OpenShowreel

An open-source Model Context Protocol (MCP) server for Adobe After Effects — built so an AI assistant can drive After Effects the way a senior motion designer does: not just dropping keyframes, but applying the mechanics that make a showreel feel premium.

The goal is simple: let an agent take a brief ("animate this UI walkthrough as a 60fps showreel") and produce buttery-smooth, organically-timed motion using the same techniques pros reach for by hand.

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Why this exists

Most automated AE tooling produces stiff, robotic motion — linear paths, simultaneous movement, hard fades. The difference between "a computer animated this" and "a designer animated this" comes down to a handful of repeatable mechanics. OpenShowreel encodes those mechanics as MCP tools so they can be composed programmatically.

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Core After Effects mechanics the server models

1. 60 FPS + Motion Blur (the baseline for "premium")

Before anything is animated, the composition is set to 60 frames per second and motion blur is enabled. This is the single biggest lever for a "buttery smooth" look — every other technique builds on top of it.

2. Morphing shapes

Basic shape layers become expressive when you uncheck "Constrain Proportions" on the Size property. That lets the X and Y axes scale independently — e.g. a moving button can appear to physically push and stretch a background frame as it travels.

3. Expressions over manual keyframes

Instead of hand-animating physics, the server pastes bounce expressions (small code snippets) into the stopwatch of properties like Scale or Position. Physics for free, tweakable by parameter.

4. Timing offsets — the secret to organic motion

Nested elements should never move with their parent — they lag, just slightly. By appending .valueAtTime(time - 0.1) to an expression, child elements (an arrow inside a button, an icon inside a card) are mathematically forced to animate a fraction of a second behind their container. This kills the stiff, "everything moves at once" feel.

5. Simulated micro-interactions

To make a digital interface feel tactile, the server adds a quick scale-down "button press" keyframe right before a major on-screen movement begins — the same anticipation beat a real tap would produce.

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Essential tools the server wraps

Parenting & the Pick Whip

Linking properties together: pick-whip an icon's Scale to its container's Scale, or parent text to a moving shape so it tracks along automatically.

Text Animators + Expression Selectors

Premium text reveals don't just fade in. A Text Animator pushes the starting Position off-screen (e.g. Y → -100) with Opacity at 0%, then an Expression Selector pulls the text into place per-word or per-character — staggered, not all at once.

Null Objects for curved paths

Straight linear motion looks unnatural, so paths are drawn with the pen tool and curved. But curve data can make an object drift when it's meant to be stationary. The fix: snap an invisible Null Object's anchor point to the shape's center, parent the shape to the Null, and animate the Null instead — clean movement, no drift.

The master "camera" finisher

The ultimate polish: create one final master Null Object, attach every otherwise-unlinked element to it, apply an expression, and add a very slight rotation (a small positive tilt followed by a negative one). Moving the whole composition together "stitches it all" into a single cinematic move.

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How it works

OpenShowreel is a Node MCP server. Each tool generates a small ExtendScript snippet and runs it inside a running After Effects via macOS AppleScript (osascript → DoScript), wrapped in an undo group, with the result handed back through a temp file. No After Effects panel/extension to install — just the CLI server.

MCP client (Claude, etc.)  ──stdio──►  openshowreel server  ──osascript/DoScript──►  After Effects

Requirements

• macOS with Adobe After Effects installed (auto-detects the newest Adobe After Effects <year> under /Applications; override with AE_APP_NAME).
• After Effects must be running, with Preferences ▸ Scripting & Expressions ▸ "Allow Scripts to Write Files and Access Network" enabled.
• Node.js ≥ 18.

Build & run

npm install
npm run build
npm start          # or: npm run dev   (runs from source via tsx)
npm test           # tool-builder + dry-run tests — no After Effects needed

Set OPENSHOWREEL_DRY_RUN=1 to make every tool report what it would run instead of touching After Effects — handy for testing the wiring.

Register with an MCP client

{
  "mcpServers": {
    "openshowreel": {
      "command": "node",
      "args": ["/absolute/path/to/openshowreel/dist/index.js"]
      // optional: "env": { "AE_APP_NAME": "Adobe After Effects 2025" }
    }
  }
}

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Tools

Composition & inspection

Tool	What it does
ae_scene_info	Inspect comps, layers, fps, motion-blur state
ae_setup_comp	New comp at 60 fps + motion blur — the premium baseline
ae_save_project	Save / save-as the .aep

Layers

Tool	What it does
ae_create_shape	Rounded-rect / ellipse shape layer with a fill (button, frame…)
ae_create_solid	Solid-colour layer (background / colour wash)
ae_create_text	Plain text layer
ae_import_media	Import an image / video / audio file, optionally place it in a comp
ae_parent_layer	Layer-level pick-whip / parenting
ae_link_property	Pick-whip one property to another via expression

Motion mechanics

Tool	Maps to the mechanic
ae_animate_transform	Keyframe position / scale / rotation / opacity A→B with an easing preset
ae_set_easing	Re-ease existing keyframes (linear / easeIn / easeOut / easeInOut / hold)
ae_add_fade	Opacity fade-in / fade-out at the layer in/out points
ae_morph_size	Animate Size on one axis only — the "constrain proportions OFF" stretch
ae_add_bounce_expression	Paste a physics bounce/overshoot expression onto scale / position / rotation
ae_add_timing_offset	.valueAtTime(time − delay) — make a child trail its parent for organic motion
ae_add_button_press	Tactile scale-down dip just before a major move
ae_add_text_reveal	Text Animator + Expression Selector staggered reveal (per char / word / line)
ae_create_null_path	Pin a layer to an invisible Null, keyframe a curved, drift-free path
ae_add_master_camera	One master Null over everything + slight tilt expression — the cinematic stitch

Effects, masks, mattes, camera

Tool	What it does
ae_add_effect / ae_set_effect_param	Add any effect; set or keyframe any parameter
ae_add_drop_shadow / ae_add_glow / ae_add_gaussian_blur	One-call effect presets
ae_add_adjustment_layer	Full-frame adjustment layer for a global grade/treatment
ae_set_blend_mode	Layer blending modes (screen, add, multiply, …)
ae_add_mask / ae_animate_mask	Rect/ellipse masks; keyframe expansion or feather for wipes
ae_add_trim_path	Trim Paths line draw-on (adds a stroke if needed)
ae_set_track_matte	Use the layer above as an alpha/luma matte
ae_set_layer_3d	Toggle the 3D switch on a layer (or all of them)
ae_add_camera / ae_animate_camera	Add a camera; keyframe a dolly / push-in / pan

Scenes, timing, output, escape hatch

Tool	What it does
ae_create_precomp	Precompose layers into a scene
ae_add_layer_to_comp	Drop a precomp / footage item into another comp
ae_add_markers	Comp or layer markers (beat / section sync)
ae_enable_time_remap / ae_animate_time_remap	Speed ramps / freezes / reverse on footage & precomps
ae_add_device_frame	Wrap a layer in a card / browser / phone mockup
ae_render_frame / ae_render_frames	Render frame(s) to PNG and return the path(s) — the agent's review loop
ae_render_comp	Render a comp to a video file via the Render Queue
ae_save_project	Save / save-as the .aep
ae_eval	Run arbitrary ExtendScript

See docs/SHOWREEL_PLAYBOOK.md for how to sequence these into a polished reel, and examples/demo-showreel.mjs for a runnable mini-build.

Notes: ExtendScript match-names target current After Effects builds — if a tool errors on another version, ae_eval lets you patch around it (PRs welcome). Under the Advanced 3D renderer the .value getter on shape-layer spatial properties can throw, so OpenShowreel never reads it: pass from explicitly to ae_animate_transform if you need a non-default start value.

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Status

🚧 Active development — the bridge and ~40 tools (composition, layers, motion mechanics, effects, masks/mattes, 3D camera, precomps, time remap, device mockups, rendering) are in place and verified live against After Effects 2026. Live behaviour depends on your After Effects version; expect to file/fix the odd match-name. The remaining gap toward fully autonomous reels is mostly direction + assets, not capability — see the playbook.

License

MIT — see LICENSE.