SKILL: Sileo (React Toast Notifications)

Official documentation: https://sileo.aaryan.design/docs API Reference: https://sileo.aaryan.design/docs/api Toaster API: https://sileo.aaryan.design/docs/api/toaster Styling Guide: https://sileo.aaryan.design/docs/styling Playground: https://sileo.aaryan.design/play GitHub: https://github.com/hiaaryan/sileo

What is Sileo?

Sileo is a tiny, opinionated, physics-based toast component for React. It uses gooey SVG morphing (via an feGaussianBlur + feColorMatrix filter chain) and spring animations (powered by motion/react, formerly Framer Motion) to create buttery-smooth notifications that look beautiful by default with zero configuration.

Sileo is not a general-purpose notification center. It is a highly polished, visually distinctive toast system designed for single-line feedback messages with optional expandable descriptions.

Key characteristics:

Framework: React only (ships with "use client" directive for Next.js App Router compatibility)
Peer dependency: motion (spring physics engine, motion/react)
Architecture: SVG-based rendering with gooey blob morphing between pill (collapsed) and card (expanded) states
TypeScript-first: All types are exported (SileoOptions, SileoPosition, SileoState, SileoStyles, SileoButton)
Accessibility: Uses aria-live="polite" on viewport sections, respects prefers-reduced-motion
Swipe-to-dismiss: Built-in pointer-event-based vertical swipe gesture (30px threshold)

Installation

npm install sileo

Sileo requires react and motion as peer dependencies.

Quick Setup

Mount <Toaster /> once at your app's root layout.
Fire toasts from anywhere by importing sileo.

import { sileo, Toaster } from "sileo";

export default function App() {
  return (
    <>
      <Toaster position="top-right" />
      <YourApp />
    </>
  );
}

Because sileo ships with "use client", it works seamlessly in Next.js App Router without extra wrappers.

Basic Usage

Sileo exposes a global controller sileo with state-specific shortcuts:

import { sileo } from "sileo";

// State shortcuts (each returns the toast `id` as a string)
sileo.success({ title: "Saved", description: "Your changes were stored." });
sileo.error({ title: "Failed", description: "Could not save." });
sileo.warning({ title: "Warning", description: "Disk space low." });
sileo.info({ title: "Tip", description: "Try the new feature." });

// Generic toast (defaults to success, but accepts `type` for dynamic state)
sileo.show({ title: "Done", type: "success" });

// Dynamic state selection
sileo.show({
  type: response.ok ? "success" : "error",
  title: "Upload complete",
});

All `sileo` Methods

Method	Returns	Description
`sileo.success(options)`	`string` (id)	Green success toast
`sileo.error(options)`	`string` (id)	Red error toast
`sileo.warning(options)`	`string` (id)	Amber warning toast
`sileo.info(options)`	`string` (id)	Blue info toast
`sileo.action(options)`	`string` (id)	Toast with an action button
`sileo.show(options)`	`string` (id)	Generic toast. Uses `options.type` for state, defaults to `"success"`
`sileo.promise(promise, opts)`	`Promise<T>`	Loading -> success/error flow. Returns the original promise
`sileo.dismiss(id)`	`void`	Dismiss a specific toast by id
`sileo.clear(position?)`	`void`	Clear all toasts, or only those at a specific position

`SileoOptions`

Passed to every sileo.*() call.

Prop	Type	Default	Description
`title`	`string`	--	Toast heading (displayed in the pill)
`description`	`ReactNode \| string`	--	Body content (shown when expanded). Accepts JSX for rich content
`type`	`SileoState`	--	Dynamic state for `sileo.show()`. One of `"success" \| "loading" \| "error" \| "warning" \| "info" \| "action"`
`position`	`SileoPosition`	Toaster default	Override position for this individual toast
`duration`	`number \| null`	`6000`	Auto-dismiss in milliseconds. `null` = sticky (never auto-dismisses)
`icon`	`ReactNode \| null`	State icon	Custom icon replacing the default in the badge circle
`fill`	`string`	`"#FFFFFF"`	SVG fill color for the toast background shape
`styles`	`SileoStyles`	--	CSS class overrides for sub-elements
`roundness`	`number`	`16`	Border radius in pixels for the SVG shapes
`autopilot`	`boolean \| { expand?: number; collapse?: number }`	`true`	Auto expand/collapse timing. `false` = hover only
`button`	`SileoButton`	--	Action button configuration

Action Toast

Action toasts include a clickable button inside the expanded area:

sileo.action({
  title: "New version available",
  description: "Reload to update",
  button: {
    title: "Reload",
    onClick: () => window.location.reload(),
  },
});

`SileoButton`

interface SileoButton {
  title: string;
  onClick: () => void;
}

Promise Toast

sileo.promise chains loading -> success/error states from a single promise. It returns the original promise so you can chain further.

