Within the Ghostbusters lore, there isn't a single official book called the "Ghostbusters Codex," but there are several seminal texts that serve a similar purpose:
If you are looking for information regarding the "Codex" as an in-universe concept or the technical aspects of that specific software release, 1. The In-Universe "Codex" (Gozerian Codex) ghostbusters-codex
Unlike the critically acclaimed 2009 title, this was a top-down, four-player cooperative twin-stick shooter that coincided with the 2016 film's release. 3. Historical Context of the Franchise Within the Ghostbusters lore, there isn't a single
Fans have occasionally used this name to refer to the ancient lore surrounding Gozer the Gozerian, specifically in discussions about potential prop replicas or expanded universe stories. 2. The 2016 Video Game Release Historical Context of the Franchise Fans have occasionally
Another reference text mentioned in fandom circles as a catalog of occult occurrences.
The Ghostbusters universe was originally inspired by Dan Aykroyd's real-life interest in the paranormal , stemming from his family's history with spiritualism. This history of "ghost hunting" often informs the deep lore found in modern Ghostbusters media, which collectors and fans sometimes compile into their own unofficial "codexes" or wikis to track the various classes of entities (e.g., Class V Full Roaming Vapors).
The most famous "codex" of the franchise, used by the team to identify ghosts, spirits, and deities.