RMT Syntax Basics

This page introduces the shape of a valid RMT-vNext source file. You only need basic HTML and JavaScript knowledge before you start.

Document Shape

An RMT document starts with a template. The template contains declarations such as state, selector, action, portal, resource and surface. Blocks use braces, strings use quotes and nested declarations describe ownership. tools/rmt-language/vnext-parser.js reads the accepted record forms; when an example differs, its diagnostic is authoritative.

template learn.rmt.syntax {
  state app.message type object preserve {
    initial {
      id "welcome"
      text "Hello RMT"
      tone "info"
    }
  }

  selector app.message from state app.message {
    output MessageView
  }

  surface root {
    lane visible weight 80 {
      hydrate message-card from selector app.message
    }
  }
}

Reading The Example

The template owns one state record, exposes it through one selector and hydrates one surface lane from that selector. This is the basic RMT rhythm: describe data, expose the view model, then schedule rendering work.

Next Step

Continue with Templates and Surfaces.

Validation And Transitions

Form logic does not have to live as host JavaScript next to the RMT file. Use validation to declare field rules and action gates; use transition to declare the visual change between surface groups.

validation demo.contact {
  mode blocking
  target action demo.nextContact
  field demo.email required email message "Enter a valid email address."
}

transition demo.contactToIssue {
  trigger action demo.nextContact
  from surfaces [demo.email demo.nextContact]
  to surfaces [demo.subject demo.nextIssue]
  effect slide-left
  durationMs 220
  easing "ease-out"
  lane transition
}

required, email, minLength, maxLength, pattern, message, target action, from surfaces, to surfaces, effect and durationMs are part of the vNext syntax. lane transition lets the kernel scheduler plan the change.

Maraca Relevance

Maraca reads these records from the .rmt source and, in strict mode, decides whether validation, transition and kernel layers are complete enough. When you later run xt maraca build app.rmt --orchestration strict --kernel strict --hydration strict --validation strict --transitions strict --json, missing targets, unknown components and incomplete messages become build diagnostics instead of silent runtime fallbacks. The next production context is Maraca Orchestration.