RMT Reference: Remote Surfaces

Remote surfaces describe external UI areas with owner, version, origin, integrity, trust and event facts.

Syntax

Operator	Form	Allowed contexts	Parameters	Function	Diagnostics	Related operators
from remote	remote surface cart from remote "@scope/cart"	remote surface header	static string	References remote package or manifest.	Remote ID must be a string.	remote surface
owner team	owner team "checkout-platform"	Remote surface, remote event	owner ID	Sets enterprise ownership.	Owner must be a string.	version
version	version "^2.4.0"	Remote surface	string	Documents expected version or range.	Value must be a string.	origin
origin	origin "https://cdn.example"	Remote surface	string	Sets allowed remote origin.	Value must be a string.	integrity sha256
integrity sha256	integrity sha256 "abc123"	Remote surface	algorithm, digest	Binds artifact integrity.	Digest must be a string.	trust boundary
fallback surface	fallback surface checkout.fallback	Remote surface	surface reference	Declares local degradation.	Fallback surface must be referenceable.	surface
exposes lane ->	exposes lane visible -> shell.slot "checkout"	Remote surface	lane, shell target	Binds a remote lane to a shell target.	-> and shell target are required.	lane
emits	emits checkout.updated.v1 { ... }	Remote surface	event name	Declares outbound cross-surface event.	Event needs direction and payload.	direction outbound
consumes	consumes user.changed.v1 { ... }	Remote surface	event name	Declares inbound cross-surface event.	Event needs direction and payload.	direction inbound
direction outbound	direction outbound	Remote event	direction	Marks outbound event.	Only outbound or inbound are allowed.	emits
direction inbound	direction inbound	Remote event	direction	Marks inbound event.	Only outbound or inbound are allowed.	consumes
from shell.session	from shell.session	Remote event	shell scope	Binds event to shell session scope.	Source scope must parse.	payload
remote payload	payload "xtend.schemas.event.v1"	Remote event	string schema	Declares payload schema for remote events.	Payload schema must be a string.	emits, consumes

Allowed contexts

Remote clauses appear only in remote surface. Remote event clauses appear only in emits or consumes.

Parameters

Remote facts are intentionally static: strings, identifiers, lane names and shell targets.

Description

Remote surface syntax enables discovery and degradation without executing remote code in the RMT kernel.

Examples

remote surface checkout.cart from remote "@xtend/checkout-cart" {
  owner team "checkout-platform"
  version "^2.4.0"
  origin "https://cdn.xtend.example"
  integrity sha256 "abc123"
  trust boundary "xtend.security.remote-surface.v1"
  fallback surface checkout.cart.fallback
  exposes lane visible -> shell.slot "checkout"

  emits checkout.cart.updated.v1 {
    owner team "checkout-platform"
    direction outbound
    lane visible
    from shell.session
    payload "xtend.schemas.cartUpdated.v1"
  }

  consumes user.session.changed.v1 {
    owner team "identity-platform"
    direction inbound
    lane background
    from shell.session
    payload "xtend.schemas.sessionChanged.v1"
  }
}

Diagnostics

Missing owner, version, origin, integrity, trust, fallback or payload facts block remote tooling and security reports.

Related operators

surface, lane, trust boundary, fallback, emits, consumes.

XScaler preflight

Remote surface hosts can validate scale-out readiness with XScaler Protocol before loading remote code. The preflight response complements owner, integrity, fallback and lane facts with SSR and XTension deployment compatibility.