Query Reference

@svelte-lean/query/ssr

./ssr experimental

Server rendering and SvelteKit interop: committed values moved by key from a server load into the page, tags that re-run loads, and endpoints answered by functions instead of HTTP.

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Note ./ssr is experimental: the API can still change in a minor release. Stability per entry point: Entry points.

On this page

Import

import

import { dehydrate, hydrate, kitInvalidate, source, sources } from '@svelte-lean/query/ssr';

Usage

src/lib/api/transport.ts

// src/lib/api/transport.ts
import { http } from '@svelte-lean/query/http';
import { source, sources } from '@svelte-lean/query/ssr';
import { getMember } from '$api/members';
import type { Member } from '$api/types';

// getMember is answered by a function (a remote function, an RPC call); the rest goes over HTTP.
export const transport = sources(
	[source(getMember, (params, signal) => readMember(Number(params.id), signal))],
	http({ base: '/' })
);

Size

Production Vite builds of a small consumer entry, Svelte external. A marginal row is the bytes the entry adds over the row it names.

Build	Over	gzip	brotli	Budget (gzip)
`ssr (marginal)`	`query`	568 B	514 B	700 B
`ssr every export (marginal)`	`query`	1287 B	1178 B	1500 B

Read from packages/query/artifacts/size.json. Every entry and its method: Performance.

Functions

No module state: request isolation is one client per request.

Exports

Runtime exports of the entry.

Name	Type	Default	Description
# `dehydrate`	`(client: Client, options?: { endpoints? }) => Dehydrated`	–	The successful entries of the client's scope whose access verdict is true, as a plain object.
# `hydrate`	`(client: Client, state: Dehydrated \| Promise<Dehydrated> \| null \| undefined) => () => void`	–	Apply records: each only when the entry has no value or an older one. Returns a function that drops the records not used yet.
# `kitInvalidate`	`(init: { invalidate }) => Module`	–	Every invalidation calls SvelteKit's invalidate('slq:<Name>') and invalidate('slq:<Name>:<id>'), coalesced per microtask.
# `source`	`(endpoint, run: (params, signal) => R \| Promise<R>) => Source`	–	Pairs an endpoint with the function that answers it (a remote function, an RPC call).
# `sources`	`(list: Source[], fallback?: Transport) => Transport`	–	A transport that answers the listed endpoints with their functions and the rest with fallback.

Types

What dehydrate() returns and what source() makes.

Dehydrated

A plain object the caller serializes (SvelteKit: devalue).

Name	Type	Default	Description
# `v`	`1`	–	Format version.
# `entries`	`DehydratedEntry[]`	–	The records.

DehydratedEntry

One committed value.

Name	Type	Default	Description
# `key`	`string`	–	Scope, endpoint id and canonical params (not a digest).
# `value`	`unknown`	–	The value.
# `updatedAt`	`number`	–	The server's commit time: freshness counts from the server fetch.
# `bytes`	`number`	–	Approximate size.

Source

What source() returns.

Name	Type	Default	Description
# `endpoint`	`QueryEndpoint \| MutationEndpoint`	–	The endpoint it answers.
# `run`	`(input, signal) => unknown`	–	The function that answers it.

Guide

How to use it, with examples: Server rendering. All entry points: Svelte Lean Query.