Valdres

setValdresContext

Signature
setValdresContext(storeOrOptions?: Store | SetValdresContextOptions): Store

valdres-svelte Provide a store to the component tree

Creates (or adopts) a valdres store and exposes it to descendants via Svelte context — the root of the adapter's provider tier. Call it once near the root. With no argument it creates store({ batchUpdates: true }) for the component tree, which on the server means one store per request — the canonical SvelteKit pattern that avoids a module-level shared-store leak. Returns the store now in context.

Usage

<!-- +layout.svelte -->
<script lang="ts">
    import { setValdresContext } from "valdres-svelte"

    let { children } = $props()
    setValdresContext()
</script>

{@render children()}

Descendants then read state with fromState / toStore and no explicit store argument.

Options

Pass an options object to seed the store:

OptionTypeDescription
storeStoreUse this store instead of auto-creating one (warns if not created with batchUpdates: true)
initializeInitializeCallbackSeed the store inside a transaction before it's exposed
hydrateDehydratedStateApply a dehydrate(store) payload to the fresh store
hydrateOptionsHydrateOptionsForwarded to core hydrate ({ invalid: "throw" | "skip" })

When both initialize and hydrate are given, initialize runs first so transferred values win.

SvelteKit (SSR)

Load data on the server, then map it to atoms with initialize. Because initialize runs on both the server render and client hydration, the atoms hold the right values in both passes — no custom serializer needed.

// +layout.server.ts
export const load = async () => {
    return { count: 7 } // plain, serializable
}
<!-- +layout.svelte -->
<script lang="ts">
    import { setValdresContext } from "valdres-svelte"
    import { countAtom } from "$lib/state"

    let { data, children } = $props()
    setValdresContext({ initialize: txn => [[countAtom, data.count]] })
</script>

{@render children()}

If your load data is itself a dehydrate(store) payload (e.g. from an API that ran a server-side store), pass it as hydrate instead. Atoms carrying a codec schema round-trip BigInt / Date / Map / Set over plain JSON automatically.

See also