Two changes, both driven by measurement against 128 production gifsmith runs
and a local replica of the agent loop (docs/audits/2026-07-24-gifsmith-quality.md
in mort).
Staging rules. The renders that "worked" still read badly, always the same four
ways: the subject drawn 5-10% of the frame height under an empty sky, long runs
of pixel-identical frames, captions narrating action that was never drawn, and
flat untextured shapes. The recipe never asked for anything else. SKILL.md now
states four checkable rules — fill the frame, every frame moves, show it don't
caption it, give it depth — plus easing/anticipation/squash-and-stretch, and the
self-critique makes a "no" on depiction, subject size or caption legibility a
mandatory re-render instead of a suggestion.
Render harness. 26% of production code_exec calls end in a traceback, and every
crash class lives in plumbing the agent re-derives each run: scratch dir, frame
loop, numbering, canvas size, contact sheet, encode. scripts/gifsmith.py owns all
of it and the agent writes only @anim.scene drawing functions. A scene that
raises is now skipped while the others still render and ship, the canvas is
size-locked so ffmpeg cannot fail on jittering frames, and the drawing vocabulary
is re-exported so a missing import cannot NameError.
The harness also unblocks the multi-minute pieces this skill advertises but could
never produce: /tmp is a 16 MiB tmpfs (~13s of frames) and /workspace 64 MiB
(~51s), which is why "No space left on device" is 15% of all production crashes.
Anything past the GIF length threshold is an MP4, and an MP4 encodes in one
streaming pass, so those frames now go straight into ffmpeg's stdin and never
touch disk — verified at 1350 frames / 90 s with 0 MiB on disk.
encode.py is removed; the harness supersedes it.
Adapts mort's builtin animate skill into an executus/skillpack:
- plans scenes + a reusable cast so recurring people/props stay consistent
(built for funny bits 'about ourselves'), incl. multi-minute pieces
- bundled scripts/encode.py owns the fragile encode + format decision: GIF for
short loops, H.264 MP4 (yuv420p, even dims, +faststart — plays inline in
Discord) for long pieces OR when a GIF comes out too big, with a
gifski→ffmpeg-palette fallback
- keeps the workspace discipline, text-readability pacing, and <=3-pass vision
self-critique from the original; adds a frame budget for long renders
encode.py verified end-to-end (short->gif, long->mp4 confirmed h264/yuv420p/
even/faststart); SKILL.md parses cleanly via the executus skillpack loader.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
steve
