after-effects by aedev-tools/skills

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

Run scripts/runner.sh with any query script to detect the AE version
If multiple AE versions are installed, the user must choose one — runner.sh will prompt
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)

Run the active state query:

bash scripts/runner.sh scripts/active-state.jsx

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:

bash scripts/runner.sh scripts/project-overview.jsx

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:

bash scripts/runner.sh scripts/project-overview.jsx '{"mode": "folder", "folderName": "Images"}'

Only use full mode when you actually need every item listed:

bash scripts/runner.sh scripts/project-overview.jsx '{"mode": "full"}'

Step 2: Drill down if needed (auto-run)

If the task targets a specific comp:

bash scripts/runner.sh scripts/comp-detail.jsx '{"compName": "Comp Name"}'

If the task targets specific layers:

bash scripts/runner.sh scripts/layer-detail.jsx '{"layerNames": ["Layer 1", "Layer 2"]}'

Omit compName to use the active comp. Omit layerNames to use selected layers.

Additional query scripts

Expression errors — scan for broken expressions:

bash scripts/runner.sh scripts/expression-errors.jsx
bash scripts/runner.sh scripts/expression-errors.jsx '{"compName": "Main Comp"}'

Font inventory — list all fonts used across the project:

bash scripts/runner.sh scripts/font-inventory.jsx

Project audit — comprehensive health check (unused footage, missing files, expression errors, duplicate solids, font issues, empty folders):

bash scripts/runner.sh scripts/project-audit.jsx
bash scripts/runner.sh scripts/project-audit.jsx '{"checks": ["unused", "missing", "expressions"]}'

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
Keyframes, animation, easing	rules/keyframes-animation.md
Expressions	rules/expressions.md
Compositions (create, precompose, nest)	rules/composition-management.md
Effects and parameters	rules/effects.md
Import, footage, assets	rules/assets-footage.md
Render queue, export	rules/rendering.md
Bulk/batch operations	rules/batch-operations.md
Version-specific features	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:

SKILL_SCRIPTS="$(readlink -f ~/.claude/skills/after-effects-assistant/scripts 2>/dev/null || readlink ~/.claude/skills/after-effects-assistant/scripts)"
echo "$SKILL_SCRIPTS"

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:

#include "lib/json2.jsx"
#include "lib/utils.jsx"

(function() {
    app.beginUndoGroup("AE Assistant: <action description>");
    try {
        var args = readArgs();
        var comp = app.project.activeItem;
        if (!comp || !(comp instanceof CompItem)) {
            writeResult({ error: "No active composition" });
            return;
        }

        // ... action code ...

        writeResult({ success: true, message: "<what was done>" });
    } catch (e) {
        try { writeResult({ error: e.toString(), line: e.line, fileName: e.fileName }); }
        catch(e2) { writeError(e.toString(), "line:" + e.line); }
    } finally {
        app.endUndoGroup();
    }
})();

Write the script using the Write tool, then execute with a short bash command:

Use the Write tool to write the script to $SKILL_SCRIPTS/ae-action.jsx (the resolved real path)
Execute it with bash:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/ae-action.jsx"

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):

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/true-comp-duplicator.jsx" '{"compName": "Main Comp", "suffix": " COPY"}'

Font Replace — find and replace fonts across the project. Always dryRun first:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/font-replace.jsx" '{"find": "Helvetica", "replace": "Inter-Regular", "dryRun": true}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/font-replace.jsx" '{"find": "Helvetica", "replace": "Inter-Regular"}'

Project Cleanup — remove unused footage, consolidate duplicate solids, remove empty folders. Always dryRun first:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/project-cleanup.jsx" '{"dryRun": true}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/project-cleanup.jsx"

Batch Rename — rename layers, comps, or project items in bulk:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/batch-rename.jsx" '{"target": "layers", "mode": "find-replace", "find": "Layer", "replace": "Element"}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/batch-rename.jsx" '{"target": "layers", "mode": "prefix", "prefix": "BG_"}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/batch-rename.jsx" '{"target": "layers", "mode": "sequence", "base": "Card", "start": 1}'

Layer Stagger — offset selected layers in time for cascade animations:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/layer-stagger.jsx" '{"offset": 0.1, "unit": "seconds", "direction": "forward"}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/layer-stagger.jsx" '{"offset": 2, "unit": "frames"}'

Expression Replace — find/replace text in expressions project-wide. Always dryRun first:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/expression-replace.jsx" '{"find": "comp(\"Old\")", "replace": "comp(\"New\")", "dryRun": true}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/expression-replace.jsx" '{"find": "comp(\"Old\")", "replace": "comp(\"New\")"}'

Organize Project — auto-sort project panel items into folders by type:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/organize-project.jsx" '{"structure": "by-type"}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/organize-project.jsx" '{"structure": "by-extension"}'

