Slack GIF Creator Skill

npx degit anthropics/skills/skills/slack-gif-creator ~/.claude/skills/slack-gif-creator

slack-gif-creator is a small but very specific skill: produce GIFs that upload cleanly to Slack as either custom emoji or message attachments.

Slack’s hard limits (encoded in the skill)

Use	Dimension	Recommended
Custom emoji	128×128	10 fps, ≤ 3s, 48 colors
Message GIF	480×480	24 fps OK, longer fine, 128 colors

How it builds

from core.gif_builder import GIFBuilder
from PIL import Image, ImageDraw

builder = GIFBuilder(width=128, height=128, fps=10)
for i in range(12):
    frame = Image.new('RGB', (128, 128), (240, 248, 255))
    draw = ImageDraw.Draw(frame)
    # animate something via PIL primitives
    builder.add_frame(frame)
builder.save('output.gif', num_colors=48, optimize_for_emoji=True)

What it’s good at

• Reaction emoji — typing animations, thumbs ups, rolling eyes
• Loading indicators — spinners, progress bars
• Tiny visual jokes — the “you had to be there” of Slack culture

Pairs with

• A user-uploaded image (it can animate or transform from a still)
• algorithmic-art — for generative motion you can crop to 128px

Notes from curation

The constraint is the feature here. Working within 128×128 + 48 colors forces clarity. Same logic as why Twitter’s character limit produces better writing.

Make me a 128×128 Slack emoji GIF of a coffee cup with steam rising.
10 fps, under 3 seconds, optimized for emoji.