Author: Sébastien Helleu

# WeeChat Relay protocol

Sébastien Helleu
flashcode@flashtux.org
version 2.0

## 1. Introduction

This document is the specification of WeeChat Relay protocol: the protocol used to relay WeeChat data to clients, which are mostly remote interfaces.

### 1.1. Terminology

The following terms are used in this document:

- relay: this is the WeeChat with relay plugin, which acts as "server" and allows clients to connect

- client: this is another software, connected to relay via a network connection; in most cases, this client is a remote interface.

### 1.2. Network diagram

The clients are connected to relay like shown in this diagram:

                                                  ┌──────────┐ Workstation
     ┌────────┐                               ┌───┤ client 1 │ (Linux, Windows,
     │  irc   │◄──┐  ╔═══════════╤═══════╗    │   └──────────┘ BSD, Mac OS X ...)
     └────────┘   └──╢           │       ║◄───┘   ┌──────────┐
       ......        ║  WeeChat  │ Relay ║◄───────┤ client 2 │ Mobile device
     ┌────────┐   ┌──╢           │       ║◄───┐   └──────────┘ (Android, iPhone ...)
     │ jabber │◄──┘  ╚═══════════╧═══════╝    │      ......
     └────────┘                               │   ┌──────────┐
       ......                                 └───┤ client N │ Other devices
                                                  └──────────┘

    └────────────┘   └───────────────────┘╘══════╛└────────────────────────────────┘
    network servers    ncurses interface    relay         remote interfaces
                                          protocol

| All clients here are clients using weechat protocol in relay plugin. The relay plugin also allows IRC clients, then relay plugin acts as an IRC proxy (not described in this document).

## 2. Protocol generalities

- Connections from client to relay are made using TCP sockets on IP/port used by relay plugin to listen to new connections.

- Number of clients is limited by the option relay.network.max_clients.

- Each client is independent from other clients.

- Messages from client to relay are called commands, they are sent as text (a string).

- Messages from relay to client are called messages, they are sent as binary data.

## 3. Commands (client → relay)

Commands have format:

    (id) command arguments\n

Fields are:

- id: optional message identifier that will be sent in answer from relay; it must be enclosed in parentheses, and must not start with an underscore (ids starting with underscore are reserved for WeeChat event messages)

- command: a command (see table below)

- arguments: optional arguments for command (many arguments are separated by spaces).

List of available commands (detail in next chapters):

Command | Description
--- | ---
`init` | Initialize connection with relay.
`hdata` | Request a hdata.
`info` | Request an info.
`infolist` | Request an infolist.
`nicklist` | Request a nicklist.
`input` | Send data to a buffer (text or command).
`sync` | Synchronize buffer(s): get updates for buffer(s).
`desync` | Desynchronize buffer(s): stop updates for buffer(s).
`quit` | Disconnect from relay.

### 3.1. init

Initialize connection with relay. This must be first command sent to relay. If not sent, relay will close connection on first command received, without warning.

Syntax:

    init [<option>=<value>,[<option>=<value>,...]]

Arguments:

- option: one of following options:

  - password: password used to authenticate on relay (option relay.network.password in WeeChat)

  - compression: compression type:

    - zlib: enable zlib compression for messages sent by relay (enabled by default if relay supports zlib compression)

    - off: disable compression

| With WeeChat ≥ 1.6, commas can be escaped in the value, for example `init password=foo\,bar` to send the password "foo,bar".

Examples:

    # initialize and use zlib compression by default (if WeeChat supports it)
    init password=mypass

    # initialize with commas in the password (WeeChat ≥ 1.6)
    init password=mypass\,with\,commas

    # initialize and disable compression
    init password=mypass,compression=off

### 3.2. hdata

Request a hdata.

Syntax:

    (id) hdata <path> [<keys>]

Arguments:

- path: path to a hdata, with format: "hdata:pointer/var/var/…​/var", the last var is the hdata returned:

  - hdata: name of hdata

  - pointer: pointer ("0x12345") or list name (for example: "gui_buffers") (count allowed, see below)

  - var: a variable name in parent hdata (previous name in path) (count allowed, see below)

- keys: comma-separated list of keys to return in hdata (if not specified, all keys are returned, which is not recommended on large hdata structures)

A count is allowed after pointer and variables, with format "(N)". Possible values are:

- positive number: iterate using next element, N times

- negative number: iterate using previous element, N times

- *: iterate using next element, until end of list

| With WeeChat ≥ 1.6, if the hdata path is invalid or if a NULL pointer is found, an empty hdata is returned (see example in hdata object). With older versions, nothing was returned.

