Jianying Headless turns a GUI video editor into a local rendering engine you script

Jianying Headless treats the Jianying Pro video editor on macOS as a local rendering engine rather than a GUI application. You feed it a structured JSON plan describing clips, tracks, timing, and text, and it writes a native Jianying draft that you can open, inspect, and export as H.264/AAC MP4 — all without touching the interface. The export runs in an isolated process, offline by default, invoking the same native codec the application itself uses.

The scope is specific and the constraints are real. The tool targets version 11.5.0 of Jianying Pro, with partial support for 11.4.2. It checks application version, build number, official library hashes, and developer identity before doing anything; a mismatch stops execution rather than proceeding with relaxed checks. The required environment is Apple Silicon, macOS 26.0 or later, Python 3.9+, FFmpeg, and Xcode Command Line Tools. Clean-machine installation has not yet been validated, and the README says explicitly that passing the environment check does not mean any arbitrary draft will render correctly.

The demonstration case is a roughly 50-second Instagram scroll animation transferred from a tool called Hypit. The resulting Jianying project contains 23 tracks and 154 segments across video, image, voiceover, and text layers, built from 39 source assets. The export passed a full 1,507-frame decode check. The README is careful to say this is an editable project handoff, not a visually lossless conversion: special fonts, per-word color animation, some cropping, and shadow effects were not preserved, and a subjective audio-visual review has not been completed.

For agent workflows the repo includes a packaged skill under skills/yichen-jianying-edit/ that exposes the draft-building pipeline as a callable entry point. The skill requires the core repository to be checked out separately and pointed to via an environment variable — the engine is not bundled.

The current limitations are stated without softening. Compound clips support only experimental offline modification and frozen snapshot export; they cannot be delivered as reliably saveable nested drafts. An intermittent off-by-one frame bug in image and GIF handling remains unresolved, though strict frame-count checking will reject defective output rather than silently pass it. Online templates, cloud projects, and account entitlements are entirely out of scope. Two previously supported effects — a high-definition black-and-white filter and an orange-outlined stylized title — have been dropped, and plans referencing them will error explicitly.

The license is non-commercial for individuals; commercial use requires written permission from the author. Critically, the code license does not include Jianying integration rights, account entitlements, or asset permissions — those remain entirely with ByteDance.