########################################################################
# owuitools prompt test result
# prompt dir : easy/e12-http-418
# chat id    : 697f8c25-afff-4166-8a2c-91a584b1bd9e
# chat title : HTTP 418 Status Code
# user       : the operator
# model      : qwen3.8:latest
# turns      : 2 messages on selected branch
# tool calls : 3  lookup_rfc x2, network_reference x1
# dumped at  : 2026-09-11T04:38:01Z
########################################################################

=== USER  (2026-09-11T04:37:29Z) ===
What does HTTP status code 418 mean, which document defined it, and is it part of the actual HTTP standard?

=== ASSISTANT  (2026-09-11T04:37:29Z, model qwen3.8:latest) ===
usage: prompt_eval_count=14112 eval_count=426 prompt_tokens=14112 completion_tokens=426 total=13.7s prefill=2.5s decode=11.1s 38.5 tok/s

=== [1] THINKING ===
The user is asking about HTTP 418, which is a joke status code "I'm a teapot" from RFC 2324, the Hyper Text Coffee Pot Control Protocol. I can verify this using the network_reference tool and lookup_rfc to confirm the details.

=== [2] TOOL CALL: network_reference  (call_u5hvt3fe) ===
{
  "value": "418",
  "lookup_type": "http_status"
}

=== [3] TOOL CALL: lookup_rfc  (call_684q3p1y) ===
{
  "number": 2324
}

=== [4] TOOL RESULT: network_reference  (call_u5hvt3fe) ===
# HTTP 418 I'm a teapot

Class: Client error (4xx)

=== [5] TOOL RESULT: lookup_rfc  (call_684q3p1y) ===
# RFC 2324
Source: https://www.rfc-editor.org/rfc/rfc2324.txt

[characters 0-7,000 of 18,093]
Network Working Group                                       L. Masinter
Request for Comments: 2324                                 1 April 1998
Category: Informational

          Hyper Text Coffee Pot Control Protocol (HTCPCP/1.0)

Status of this Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard of any kind.  Distribution of this
   memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (1998).  All Rights Reserved.

Abstract

   This document describes HTCPCP, a protocol for controlling,
   monitoring, and diagnosing coffee pots.

1. Rationale and Scope

   There is coffee all over the world. Increasingly, in a world in which
   computing is ubiquitous, the computists want to make coffee. Coffee
   brewing is an art, but the distributed intelligence of the web-
   connected world transcends art.  Thus, there is a strong, dark, rich
   requirement for a protocol designed espressoly for the brewing of
   coffee. Coffee is brewed using coffee pots.  Networked coffee pots
   require a control protocol if they are to be controlled.

   Increasingly, home and consumer devices are being connected to the
   Internet. Early networking experiments demonstrated vending devices
   connected to the Internet for status monitoring [COKE]. One of the
   first remotely _operated_ machine to be hooked up to the Internet,
   the Internet Toaster, (controlled via SNMP) was debuted in 1990
   [RFC2235].

   The demand for ubiquitous appliance connectivity that is causing the
   consumption of the IPv4 address space. Consumers want remote control
   of devices such as coffee pots so that they may wake up to freshly
   brewed coffee, or cause coffee to be prepared at a precise time after
   the completion of dinner preparations.

   This document specifies a Hyper Text Coffee Pot Control Protocol
   (HTCPCP), which permits the full request and responses necessary to
   control all devices capable of making the popular caffeinated hot
   beverages.

   HTTP 1.1 ([RFC2068]) permits the transfer of web objects from origin
   servers to clients. The web is world-wide.  HTCPCP is based on HTTP.
   This is because HTTP is everywhere. It could not be so pervasive
   without being good. Therefore, HTTP is good. If you want good coffee,
   HTCPCP needs to be good. To make HTCPCP good, it is good to base
   HTCPCP on HTTP.

   Future versions of this protocol may include extensions for espresso
   machines and similar devices.

