Automate Adobe After Effects via ExtendScript. Use when the user asks to create, modify, or query anything in an After Effects project — layers, keyframes, expressions, effects, compositions, assets, rendering, batch operations. Generates and executes JSX ExtendScript via osascript on macOS.

Overview This skill automates After Effects by generating ExtendScript (.jsx) and executing it via osascript. It reads project state through query scripts, uses rule files for domain knowledge, and wraps all mutations in undo groups. First Time Setup 1. Run scripts/runner.sh with any query script to detect the AE version 2. If multiple AE versions are installed, the user must choose one — runner.sh will prompt 3. Ensure AE Preferences Scripting & Expressions "Allow Scripts to Write Files and Access Network" is enabled Workflow For every user request: Step 1: Gather context (auto run, no confirmation needed) Use background for all query scripts — this skips ae.activate() so AE doesn't steal focus: Then read /tmp/ae assistant result.json for active comp, selected layers, CTI. If this is the first interaction or the project context is unknown, also run: This returns a summary by default: folder tree with counts, all comps listed, footage grouped by file type. NOT every individual file. To drill into a specific folder: Only use full mode when you actually need every item listed: Step 2: Drill down if needed (auto run) If the task targets a specific comp: If the task targets specific layers: Omit compName to use the active comp. Omit layerNames to use selected layers. Additional query scripts Expression errors — scan for broken expressions: Font inventory — list all fonts used across the project: Project audit — comprehensive health check (unused footage, missing files, expression errors, duplicate solids, font issues, empty folders): Step 3: Load domain knowledge Read the relevant rule file from rules/ . Always read rules/extendscript fundamentals.md — it contains ES3 constraints that apply to every generated script. Task involves Load rule file Layers (create, move, parent, duplicate) [rules/layer manipulation.md](rules/layer manipulation.md) Keyframes, animation, easing [rules/keyframes animation.md](rules/keyframes animation.md) Expressions [rules/expressions.md](rules/expressions.md) Compositions (create, precompose, nest) [rules/composition management.md](rules/composition management.md) Effects and parameters [rules/effects.md](rules/effects.md) Import, footage, assets [rules/assets footage.md](rules/assets footage.md) Render queue, export [rules/rendering.md](rules/rendering.md) Bulk/batch operations [rules/batch operations.md](rules/batch operations.md) Version specific features [references/ae api versions.md](references/ae api versions.md) Step 4: Generate the action script CRITICAL: Resolve the skill's real path first Before writing or executing any action script, resolve the skill's real (non symlinked) path. ExtendScript include cannot follow symlinks, so you MUST use the real filesystem path. Run this once at the start of each session: Use the resolved path ( $SKILL SCRIPTS ) for all subsequent Write and Bash commands in this session. Why this matters: ~/.claude/skills/ is typically a symlink — ExtendScript include fails through symlinks Writing to the real scripts/ directory lets include "lib/json2.jsx" resolve correctly The resolved path changes per machine, so never hardcode it Every generated script MUST follow this template: utils.jsx helpers available for generated scripts Function Purpose writeResult(obj) Write JSON result to /tmp/ae assistant result.json writeError(msg, detail) Last resort error capture when JSON.stringify fails readArgs() Read args from /tmp/ae assistant args.json getLayerType(layer) Returns type string: "shape", "text", "null", "precomp", etc. getBlendModeName(mode) BlendingMode enum → string name getActiveComp() Returns active comp or writes error and returns null getSelectedOrAllLayers(comp) Selected layers array, or all layers if none selected hexToRGB(hex) " ff0000" → [1, 0, 0] getCompByName(name) Find comp in project items by name walkProperties(group, leafFn, path) Recursive property tree walker — calls leafFn(prop, path) on leaves bubbleSort(arr, compareFn) ES3 compatible in place sort framesToSeconds(frames, comp) Frame count → seconds via comp.frameDuration appendLog(message) Append to ~/.ae assistant extendscript.log Write the script using the Write tool, then execute with a short bash command: 1. Use the Write tool to write the script to $SKILL SCRIPTS/ae action.jsx (the resolved real path) 2. Execute it with bash: IMPORTANT: Do NOT use cat file << 'SCRIPT' heredocs — they put the entire script in the bash command, cluttering the permission prompt. Always use the Write tool for the script content, then a short bash command to run it. Step 5: Execute or confirm Auto run (no confirmation needed): All read only queries (active state, project overview, comp detail, layer detail, expression errors, font inventory, project audit) Non