doorkeeper

A doorkeeper is a person or entity responsible for guarding entry to a building, room, or event and for controlling access. The term is used for both historical occupations and modern roles, and it can also refer to a software project that carries the same name.

Historically, doorkeepers staffed entrances in houses, castles, monasteries, and public institutions. Duties commonly included admitting visitors, announcing guests, collecting tolls or fees, and maintaining order. In larger establishments, the role evolved into more specialized positions such as doormen, porters, or ushers who assist occupants and manage security and crowd flow.

In many cultures, doorkeepers also held ceremonial or symbolic significance, guarding sacred or restricted spaces at temple gates or city gates and controlling access according to custom or ritual rules.

In contemporary usage, doorkeeper remains a broad term for someone who controls entry. In hotels and theaters, the term often aligns with doorman or usher. In apartment buildings, it may refer to a building’s porter who answers intercoms and assists residents.

Doorkeeper is also the name of an open-source software project that provides an OAuth 2 provider for Ruby on Rails applications. It implements OAuth 2 authorization flows, enabling third-party apps to obtain access tokens to protected resources.