Glossary
========
This glossary defines terms used throughout the MicroPie documentation.
.. glossary::
ASGI
The Asynchronous Server Gateway Interface. A standard for
asynchronous communication between Python applications and
servers. MicroPie applications implement the ASGI call
interface. See the `ASGI specification <https://asgi.readthedocs.io>`_.
route handler
A method on your :class:`~micropie.App` subclass that handles an
incoming HTTP request. The first segment of the URL path maps to
the handler name, and remaining segments or query parameters map
to arguments. Handlers may be synchronous or asynchronous.
session
A dictionary of data associated with a client across multiple
requests. MicroPie stores the session in a pluggable back‑end
and identifies it using a ``session_id`` cookie. See
:doc:`howto/sessions`.
middleware
Code that runs before and/or after a request handler. Middleware
can short‑circuit requests, modify responses, enforce security
policies or implement custom routing. MicroPie defines
:class:`~micropie.HttpMiddleware` and
:class:`~micropie.WebSocketMiddleware` base classes.
WebSocket
A persistent, bidirectional communication channel over TCP. In
MicroPie, WebSocket handlers are methods prefixed with ``ws_``.
They receive an instance of :class:`~micropie.WebSocket` and
optionally additional parameters. See :doc:`tutorial/websockets`.
context variable
An object from the :mod:`contextvars` module that stores data
local to the current asynchronous context. MicroPie stores the
current request in a context variable so it is accessible via
:meth:`~micropie.App.request` without passing it through your
function calls.
lifespan
The ASGI lifecycle protocol that allows applications to run
startup and shutdown hooks. MicroPie exposes
``startup_handlers`` and ``shutdown_handlers`` lists so you can
register functions that prepare resources before serving traffic.
session backend
The implementation responsible for persisting session data.
MicroPie ships with an in-memory backend but allows you to
implement :class:`~micropie.SessionBackend` to store sessions in
Redis, databases or other stores.
ASGI server
A web server capable of speaking the ASGI protocol and invoking
your application callable. Examples include ``uvicorn``,
``hypercorn`` and ``daphne``.