destructive additions: adding a keyframe, adding an effect, creating a layer, creating a comp Confirm before running (show the script and ask the user): Deleting layers or comps Removing keyframes Replacing footage Clearing expressions Render queue operations Project cleanup (removing unused items, consolidating solids) Any operation the user might not expect Built in action scripts Before generating a custom ae action.jsx , check if a built in script already handles the task. These are permanent, tested scripts with args based behavior: True Comp Duplicator — deep clone a comp with independent sub comps (confirm before running): Font Replace — find and replace fonts across the project. Always dryRun first: Project Cleanup — remove unused footage, consolidate duplicate solids, remove empty folders. Always dryRun first: Batch Rename — rename layers, comps, or project items in bulk: Layer Stagger — offset selected layers in time for cascade animations: Expression Replace — find/replace text in expressions project wide. Always dryRun first: Organize Project — auto sort project panel items into folders by type: Batch Comp Settings — change fps, resolution, duration across multiple comps: Easing Presets — apply professional easing or bounce/elastic expressions: Anchor Point Mover — reposition anchor point with visual position compensation: Reverse Keyframes — reverse animation on selected properties: Select Layers — select layers by type, label, attribute, or name: Layer Sort — reorder layers in timeline by name, position, in point, type, or label: Smart Precompose — precompose with auto trimmed duration: Copy Ease — copy easing from one keyframe and paste to others: Relink Footage — batch relink missing footage from search directories. Always dryRun first: SRT Import — create timed subtitle text layers from an SRT file: Text Export/Import — export all text to CSV, edit externally, reimport: Batch Expression — apply, remove, enable, or disable expressions in bulk: Randomize Properties — apply random values to transform properties: Un PreCompose — extract layers from a precomp back into parent (confirm before running): Comp from CSV — generate comp variations from spreadsheet data (confirm before running): Render Queue Batch — add multiple comps to render queue (confirm before running): Explode Shape Layer — split shape groups into individual layers: Incremental Save — save project with auto incrementing version number: Purge Cache — clear memory caches, disk cache, and free resources. dryRun to check size first: Trim Comp to Content — trim/extend comp duration to exactly fit layer content: Null from Layers — create a null at each selected layer's position, auto parent: Fit to Comp — scale selected layers to fit/fill comp dimensions: Label Layers — batch set label colors on layers by type, name, or selection: Blend Mode Set — set blending mode on selected layers: Split Layer — split selected layers at CTI (confirm before running — modifies layer timing): Step 6: Execute and read result Read /tmp/ae assistant result.json for the result. Debugging failures If a script fails, check these in order: 1. ~/.ae assistant log — runner.sh logs every execution, args, results, and errors here 2. /tmp/ae assistant error.txt — JXA level errors (AE not responding, DoScriptFile failure) 3. ~/.ae assistant extendscript.log — ExtendScript level logs from appendLog() in utils.jsx 4. AE Preferences — Ensure "Allow Scripts to Write Files and Access Network" is enabled When an error occurs, read ~/.ae assistant log to understand what happened, fix the script, and retry. MUST ALWAYS wrap mutations in app.beginUndoGroup() / app.endUndoGroup() ALWAYS use matchNames for property access, not display names (display names are localized) ALWAYS use 1 based indexing for layers and project items ALWAYS write action scripts to $SKILL SCRIPTS/ae action.jsx (the resolved real path, NOT /tmp/ ) ALWAYS use relative include "lib/json2.jsx" and include "lib/utils.jsx" (NOT absolute paths) ALWAYS wrap in an IIFE to avoid global scope pollution ALWAYS use var , never let or const (ES3) ALWAYS write results to /tmp/ae assistant result.json via writeResult() ALWAYS use getActiveComp() to get the active comp (handles the null/CompItem check and writes error) ALWAYS use background flag for query scripts to avoid focus steal FORBIDDEN NEVER use ES5+ syntax: let, const, arrow functions, template literals, destructuring NEVER use Array.map, Array.filter, Array.reduce, Array.forEach (not in ES3) NEVER use JSON.parse or JSON.stringify without including json2.jsx NEVER write action scripts to /tmp/ — ExtendScript include can't resolve paths from there NEVER use absolute paths in include — they break through symlinks NEVER hardcode layer indices — use names, selection, or iteration NEVER run destructive operations without user confirmation NEVER assume a comp is active without checking NEVER use cat file << 'SCRIPT' heredocs to write scripts — use the Write tool instead, then execute with a short bash command

after-effects