htmforge v0.4.0 released

Mondi — Fri, 22 May 2026 09:34:49 +0000

v0.4.0

One week out — here's what changed.

Added

Page.lang

The Page component now accepts a lang field that sets the
lang attribute on the <html> element:

class MyPage(Page):
    def _body_content(self):
        return [div(h1("Hello"))]

MyPage(title="Home", lang="de").to_html()
# <!DOCTYPE html><html lang="de">...

Default is "en". Small thing, but accessibility tools and
screen readers depend on it — it was an obvious gap.

Component.to_json()

Useful for API endpoints that need to return rendered HTML
alongside metadata:

card = UserCard(name="Ada", role="admin")
card.to_json()
# {"html": "<div class='card'>...", "component": "UserCard"}

Trusted Publishing

Optional CI-based publish path via GitHub Actions —
no local API token needed anymore.
Documented in docs/guide/trusted-publishing.md.

Changed

hatch-vcs

Version is now sourced directly from git tags.
No more manual version bumps in pyproject.toml —
tag the commit, the version follows automatically.

[tool.hatch.version]
source = "vcs"

release.py and push.py now read the version
from the git tag instead of pyproject.toml.

Fixed

README: all relative links replaced with absolute GitHub URLs for correct rendering on PyPI
DataTable docs updated — ColumnDef, dict_rows, sort_url, current_sort, sort_dir, empty_message now fully documented
docs/guide/components.md: broken code block fences and garbled method names fixed
CONTRIBUTING.md: Good First Issues updated to reflect actual open tasks

Install

pip install --upgrade htmforge

👉 github.com/mondi04/htmforge

👉 Full changelog

Type-safe HTML in Python — no templates, no runtime surprises

Mondi — Fri, 22 May 2026 09:04:21 +0000

Type-safe HTML in Python — no templates, no runtime surprises

Been building FastAPI apps for a while.
Every time the same thing: Jinja2 works until it doesn't.

Misspelled variable? Silent empty cell. Missing context key? Crash on render.
No mypy, no autocomplete, no safety net.

I wanted something different, so I built htmforge —
HTML entirely in Python, validated by Pydantic v2.

Before

{# users.html #}
{% for user in users %}
  <td>{{ user.naem }}</td>  {# typo — silent empty cell #}
  <td>{{ user.role }}</td>  {# wrong variant? find out at runtime #}
{% endfor %}

After

from htmforge.components import DataTable, ColumnDef, Badge, BadgeVariant

DataTable(
    columns=[
        ColumnDef(key="name", label="Name"),
        ColumnDef(key="role", label="Role"),
    ],
    dict_rows=[
        {
            "name": user["name"],
            "role": Badge(
                text=user["role"].title(),
                variant=BadgeVariant.DANGER
                if user["role"] == "admin"
                else BadgeVariant.SUCCESS,
            ),
        }
        for user in users
    ],
)

Typo in "name"? Pydantic catches it on startup.
Wrong BadgeVariant? mypy catches it.
XSS? Escaped automatically — no | safe to misuse.

HTMX is typed too

from htmforge.htmx import HxSwap, HxTarget
from htmforge.elements import button

button(
    "Delete",
    hx_delete=f"/users/{user_id}",
    hx_swap=HxSwap.OUTER_HTML,
    hx_target=HxTarget.CLOSEST_TR,
)

No more "outerHTML" string guessing. Full autocomplete.

Stack

Pydantic v2 — prop validation on construction and assignment
MarkupSafe — XSS protection, automatic, no opt-out
20+ components — DataTable, Form, Modal, Toast, Tabs, Accordion...
Framework adapters — FastAPI, Flask, Django built in
240 tests, mypy strict, ruff clean

Looking for contributors

The project is early but functional. Good first issues are documented
in CONTRIBUTING.md — from small things like adding a lang attribute
to Page, to rendering improvements in DataTable.

If this approach interests you:

👉 github.com/mondi04/htmforge
👉 pip install htmforge

DEV Community: Mondi

htmforge v0.4.0 released

v0.4.0

Added

Page.lang

Component.to_json()

Trusted Publishing

Changed

hatch-vcs

Fixed

Install

Type-safe HTML in Python — no templates, no runtime surprises

Type-safe HTML in Python — no templates, no runtime surprises

Before

After

HTMX is typed too

Stack

Looking for contributors