The first argument can be a Promise<T> or a function () => Promise<T> (useful for lazy execution).
success and error can be static options or callbacks that receive the resolved/rejected value.
The optional action field, when provided, replaces the success toast with an action-state toast.

type User = { name: string };

const result = await sileo.promise<User>(createUser(data), {
  loading: { title: "Creating account..." },
  success: (user) => ({
    title: `Welcome, ${user.name}!`,
  }),
  error: (err: any) => ({
    title: "Signup failed",
    description: err?.message ?? "Unknown error",
  }),
});
// `result` is the resolved User object

With lazy promise (function):

sileo.promise(() => fetch("/api/data").then((r) => r.json()), {
  loading: { title: "Fetching data..." },
  success: { title: "Data loaded" },
  error: { title: "Failed to load" },
});

With action replacing success:

sileo.promise<{ url: string }>(uploadFile(file), {
  loading: { title: "Uploading..." },
  success: { title: "Uploaded" }, // Ignored when `action` is present
  error: { title: "Upload failed" },
  action: (data) => ({
    title: "File ready",
    description: "Click to open",
    button: {
      title: "Open",
      onClick: () => window.open(data.url),
    },
  }),
});

`SileoPromiseOptions<T>`

interface SileoPromiseOptions<T = unknown> {
  loading: SileoOptions;
  success: SileoOptions | ((data: T) => SileoOptions);
  error: SileoOptions | ((err: unknown) => SileoOptions);
  action?: SileoOptions | ((data: T) => SileoOptions);
  position?: SileoPosition;
}

Positions

Six positions available. Set a default on <Toaster />, or override per toast:

type SileoPosition =
  | "top-left"
  | "top-center"
  | "top-right"     // default
  | "bottom-left"
  | "bottom-center"
  | "bottom-right";

<Toaster position="bottom-center" />

// Override for a specific toast
sileo.success({ title: "Saved", position: "top-left" });

The SILEO_POSITIONS constant array is also exported for iteration:

import { SILEO_POSITIONS } from "sileo"; // Not exported from index (internal)

Toaster (Viewport Component)

<Toaster /> is the viewport component that renders toasts. Add it once at your root layout.

import { Toaster } from "sileo";

Props

Prop	Type	Default	Description
`children`	`ReactNode`	--	App content to render alongside toasts
`position`	`SileoPosition`	`"top-right"`	Default position for all toasts
`offset`	`number \| string \| { top?, right?, bottom?, left? }`	--	Distance from viewport edges
`options`	`Partial<SileoOptions>`	--	Default options merged into every toast
`theme`	`"light" \| "dark" \| "system"`	--	Automatic fill based on color scheme. `"system"` follows OS preference

Theme

The theme prop automatically sets the toast fill color based on the selected scheme, saving you from manually configuring dark/light fills:

"light" -> fill is #1a1a1a (dark toast on light backgrounds) + light description text
"dark" -> fill is #f2f2f2 (light toast on dark backgrounds) + dark description text
"system" -> Follows prefers-color-scheme media query, reactively updates on OS change

<Toaster position="top-right" theme="system" />

When theme is set, the viewport renders data-theme="light" or data-theme="dark" which CSS uses to auto-style description text opacity.

If you set both theme and fill on individual toasts, the per-toast fill takes precedence.

Offset

Accepts a number (px), a CSS string, or a per-side object:

<Toaster offset={20} />
<Toaster offset="1.5rem" />
<Toaster offset={{ top: 20, right: 16 }} />

Default Options (global)

<Toaster
  options={{
    fill: "#171717",
    styles: { description: "text-white/75!" },
  }}
/>

Every toast will inherit these defaults. Per-toast options override them. The styles object is shallow-merged (per-toast styles overlay global styles).

Styling

Sileo looks great out of the box. When customization is needed, there are several escape hatches.

Fill Color

fill sets the SVG background color of the toast shape. Default: "#FFFFFF".

For dark toasts, use a dark fill and pair it with light text via styles:

sileo.success({
  title: "Dark toast",
  fill: "#171717",
  styles: {
    title: "text-white!",
    description: "text-white/75!",
  },
});

Style Overrides (`styles`)

Override CSS classes on individual sub-elements. When using Tailwind, add ! for specificity.

