Create animated GIFs optimized for Slack with proper constraints
Catalog skill by anthropic: Create animated GIFs optimized for Slack with proper constraints Install into Cursor, Claude, Codex, or VS Code from this page or review the source for Slack GIF Creator.
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/plugin install document-skills@anthropic-agent-skills
Install guides: Cursor skills, Claude Code skills, Codex skills, or VS Code Copilot skills.
A toolkit providing utilities and knowledge for creating animated GIFs optimized for Slack.
Dimensions:
Parameters:
from core.gif_builder import GIFBuilder
from PIL import Image, ImageDraw
# 1. Create builder
builder = GIFBuilder(width=128, height=128, fps=10)
# 2. Generate frames
for i in range(12):
frame = Image.new('RGB', (128, 128), (240, 248, 255))
draw = ImageDraw.Draw(frame)
# Draw your animation using PIL primitives
# (circles, polygons, lines, etc.)
builder.add_frame(frame)
# 3. Save with optimization
builder.save('output.gif', num_colors=48, optimize_for_emoji=True)
If a user uploads an image, consider whether they want to:
Load and work with images using PIL:
from PIL import Image
uploaded = Image.open('file.png')
# Use directly, or just as reference for colors/style
When drawing graphics from scratch, use PIL ImageDraw primitives:
from PIL import ImageDraw
draw = ImageDraw.Draw(frame)
# Circles/ovals
draw.ellipse([x1, y1, x2, y2], fill=(r, g, b), outline=(r, g, b), width=3)
# Stars, triangles, any polygon
points = [(x1, y1), (x2, y2), (x3, y3), ...]
draw.polygon(points, fill=(r, g, b), outline=(r, g, b), width=3)
# Lines
draw.line([(x1, y1), (x2, y2)], fill=(r, g, b), width=5)
# Rectangles
draw.rectangle([x1, y1, x2, y2], fill=(r, g, b), outline=(r, g, b), width=3)
Don't use: Emoji fonts (unreliable across platforms) or assume pre-packaged graphics exist in this skill.
Graphics should look polished and creative, not basic. Here's how:
Use thicker lines - Always set width=2 or higher for outlines and lines. Thin lines (width=1) look choppy and amateurish.
Add visual depth:
create_gradient_background)Make shapes more interesting:
Pay attention to colors:
For complex shapes (hearts, snowflakes, etc.):
Be creative and detailed! A good Slack GIF should look polished, not like placeholder graphics.
core.gif_builder)Assembles frames and optimizes for Slack:
builder = GIFBuilder(width=128, height=128, fps=10)
builder.add_frame(frame) # Add PIL Image
builder.add_frames(frames) # Add list of frames
builder.save('out.gif', num_colors=48, optimize_for_emoji=True, remove_duplicates=True)
core.validators)Check if GIF meets Slack requirements:
from core.validators import validate_gif, is_slack_ready
# Detailed validation
passes, info = validate_gif('my.gif', is_emoji=True, verbose=True)
# Quick check
if is_slack_ready('my.gif'):
print("Ready!")
core.easing)Smooth motion instead of linear:
from core.easing import interpolate
# Progress from 0.0 to 1.0
t = i / (num_frames - 1)
# Apply easing
y = interpolate(start=0, end=400, t=t, easing='ease_out')
# Available: linear, ease_in, ease_out, ease_in_out,
# bounce_out, elastic_out, back_out
core.frame_composer)Convenience functions for common needs:
from core.frame_composer import (
create_blank_frame, # Solid color background
create_gradient_background, # Vertical gradient
draw_circle, # Helper for circles
draw_text, # Simple text rendering
draw_star # 5-pointed star
)
Offset object position with oscillation:
math.sin() or math.cos() with frame indexScale object size rhythmically:
math.sin(t * frequency * 2 * math.pi) for smooth pulseObject falls and bounces:
interpolate() with easing='bounce_out' for landingeasing='ease_in' for falling (accelerating)Rotate object around center:
image.rotate(angle, resample=Image.BICUBIC)Gradually appear or disappear:
Image.blend(image1, image2, alpha)Move object from off-screen to position:
interpolate() with easing='ease_out' for smooth stopeasing='back_out'Scale and position for zoom effect:
Create particles radiating outward:
x += vx, y += vyvy += gravity_constantOnly when asked to make the file size smaller, implement a few of the following methods:
num_colors=48 instead of 128remove_duplicates=True in save()optimize_for_emoji=True auto-optimizes# Maximum optimization for emoji
builder.save(
'emoji.gif',
num_colors=48,
optimize_for_emoji=True,
remove_duplicates=True
)
This skill provides:
It does NOT provide:
Note on user uploads: This skill doesn't include pre-built graphics, but if a user uploads an image, use PIL to load and work with it - interpret based on their request whether they want it used directly or just as inspiration.
Be creative! Combine concepts (bouncing + rotating, pulsing + sliding, etc.) and use PIL's full capabilities.
pip install pillow imageio numpy