2. HTCPCP Protocol

   The HTCPCP protocol is built on top of HTTP, with the addition of a
   few new methods, header fields and return codes.  All HTCPCP servers
   should be referred to with the "coffee:" URI scheme (Section 4).

2.1 HTCPCP Added Methods

2.1.1 The BREW method, and the use of POST

   Commands to control a coffee pot are sent from client to coffee
   server using either the BREW or POST method, and a message body with
   Content-Type set to "application/coffee-pot-command".

   A coffee pot server MUST accept both the BREW and POST method
   equivalently.  However, the use of POST for causing actions to happen
   is deprecated.

   Coffee pots heat water using electronic mechanisms, so there is no
   fire. Thus, no firewalls are necessary, and firewall control policy
   is irrelevant. However, POST may be a trademark for coffee, and so
   the BREW method has been added. The BREW method may be used with
   other HTTP-based protocols (e.g., the Hyper Text Brewery Control
   Protocol).

2.1.2 GET method

   In HTTP, the GET method is used to mean "retrieve whatever
   information (in the form of an entity) identified by the Request-
   URI." If the Request-URI refers to a data-producing process, it is
   the produced data which shall be returned as the entity in the
   response and not the source text of the process, unless that text
   happens to be the output of the process.

   In HTCPCP, the resources associated with a coffee pot are physical,
   and not information resources. The "data" for most coffee URIs
   contain no caffeine.

2.1.3 PROPFIND method

   If a cup of coffee is data, metadata about the brewed resource is
   discovered using the PROPFIND method [WEBDAV].

2.1.4 WHEN method

   When coffee is poured, and milk is offered, it is necessary for the
   holder of the recipient of milk to say "when" at the time when
   sufficient milk has been introduced into the coffee. For this
   purpose, the "WHEN" method has been added to HTCPCP. Enough? Say
   WHEN.

2.2 Coffee Pot Header fields

   HTCPCP recommends several HTTP header fields and defines some new
   ones.

2.2.1 Recommended header fields

2.2.1.1 The "safe" response header field.

   [SAFE] defines a HTTP response header field, "Safe", which can be
   used to indicate that repeating a HTTP request is safe. The inclusion
   of a "Safe: Yes" header field allows a client to repeat a previous
   request if the result of the request might be repeated.

   The actual safety of devices for brewing coffee varies widely, and
   may depend, in fact, on conditions in the client rather than just in
   the server. Thus, this protocol includes an extension to the "Safe"
   response header:

          Safe                = "Safe" ":" safe-nature
          safe-nature         = "yes" | "no" | conditionally-safe
          conditionally-safe  = "if-" safe-condition
          safe-condition      = "user-awake" | token

   indication will allow user agents to handle retries of some safe
   requests, in particular safe POST requests, in a more user-friendly
   way.

2.2.2 New header fields

2.2.2.1 The Accept-Additions header field

   In HTTP, the "Accept" request-header field is used to specify media
   types which are acceptable for the response. However, in HTCPCP, the
   response may result in additional actions on the part of the
   automated pot. For this reason, HTCPCP adds a new header field,
   "Accept-Additions":

       Accept-Additions = "Accept-Additions" ":"
                          #( addition-range [ accept-params ] )

        addition-type   = ( "*"
                          | milk-type
                          | syrup-type
                          | sweetener-type
                          | spice-type
                          | alcohol-type
                          ) *( ";" parameter )
        milk-type       = ( "Cream" | "Half-and-half" | "Whole-milk"
                          | "Part-Skim" | "Skim" | "Non-Dairy" )
        syrup-type      = ( "Vanilla" | "Almond" | "Raspberry"
                          | "Chocolate" )
        alcohol-type    = ( "Whisky" | "Rum" | "Kahlua" | "Aquavit" )

2.2.3 Omitted Header Fields

   No options were given for decaffeinated coffee. What's the point?

2.3 HTCPCP return codes

   Normal HTTP return codes are used to indicate difficulties of the
   HTCPCP server. This section identifies special interpretations and
   new return codes.