`SileoStyles`

interface SileoStyles {
  title?: string;       // The heading text
  description?: string; // The body/description area
  badge?: string;       // The icon badge circle
  button?: string;      // The action button
}

Available Data-Attribute Selectors

Key	Element	CSS Selector
`title`	Heading text	`[data-sileo-title]`
`description`	Body/description area	`[data-sileo-description]`
`badge`	Icon badge circle	`[data-sileo-badge]`
`button`	Action button	`[data-sileo-button]`

Additional data-attributes available for CSS targeting:

Selector	Description
`[data-sileo-toast]`	The outermost toast element (a `<button>`)
`[data-sileo-toast][data-state="success"]`	Toast filtered by state
`[data-sileo-toast][data-expanded="true"]`	Expanded toast
`[data-sileo-toast][data-exiting="true"]`	Toast in exit animation
`[data-sileo-viewport]`	The fixed viewport `<section>`
`[data-sileo-viewport][data-position="top-right"]`	Viewport filtered by position
`[data-sileo-viewport][data-theme="dark"]`	Viewport with theme applied
`[data-sileo-canvas]`	The SVG canvas wrapper
`[data-sileo-svg]`	The inner SVG element
`[data-sileo-pill]`	Animated collapsed pill rect
`[data-sileo-body]`	Animated expanded body rect
`[data-sileo-header]`	The header row container
`[data-sileo-content]`	The expandable content area

Example: Full dark theme with Tailwind

sileo.success({
  title: "Custom styled",
  fill: "black",
  styles: {
    title: "text-white!",
    description: "text-white/75!",
    badge: "bg-white/20!",
    button: "bg-white/10!",
  },
});

Custom Icons

Pass any React node as icon to replace the default state icon:

sileo.info({
  title: "Custom icon",
  icon: <MyIcon />,
});

Pass icon: null to render no icon at all.

Default icons by state (Lucide-style SVG inlined):

success -> checkmark
error -> X
warning -> circle with exclamation
info -> life buoy
loading -> spinning circle (CSS animation)
action -> arrow right

Custom Description (JSX)

description accepts JSX, enabling rich content inside the expanded area:

sileo.info({
  title: "Rich content",
  description: (
    <div style={{ display: "flex", flexDirection: "column", gap: 8 }}>
      <span>Multiple elements supported</span>
      <img src="/preview.png" alt="Preview" width={120} />
    </div>
  ),
});

Roundness

Control the border radius via roundness (default 16):

sileo.success({ title: "Sharp", roundness: 8 });   // Sharper corners
sileo.success({ title: "Pill", roundness: 24 });    // More pill-like

Performance: Higher roundness increases the SVG blur radius for the gooey morph effect (blur = roundness * 0.5), which is more expensive to render. The recommended value is 16.

Autopilot

By default, toasts auto-expand after ~150ms and collapse ~4 seconds before dismissing. Control this behavior:

// Disable entirely (hover to expand, click away to collapse)
sileo.info({ title: "Manual", autopilot: false });

// Custom timing (milliseconds)
sileo.info({
  title: "Custom timing",
  autopilot: { expand: 250, collapse: 300 },
});

Internal defaults (derived from DEFAULT_TOAST_DURATION of 6000ms):

AUTO_EXPAND_DELAY = 150ms (6000 * 0.025)
AUTO_COLLAPSE_DELAY = 4000ms (6000 - 2000)

When autopilot is false or duration is null/0, auto expand/collapse is disabled.

Dismiss / Clear

// Dismiss a specific toast
const id = sileo.success({ title: "Will dismiss" });
sileo.dismiss(id);

// Clear all toasts
sileo.clear();

// Clear only toasts at a specific position
sileo.clear("bottom-center");

Toasts can also be swiped vertically (30px threshold) to dismiss them. This is built-in pointer-event swipe gesture behavior.

Sticky Toasts

Set duration: null to prevent auto-dismissal. The toast stays until dismissed programmatically or swiped:

sileo.warning({
  title: "Requires attention",
  description: "This won't go away on its own.",
  duration: null,
});

Global Defaults (Consistent Dark Theme)

<Toaster
  position="top-right"
  options={{
    fill: "#171717",
    roundness: 16,
    styles: {
      title: "text-white!",
      description: "text-white/75!",
      badge: "bg-white/10!",
      button: "bg-white/10! hover:bg-white/15!",
    },
  }}
/>

CSS Variables

Sileo exposes CSS custom properties for global overrides. Override them in :root or any parent element:

:root {
  /* State colors (oklch format) */
  --sileo-state-success: oklch(0.723 0.219 142.136);
  --sileo-state-loading: oklch(0.556 0 0);
  --sileo-state-error: oklch(0.637 0.237 25.331);
  --sileo-state-warning: oklch(0.795 0.184 86.047);
  --sileo-state-info: oklch(0.685 0.169 237.323);
  --sileo-state-action: oklch(0.623 0.214 259.815);

