light cone angle (0-180)
coneFeather	number	no	Spot light cone feather (0-100)
castsShadows	boolean	no	Enable shadow casting
shadowDarkness	number	no	Shadow darkness (0-100)
shadowDiffusion	number	no	Shadow diffusion

Shape-layer specific

Property	Type	Required	Description
shapes	array	yes for shape	Array of shapes (see below)

shapes (Shape Layers)

Shape layers support parametric shapes (rectangle, ellipse, polygon, star) and custom paths with fill and stroke. Each shape layer requires a shapes array with at least one shape.

Note

Shape-group gradient fills (fill.gradient) are not part of the schema. For gradient looks, use layer styles/effects on the layer.

Shape types and properties:

Shape Type	Required Properties	Optional Properties
rectangle	size: [w, h]	position, roundness, fill, stroke, name
ellipse	size: [w, h]	position, fill, stroke, name
polygon	points, outerRadius	position, outerRoundness, rotation, fill, stroke, name
star	points, outerRadius, innerRadius	position, outerRoundness, innerRoundness, rotation, fill, stroke, name
path	vertices	inTangents, outTangents, closed, position, fill, stroke, name

Fill and stroke:

Property	Type	Description
fill.color	string	6-char hex color (required for fill)
fill.opacity	number	Opacity 0-100 (default: 100)
stroke.color	string	6-char hex color (required for stroke)
stroke.width	number	Stroke width (default: 1)
stroke.opacity	number	Opacity 0-100 (default: 100)

Shape operators (operators on each shape):

Operator type	Supported properties
trimPaths	start, end, offset, trimMultipleShapes
zigZag	size, ridgesPerSegment, points
repeater	copies, offset, transform.anchorPoint, transform.position, transform.scale, transform.rotation, transform.startOpacity, transform.endOpacity
offsetPaths	amount, lineJoin, miterLimit
puckerBloat	amount
roundCorners	radius
mergePaths	mode
twist	angle, center
wigglePaths	size, detail, points, wigglesPerSecond, correlation, temporalPhase, spatialPhase, randomSeed

Example:

layers:
  - name: Shape Layer
    type: shape
    shapes:
      - type: rectangle
        name: Background
        size: [400, 200]
        position: [0, 0]
        roundness: 20
        fill:
          color: FF5500
          opacity: 100
        stroke:
          color: "000000"
          width: 2

      - type: ellipse
        name: Circle
        size: [100, 100]
        position: [50, 50]
        fill:
          color: 00FF00

      - type: polygon
        name: Triangle
        points: 3
        outerRadius: 50
        fill:
          color: 0000FF

      - type: star
        name: Star
        points: 5
        outerRadius: 100
        innerRadius: 40
        fill:
          color: FFFF00

      - type: path
        name: Custom Path
        vertices:
          - [0, 0]
          - [120, 0]
          - [120, 80]
          - [0, 80]
        closed: true
        stroke:
          color: "00FFFF"
          width: 2

  - name: VO
    type: audio
    file: voiceover-01

Note

For path shapes, inTangents and outTangents are optional. If omitted, tangents default to [0, 0].

masks

Masks can be added to any layer type.

Property	Type	Required	Description
name	string	no	Mask name
path	object or array	yes	Mask path (see below)
mode	string	no	add, subtract, intersect, lighten, darken, difference, none
opacity	number	no	Opacity 0-100
feather	[number, number]	no	Feather [x, y]
expansion	number	no	Expansion in pixels
inverted	boolean	no	Invert mask

Mask path:

path:
  vertices:
    - [0, 0]
    - [100, 0]
    - [100, 100]
    - [0, 100]
  inTangents:  # optional
    - [0, 0]
    - [0, 0]
    - [0, 0]
    - [0, 0]
  outTangents: # optional
    - [0, 0]
    - [0, 0]
    - [0, 0]
    - [0, 0]
  closed: true

Example:

layers:
  - name: Masked Solid
    type: solid
    color: FF0000
    masks:
      - name: Hole
        mode: subtract
        feather: [8, 8]
        path:
          vertices:
            - [200, 200]
            - [400, 200]
            - [400, 400]
            - [200, 400]

textAnimators

Text animators are available on text layers and let you animate properties per-character.

Property	Type	Required	Description
name	string	no	Animator name
properties	object	yes	Properties to animate (see below)
selector	object	no	Range selector settings

Animator properties (supported):

opacity, position, scale, rotation, anchorPoint, tracking

Selector properties (supported):

start, end, offset, smoothness

Example:

layers:
  - name: Title
    type: text
    text: "Compdown"
    textAnimators:
      - name: Fade In
        properties:
          opacity:
            - time: 0
              value: 0
            - time: 1
              value: 100
              easing: easeOut
        selector:
          start: 0
          end: 100

effects

An optional array on each layer. Each effect has:

Property	Type	Required	Description
name	string	yes	Effect display name
matchName	string	no	AE internal match name (for portability)
enabled	boolean	no	Default true; set false to disable
properties	object	no	Key-value map of property names to values
expressions	object	no	Key-value map of property names to expressions

Property value types:

Type	Example	Description
number	10	Scalar value
boolean	true	Checkbox (converted to 1/0)
number array	[960, 540]	2D point, color, etc.
keyframe array	[{time: 0, value: 10}, ...]	Animated (minimum 2 keyframes)

effects:
  - name: Gaussian Blur
    matchName: ADBE Gaussian Blur 2
    properties:
      Blurriness: 10
      Repeat Edge Pixels: true
  - name: CC Radial Fast Blur
    enabled: false
    properties:
      Amount: 50
      Center:
        - time: 0
          value: [960, 540]
        - time: 5
          value: [0, 0]

transform

Each transform property accepts either a static value or an array of keyframes (minimum 2).

