Glossary

This glossary defines terms used throughout the MicroPie documentation.

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.

route handler

A method on your 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 Managing 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 HttpMiddleware and 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 WebSocket and optionally additional parameters. See WebSocket support.

context variable

An object from the 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 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 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.