Skybolt Python
Python adapter for Skybolt - High-performance asset caching for multi-page applications.
Installation
pip install skybolt
Or with uv:
uv add skybolt
Prerequisites
- Install and configure the Vite plugin:
npm install @skybolt/vite-plugin - Build your project:
npm run build - Ensure
render-map.jsonis generated in your build output
Usage
from skybolt import Skybolt
# Initialize with render map path and cookies
sb = Skybolt("dist/.skybolt/render-map.json", cookies=request.cookies)
<!DOCTYPE html>
<html>
<head>
{{ sb.css("src/css/critical.css")|safe }}
{{ sb.launch_script()|safe }}
{{ sb.css("src/css/main.css")|safe }}
</head>
<body>
<h1>Hello Skybolt!</h1>
{{ sb.script("src/js/app.js")|safe }}
</body>
</html>
API
Skybolt(render_map_path, cookies=None, cdn_url=None)
Create a new Skybolt instance.
render_map_path- Path torender-map.jsongenerated by Vite plugincookies- Cookie dictionary (defaults toNone)cdn_url- Optional CDN URL prefix (e.g.,'https://cdn.example.com')
# Basic usage
sb = Skybolt("dist/.skybolt/render-map.json", cookies=request.cookies)
# With CDN
sb = Skybolt(
"dist/.skybolt/render-map.json",
cookies=request.cookies,
cdn_url="https://cdn.example.com"
)
css(entry: str, async_load: bool = False) -> str
Render CSS asset.
- First visit: Inlines CSS with caching attributes
- Repeat visit: Outputs
<link>tag (Service Worker serves from cache)
When async_load is True, CSS loads non-blocking:
- First visit: Uses
media="print"trick, swaps toallon load - Repeat visit: Uses
<link rel="preload">withonload
# Blocking (default) - for critical CSS
sb.css("src/css/critical.css")
# Non-blocking - for non-critical CSS
sb.css("src/css/main.css", async_load=True)
script(entry: str, module: bool = True) -> str
Render JavaScript asset.
- First visit: Inlines JS with caching attributes
- Repeat visit: Outputs
<script>tag (Service Worker serves from cache)
# ES module (default)
sb.script("src/js/app.js")
# Classic script
sb.script("src/js/legacy.js", module=False)
launch_script() -> str
Render the Skybolt client launcher. Call once in <head> before other assets.
<head>
{{ sb.launch_script()|safe }}
</head>
get_asset_url(entry: str) -> str | None
Get the URL for an asset (for manual use cases).
url = sb.get_asset_url("src/css/main.css")
# "/assets/main-Pw3rT8vL.css"
get_asset_hash(entry: str) -> str | None
Get the content hash for an asset.
hash = sb.get_asset_hash("src/css/main.css")
# "Pw3rT8vL"
preload(entry, as_type, mime_type=None, crossorigin=None, fetchpriority=None) -> str
Render preload link for critical resources like fonts and images.
# Preload hero image with high priority
sb.preload("images/hero.jpg", as_type="image", fetchpriority="high")
# Preload font
sb.preload("fonts/inter.woff2", as_type="font", mime_type="font/woff2", crossorigin="anonymous")
# Preload a Vite-built asset (resolved from render-map)
sb.preload("src/css/main.css", as_type="style")
Parameters:
entry- Source file path or direct URLas_type- Resource type ('image','font','style','script','fetch')mime_type- MIME type (e.g.,'font/woff2','image/webp')crossorigin- Crossorigin attribute ('anonymous','use-credentials')fetchpriority- Fetch priority ('high','low','auto')
Service Worker Setup
The Service Worker must be served from your domain root. Configure your web server:
Nginx:
location = /skybolt-sw.js {
alias /path/to/dist/skybolt-sw.js;
}
Apache (.htaccess):
RewriteRule ^skybolt-sw\.js$ dist/skybolt-sw.js [L]
Framework Integration
Django
# views.py
from skybolt import Skybolt
def index(request):
sb = Skybolt("static/.skybolt/render-map.json", cookies=request.COOKIES)
return render(request, "index.html", {"sb": sb})
<!-- templates/index.html -->
<!DOCTYPE html>
<html>
<head>
{{ sb.css("src/css/critical.css")|safe }}
{{ sb.launch_script()|safe }}
{{ sb.css("src/css/app.css")|safe }}
</head>
<body>
<!-- content -->
{{ sb.script("src/js/app.js")|safe }}
</body>
</html>
Flask
from flask import Flask, render_template, request
from skybolt import Skybolt
app = Flask(__name__)
@app.route("/")
def index():
sb = Skybolt("static/.skybolt/render-map.json", cookies=request.cookies)
return render_template("index.html", sb=sb)
FastAPI
from fastapi import FastAPI, Request
from fastapi.responses import HTMLResponse
from fastapi.templating import Jinja2Templates
from skybolt import Skybolt
app = FastAPI()
templates = Jinja2Templates(directory="templates")
@app.get("/", response_class=HTMLResponse)
async def index(request: Request):
sb = Skybolt("static/.skybolt/render-map.json", cookies=request.cookies)
return templates.TemplateResponse("index.html", {"request": request, "sb": sb})
Requirements
- Python 3.10+
- Vite with
@skybolt/vite-plugin
License
MIT
1 maintainer
Release files for skybolt 3.4.0
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | |
|---|---|---|---|
| skybolt-3.4.0.tar.gz | 7.6 kB | Details |
Built distribution (wheel)
| File | Interpreter | ABI | Platform | Reset |
|---|---|---|---|---|
| skybolt-3.4.0-py3-none-any.whl | Python 3 | none | any | Details |
Total release size: 16.8 kB
Release files / skybolt-3.4.0.tar.gz
| Download URL | skybolt-3.4.0.tar.gz |
|---|---|
| Size | 7.6 kB |
| Tags | Source |
|
SHA-256 checksum How to use checksums |
0e6a1ea52415f224de377a43570f7545c6b381c785886174ffe64c4d481643c2
|
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BLAKE2b-256 checksum How to use checksums |
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Transparency logRelease files / skybolt-3.4.0-py3-none-any.whl
| Download URL | skybolt-3.4.0-py3-none-any.whl |
|---|---|
| Size | 9.2 kB |
| Tags | Python 3 |
|
SHA-256 checksum How to use checksums |
f89ed4f43313b09de607459fe6a8015f815ffe3a9396dae42a757ca6799b7257
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b5bebbe6bed0383238dbf26640ff9633127bcac40ddf86518195752cd5cc2737
|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/6.1.0 CPython/3.13.7
|
Provenance
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PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Dec 1, 2025.
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