Instance-safe commands
Two instances of the same Module register independent command targets.
Runtime
Module commands and lifecycle
Connect Modules safely and load server data before a page renders.
Updated August 18, 2026 · 7 of 13
What is a public Module command?
A public command exposes an internal Module function through a stable command ID and an explicit argument schema. Applications can target a particular Module instance without depending on the function's display name.
Execution policy
Schema validation, timeout, cancellation, concurrency, and cleanup rules apply at runtime.
Server load
A Module can run a canonical server loader before render and hydrate its validated result as serverData.
Failure policy
Choose whether server-load failure stops rendering or supplies a configured fallback object.
Client
onMount runs after hydration and is separate from lifecycle.serverLoad. Use server load for data required before render; use on-mount behavior for browser-only work.