Examples:

    # request all buffers, hdata of type "buffer" is returned
    # keys "number" and "name" are returned for each buffer
    hdata buffer:gui_buffers(*) number,name

    # request all lines of all buffers, hdata of type "line_data" is returned
    # all keys are returned
    hdata buffer:gui_buffers(*)/lines/first_line(*)/data

    # request full name of first buffer
    hdata buffer:gui_buffers full_name

    # request the hotlist content
    hdata hotlist:gui_hotlist(*)

### 3.3. info

Request an info.

Syntax:

    (id) info <name>

Arguments:

- name: name of info to retrieve

Example:

    info version

### 3.4. infolist

Request an infolist.

| Content of infolist is a duplication of actual data. Wherever possible, use command hdata, which is direct access to data (it is faster, uses less memory and returns smaller objects in message).

Syntax:

    (id) infolist <name> [<pointer> [<arguments>]]

Arguments:

- name: name of infolist to retrieve

- pointer: pointer (optional)

- arguments: arguments (optional)

Example:

    infolist buffer

### 3.5. nicklist

Request a nicklist, for one or all buffers.

Syntax:

    (id) nicklist [<buffer>]

Arguments:

- buffer: pointer (0x12345) or full name of buffer (for example: core.weechat or irc.freenode.#weechat)

Examples:

    # request nicklist for all buffers
    nicklist

    # request nicklist for irc.freenode.#weechat
    nicklist irc.freenode.#weechat

### 3.6. input

Send data to a buffer.

Syntax:

    input <buffer> <data>

Arguments:

- buffer: pointer (0x12345) or full name of buffer (for example: core.weechat or irc.freenode.#weechat)

- data: data to send to buffer: if beginning by `/`, this will be executed as a command on buffer, otherwise text is sent as input of buffer

Examples:

    input core.weechat /help filter
    input irc.freenode.#weechat hello!

### 3.7. sync

Updated in version 0.4.1.

Synchronize one or more buffers, to get updates.

| It is recommended to send this command immediately after you asked data for buffers (lines, …​). It can be send in same message (after a new line char: "\n").

Syntax:

    sync [<buffer>[,<buffer>...] <option>[,<option>...]]

Arguments:

- buffer: pointer (0x12345) or full name of buffer (for example: core.weechat or irc.freenode.#weechat); name "*" can be used to specify all buffers

- options: one of following keywords, separated by commas (default is buffers,upgrade,buffer,nicklist for "*" and buffer,nicklist for a buffer):

  - buffers: receive signals about buffers (opened/closed, moved, renamed, merged/unmerged, hidden/unhidden); this can be used only with name "*" (WeeChat ≥ 0.4.1)

  - upgrade: receive signals about WeeChat upgrade (upgrade, upgrade ended); this can be used only with name "*" (WeeChat ≥ 0.4.1)

  - buffer: receive signals about buffer (new lines, type changed, title changed, local variable added/removed, and same signals as buffers for the buffer) (updated in version 0.4.1)

  - nicklist: receive nicklist after changes

Examples:

    # synchronize all buffers with nicklist
    # (the 3 commands are equivalent, but the first one is recommended
    # for compatibility with future versions)
    sync
    sync *
    sync * buffers,upgrade,buffer,nicklist

    # synchronize core buffer
    sync core.buffer

    # synchronize #weechat channel, without nicklist
    sync irc.freenode.#weechat buffer

    # get general signals + all signals for #weechat channel
    sync * buffers,upgrade
    sync irc.freenode.#weechat

### 3.8. desync

Updated in version 0.4.1.

Desynchronize one or more buffers, to stop updates.

| This will remove options for buffers. If some options are still active for buffers, the client will still receive updates for these buffers.

Syntax:

    desync [<buffer>[,<buffer>...] <option>[,<option>...]]

Arguments:

- buffer: pointer (0x12345) or full name of buffer (for example: core.weechat or irc.freenode.#weechat); name "*" can be used to specify all buffers

- options: one of following keywords, separated by commas (default is buffers,upgrade,buffer,nicklist for "*" and buffer,nicklist for a buffer); see command sync for values

| When using buffer "*", the other buffers synchronized (using a name) are kept. So if you send: "sync *", then "sync irc.freenode.#weechat", then "desync *", the updates on #weechat channel will still be sent by WeeChat (you must remove it explicitly to stop updates).

