Create Optimized GIFs for Slack

Provides utilities and knowledge for creating animated GIFs sized and optimized for Slack. Slack's own requirements: emoji GIFs at 128x128 recommended, message GIFs at 480x480, FPS 10-30 (lower is smaller), 48-128 colors (fewer is smaller), and emoji GIFs kept under 3 seconds. The core workflow builds frames with PIL (Image, ImageDraw) and assembles them with a GIFBuilder(width, height, fps) via add_frame/add_frames, saving with save(path, num_colors=48, optimize_for_emoji=True, remove_duplicates=True).

pip install pillow imageio numpy

Graphics are drawn from scratch with PIL ImageDraw primitives - ellipses, polygons, lines, rectangles - explicitly avoiding emoji fonts (unreliable across platforms) and any assumption of pre-packaged graphics. Polish guidance: use line/outline widths of 2 or higher (width=1 looks amateurish), add depth with gradient backgrounds and layered shapes, make shapes more interesting with highlights/glows/combined shapes, use vibrant complementary colors with outline contrast, and build complex shapes (hearts, snowflakes) from combined polygons and ellipses with careful symmetry. If a user uploads an image, the skill loads it with PIL and asks or infers whether it should be used directly (e.g. "animate this") or only as stylistic inspiration.

Bundled utilities: core.gif_builder.GIFBuilder for assembly and Slack optimization; core.validators (validate_gif, is_slack_ready) to check Slack compliance; core.easing.interpolate for smooth motion (linear, ease_in, ease_out, ease_in_out, bounce_out, elastic_out, back_out) instead of linear movement; and core.frame_composer helpers (create_blank_frame, create_gradient_background, draw_circle, draw_text, draw_star). Documented animation techniques cover shake/vibrate (sine/cosine position oscillation), pulse/heartbeat (sine-wave scale between 0.8 and 1.2), bounce (bounce_out/ease_in easing plus simulated gravity), spin/rotate (PIL image.rotate, sine wave for wobble), fade in/out (RGBA alpha or Image.blend), slide (ease_out or back_out for overshoot), zoom (scale plus center crop, optional motion blur), and explode/particle bursts (randomized velocity particles with gravity and alpha fade).

Optimization is applied only when file size is explicitly requested to shrink: fewer frames or lower FPS, fewer colors (num_colors=48), smaller dimensions (128x128), remove_duplicates=True, and optimize_for_emoji=True. By design the skill provides knowledge, utilities, and drawing flexibility, but not rigid animation templates, emoji-font rendering, or a built-in graphics library - animation logic is composed from PIL primitives per request.

Use it to create animated GIFs for Slack emoji or messages, whether drawn from scratch with PIL primitives or built from a user-uploaded image.

Takes optional user-uploaded images (loaded via PIL, used directly or as style reference) and produces a Slack-compliant .gif file validated against dimension, FPS, color-count, and duration requirements via core.validators.

Developers or automations generating custom animated Slack emoji or message GIFs who need Slack's exact size/color/duration constraints plus reusable easing and compositing utilities rather than a fixed template library.