Batch Comp Settings — change fps, resolution, duration across multiple comps:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/batch-comp-settings.jsx" '{"scope": "all", "fps": 25}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/batch-comp-settings.jsx" '{"compNames": ["Comp 1", "Comp 2"], "width": 3840, "height": 2160}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/batch-comp-settings.jsx" '{"scope": "nested", "fps": 30, "duration": 10}'

Easing Presets — apply professional easing or bounce/elastic expressions:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/easing-presets.jsx" '{"preset": "smooth"}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/easing-presets.jsx" '{"preset": "snappy"}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/easing-presets.jsx" '{"preset": "bounce"}'

Anchor Point Mover — reposition anchor point with visual position compensation:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/anchor-point-mover.jsx" '{"position": "center"}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/anchor-point-mover.jsx" '{"position": "bottom-left"}'

Reverse Keyframes — reverse animation on selected properties:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/reverse-keyframes.jsx"

Select Layers — select layers by type, label, attribute, or name:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/select-layers.jsx" '{"type": "text"}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/select-layers.jsx" '{"hasExpressions": true}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/select-layers.jsx" '{"nameContains": "BG"}'

Layer Sort — reorder layers in timeline by name, position, in-point, type, or label:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/layer-sort.jsx" '{"sortBy": "name", "order": "ascending"}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/layer-sort.jsx" '{"sortBy": "position-y"}'

Smart Precompose — precompose with auto-trimmed duration:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/smart-precompose.jsx" '{"name": "My Precomp", "trimToContent": true}'

Copy Ease — copy easing from one keyframe and paste to others:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/copy-ease.jsx" '{"mode": "both"}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/copy-ease.jsx" '{"sourceLayer": "Logo", "sourceProperty": "Position", "sourceKeyIndex": 2}'

Relink Footage — batch-relink missing footage from search directories. Always dryRun first:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/relink-footage.jsx" '{"searchPaths": ["/Volumes/Projects/footage"], "dryRun": true}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/relink-footage.jsx" '{"searchPaths": ["/Volumes/Projects/footage"]}'

SRT Import — create timed subtitle text layers from an SRT file:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/srt-import.jsx" '{"srtPath": "/path/to/subs.srt", "fontSize": 48}'

Text Export/Import — export all text to CSV, edit externally, reimport:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/text-export-import.jsx" '{"mode": "export", "csvPath": "/tmp/text.csv"}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/text-export-import.jsx" '{"mode": "import", "csvPath": "/tmp/text.csv"}'

Batch Expression — apply, remove, enable, or disable expressions in bulk:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/batch-expression.jsx" '{"property": "opacity", "expression": "wiggle(2, 10)", "mode": "apply"}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/batch-expression.jsx" '{"mode": "remove"}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/batch-expression.jsx" '{"mode": "disable"}'

Randomize Properties — apply random values to transform properties:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/randomize-properties.jsx" '{"property": "rotation", "min": -15, "max": 15}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/randomize-properties.jsx" '{"property": "position", "minX": 0, "maxX": 1920, "minY": 0, "maxY": 1080}'

Un-PreCompose — extract layers from a precomp back into parent (confirm before running):

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/un-precompose.jsx" '{"precompLayerName": "Precomp 1"}'

Comp from CSV — generate comp variations from spreadsheet data (confirm before running):

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/comp-from-csv.jsx" '{"templateComp": "Lower Third", "csvPath": "/path/data.csv"}'

Render Queue Batch — add multiple comps to render queue (confirm before running):

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/render-queue-batch.jsx" '{"compNames": ["Final_16x9", "Final_9x16"], "outputPath": "~/Desktop/renders/"}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/render-queue-batch.jsx" '{"scope": "folder", "folderName": "Finals"}'

Explode Shape Layer — split shape groups into individual layers:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/explode-shape-layer.jsx" '{"layerName": "AI Import"}'

Incremental Save — save project with auto-incrementing version number:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/incremental-save.jsx" '{"comment": "before revisions"}'

Purge Cache — clear memory caches, disk cache, and free resources. dryRun to check size first:

bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/purge-cache.jsx" '{"dryRun": true}'
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/purge-cache.jsx"
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/purge-cache.jsx" '{"memory": true, "disk": false}'

Step 6: Execute and read result

# Execute the action script (already written to $SKILL_SCRIPTS/ae-action.jsx in Step 4)
bash "$SKILL_SCRIPTS/runner.sh" "$SKILL_SCRIPTS/ae-action.jsx" '{"arg1": "value1"}'

Read /tmp/ae-assistant-result.json for the result.

Debugging failures

If a script fails, check these in order:

~/.ae-assistant-log — runner.sh logs every execution, args, results, and errors here
/tmp/ae-assistant-error.txt — JXA-level errors (AE not responding, DoScriptFile failure)
~/.ae-assistant-extendscript.log — ExtendScript-level logs from appendLog() in utils.jsx
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 check comp instanceof CompItem before accessing comp properties

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