Private
Public Access
Site-wide, any user can upload -- usable both as reactions and inline in message text via :shortcode:, alongside the existing built-in Unicode picker. A :shortcode: reference is stored/sent as literal text (same as the built-in shortcode convention) and resolved to an image at render time, so it degrades to plain text if the emoji is later deleted. Backend: new custom_emoji table (shortcode unique, sized to fit MessageReaction.emoji's existing column alongside its colons), upload/ list/delete endpoints (delete restricted to uploader or site admin). Frontend: a CustomEmojiProvider context feeds a new "Custom" category in the emoji picker (inline upload + hover-to-remove), extends the composer's shortcode autocomplete, and a shared EmojiGlyph resolver renders custom emoji wherever a value can appear -- message text, reaction pills, and the picker itself. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>