How ETA Works

ETA intercepts Minecraft’s text rendering pipeline via Mixin to add two separate surfaces for styled and animated text.

Two surfaces

Surface A: inline markup

ETA tags work inside any text component that Minecraft renders on the client. This includes item names, lore, signs, written books, chat messages, and translation arguments. The hooks are LiteralContentsMixin (targeting PlainTextContents.LiteralContents) and TranslatableContentsMixin (targeting TranslatableContents), both injecting into the visit method that vanilla calls when walking a component tree for rendering. StringRenderOutputMixin (targeting Font$StringRenderOutput) then intercepts each glyph’s accept call to apply per-character effects.

Because the hooks sit inside the renderer, they fire for every surface that eventually calls through Font.drawString. No special API call or server-side change is needed to get markup in item names or signs.

Surface B: immersive messages

Immersive messages are HUD popups that exist outside the normal component tree. They’re created via the /eta send command or the ImmersiveMessage Java API and rendered directly to the overlay layer. Unlike inline markup, they carry their own duration, fade-in/out, anchor, offset, text scale, background, and message-level effects. These properties have no equivalent in inline markup.

The text pipeline

When ETA processes a string of markup:

1. MarkupParser.parse(markup) (for inline text) or MarkupParser.parseFull(markup) (for immersive messages) splits the input into a list of TextSpan objects. Each span holds a text fragment plus its style properties and an effect list.
2. As the parser walks the tag stack it resolves nesting, applies attribute values, and attaches effect instances to each span.
3. parseFull additionally strips [bracket] message tags from the string before span parsing and returns a ParseResult containing the spans, the extracted MessageEffect list, the MessageAttribute list, and the stripped markup string.
4. At render time, StringRenderOutputMixin calls EffectApplicator for each character. Effects mutate the character’s position, color, alpha, or queue extra draw passes (neon glow, outline, etc.) through an EffectSettings object.

Where effects apply

Surface	Inline markup tags	Layout and positioning	Message effects
Chat messages	yes
Item names	yes
Item lore	yes
Signs	yes
Written books	yes
Anvil renames	yes
Translation arguments	yes
Immersive HUD messages	yes	yes	yes

All inline surfaces go through the same mixin hooks; only immersive HUD messages have per-message layout controls and message-level effects.

Glossary Definitions for terms used throughout the docs.

Markup Syntax The full tag and attribute syntax.