Asset Transformer (pxz) Scripting — Authoring Guide

This skill is the source of truth for writing Python against the Asset Transformer SDK (pxz). It serves two audiences:

1. The local Asset Transformer MCP run_python tool — the primary target. Code runs in-process inside the running Pixyz session.
2. Other skills — notably at-upa-scripting, which layers UPA-container conventions (argparse, workspace paths, no-Asset-Manager-write) on top of this same API. Both defer to pxz-api-reference.md in this folder for the API surface.

The API surface is documented in pxz-api-reference.md next to this file. It is authoritative: if a function, class, parameter, or constant is not listed there, it does not exist in this SDK version — do not call it. See Accuracy guardrails.

Execution context — the in-process run_python tool

The Asset Transformer MCP runs code like this:

exec(compile(code, "<mcp_run_python>", "exec"), {"pxz": pxz})

So when you write a script for run_python: