slack-gif-creator

Toolkit for creating animated GIFs optimized for Slack, with validators for size constraints and composable animation primitives. This skill applies when users request animated GIFs or emoji animations for Slack from descriptions like "make me a GIF for Slack of X doing Y".

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name:slack-gif-creatordescription:Toolkit for creating animated GIFs optimized for Slack, with validators for size constraints and composable animation primitives. This skill applies when users request animated GIFs or emoji animations for Slack from descriptions like "make me a GIF for Slack of X doing Y".license:Complete terms in LICENSE.txt

Slack GIF Creator - Flexible Toolkit

A toolkit for creating animated GIFs optimized for Slack. Provides validators for Slack's constraints, composable animation primitives, and optional helper utilities. Apply these tools however needed to achieve the creative vision.

Slack's Requirements

Slack has specific requirements for GIFs based on their use:

Message GIFs:

  • Max size: ~2MB

  • Optimal dimensions: 480x480

  • Typical FPS: 15-20

  • Color limit: 128-256

  • Duration: 2-5s
  • Emoji GIFs:

  • Max size: 64KB (strict limit)

  • Optimal dimensions: 128x128

  • Typical FPS: 10-12

  • Color limit: 32-48

  • Duration: 1-2s
  • Emoji GIFs are challenging - the 64KB limit is strict. Strategies that help:

  • Limit to 10-15 frames total

  • Use 32-48 colors maximum

  • Keep designs simple

  • Avoid gradients

  • Validate file size frequently
  • Toolkit Structure

    This skill provides three types of tools:

  • Validators - Check if a GIF meets Slack's requirements

  • Animation Primitives - Composable building blocks for motion (shake, bounce, move, kaleidoscope)

  • Helper Utilities - Optional functions for common needs (text, colors, effects)
  • Complete creative freedom is available in how these tools are applied.

    Core Validators

    To ensure a GIF meets Slack's constraints, use these validators:

    from core.gif_builder import GIFBuilder

    After creating your GIF, check if it meets requirements


    builder = GIFBuilder(width=128, height=128, fps=10)

    ... add your frames however you want ...

    Save and check size


    info = builder.save('emoji.gif', num_colors=48, optimize_for_emoji=True)

    The save method automatically warns if file exceeds limits


    info dict contains: size_kb, size_mb, frame_count, duration_seconds

    File size validator:

    from core.validators import check_slack_size

    Check if GIF meets size limits


    passes, info = check_slack_size('emoji.gif', is_emoji=True)

    Returns: (True/False, dict with size details)

    Dimension validator:

    from core.validators import validate_dimensions

    Check dimensions


    passes, info = validate_dimensions(128, 128, is_emoji=True)

    Returns: (True/False, dict with dimension details)

    Complete validation:

    from core.validators import validate_gif, is_slack_ready

    Run all validations


    all_pass, results = validate_gif('emoji.gif', is_emoji=True)

    Or quick check


    if is_slack_ready('emoji.gif', is_emoji=True):
    print("Ready to upload!")

    Animation Primitives

    These are composable building blocks for motion. Apply these to any object in any combination:

    Shake


    from templates.shake import create_shake_animation

    Shake an emoji


    frames = create_shake_animation(
    object_type='emoji',
    object_data={'emoji': '😱', 'size': 80},
    num_frames=20,
    shake_intensity=15,
    direction='both' # or 'horizontal', 'vertical'
    )

    Bounce


    from templates.bounce import create_bounce_animation

    Bounce a circle


    frames = create_bounce_animation(
    object_type='circle',
    object_data={'radius': 40, 'color': (255, 100, 100)},
    num_frames=30,
    bounce_height=150
    )

    Spin / Rotate


    from templates.spin import create_spin_animation, create_loading_spinner

    Clockwise spin


    frames = create_spin_animation(
    object_type='emoji',
    object_data={'emoji': '🔄', 'size': 100},
    rotation_type='clockwise',
    full_rotations=2
    )

    Wobble rotation


    frames = create_spin_animation(rotation_type='wobble', full_rotations=3)

    Loading spinner


    frames = create_loading_spinner(spinner_type='dots')

    Pulse / Heartbeat


    from templates.pulse import create_pulse_animation, create_attention_pulse

    Smooth pulse


    frames = create_pulse_animation(
    object_data={'emoji': '❤️', 'size': 100},
    pulse_type='smooth',
    scale_range=(0.8, 1.2)
    )

    Heartbeat (double-pump)


    frames = create_pulse_animation(pulse_type='heartbeat')

    Attention pulse for emoji GIFs


    frames = create_attention_pulse(emoji='⚠️', num_frames=20)

    Fade


    from templates.fade import create_fade_animation, create_crossfade

    Fade in


    frames = create_fade_animation(fade_type='in')

    Fade out


    frames = create_fade_animation(fade_type='out')

    Crossfade between two emojis


    frames = create_crossfade(
    object1_data={'emoji': '😊', 'size': 100},
    object2_data={'emoji': '😂', 'size': 100}
    )

    Zoom


    from templates.zoom import create_zoom_animation, create_explosion_zoom

    Zoom in dramatically


    frames = create_zoom_animation(
    zoom_type='in',
    scale_range=(0.1, 2.0),
    add_motion_blur=True
    )

    Zoom out


    frames = create_zoom_animation(zoom_type='out')

    Explosion zoom


    frames = create_explosion_zoom(emoji='💥')

    Explode / Shatter


    from templates.explode import create_explode_animation, create_particle_burst

    Burst explosion


    frames = create_explode_animation(
    explode_type='burst',
    num_pieces=25
    )

    Shatter effect


    frames = create_explode_animation(explode_type='shatter')

    Dissolve into particles


    frames = create_explode_animation(explode_type='dissolve')

    Particle burst


    frames = create_particle_burst(particle_count=30)

    Wiggle / Jiggle


    from templates.wiggle import create_wiggle_animation, create_excited_wiggle

    Jello wobble


    frames = create_wiggle_animation(
    wiggle_type='jello',
    intensity=1.0,
    cycles=2
    )

    Wave motion


    frames = create_wiggle_animation(wiggle_type='wave')

    Excited wiggle for emoji GIFs


    frames = create_excited_wiggle(emoji='🎉')

    Slide


    from templates.slide import create_slide_animation, create_multi_slide

    Slide in from left with overshoot


    frames = create_slide_animation(
    direction='left',
    slide_type='in',
    overshoot=True
    )

    Slide across


    frames = create_slide_animation(direction='left', slide_type='across')

    Multiple objects sliding in sequence


    objects = [
    {'data': {'emoji': '🎯', 'size': 60}, 'direction': 'left', 'final_pos': (120, 240)},
    {'data': {'emoji': '🎪', 'size': 60}, 'direction': 'right', 'final_pos': (240, 240)}
    ]
    frames = create_multi_slide(objects, stagger_delay=5)

    Flip


    from templates.flip import create_flip_animation, create_quick_flip

    Horizontal flip between two emojis


    frames = create_flip_animation(
    object1_data={'emoji': '😊', 'size': 120},
    object2_data={'emoji': '😂', 'size': 120},
    flip_axis='horizontal'
    )

    Vertical flip


    frames = create_flip_animation(flip_axis='vertical')

    Quick flip for emoji GIFs


    frames = create_quick_flip('👍', '👎')

    Morph / Transform


    from templates.morph import create_morph_animation, create_reaction_morph

    Crossfade morph


    frames = create_morph_animation(
    object1_data={'emoji': '😊', 'size': 100},
    object2_data={'emoji': '😂', 'size': 100},
    morph_type='crossfade'
    )

    Scale morph (shrink while other grows)


    frames = create_morph_animation(morph_type='scale')

    Spin morph (3D flip-like)


    frames = create_morph_animation(morph_type='spin_morph')

    Move Effect


    from templates.move import create_move_animation

    Linear movement


    frames = create_move_animation(
    object_type='emoji',
    object_data={'emoji': '🚀', 'size': 60},
    start_pos=(50, 240),
    end_pos=(430, 240),
    motion_type='linear',
    easing='ease_out'
    )

    Arc movement (parabolic trajectory)


    frames = create_move_animation(
    object_type='emoji',
    object_data={'emoji': '⚽', 'size': 60},
    start_pos=(50, 350),
    end_pos=(430, 350),
    motion_type='arc',
    motion_params={'arc_height': 150}
    )

    Circular movement


    frames = create_move_animation(
    object_type='emoji',
    object_data={'emoji': '🌍', 'size': 50},
    motion_type='circle',
    motion_params={
    'center': (240, 240),
    'radius': 120,
    'angle_range': 360 # full circle
    }
    )

    Wave movement


    frames = create_move_animation(
    motion_type='wave',
    motion_params={
    'wave_amplitude': 50,
    'wave_frequency': 2
    }
    )

    Or use low-level easing functions


    from core.easing import interpolate, calculate_arc_motion

    for i in range(num_frames):
    t = i / (num_frames - 1)
    x = interpolate(start_x, end_x, t, easing='ease_out')
    # Or: x, y = calculate_arc_motion(start, end, height, t)

    Kaleidoscope Effect


    from templates.kaleidoscope import apply_kaleidoscope, create_kaleidoscope_animation

    Apply to a single frame


    kaleido_frame = apply_kaleidoscope(frame, segments=8)

    Or create animated kaleidoscope


    frames = create_kaleidoscope_animation(
    base_frame=my_frame, # or None for demo pattern
    num_frames=30,
    segments=8,
    rotation_speed=1.0
    )

    Simple mirror effects (faster)


    from templates.kaleidoscope import apply_simple_mirror

    mirrored = apply_simple_mirror(frame, mode='quad') # 4-way mirror

    modes: 'horizontal', 'vertical', 'quad', 'radial'

    To compose primitives freely, follow these patterns:

    # Example: Bounce + shake for impact
    for i in range(num_frames):
    frame = create_blank_frame(480, 480, bg_color)

    # Bounce motion
    t_bounce = i / (num_frames - 1)
    y = interpolate(start_y, ground_y, t_bounce, 'bounce_out')

    # Add shake on impact (when y reaches ground)
    if y >= ground_y - 5:
    shake_x = math.sin(i 2) 10
    x = center_x + shake_x
    else:
    x = center_x

    draw_emoji(frame, '⚽', (x, y), size=60)
    builder.add_frame(frame)

    Helper Utilities

    These are optional helpers for common needs. Use, modify, or replace these with custom implementations as needed.

    GIF Builder (Assembly & Optimization)

    from core.gif_builder import GIFBuilder

    Create builder with your chosen settings


    builder = GIFBuilder(width=480, height=480, fps=20)

    Add frames (however you created them)


    for frame in my_frames:
    builder.add_frame(frame)

    Save with optimization


    builder.save('output.gif',
    num_colors=128,
    optimize_for_emoji=False)

    Key features:

  • Automatic color quantization

  • Duplicate frame removal

  • Size warnings for Slack limits

  • Emoji mode (aggressive optimization)
  • Text Rendering

    For small GIFs like emojis, text readability is challenging. A common solution involves adding outlines:

    from core.typography import draw_text_with_outline, TYPOGRAPHY_SCALE

    Text with outline (helps readability)


    draw_text_with_outline(
    frame, "BONK!",
    position=(240, 100),
    font_size=TYPOGRAPHY_SCALE['h1'], # 60px
    text_color=(255, 68, 68),
    outline_color=(0, 0, 0),
    outline_width=4,
    centered=True
    )

    To implement custom text rendering, use PIL's ImageDraw.text() which works fine for larger GIFs.

    Color Management

    Professional-looking GIFs often use cohesive color palettes:

    from core.color_palettes import get_palette

    Get a pre-made palette


    palette = get_palette('vibrant') # or 'pastel', 'dark', 'neon', 'professional'

    bg_color = palette['background']
    text_color = palette['primary']
    accent_color = palette['accent']

    To work with colors directly, use RGB tuples - whatever works for the use case.

    Visual Effects

    Optional effects for impact moments:

    from core.visual_effects import ParticleSystem, create_impact_flash, create_shockwave_rings

    Particle system


    particles = ParticleSystem()
    particles.emit_sparkles(x=240, y=200, count=15)
    particles.emit_confetti(x=240, y=200, count=20)

    Update and render each frame


    particles.update()
    particles.render(frame)

    Flash effect


    frame = create_impact_flash(frame, position=(240, 200), radius=100)

    Shockwave rings


    frame = create_shockwave_rings(frame, position=(240, 200), radii=[30, 60, 90])

    Easing Functions

    Smooth motion uses easing instead of linear interpolation:

    from core.easing import interpolate

    Object falling (accelerates)


    y = interpolate(start=0, end=400, t=progress, easing='ease_in')

    Object landing (decelerates)


    y = interpolate(start=0, end=400, t=progress, easing='ease_out')

    Bouncing


    y = interpolate(start=0, end=400, t=progress, easing='bounce_out')

    Overshoot (elastic)


    scale = interpolate(start=0.5, end=1.0, t=progress, easing='elastic_out')

    Available easings: linear, ease_in, ease_out, ease_in_out, bounce_out, elastic_out, back_out (overshoot), and more in core/easing.py.

