Which interaction API?

Hedron 1.0 has one ordinary interaction model. Use @app.view for safe replaceable reads and @app.action for unsafe operations; describe local or combined browser behavior with Interaction. HedronRouter remains the Advanced escape hatch for an explicit selector or raw HTTP boundary.

Use this	When
@app.view + @app.action	Canonical function roles. Views own replaceable handles; actions own unsafe requests and outcomes.
HedronRouter.view / HedronRouter.action	Advanced route integration when a lower-level HTTP/target contract is required.

Both compile to the same fail-closed fragment/OOB stack. A view or action decorator returns a handle whose controls keep the request URL, target, and CSRF wiring synchronized.

Canonical: view and action

from hedron import Hedron, Stack, Text, ToastHost, html

app = Hedron(title="Demo", security="standard", session_secret="dev", explorer="off")


@app.view("/status")
def status():
    return html.div(Text("ok"), role="status")


@app.action("/ping", fallback="/")
def ping():
    from hedron import refresh

    return refresh(status).toast("Refreshed")


@app.page("/")
def home():
    return Stack(
        status(),
        status.refresh_button("Refresh"),
        ping.button("Ping"),
        ToastHost(),
    )

Continue: Build your first app → HTMX interactions → Interaction.

Explicit: region and fragment

status = app.region("service-status")


def status_panel():
    return html.div(Text("ok"), id=status.id)


@app.view("/status", fragment_regions=(status,))
def refresh_status():
    return swap(status_panel())

Continue: Interaction.

Flask and Django

Adapter hosts use hedron_route / hedron_view rather than FastAPI's @app.view. See Flask and Django.