clacks-gnu-middleware 0.0.1

A FastAPI middleware to handle the GNU Headers (Memorial Headers) of the Clacks (Going Postal Terry Pratchett) for 'sending people home'.

Clacks GNU middleware

Lightweight FastAPI/Starlette middleware that keeps the tradition alive by adding the X-Clacks-Overhead HTTP header. Incoming headers are preserved, defaults can be configured, and duplicates are removed case-insensitively.

What it does

• Adds X-Clacks-Overhead to every response, prefixed with GNU and joined by commas.
• Merges incoming request names, your configured defaults, and any names already set on the response.
• Deduplicates names case-insensitively to avoid repeated entries.
• Simple configuration via a shared clacks_config object.

Install

pip install clacks-gnu-middleware

For local development:

pip install -e .
pip install -r requirements.txt  # tooling & test extras

Quick start (FastAPI)

from fastapi import FastAPI
from clacks_gnu_middleware.clacks_middleware import clacks_middleware, clacks_config

app = FastAPI()

# Optional: customize defaults before registering the middleware
clacks_config.default_names.extend([
    "Ada Lovelace",
    "Alan Turing",
])

app.middleware("http")(clacks_middleware)

@app.get("/ping")
async def ping():
    return {"status": "ok"}

# Run with: uvicorn app.application:app --reload

Header behavior

• Header name: X-Clacks-Overhead.
• Values are emitted as GNU <name>, joined with commas.
• Order: configured defaults → incoming header values → names already set on the response.
• Names are deduplicated (case-insensitive). Empty or non-GNU values are ignored.

Testing

pytest

Notes

• The middleware uses a module-level clacks_config; set defaults before registering the middleware to avoid runtime mutation.
• License: GPL-3.0 (see LICENSE).