  /* Dimensions */
  --sileo-width: 350px;
  --sileo-height: 40px;

  /* Animation */
  --sileo-duration: 600ms;
}

Example: custom brand success color:

:root {
  --sileo-state-success: oklch(0.7 0.2 200);
}

Internal CSS Variables (per-toast, set via inline styles)

These are computed per-toast and set as CSS custom properties on [data-sileo-toast]:

Variable	Description
`--_h`	Current toast height (collapsed or expanded)
`--_pw`	Pill width
`--_px`	Pill X offset
`--_ht`	Header transform (translate + scale)
`--_co`	Content opacity (0 or 1)

Internal Color Variables (per-state, set via CSS)

Variable	Description
`--sileo-tone`	The resolved state color for badge/title
`--sileo-tone-bg`	The state color at 20% opacity for badge background
`--sileo-btn-color`	Button text color (equals state color)
`--sileo-btn-bg`	Button background (state color at 15%)
`--sileo-btn-bg-hover`	Button hover background (state color at 25%)

TypeScript Exports

All types are exported from "sileo":

import type {
  SileoButton,
  SileoOptions,
  SileoPosition,
  SileoState,
  SileoStyles,
} from "sileo";

// SileoState = "success" | "loading" | "error" | "warning" | "info" | "action"

The SileoPromiseOptions<T> type is also exported from the toast module.

Accessibility

The viewport uses <section> with aria-live="polite" so screen readers announce new toasts without interrupting the user.
The toast root element is a <button> for keyboard focusability.
Each SVG icon has a <title> element for screen reader labeling.
Sileo respects prefers-reduced-motion: reduce by disabling all animations and transitions when the OS preference is set.

Architecture (Internal Details)

Understanding Sileo's internals helps when debugging or deeply customizing:

Global store: A module-level singleton (store) holds all active toasts and notifies React via a listener Set. The Toaster component subscribes to this store and re-renders when toasts change.
Toast IDs: When no id is provided by the user, toasts use "sileo-default" as their id. This means calling sileo.success(...) repeatedly without an id will replace the previous toast (same-id update behavior). Provide a unique id for multiple simultaneous toasts of the same state.
SVG Gooey Effect: Each toast renders an <svg> with:
- A <filter> containing feGaussianBlur (stdDeviation = roundness * 0.5) + feColorMatrix + feComposite
- Two <motion.rect> elements (pill + body) animated via motion/react spring transitions
- The gooey filter creates the organic blob-merging effect between pill and expanded card
Spring Physics: Animations use motion/react's spring transition with bounce: 0.25 and computed duration (default 0.6s). CSS transitions use a linear() easing approximation of the same spring curve.
Expand Direction: Toasts at top-* positions expand downward; toasts at bottom-* positions expand upward (via CSS scaleY(-1) transform on the canvas).
Timer Management: Each Toaster instance manages auto-dismiss timers per toast. Hovering over any toast pauses all timers; leaving resumes them. This hover-pause behavior is Toaster-level, not per-toast.
Header Morphing: When a toast's state changes (e.g., loading -> success via promise), the header performs a blur-based crossfade animation between the old and new state, using two stacked layers (current + prev).

Integration Checklist

Install sileo (and ensure motion peer dep is available)
Mount one <Toaster /> at the root layout
Use sileo.success/error/warning/info/show/action based on context
For async flows, prefer sileo.promise(...)
For theming, either use theme prop or manual fill + styles + CSS variables
For programmatic dismissal, use dismiss(id) or clear(...)
Provide unique id values when multiple toasts should coexist simultaneously

Common Patterns

Form submission feedback

const handleSubmit = async (data: FormData) => {
  await sileo.promise(saveForm(data), {
    loading: { title: "Saving..." },
    success: { title: "Form saved" },
    error: (err: any) => ({
      title: "Save failed",
      description: err?.message,
    }),
  });
};

Undo action toast

const id = sileo.action({
  title: "Item deleted",
  description: "This action can be undone",
  duration: 8000,
  button: {
    title: "Undo",
    onClick: () => {
      restoreItem(itemId);
      sileo.dismiss(id);
    },
  },
});

Multiple simultaneous toasts

// Use unique ids to prevent replacement
sileo.info({ title: "Downloading file 1...", id: "download-1", duration: null });
sileo.info({ title: "Downloading file 2...", id: "download-2", duration: null });

// Dismiss individually
sileo.dismiss("download-1");
sileo.dismiss("download-2");

sileo-react-toasts