2.3.1 406 Not Acceptable

   This 

[MORE AVAILABLE: 11,093 characters (~3,466 tokens) remain. To continue, call lookup_rfc with number=2324 and offset=7000, or with search='<section or term>' to jump straight to it. Only do so if this section did not answer the question.]

=== [6] THINKING ===
I need to pull the 418 section from RFC 2324 to get the exact wording.

=== [7] TOOL CALL: lookup_rfc  (call_lgmxcxwu) ===
{
  "number": 2324,
  "search": "418"
}

=== [8] TOOL RESULT: lookup_rfc  (call_lgmxcxwu) ===
# RFC 2324
Source: https://www.rfc-editor.org/rfc/rfc2324.txt

[Jumped to '418' at character 7,595 of 18,093]

…
 a HEAD request, the
   response SHOULD include an entity containing a list of available
   coffee additions.

   In practice, most automated coffee pots cannot currently provide
   additions.

2.3.2 418 I'm a teapot

   Any attempt to brew coffee with a teapot should result in the error
   code "418 I'm a teapot". The resulting entity body MAY be short and
   stout.

3. The "coffee" URI scheme

   Because coffee is international, there are international coffee URI
   schemes.  All coffee URL schemes are written with URL encoding of the
   UTF-8 encoding of the characters that spell the word for "coffee" in
   any of 29 languages, following the conventions for
   internationalization in URIs [URLI18N].

coffee-url  =  coffee-scheme ":" [ "//" host ]
                ["/" pot-designator ] ["?" additions-list ]

coffee-scheme = ( "koffie"                      ; Afrikaans, Dutch
                  | "q%C3%A6hv%C3%A6"          ; Azerbaijani
                  | "%D9%82%D9%87%D9%88%D8%A9" ; Arabic
               | "akeita"                   ; Basque
               | "koffee"                   ; Bengali
               | "kahva"                    ; Bosnian
               | "kafe"                     ; Bulgarian, Czech
               | "caf%C3%E8"                ; Catalan, French, Galician
                  | "%E5%92%96%E5%95%A1"       ; Chinese
                  | "kava"                     ; Croatian
               | "k%C3%A1va                 ; Czech
               | "kaffe"                    ; Danish, Norwegian, Swedish
               | "coffee"                   ; English
               | "kafo"                     ; Esperanto
                  | "kohv"                     ; Estonian
               | "kahvi"                    ; Finnish
               | "%4Baffee"                 ; German
               | "%CE%BA%CE%B1%CF%86%CE%AD" ; Greek
               | "%E0%A4%95%E0%A5%8C%E0%A4%AB%E0%A5%80" ; Hindi
               | "%E3%82%B3%E3%83%BC%E3%83%92%E3%83%BC" ; Japanese
               | "%EC%BB%A4%ED%94%BC"       ; Korean
               | "%D0%BA%D0%BE%D1%84%D0%B5" ; Russian
               | "%E0%B8%81%E0%B8%B2%E0%B9%81%E0%B8%9F" ; Thai
               )

   pot-designator = "pot-" integer  ; for machines with multiple pots
   additions-list = #( addition )

   All alternative coffee-scheme forms are equivalent.  However, the use
   of coffee-scheme in various languages MAY be interpreted as an
   indication of the kind of coffee produced by the coffee pot.  Note
   that while URL scheme names are case-independent, capitalization is
   important for German and thus the initial "K" must be encoded.

4. The "message/coffeepot" media type

   The entity body of a POST or BREW request MUST be of Content-Type
   "message/coffeepot". Since most of the information for controlling
   the coffee pot is conveyed by the additional headers, the content of
   "message/coffeepot" contains only a coffee-message-body:

   coffee-message-body = "start" | "stop"

5. Operational constraints

   This section lays out some of the operational issues with deployment
   of HTCPCP ubiquitously.

5.1 Timing Considerations

   A robust quality of service is required between the coffee pot user
   and the coffee pot service.  Coffee pots SHOULD use the Network Time
   Protocol [NTP] to synchronize their clocks to a globally accurate
   time standard.

