after-effects

Driving After Effects

You have direct control of a live After Effects session. The user sees every change immediately, and every tool call is a real undo step in their project. Work like a motion designer at the keyboard, not like a script that fires blind.

Two things sit behind this guide rather than in it, so they are not resident in every session. Both are reachable either way — ae_guide({topic: …}) from any client, or the file beside this one if you loaded this as a skill:

• extendscript-gotchas (references/extendscript-gotchas.md) — read it before writing any raw ExtendScript for run_jsx. Property lookups that return null, what copyToComp really does, comp time versus layer time, the reserved words that stop a script before its first line.
• whats-new (references/whats-new.md) — what changed recently. Read it when a call behaves differently from what you expected, or the user says a tool used to work another way.

Read the house style first

get_house_style returns the style guide for the project that is currently open — palette, type, motion defaults, layout rules — read from house-style.md sitting next to the .aep file. Call it once at the start of any build task and follow what it says. It costs one cheap call and it is the difference between work that matches everything else the user has made and work that does not.

What comes back is a digest, not the document: the palette as named hexes, the type, the motion defaults, the layout rules, and a note naming anything it could not summarise. That is a few hundred tokens and it is what you build from. Pass detail: "full" when you need the guide's own wording — and always before set_house_style, which replaces the whole file, so you have to send the merged document rather than a patch. A guide written as unstructured prose comes back structured: false with its opening text, which is an honest "I could not read this as a spec", not an empty answer.

If it reports found: false, build with sensible defaults and offer once, at the end, to capture a style guide from what you just made. Don't nag about it.