| name | animated-message-composer |
| description | Create animated GIFs for messaging platforms. Generates animated content optimized for sharing in chat applications. |
| license | Proprietary. LICENSE.txt has complete terms |
Slack GIF Creator
A toolkit providing utilities and knowledge for creating animated GIFs optimized for Slack.
Slack Requirements
Emoji GIFs (Slack emoji uploads):
- Max size: 64 KB
- Dimensions: 128x128 recommended (square)
- FPS: 10-12
- Colors: 32-48
- Duration: 1-2s
Message GIFs:
- Max size: ~2 MB
- Dimensions: 480x480 typical
- FPS: 15-20
- Colors: 128-256
- Duration: 2-5s
Core Workflow
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)
builder.add_frame(frame)
builder.save('output.gif', num_colors=48, optimize_for_emoji=True)
Optional shortcut: use animation templates in templates/ to generate frames quickly:
from templates.shake import create_shake_animation
frames = create_shake_animation(
object_type='circle',
object_data={'radius': 30, 'color': (100, 150, 255)},
num_frames=20,
direction='both'
)
builder.add_frames(frames)
Drawing Graphics
Working with User-Uploaded Images
If a user uploads an image, consider whether they want to:
- Use it directly (e.g., "animate this", "split this into frames")
- Use it as inspiration (e.g., "make something like this")
Load and work with images using PIL:
from PIL import Image
uploaded = Image.open('file.png')
Drawing from Scratch
When drawing graphics from scratch, use PIL ImageDraw primitives:
from PIL import ImageDraw
draw = ImageDraw.Draw(frame)
draw.ellipse([x1, y1, x2, y2], fill=(r, g, b), outline=(r, g, b), width=3)
points = [(x1, y1), (x2, y2), (x3, y3), ...]
draw.polygon(points, fill=(r, g, b), outline=(r, g, b), width=3)
draw.line([(x1, y1), (x2, y2)], fill=(r, g, b), width=5)
draw.rectangle([x1, y1, x2, y2], fill=(r, g, b), outline=(r, g, b), width=3)
Avoid relying solely on emoji fonts: they are platform-specific. If you use draw_emoji or draw_emoji_enhanced, expect rendering differences and be ready to adjust with shapes or text.
Making Graphics Look Good
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:
- Use gradients for backgrounds (
create_gradient_background)
- Layer multiple shapes for complexity (e.g., a star with a smaller star inside)
Make shapes more interesting:
- Don't just draw a plain circle - add highlights, rings, or patterns
- Stars can have glows (draw larger, semi-transparent versions behind)
- Combine multiple shapes (stars + sparkles, circles + rings)
Pay attention to colors:
- Use vibrant, complementary colors
- Add contrast (dark outlines on light shapes, light outlines on dark shapes)
- Consider the overall composition
For complex shapes (hearts, snowflakes, etc.):
- Use combinations of polygons and ellipses
- Calculate points carefully for symmetry
- Add details (a heart can have a highlight curve, snowflakes have intricate branches)
Be creative and detailed! A good Slack GIF should look polished, not like placeholder graphics.
Available Utilities
GIFBuilder (core.gif_builder)
Assembles frames and optimizes for Slack:
builder = GIFBuilder(width=128, height=128, fps=10)
builder.add_frame(frame)
builder.add_frames(frames)
builder.save('out.gif', num_colors=48, optimize_for_emoji=True, remove_duplicates=True)
Validators (core.validators)
Check if GIF meets Slack requirements:
from core.validators import (
validate_gif,
is_slack_ready,
check_slack_size,
validate_dimensions
)
passes, info = validate_gif('my.gif', is_emoji=True, verbose=True)
if is_slack_ready('my.gif'):
print("Ready!")
passes, info = check_slack_size('my.gif', is_emoji=True)
passes, info = validate_dimensions(128, 128, is_emoji=True)
Easing Functions (core.easing)
Smooth motion instead of linear:
from core.easing import interpolate
t = i / (num_frames - 1)
y = interpolate(start=0, end=400, t=t, easing='ease_out')
Frame Helpers (core.frame_composer)
Convenience functions for common needs:
from core.frame_composer import (
create_blank_frame,
create_gradient_background,
draw_circle,
draw_rectangle,
draw_line,
draw_text,
draw_emoji,
draw_star
)
Other helpers include draw_emoji_enhanced, draw_circle_with_shadow, draw_rounded_rectangle, and add_vignette.
