Astro

Tegaki provides a native Astro component that renders full HTML at build time and hydrates on the client. No JavaScript framework required — text is visible even before hydration.

Installation

npm

npm install tegaki

pnpm

pnpm add tegaki

yarn

yarn add tegaki

bun

bun add tegaki

Basic example

---
import TegakiRenderer from 'tegaki/astro';
import bundle from 'tegaki/fonts/caveat';
---

<TegakiRenderer
  font={bundle}
  text="Hello World"
  time={{ mode: 'uncontrolled', speed: 1, loop: true }}
  style="font-size: 48px"
/>

Hello WorldHello World

Font registration

When using the same font across multiple components on a page, you can register the bundle once and reference it by name. This avoids duplicating the font data in the HTML output.

Register the bundle

Use the bundle prop on a dedicated instance — it serializes the font data into a <script type="application/json"> tag and registers it on the client. Once registered, reference the font by its family name (the fullFamily field of the bundle, e.g. "Caveat"):

---
import TegakiRenderer from 'tegaki/astro';
import bundle from 'tegaki/fonts/caveat';
---

<!-- Register the bundle once (renders nothing visible) -->
<TegakiRenderer font={bundle} bundle />

<!-- Use the font by name -->
<TegakiRenderer font="Caveat" text="First line" />
<TegakiRenderer font="Caveat" text="Second line" />

Preload the font

Add loadFont to inject an @font-face rule so the browser starts downloading the font file immediately:

<TegakiRenderer font={bundle} bundle loadFont />

Effects

---
import TegakiRenderer from 'tegaki/astro';
import bundle from 'tegaki/fonts/caveat';
---

<TegakiRenderer
  font={bundle}
  text="Fancy effects"
  time={{ mode: 'uncontrolled', speed: 1, loop: true }}
  effects={{
    glow: { radius: 8, color: '#00ccff' },
    pressureWidth: true,
    strokeGradient: { colors: 'rainbow' },
  }}
  style="font-size: 48px"
/>

Fancy effectsFancy effects

How it works

1. Build time — The Astro component calls TegakiEngine.renderElements() to produce the full HTML (canvas fallback text, overlay, sentinel). Text is visible in the initial HTML even without JavaScript.
2. Bundle serialization — Because font glyph data lives in server memory during SSR, it must be embedded into the HTML to reach the browser. When font={bundle} is passed as an object, the component automatically serializes the bundle into a <script type="application/json"> tag. If the same font is used across multiple renderers on the same page, use the bundle prop once to serialize it and reference by name afterward — this avoids duplicating the bundle data in the HTML output.
3. Client hydration — A module script reads any serialized bundle tags and registers them, then finds all [data-tegaki-options] elements, creates a TegakiEngine with adopt: true (reusing existing DOM), and starts the animation.
4. Dynamic elements — A MutationObserver watches for elements added after initial load (e.g., from View Transitions or client-side routing) and hydrates them automatically.

Props

The Astro component accepts all TegakiEngineOptions plus:

Prop	Type	Description
bundle	boolean	Register the font bundle for client-side lookup by name
loadFont	boolean	Inject @font-face CSS for early font loading
class	string	CSS class on the container