The Hyper Text Coffee Pot Control Protocol (HTCPCP) is a facetious

communication protocol A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any variation of a physical quantity. The protocol defines the rules, syntax, semantics (computer science), sem ...

for controlling, monitoring, and diagnosing coffee pots. It is specified in , published on 1 April 1998 as an April Fools' Day RFC, as part of an April Fools prank. An extension, HTCPCP-TEA, was published a
RFC 7168
on 1 April 2014 to support brewing teas, also as an April Fools' Day RFC in error 418.

Protocol

RFC 2324
was written by Larry Masinter, who describes it as a satire, saying "This has a serious purpose – it identifies many of the ways in which

HTTP HTTP (Hypertext Transfer Protocol) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web, wher ...

has been extended inappropriately." The wording of the protocol made it clear that it was not entirely serious; for example, it notes that "there is a strong, dark, rich requirement for a protocol designed

espresso Espresso (, ) is a concentrated form of coffee produced by forcing hot water under high pressure through finely ground coffee beans. Originating in Italy, espresso has become one of the most popular coffee-brewing methods worldwide. It is cha ...

ly for the brewing of coffee". Despite the joking nature of its origins, or perhaps because of it, the protocol has remained as a minor presence online. The editor

Emacs Emacs (), originally named EMACS (an acronym for "Editor Macros"), is a family of text editors that are characterized by their extensibility. The manual for the most widely used variant, GNU Emacs, describes it as "the extensible, customizable, s ...

includes a fully functional client-side implementation of it, and a number of bug reports exist complaining about

Mozilla Mozilla is a free software community founded in 1998 by members of Netscape. The Mozilla community uses, develops, publishes and supports Mozilla products, thereby promoting free software and open standards. The community is supported institution ...

's lack of support for the protocol. Ten years after the publication of HTCPCP, the Web-Controlled Coffee Consortium (WC3) published a first draft of "HTCPCP Vocabulary in RDF" in parody of the

World Wide Web Consortium The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web. Founded in 1994 by Tim Berners-Lee, the consortium is made up of member organizations that maintain full-time staff working together in ...

(W3C)'s "HTTP Vocabulary in RDF". On April 1, 2014
RFC 7168
extended HTCPCP to fully handle teapots.

Commands and replies

HTCPCP is an extension of

. HTCPCP requests are identified with the

Uniform Resource Identifier A Uniform Resource Identifier (URI), formerly Universal Resource Identifier, is a unique sequence of characters that identifies an abstract or physical resource, such as resources on a webpage, mail address, phone number, books, real-world obje ...

(URI) scheme coffee (or the corresponding word in any other of the 29 listed languages) and contain several additions to the HTTP methods: It also defines four error responses:

Save 418 movement

On 5 August 2017, Mark Nottingham, chairman of the

IETF The Internet Engineering Task Force (IETF) is a standards organization for the Internet standard, Internet and is responsible for the technical standards that make up the Internet protocol suite (TCP/IP). It has no formal membership roster ...

HTTPBIS Working Group, called for the removal of status code 418 "I'm a teapot" from the Node.js platform, a code implemented in reference to the original 418 "I'm a teapot" established in Hyper Text Coffee Pot Control Protocol. On 6 August 2017, Nottingham requested that references to 418 "I'm a teapot" be removed from the programming language Go and subsequently from Python's Requests and

ASP.NET ASP.NET is a server-side web-application framework designed for web development to produce dynamic web pages. It was developed by Microsoft to allow programmers to build dynamic web sites, applications and services. The name stands for Ac ...

's HttpAbstractions library as well. In response, 15-year-old developer Shane Brunswick created a website, save418.com, and established the "Save 418 Movement", asserting that references to 418 "I'm a teapot" in different projects serve as "a reminder that the underlying processes of computers are still made by humans". Brunswick's site went viral in the hours following its publishing, garnering thousands of upvotes on the social platform

Reddit Reddit ( ) is an American Proprietary software, proprietary social news news aggregator, aggregation and Internet forum, forum Social media, social media platform. Registered users (commonly referred to as "redditors") submit content to the ...

, and causing the mass adoption of the "#save418"

Twitter Twitter, officially known as X since 2023, is an American microblogging and social networking service. It is one of the world's largest social media platforms and one of the most-visited websites. Users can share short text messages, image ...

hashtag he introduced on his site. Heeding the public outcry, Node.js, Go, Python's Requests, and ASP.NET's HttpAbstractions library decided against removing 418 "I'm a teapot" from their respective projects. The unanimous support from the aforementioned projects and the general public prompted Nottingham to begin the process of having 418 marked as a reserved HTTP status code, ensuring that 418 will not be replaced by an official status code for the foreseeable future. On 5 October 2020, Python 3.9 released with an updated HTTP library including 418 IM_A_TEAPOT status code. In the corresponding pull request, the Save 418 movement was directly cited in support of adoption.

Usage

The status code 418 is sometimes returned by servers when blocking a request, instead of the more appropriate 403 Forbidden, or

404 Not Found In Data communication, computer network communications, the HTTP 404, 404 not found, 404, 404 error, page not found, or file not found error message is a hypertext transfer protocol (HTTP) List of HTTP status codes, standard response code, to ...

. Around the time of the 2022

Russian invasion of Ukraine On 24 February 2022, , starting the largest and deadliest war in Europe since World War II, in a major escalation of the Russo-Ukrainian War, conflict between the two countries which began in 2014. The fighting has caused hundreds of thou ...

, the

Russian military The Armed Forces of the Russian Federation, commonly referred to as the Russian Armed Forces, are the military of Russia. They are organized into three service branches—the Ground Forces, Navy, and Aerospace Forces—two independent comba ...

website mil.ru returned the HTTP 418 status code when accessed from outside of Russia as a DDoS attack protection measure. The change was first noticed in December of 2021.

References

External links