clacks_overhead

A man is not dead while his name is still spoken.

Package Version Hex Docs

X-Clacks-Overhead is a non-standardised HTTP header based upon the fictional work of the late, great, Sir Terry Pratchett.

In Terry Pratchett's science-fantasy Discworld series, "The Clacks" is a network infrastructure of Semaphore Towers, that operate in a similar fashion to telegraph - named "Clacks" because of the clicking sound the system makes as signals send.

In Sir Terry's novel "Going Postal", the story explains that the inventor of the Clacks - a man named Robert Dearheart, lost his only son in a suspicious workplace accident, and in order to keep the memory of his son alive, he transmitted his son's name as a special operational signal through the Clacks to forever preserve his memory:

GNU John Dearheart



G: Send the message onto the next Clacks Tower.



N: Do not log the message.



U: At the end of the line, return the message.

The nature of the 'GNU' code would keep the name of his son forever transmitting through The Clacks network so long as the network still existed.

Credit: https://xclacksoverhead.org/home/about 2026

gleam add clacks_overhead@1

import clacks_overhead

import gleam/http/request.{type Request}

import gleam/http/response.{type Response}

import my_app



pub fn page_one(request: Request(String)) -> Response(String) {

  // Commemorate Terry with the header `x-clacks-overhead: GNU Terry Pratchett`

  my_app.make_page_one_response(request)

  |> clacks_overhead.commemorate_terry

}



pub fn page_two(request: Request(String)) -> Response(String) {

  // Or commemorate someone else with the `x-clacks-overhead` header

  my_app.make_page_two_response(request)

  |> clacks_overhead.commemorate(["Chris Young"])

}

Further documentation can be found at https://clacks-overhead.hexdocs.pm/.