Supported Liquid tags
Upstorr intentionally supports a small, predictable Liquid tag set.
Decisions and loops
if,unlessandcasechoose content.forandtablerowrepeat content.breakandcontinuecontrol a loop.cyclealternates values while looping.
Variables and output
assignstores a value.capturestores rendered text.incrementanddecrementmaintain a small counter.echoprints a value inside aliquidblock.
Source organization
rendercalls a theme snippet with its own local scope.liquidwrites several Liquid statements inside one tag.commentand#hold developer comments that do not render.rawprints text without interpreting Liquid delimiters.render_fragmentrenders an approved theme fragment context.
schema and endschema form one special JSON block in a section or reusable block file. The schema parser reads it before Liquid rendering; it does not output HTML.
Script tags, inline browser-event attributes and arbitrary include mechanisms are not supported. Put developer-mode browser behavior in theme/assets/theme.ts and use the public SDK.