Color Palettes (core.color_palettes)
Hand-picked palettes and helpers for readable colors:
from core.color_palettes import get_palette, get_text_color_for_background
palette = get_palette('vibrant')
text_color = get_text_color_for_background(palette['background'])
Typography (core.typography)
High-quality outlined or shadowed text:
from core.typography import draw_text_with_outline
draw_text_with_outline(frame, "SALE!", position=(240, 240), font_size=48, centered=True)
Visual Effects (core.visual_effects)
Particles, blur, impacts, and motion effects:
from core.visual_effects import ParticleSystem
particles = ParticleSystem()
particles.emit(240, 240, count=20)
Animation Templates (templates/)
Ready-made animations (shake, bounce, spin, zoom, slide, fade, flip, explode, etc.).
Use them to generate frames and then pass to GIFBuilder.
Animation Concepts
Shake/Vibrate
Offset object position with oscillation:
- Use
math.sin() or math.cos() with frame index
- Add small random variations for natural feel
- Apply to x and/or y position
Pulse/Heartbeat
Scale object size rhythmically:
- Use
math.sin(t * frequency * 2 * math.pi) for smooth pulse
- For heartbeat: two quick pulses then pause (adjust sine wave)
- Scale between 0.8 and 1.2 of base size
Bounce
Object falls and bounces:
- Use
interpolate() with easing='bounce_out' for landing
- Use
easing='ease_in' for falling (accelerating)
- Apply gravity by increasing y velocity each frame
Spin/Rotate
Rotate object around center:
- PIL:
image.rotate(angle, resample=Image.BICUBIC)
- For wobble: use sine wave for angle instead of linear
Fade In/Out
Gradually appear or disappear:
- Create RGBA image, adjust alpha channel
- Or use
Image.blend(image1, image2, alpha)
- Fade in: alpha from 0 to 1
- Fade out: alpha from 1 to 0
Slide
Move object from off-screen to position:
- Start position: outside frame bounds
- End position: target location
- Use
interpolate() with easing='ease_out' for smooth stop
- For overshoot: use
easing='back_out'
Zoom
Scale and position for zoom effect:
- Zoom in: scale from 0.1 to 2.0, crop center
- Zoom out: scale from 2.0 to 1.0
- Can add motion blur for drama (PIL filter)
Explode/Particle Burst
Create particles radiating outward:
- Generate particles with random angles and velocities
- Update each particle:
x += vx, y += vy
- Add gravity:
vy += gravity_constant
- Fade out particles over time (reduce alpha)
Optimization Strategies
Only when asked to make the file size smaller, implement a few of the following methods:
- Fewer frames - Lower FPS (10 instead of 20) or shorter duration
- Fewer colors -
num_colors=48 instead of 128
- Smaller dimensions - 128x128 instead of 480x480
- Remove duplicates -
remove_duplicates=True in save()
- Emoji mode -
optimize_for_emoji=True auto-optimizes
builder.save(
'emoji.gif',
num_colors=48,
optimize_for_emoji=True,
remove_duplicates=True
)
Philosophy
This skill provides:
- Knowledge: Slack's requirements and animation concepts
- Utilities: GIFBuilder, validators, easing functions
- Flexibility: Create the animation logic using PIL primitives
It does NOT provide:
- Rigid animation templates or pre-made functions
- Emoji font rendering (unreliable across platforms)
- A library of pre-packaged graphics built into the skill
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.
Dependencies
pip install pillow imageio numpy