SvelteKit integration¶
SvelteKit is a framework for building Svelte applications with file-based routing, SSR, and static export. Use seoslug in your load functions to generate SEO metadata and render it via <svelte:head>.
How it works¶
Two approaches are available. For SSG, a pre-build Python script generates a JSON manifest that your +layout.js load function reads and exposes as page data. For SSR, call seoslug directly in +page.js or +page.server.js and return the payload alongside your content data. Both use <svelte:head> in the page or layout component to render the tags.
Setup¶
1. Write the SEO generation script (static export)¶
Create scripts/generate_seo.py. This script walks your src/content/ or src/routes/ directory, builds an SEO payload per route, and writes a JSON manifest:
"""Pre-build: generates SEO JSON manifest for SvelteKit."""
from __future__ import annotations
import json
import re
import sys
from pathlib import Path
import yaml
from seoslug import (
SEOConfig,
URLPolicy,
SEOEntity,
OGImage,
Robots,
build_seo_payload,
)
PROJECT_ROOT = Path(__file__).resolve().parent.parent
CONTENT_DIR = PROJECT_ROOT / "src" / "content"
SITE_URL = "https://yoursite.com"
SITE_NAME = "Your Site"
SEO_CONFIG = SEOConfig(
canonical_host="yoursite.com",
public_base_url=SITE_URL,
url_policy=URLPolicy(
enforce_https=True,
lowercase_paths=True,
trailing_slash="always",
),
site_name=SITE_NAME,
default_og_image=OGImage(
url=f"{SITE_URL}/images/default-og.png",
width=1200,
height=630,
),
publisher_name="Your Name",
title_template="{title} | Your Site",
default_robots=Robots(index=True, follow=True),
locale="en_US",
twitter_site="@yourhandle",
)
FM_RE = re.compile(
r"^-{3}[ \r\t]*?\n(.*?\r?\n)(?:\.{3}|-{3})[ \r\t]*\n",
re.UNICODE | re.DOTALL,
)
def route_path_from_file(filepath: Path) -> str:
rel = filepath.relative_to(CONTENT_DIR)
parts = list(rel.parts)
if parts[-1] in ("index.md", "_index.md"):
parts.pop()
if not parts:
return "/"
return "/" + "/".join(parts) + "/"
stem = Path(*parts).with_suffix("")
return "/" + str(stem) + "/"
def extract_excerpt(body: str, max_chars: int = 160) -> str:
body = re.sub(r"^#\s+.*\n?", "", body, count=1).strip()
para = re.split(r"\n\s*\n", body, maxsplit=1)[0].strip()
clean = re.sub(r"[`*_\[\]()>|#{}]", "", para)
clean = re.sub(r"\s+", " ", clean).strip()
if not clean:
return ""
if len(clean) <= max_chars:
return clean
break_at = clean.rfind(" ", 0, max_chars)
return clean[:break_at] + "..." if break_at > 0 else clean[:max_chars] + "..."
def main() -> int:
manifest: dict[str, dict] = {}
for md_file in sorted(CONTENT_DIR.rglob("*.md")):
text = md_file.read_text(encoding="utf-8")
meta: dict = {}
body = text
if text.startswith("---"):
m = FM_RE.match(text)
if m:
try:
parsed = yaml.safe_load(m.group(1))
if isinstance(parsed, dict):
meta = parsed
except Exception:
pass
body = text[m.end():].lstrip("\n")
route = route_path_from_file(md_file)
title = meta.get("title") or ""
if not title:
m = re.search(r"^#\s+(.+)", body, re.MULTILINE)
if m:
title = re.sub(r"[`*_]", "", m.group(1).strip())
description = meta.get("description") or extract_excerpt(body)
entity = SEOEntity(
entity_type="page",
title=title or SITE_NAME,
excerpt=description or None,
)
payload = build_seo_payload(entity, route, SEO_CONFIG)
if payload is None:
continue
manifest[route] = payload.to_dict()
output = PROJECT_ROOT / "static" / "seo-manifest.json"
output.write_text(json.dumps(manifest, indent=2, ensure_ascii=False))
print(f"Written {output} ({len(manifest)} routes)")
return 0
if __name__ == "__main__":
sys.exit(main())
2. Load the manifest in a layout¶
Create src/routes/+layout.js (or +layout.server.js) that imports the manifest and makes it available:
import seoManifest from "$static/seo-manifest.json";
export function load({ url }) {
const seo = seoManifest[url.pathname] || null;
return { seo };
}
3. Render tags with <svelte:head>¶
In your layout component (src/routes/+layout.svelte), use <svelte:head> to inject the SEO tags:
<script>
export let data;
$: seo = data.seo;
</script>
<svelte:head>
{#if seo}
<title>{seo.title}</title>
<link rel="canonical" href={seo.canonical} />
<meta name="robots" content={seo.robots} />
<meta property="og:type" content={seo.og.type} />
<meta property="og:title" content={seo.og.title} />
<meta property="og:description" content={seo.og.description} />
<meta property="og:url" content={seo.og.url} />
<meta property="og:image" content={seo.og.image} />
<meta property="og:site_name" content={seo.og.site_name} />
<meta property="og:locale" content={seo.og.locale} />
<meta name="twitter:card" content={seo.twitter.card} />
<meta name="twitter:title" content={seo.twitter.title} />
<meta name="twitter:description" content={seo.twitter.description} />
<meta name="twitter:image" content={seo.twitter.image} />
{#if seo.schema_jsonld}
<script type="application/ld+json">
{JSON.stringify(seo.schema_jsonld)}
</script>
{/if}
{:else}
<title>Default Title</title>
<meta name="robots" content="index,follow" />
{/if}
</svelte:head>
<slot />
Runtime approach (SSR)¶
For dynamic content, call seoslug directly inside a +page.js load function:
# api/seo_builder.py
from seoslug import SEOConfig, SEOEntity, build_seo_payload
config = SEOConfig(
canonical_host="yoursite.com",
public_base_url="https://yoursite.com/",
site_name="Your Site",
title_template="{title} | Your Site",
)
def page_seo(title: str, description: str, route: str) -> dict:
entity = SEOEntity(entity_type="page", title=title, excerpt=description)
payload = build_seo_payload(entity, route, config)
return payload.to_dict() if payload else {}
Then import it in +page.server.js:
import { page_seo } from "$lib/seo_builder";
export async function load({ params, fetch }) {
const post = await fetch(`/api/posts/${params.slug}`).then(r => r.json());
const seo = page_seo(post.title, post.excerpt, `/blog/${params.slug}/`);
return { post, seo };
}
The same <svelte:head> snippet renders the result in the page component.
CI/CD¶
For the static manifest approach:
- uses: actions/setup-python@v5
with:
python-version: "3.x"
- run: pip install "seoslug>=2.0.1" pyyaml
- run: python scripts/generate_seo.py
- run: npm ci
- run: npm run build
For SSR, install seoslug in your deployment image and import directly in +page.server.js.