    Frame Composition

    Basic drawing utilities if you need them:

    from core.frame_composer import (
    create_gradient_background, # Gradient backgrounds
    draw_emoji_enhanced, # Emoji with optional shadow
    draw_circle_with_shadow, # Shapes with depth
    draw_star # 5-pointed stars
    )

    Gradient background


    frame = create_gradient_background(480, 480, top_color, bottom_color)

    Emoji with shadow


    draw_emoji_enhanced(frame, '🎉', position=(200, 200), size=80, shadow=True)

    Optimization Strategies

    When your GIF is too large:

    For Message GIFs (>2MB):

  • Reduce frames (lower FPS or shorter duration)

  • Reduce colors (128 → 64 colors)

  • Reduce dimensions (480x480 → 320x320)

  • Enable duplicate frame removal
  • For Emoji GIFs (>64KB) - be aggressive:

  • Limit to 10-12 frames total

  • Use 32-40 colors maximum

  • Avoid gradients (solid colors compress better)

  • Simplify design (fewer elements)

  • Use optimize_for_emoji=True in save method
  • Example Composition Patterns

    Simple Reaction (Pulsing)


    builder = GIFBuilder(128, 128, 10)

    for i in range(12):
    frame = Image.new('RGB', (128, 128), (240, 248, 255))

    # Pulsing scale
    scale = 1.0 + math.sin(i 0.5) 0.15
    size = int(60 scale)

    draw_emoji_enhanced(frame, '😱', position=(64-size//2, 64-size//2),
    size=size, shadow=False)
    builder.add_frame(frame)

    builder.save('reaction.gif', num_colors=40, optimize_for_emoji=True)

    Validate


    from core.validators import check_slack_size
    check_slack_size('reaction.gif', is_emoji=True)

    Action with Impact (Bounce + Flash)


    builder = GIFBuilder(480, 480, 20)

    Phase 1: Object falls


    for i in range(15):
    frame = create_gradient_background(480, 480, (240, 248, 255), (200, 230, 255))
    t = i / 14
    y = interpolate(0, 350, t, 'ease_in')
    draw_emoji_enhanced(frame, '⚽', position=(220, int(y)), size=80)
    builder.add_frame(frame)

    Phase 2: Impact + flash


    for i in range(8):
    frame = create_gradient_background(480, 480, (240, 248, 255), (200, 230, 255))

    # Flash on first frames
    if i < 3:
    frame = create_impact_flash(frame, (240, 350), radius=120, intensity=0.6)

    draw_emoji_enhanced(frame, '⚽', position=(220, 350), size=80)

    # Text appears
    if i > 2:
    draw_text_with_outline(frame, "GOAL!", position=(240, 150),
    font_size=60, text_color=(255, 68, 68),
    outline_color=(0, 0, 0), outline_width=4, centered=True)

    builder.add_frame(frame)

    builder.save('goal.gif', num_colors=128)

    Combining Primitives (Move + Shake)


    from templates.shake import create_shake_animation

    Create shake animation


    shake_frames = create_shake_animation(
    object_type='emoji',
    object_data={'emoji': '😰', 'size': 70},
    num_frames=20,
    shake_intensity=12
    )

    Create moving element that triggers the shake


    builder = GIFBuilder(480, 480, 20)
    for i in range(40):
    t = i / 39

    if i < 20:
    # Before trigger - use blank frame with moving object
    frame = create_blank_frame(480, 480, (255, 255, 255))
    x = interpolate(50, 300, t
    2, 'linear')
    draw_emoji_enhanced(frame, '🚗', position=(int(x), 300), size=60)
    draw_emoji_enhanced(frame, '😰', position=(350, 200), size=70)
    else:
    # After trigger - use shake frame
    frame = shake_frames[i - 20]
    # Add the car in final position
    draw_emoji_enhanced(frame, '🚗', position=(300, 300), size=60)

    builder.add_frame(frame)

    builder.save('scare.gif')

    Philosophy

    This toolkit provides building blocks, not rigid recipes. To work with a GIF request:

  • Understand the creative vision - What should happen? What's the mood?

  • Design the animation - Break it into phases (anticipation, action, reaction)

  • Apply primitives as needed - Shake, bounce, move, effects - mix freely

  • Validate constraints - Check file size, especially for emoji GIFs

  • Iterate if needed - Reduce frames/colors if over size limits
  • The goal is creative freedom within Slack's technical constraints.

    Dependencies

    To use this toolkit, install these dependencies only if they aren't already present:

    pip install pillow imageio numpy

      slack-gif-creator - Agent Skills