Property	Static type	Keyframe value	Description
anchorPoint	[x, y]	[x, y]	Anchor point
position	[x, y]	[x, y]	Position (combined X/Y)
positionX	number	number	X position (separate)
positionY	number	number	Y position (separate)
positionZ	number	number	Z position (3D layers)
scale	[x, y]	[x, y]	Scale (percent)
rotation	number	number	Z Rotation (degrees)
rotationX	number	number	X Rotation (3D layers)
rotationY	number	number	Y Rotation (3D layers)
opacity	number	number (0-100)	Opacity

Note: Use either position OR positionX/positionY/positionZ, not both. Separate dimensions allow independent easing per axis. Using positionZ, rotationX, or rotationY automatically enables the layer's 3D switch.

Keyframe syntax: each keyframe is an object with time (seconds, >= 0), value, and optional easing. You can mix static and keyframed properties on the same layer.

transform:
  rotation: 45 # static
  position: # keyframed with easing
    - time: 0
      value: [0, 0]
      easing: easeOut
    - time: 5
      value: [1920, 1080]
      easing: easeIn
  opacity:
    - time: 0
      value: 0
    - time: 2
      value: 100

Easing types: linear (default), easeIn, easeOut, easeInOut, hold

Easing	Description
linear	Constant speed (default, no need to specify)
easeIn	Slow arrival at this keyframe
easeOut	Slow departure from this keyframe
easeInOut	Slow arrival and departure
hold	Hold value until next keyframe (no interpolation)

Expressions: Add an expressions object to apply AE expressions to transform properties:

transform:
  position: [960, 540]
  rotation: 0
  expressions:
    position: "wiggle(5, 50)"
    rotation: "time * 36"

markers

Optional array on compositions. Each marker has:

Property	Type	Required	Description
time	number	yes	Marker time in seconds
comment	string	no	Marker comment/label
duration	number	no	Marker duration (for range markers)
chapter	string	no	Chapter name
url	string	no	URL link
label	int	no	Color label (0-16)

compositions:
  - name: My Comp
    markers:
      - time: 0
        comment: "Intro"
      - time: 5
        comment: "Main Content"
        duration: 10
      - time: 15
        comment: "Outro"
        chapter: "Credits"

Blending modes

normal, dissolve, darken, multiply, colorBurn, linearBurn, darkerColor, lighten, screen, colorDodge, linearDodge, lighterColor, overlay, softLight, hardLight, vividLight, linearLight, pinLight, hardMix, difference, exclusion, subtract, divide, hue, saturation, color, luminosity

essentialGraphics

Expose layer properties to the Essential Graphics Panel for creating Motion Graphics Templates (.mogrt). Each composition can have an optional essentialGraphics array.

Two forms are supported:

Simple form (string path, uses property path as display name):

essentialGraphics:
  - title.transform.position
  - title.text

Expanded form (custom display name and options):

essentialGraphics:
  - property: title.transform.position
    name: "Logo Position"
  - property: title.text
    name: "Headline"
  - property: bar.transform.opacity
    encodePathInName: false  # Disable round-trip encoding

Property	Type	Required	Description
property	string	yes	Property path (e.g. layer.transform.position)
name	string	no	Custom display name (defaults to property path)
encodePathInName	boolean	no	Encode property path for round-trip (default: true)

Property path format: layerName.propertyPath

Path Pattern	Description
layer.transform.position	Position property
layer.transform.scale	Scale property
layer.transform.rotation	Rotation property
layer.transform.opacity	Opacity property
layer.transform.anchorPoint	Anchor point property
layer.text	Text source property
layer.effects.EffectName.PropName	Effect property

Full example:

compositions:
  - name: Lower Third
    layers:
      - name: title
        type: text
        text: "Breaking News"
      - name: bar
        type: solid
        color: FF0000
        effects:
          - name: Gaussian Blur
            properties:
              Blurriness: 10

    essentialGraphics:
      - property: title.text
        name: "Headline"
      - property: title.transform.position
        name: "Title Position"
      - property: bar.effects.Gaussian Blur.Blurriness
        name: "Bar Blur"

Round-trip support:

By default, Compdown encodes the property path in the controller name (format: Display Name [path:layer.transform.position]). This allows exported YAML to include the full property path, enabling true round-trip workflows:

1. Create a comp from YAML with Essential Graphics entries
2. Export the comp back to YAML
3. The exported YAML includes both the property path and display name

To disable this encoding (for cleaner controller names in Premiere):

essentialGraphics:
  - property: title.text
    name: "Headline"
    encodePathInName: false  # Controller name will be just "Headline"

Note

• Not all properties can be added to the Essential Graphics Panel. Compdown checks canAddToMotionGraphicsTemplate() and skips unsupported properties silently.
• addToMotionGraphicsTemplateAs() (custom names) requires After Effects CC 2019 (16.1) or later.
• Legacy Essential Graphics entries (created manually or without path encoding) export as name-only objects.

Architecture

The extension runs two separate runtimes connected by Bolt CEP:

• Panel (React + TypeScript): UI, YAML editing, schema validation. All parsing and validation happen here before anything is sent to AE.
• ExtendScript (ES3, runs inside AE): Receives validated JSON and executes After Effects API calls. Handles creation of project items and reading of compositions.

Creation order when building from YAML: folders -> files -> compositions -> layers. Each step's output feeds into the next (layers need composition references, file-based layers need footage references).

Tech stack

• React 19 + TypeScript
• CodeMirror 6 (YAML editor)
• Zod (schema validation)
• js-yaml (YAML parsing)
• Vite + Bolt CEP (build tooling)