Examples:

    # desynchronize all buffers
    # (the 3 commands are equivalent, but the first one is recommended
    # for compatibility with future versions)
    desync
    desync *
    desync * buffers,upgrade,buffer,nicklist

    # desynchronize nicklist for #weechat channel (keep buffer updates)
    desync irc.freenode.#weechat nicklist

    # desynchronize #weechat channel
    desync irc.freenode.#weechat

### 3.9. test

Test command: WeeChat will reply with various different objects.

This command is useful to test the decoding of binary objects returned by WeeChat.

| You must not use the pointer values returned by this command, they are not valid. This command must be used only to test decoding of a message sent by WeeChat.

Syntax:

    test

Example:

    test

Returned objects (in this order):

Type | Type (in message) | Value
--- | --- | ---
char | `chr` | `65 ("A")`
integer | `int` | `123456`
integer | `int` | `-123456`
long | `lon` | `1234567890`
long | `lon` | `-1234567890`
string | `str` | `"a string"`
string | `str` | `""`
string | `str` | `NULL`
buffer | `buf` | `"buffer"`
buffer | `buf` | `NULL`
pointer | `ptr` | `0x1234abcd`
pointer | `ptr` | `NULL`
time | `tim` | `1321993456`
array of strings | `arr str` | `[ "abc", "de" ]`
array of integers | `arr int` | `[ 123, 456, 789 ]`

### 3.10. ping

WeeChat ≥ 0.4.2.

Send a ping to WeeChat which will reply with a message "_pong" and same arguments.

This command is useful to test that connection with WeeChat is still alive and measure the response time.

Syntax:

    ping [<arguments>]

Example:

    ping 1370802127000

### 3.11. quit

Disconnect from relay.

Syntax:

    quit

Example:

    quit

## 4. Messages (relay → client)

Messages are sent as binary data, using following format (with size in bytes):

    ┌────────╥─────────────╥────╥────────┬──────────╥───────╥────────┬──────────┐
    │ length ║ compression ║ id ║ type 1 │ object 1 ║  ...  ║ type N │ object N │
    └────────╨─────────────╨────╨────────┴──────────╨───────╨────────┴──────────┘
     └──────┘ └───────────┘ └──┘ └──────┘ └────────┘         └──────┘ └────────┘
         4          1        ??      3        ??                 3        ??
     └────────────────────┘ └──────────────────────────────────────────────────┘
           header (5)                        compressed data (??)
     └─────────────────────────────────────────────────────────────────────────┘
                                   _length_ bytes

- length (unsigned integer): number of bytes of whole message (including this field)

- compression (byte): flag:

  - 0x00: following data is not compressed

  - 0x01: following data is compressed with zlib

- id (string): identifier sent by client (before command name); it can be empty (string with zero length and no content) if no identifier was given in command

- type (3 chars): a type: 3 letters (see table below)

- object: an object (see table below)

### 4.1. Compression

If flag compression is equal to 0x01, then all data after is compressed with zlib, and therefore must be uncompressed before being processed.

### 4.2. Identifier

There are two types of identifiers (id):

- id sent by client: relay will answer with same id in its answer

- id of an event: on some events, relay will send message to client using a specific id, beginning with underscore (see table below)

WeeChat reserved identifiers:

Identifier | Received with sync | Data sent | Description | Recommended action in client
--- | --- | --- | --- | ---
`_buffer_opened` | buffers / buffer | hdata: buffer | Buffer opened. | Open buffer.
`_buffer_type_changed` | buffers / buffer | hdata: buffer | Type of buffer changed. | Change type of buffer.
`_buffer_moved` | buffers / buffer | hdata: buffer | Buffer moved. | Move buffer.
`_buffer_merged` | buffers / buffer | hdata: buffer | Buffer merged. | Merge buffer.
`_buffer_unmerged` | buffers / buffer | hdata: buffer | Buffer unmerged. | Unmerge buffer.
`_buffer_hidden` | buffers / buffer | hdata: buffer | Buffer hidden. | Hide buffer.
`_buffer_unhidden` | buffers / buffer | hdata: buffer | Buffer unhidden. | Unhide buffer.
`_buffer_renamed` | buffers / buffer | hdata: buffer | Buffer renamed. | Rename buffer.
`_buffer_title_changed` | buffers / buffer | hdata: buffer | Title of buffer changed. | Change title of buffer.
`_buffer_localvar_added` | buffers / buffer | hdata: buffer | Local variable added. | Add local variable in buffer.
`_buffer_localvar_changed` | buffers / buffer | hdata: buffer | Local variable changed. | Change local variable in buffer.
`_buffer_localvar_removed` | buffers / buffer | hdata: buffer | Local variable removed. | Remove local variable from buffer.
`_buffer_closing` | buffers / buffer | hdata: buffer | Buffer closing. | Close buffer.
`_buffer_cleared` | buffer | hdata: buffer | Buffer cleared. | Clear buffer.
`_buffer_line_added` | buffer | hdata: line | Line added in buffer. | Display line in buffer.
`_nicklist` | nicklist | hdata: nicklist_item | Nicklist for a buffer. | Replace nicklist.
`_nicklist_diff` | nicklist | hdata: nicklist_item | Nicklist diffs for a buffer . | Update nicklist.
`_pong` | (always) | string: ping arguments | Answer to a "ping". | Measure response time.
`_upgrade` | upgrade | (empty) | WeeChat is upgrading. | Desync from WeeChat (or disconnect).
`_upgrade_ended` | upgrade | (empty) | Upgrade of WeeChat done. | Sync/resync with WeeChat.

