oekazuma/svelte-meta-tags/svelte-meta-tags-setup

svelte-meta-tags: Setup

Step 1: Install the package

Check whether svelte-meta-tags is already in package.json. If it is, skip to Step 2.

If it isn't, pick the command from the project's lockfile — not from whatever package manager happens to be installed globally:

If none of these lockfiles exists, fall back to the packageManager field in package.json; if that is absent too, ask which package manager to use rather than guessing.

Install it as a dev dependency: the components compile into the consuming app, so nothing from this package is needed at runtime.

Step 2: Detect whether this is a SvelteKit project

Check for @sveltejs/kit in package.json dependencies/devDependencies, and for a src/routes/ directory.

If this is NOT a SvelteKit project (plain Svelte, or another framework/router): skip the rest of this skill. Import MetaTags and pass props directly to it from whatever data-fetching mechanism the project already uses:

<script>
  import { MetaTags } from 'svelte-meta-tags';
</script>
 
<MetaTags title="My Page" description="A short description of this page." />

Do not introduce deepMerge, defineBaseMetaTags, or definePageMetaTags — those exist specifically for SvelteKit's load-based data flow across +layout.ts/+page.ts, and add unnecessary complexity outside that context.

If this IS a SvelteKit project, continue to Step 3.

Step 3: Find or create the base layout load file

Look for src/routes/+layout.ts (or +layout.server.ts if the project uses server-only data).

• If it exists: read it. If its load function already returns other data, merge defineBaseMetaTags's result into the existing return object — do not overwrite unrelated fields.
• If it doesn't exist: create it.

The base layout file should look like this:

// src/routes/+layout.ts
import { defineBaseMetaTags } from 'svelte-meta-tags';
export const load = () => {
  return {
    ...defineBaseMetaTags({
      title: 'My Site',
      titleTemplate: '%s | My Site',
      description: 'Default description for pages that do not set their own.'
    })
  };
};

Step 4: Check for nested layouts

Look for additional +layout.ts files in nested route directories (e.g. src/routes/blog/+layout.ts). If a section of the site needs its own base tags on top of the root layout's, chain deepMerge calls rather than duplicating defineBaseMetaTags calls:

// src/routes/blog/+layout.ts
import { deepMerge, defineBaseMetaTags } from 'svelte-meta-tags';
import type { LayoutLoad } from './$types';
export const load: LayoutLoad = async ({ parent }) => {
  const { baseMetaTags } = await parent();
  return {
    ...defineBaseMetaTags(
      deepMerge(baseMetaTags, {
        titleTemplate: '%s | Blog | My Site'
      })
    )
  };
};

When a nested layout overrides baseMetaTags like this, wire Step 6 with page.data.baseMetaTags instead of data.baseMetaTags. A layout's data prop only contains its own and ancestor load results — a child layout's override never reaches the root layout through data. It only surfaces through page.data, which merges every load on the current page with the deepest one winning.

If there are no nested layouts, skip this step — the standard two-layer (base + page) pattern from Step 3 and Step 5 is enough.

Step 5: Add page-level tags with definePageMetaTags

In the relevant +page.ts (or +page.server.ts), return page-specific overrides:

// src/routes/+page.ts
import { definePageMetaTags } from 'svelte-meta-tags';
export const load = () => {
  return {
    ...definePageMetaTags({
      title: 'Home',
      description: 'Welcome to my site.'
    })
  };
};

Not every route needs its own +page.ts — only add one where the page needs to override the base tags.

Step 6: Wire up +layout.svelte

<script>
  import { page } from '$app/state';
  import { MetaTags, deepMerge } from 'svelte-meta-tags';
 
  let { data, children } = $props();
 
  let metaTags = $derived(deepMerge(data.baseMetaTags, page.data.pageMetaTags));
</script>
 
<MetaTags {...metaTags} />
 
{@render children()}

Import page from `$app/state`, not $app/stores — the store-based module was removed in SvelteKit 3 and $app/state is its Svelte 5 replacement.

If Step 4 added nested-layout overrides, read the base tags from page.data instead, so section-level overrides actually reach this component:

let metaTags = $derived(deepMerge(page.data.baseMetaTags, page.data.pageMetaTags));

Step 7: JSON-LD (optional)

If the project needs structured data (e.g. for rich search results), mention that <JsonLd schema={...} /> exists as a separate component and point to https://oekazuma.github.io/svelte-meta-tags/json-ld/ for details — don't design a JSON-LD schema as part of this setup flow.

Step 8: Verify

Run the project's typecheck command (e.g. pnpm check, svelte-check, or whatever package.json defines) and confirm it passes with no new errors before considering the setup done.