   Telerobotics has been an expensive technology. However, with the
   advent of the Cambridge Coffee Pot [CAM], the use of the web (rather
   than SNMP) for remote system monitoring and management has been
   proven.  Additional coffee pot maintenance tasks might be
   accomplished by remote robotics.

   Web data is normally static. Therefore to save data transmission and
   time, Web browser programs store each Web page retrieved by a user on
   the user's computer. Thus, if the user wants to return to that page,
   it is now stored locally and does not need to be requested again from
   the server. An image used for robot control or for monitoring a
   changing scene is dynamic. A fresh version needs to be retrieved from
   the server each time it is accessed.

5.2 Crossing firewalls

   In most organizations HTTP traffic crosses firewalls fairly easily.
   Modern coffee pots do not use fire. However, a "firewall" is useful
   for protection of any source from any manner of heat, and not just
   fire. Every home computer network SHOULD be protected by a firewall
   from sources of heat. However, remote control of coffee pots is

   important from outside the home. Thus, it is important that HTCPCP
   cross firewalls easily.

   By basing HTCPCP on HTTP and using port 80, it will get all of HTTP's
   firewall-crossing virtues. Of course, the home firewalls will require
   reconfiguration or new versions in order to accommodate HTCPCP-
   specific methods, headers and trailers, but such upgrades will be
   easily accommodated. Most home network system administrators drink
   coffee, and are willing to accommodate the needs of tunnelling
   HTCPCP.

6. System management considerations

   Coffee pot monitoring using HTTP protocols has been an early
   application of the web.  In the earlie
…

[Showing the region around '418'. The full page is 18,093 characters - call again with offset= to read more.]

=== [9] THINKING (1s) ===
I'm confirming that 418 is a teapot status code from RFC 2324, an informational RFC published on April 1st, 1998 by L. Masinter.

=== [10] ASSISTANT TEXT ===
**418 — "I'm a teapot"** is a 4xx client-error status code.

**What it means:** It's defined in the context of the Hyper Text Coffee Pot Control Protocol (HTCPCP). Section 2.3.2 of the defining document says:

> "Any attempt to brew coffee with a teapot should result in the error code '418 I'm a teapot'. The resulting entity body MAY be short and stout."

So semantically: the server understood the request but refuses to perform it because the requested action is impossible — a teapot can't brew coffee.

**Which document defined it:** **RFC 2324**, "Hyper Text Coffee Pot Control Protocol (HTCPCP/1.0)", written by L. Masinter and published **1 April 1998**.

**Is it part of the actual HTTP standard?** No. RFC 2324 is explicitly an **Informational** RFC — "This memo provides information for the Internet community. It does not specify an Internet standard of any kind." It's an April Fool's joke document, and 418 was never adopted into the real HTTP specifications (RFC 9110 / RFC 7231). The IANA registry lists it separately, and it's reserved as a joke/historical code rather than a standard one.

That said, it's widely recognized in practice: many servers (notably Google, which historically returned 418 for certain odd queries) and frameworks like Flask and Spring have support for it, and it's a popular easter egg on April 1st. It's also a good example of why the 4xx range has reserved gaps — 417 and 418 sit between real codes but carry no standard meaning.

=== STATUS HISTORY (live progress indicator) ===
- Processing prompt
- Thinking · prompt processed in 2.1 s
- Thought: The user is asking about HTTP 418, which is a joke status code "I'm a teapot" from RFC 2324, the Hyper Text Coffee Pot Control Protocol. I can verify this…
- Calling network_reference
- Calling lookup_rfc
- Thinking
- Thought: I need to pull the 418 section from RFC 2324 to get the exact wording.
- Calling lookup_rfc
- Thinking
- Thought: I'm confirming that 418 is a teapot status code from RFC 2324, an informational RFC published on April 1st, 1998 by L. Masinter.
- Writing response
- Done · 3 tool calls
