Rixx UI Language 0.1

Status

Version 0.1 is experimental. Workspace packages remain private at 0.0.0 during active development.

Goals

Compact, reliable model output.
Progressive parsing of complete physical statements.
Stable node identity and legal forward references.
Data-only, non-executable component composition.
Precise validation and bounded repair diagnostics.

Host-embedded fragment

This is the normal model-facing form used by RUIRenderer:

root = Answer(children=[title, body])
title = Heading(text="Welcome", level=1)
body = RichText(text="A **safe** generated answer.", format="markdown")

The host supplies the internal envelope: language/catalog version, surface, base revision, transaction ID, and commit. Models emit assignments only. The trusted host synthesizes @commit root=root after provider completion and validates the complete transaction before exposing its commit record.

Full-envelope document

Fixtures, compiler tools, and advanced protocol integrations may use:

@rui version="0.1" catalog="rixx.core@0.1" surface="main" base=0 transaction="tx-welcome"
root = Text(text="A safe generated interface.")
@commit root=root revision=1

@rui must be first when present. revision must equal base + 1 when explicit. Header and revision defaults are accepted only when a trusted host provides the missing envelope.

Statements

Each non-empty physical line is one statement. # starts a comment outside a JSON string. Calls, arrays, and objects do not span physical lines. Lines, statements, expression depth, source bytes, graph nodes, edges, and protocol records have implementation-enforced budgets. During model generation, malformed physical lines are quarantined with bounded diagnostics and parsing resumes at the next line. Valid siblings remain available for provisional rendering. Unknown or catalog-invalid nodes are dropped without weakening catalog or action validation. Final commit still requires a valid reachable root, resolved references, and an acyclic graph.

document        = [header, newline],
                  {blank | assignment, newline},
                  commit, [newline] ;
header          = "@rui", argument, {spacing, argument} ;
commit          = "@commit", argument, {spacing, argument} ;
assignment      = identifier, spacing, "=", spacing, expression ;
expression      = string | number | boolean | null | reference |
                  array | object | call ;
call            = component-name, "(", [arguments], ")" ;
arguments       = named-arguments | positional-arguments ;
named-arguments = argument, {",", argument} ;
argument        = identifier, "=", expression ;
reference       = identifier, {".", identifier} ;
array           = "[", [expression, {",", expression}], "]" ;
object          = "{", [object-entry, {",", object-entry}], "}" ;
object-entry    = (identifier | string), ":", expression ;

Component calls require named arguments. Registered pure functions and validation rules may use their documented positional form.

Assignments and references

An ordinary identifier defines one component node:

save = Button(label="Save", action="customer.save")

An identifier beginning with $ defines literal local surface data. Calls are not permitted in declarations. Runtime reference roots:

Root	Meaning
`$data`	Read-only committed protocol/tool data
`$context`	Read-only host context
`$draft`	Read-only host-provided draft values
`$item`	Current item inside an `Each` template

Forward node references are valid if they resolve before commit. Unknown local references, duplicate IDs, unsafe object keys, cycles, and excessive graph depth are errors.

Functions

Pure functions are allowlisted by the compiler. Current functions include comparisons, boolean composition, conditional values, fallback, count/sum, formatting, and responsive values. They cannot execute arbitrary code, perform I/O, or mutate application state.

Commit and previews

@commit is final and names one local root in authored documents. Model-facing hosts append it only after the provider stream completes. Complete validated statements may produce an inert provisional preview. A preview cannot activate actions, external navigation, fields, clipboard behavior, or custom components. A syntax-complete image may load according to host-selected progressive, committed, or manual timing. The renderer may display safely decoded text from an open built-in RichText(format="markdown", text="...") string as a display-only overlay. The overlay does not create a protocol record. A malformed later line cannot erase the last safe preview. Only a fully validated committed transaction enables capabilities.

Catalog validation

After parsing, the selected catalog validates:

Registered component names.
Closed prop schemas and values.
Required/optional props and enums.
Child cardinality.
Binding representations.
Graph and resource budgets.

Strict catalogs validate action names during compilation and payload schemas before host notification. Production authentication, authorization, confirmation, execution, and idempotency remain host responsibilities.

Rich text and URLs

Top-level RUI is not Markdown. A RichText component may explicitly contain sanitized CommonMark/GFM with format="markdown". Raw HTML, MDX, scripts, style attributes, and unapproved image loading are disabled. Fenced code highlighting is implemented with trusted renderer code. HTTPS URL values may appear in citation or RichText link props. External links become visible while streaming but remain inert until commit, then use a review dialog unless direct mode is selected. Catalog Image and Markdown images share one timing and policy pipeline. Progressive loading is the default; committed and manual modes avoid provisional requests. Navigation policy never implies image policy.

Explicit exclusions

Version 0.1 excludes raw HTML, CSS, model-provided SVG, JavaScript, JSX/MDX, dynamic imports, arbitrary expressions, tool execution, network definitions, model-defined event handlers, and executable third-party widgets.

Get started

Render content

Configure Rixx UI

Frameworks and tools

Security

API reference

Architecture

Project

Rixx UI Language 0.1

Rixx UI Language 0.1

Status

Goals

Host-embedded fragment

Full-envelope document

Statements

Assignments and references

Functions

Commit and previews

Catalog validation

Rich text and URLs

Explicit exclusions

​Rixx UI Language 0.1

​Status

​Goals

​Host-embedded fragment

​Full-envelope document

​Statements

​Assignments and references

​Functions

​Commit and previews

​Catalog validation

​Rich text and URLs

​Explicit exclusions

Rixx UI Language 0.1

Status

Goals

Host-embedded fragment

Full-envelope document

Statements

Assignments and references

Functions

Commit and previews

Catalog validation

Rich text and URLs

Explicit exclusions