#### 4.2.1. _buffer_opened

This message is sent to the client when the signal "buffer_opened" is sent by WeeChat.

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`number` | integer | Buffer number (≥ 1).
`full_name` | string | Full name (example: irc.freenode.#weechat).
`short_name` | string | Short name (example: #weechat).
`nicklist` | integer | 1 if buffer has a nicklist, otherwise 0.
`title` | string | Buffer title.
`local_variables` | hashtable | Local variables.
`prev_buffer` | pointer | Pointer to previous buffer.
`next_buffer` | pointer | Pointer to next buffer.

Example: channel #weechat joined on freenode, new buffer irc.freenode.#weechat:

    id: '_buffer_opened'
    hda:
      keys: {'number': 'int', 'full_name': 'str', 'short_name': 'str', 'nicklist': 'int',
             'title': 'str', 'local_variables': 'htb', 'prev_buffer': 'ptr', 'next_buffer': 'ptr'}
      path: ['buffer']
      item 1:
        __path: ['0x35a8a60']
        number: 3
        full_name: 'irc.freenode.#weechat'
        short_name: None
        nicklist: 0
        title: None
        local_variables: {'plugin': 'irc', 'name': 'freenode.#weechat'}
        prev_buffer: '0x34e7400'
        next_buffer: '0x0'

#### 4.2.2. _buffer_moved

This message is sent to the client when the signal "buffer_moved" is sent by WeeChat.

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`number` | integer | Buffer number (≥ 1).
`full_name` | string | Full name (example: irc.freenode.#weechat).
`prev_buffer` | pointer | Pointer to previous buffer.
`next_buffer` | pointer | Pointer to next buffer.

Example: buffer irc.freenode.#weechat moved to number 2:

    id: '_buffer_moved'
    hda:
      keys: {'number': 'int', 'full_name': 'str', 'prev_buffer': 'ptr', 'next_buffer': 'ptr'}
      path: ['buffer']
      item 1:
        __path: ['0x34588c0']
        number: 2
        full_name: 'irc.freenode.#weechat'
        prev_buffer: '0x347b9f0'
        next_buffer: '0x3471bc0'

#### 4.2.3. _buffer_merged

This message is sent to the client when the signal "buffer_merged" is sent by WeeChat.

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`number` | integer | Buffer number (≥ 1).
`full_name` | string | Full name (example: irc.freenode.#weechat).
`prev_buffer` | pointer | Pointer to previous buffer.
`next_buffer` | pointer | Pointer to next buffer.

Example: buffer irc.freenode.#weechat merged with buffer #2:

    id: '_buffer_merged'
    hda:
      keys: {'number': 'int', 'full_name': 'str', 'prev_buffer': 'ptr', 'next_buffer': 'ptr'}
      path: ['buffer']
      item 1:
        __path: ['0x4db4c00']
        number: 2
        full_name: 'irc.freenode.#weechat'
        prev_buffer: '0x4cef9b0'
        next_buffer: '0x0'

#### 4.2.4. _buffer_unmerged

This message is sent to the client when the signal "buffer_unmerged" is sent by WeeChat.

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`number` | integer | Buffer number (≥ 1).
`full_name` | string | Full name (example: irc.freenode.#weechat).
`prev_buffer` | pointer | Pointer to previous buffer.
`next_buffer` | pointer | Pointer to next buffer.

