hedron-jinja

Explicit standards-first .hdj templates over Jinja, HTML, and HTMX for Hedron.

HDJ lets advanced applications write ordinary HTML, CSS, JavaScript, Web Components, Jinja, and HTMX directly while preserving typed Hedron components and render metadata. Install as hedron-jinja or via the flagship extra hedron[jinja].

Package maturity: Beta · Train: 0.20.0 (Published) · pin >=0.20.0,<0.21

Install

pip install "hedron-jinja>=0.20.0,<0.21"
# or
uv add "hedron-jinja>=0.20.0,<0.21"
# via flagship:
pip install "hedron[jinja]>=0.20.0,<0.21"

Requires Python 3.11–3.14, hedron-core, and Jinja2.

Quick start

from jinja2 import Environment, FileSystemLoader
from hedron_jinja import HedronJinja, TemplateSpec

templates = HedronJinja(Environment(loader=FileSystemLoader("templates")))
result = templates.render(
    TemplateSpec("dashboard.hdj"),
    {"heading": "Operations"},
)
print(result.html)

Example templates/dashboard.hdj:

---hdj
version = 1
kind = "fragment"
profile = "standard"
regions = ["main"]
---
<main id="main" hx-history-elt>{{ view.heading }}</main>

Trust model

Templates are trusted application code, not a sandbox for hostile authors. Strict mode checks a finite dynamic sink matrix with purpose-specific URL filters. Deployment capability declarations and application policy remain separate and authoritative. Format v1 accepts static .hdj dependencies only; every source must render through HedronJinja.

Links

• Package docs
• HDJ authoring guide
• Jinja / HDJ API
• Changelog
• Source
• Issues
• HDJ progressive examples
• hedron-core · hedron

License

MIT. See LICENSE.