Example: buffer irc.freenode.#weechat unmerged:

    id: '_buffer_unmerged'
    hda:
      keys: {'number': 'int', 'full_name': 'str', 'prev_buffer': 'ptr', 'next_buffer': 'ptr'}
      path: ['buffer']
      item 1:
        __path: ['0x4db4c00']
        number: 3
        full_name: 'irc.freenode.#weechat'
        prev_buffer: '0x4cef9b0'
        next_buffer: '0x0'

#### 4.2.5. _buffer_hidden

WeeChat ≥ 1.0.

This message is sent to the client when the signal "buffer_hidden" is sent by WeeChat.

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`number` | integer | Buffer number (≥ 1).
`full_name` | string | Full name (example: irc.freenode.#weechat).
`prev_buffer` | pointer | Pointer to previous buffer.
`next_buffer` | pointer | Pointer to next buffer.

Example: buffer irc.freenode.#weechat hidden:

    id: '_buffer_hidden'
    hda:
      keys: {'number': 'int', 'full_name': 'str', 'prev_buffer': 'ptr', 'next_buffer': 'ptr'}
      path: ['buffer']
      item 1:
        __path: ['0x4db4c00']
        number: 2
        full_name: 'irc.freenode.#weechat'
        prev_buffer: '0x4cef9b0'
        next_buffer: '0x0'

#### 4.2.6. _buffer_unhidden

WeeChat ≥ 1.0.

This message is sent to the client when the signal "buffer_unhidden" is sent by WeeChat.

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`number` | integer | Buffer number (≥ 1).
`full_name` | string | Full name (example: irc.freenode.#weechat).
`prev_buffer` | pointer | Pointer to previous buffer.
`next_buffer` | pointer | Pointer to next buffer.

Example: buffer irc.freenode.#weechat unhidden:

    id: '_buffer_unhidden'
    hda:
      keys: {'number': 'int', 'full_name': 'str', 'prev_buffer': 'ptr', 'next_buffer': 'ptr'}
      path: ['buffer']
      item 1:
        __path: ['0x4db4c00']
        number: 3
        full_name: 'irc.freenode.#weechat'
        prev_buffer: '0x4cef9b0'
        next_buffer: '0x0'

#### 4.2.7. _buffer_renamed

This message is sent to the client when the signal "buffer_renamed" is sent by WeeChat.

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`number` | integer | Buffer number (≥ 1).
`full_name` | string | Full name (example: irc.freenode.#weechat).
`short_name` | string | Short name (example: #weechat).
`local_variables` | hashtable | Local variables.

Example: private buffer renamed from FlashCode to Flash2:

    id: '_buffer_renamed'
    hda:
      keys: {'number': 'int', 'full_name': 'str', 'short_name': 'str', 'local_variables': 'htb'}
      path: ['buffer']
      item 1:
        __path: ['0x4df7b80']
        number: 5
        full_name: 'irc.freenode.Flash2'
        short_name: 'Flash2'
        local_variables: {'server': 'freenode', 'plugin': 'irc', 'type': 'private',
                          'channel': 'FlashCode', 'nick': 'test', 'name': 'local.Flash2'}

#### 4.2.8. _buffer_title_changed

This message is sent to the client when the signal "buffer_title_changed" is sent by WeeChat.

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`number` | integer | Buffer number (≥ 1).
`full_name` | string | Full name (example: irc.freenode.#weechat).
`title` | string | Buffer title.

Example: topic changed on channel #weechat:

    id: '_buffer_title_changed'
    hda:
      keys: {'number': 'int', 'full_name': 'str', 'title': 'str'}
      path: ['buffer']
      item 1:
        __path: ['0x4a715d0']
        number: 3
        full_name: 'irc.freenode.#weechat'
        title: 'Welcome on #weechat!  https://weechat.org/'

#### 4.2.9. _buffer_cleared

WeeChat ≥ 1.0.

This message is sent to the client when the signal "buffer_cleared" is sent by WeeChat.

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`number` | integer | Buffer number (≥ 1).
`full_name` | string | Full name (example: irc.freenode.#weechat).

Example: buffer irc.freenode.#weechat has been cleared:

    id: '_buffer_cleared'
    hda:
      keys: {'number': 'int', 'full_name': 'str'}
      path: ['buffer']
      item 1:
        __path: ['0x4a715d0']
        number: 3
        full_name: 'irc.freenode.#weechat'

#### 4.2.10. _buffer_type_changed

This message is sent to the client when the signal "buffer_type_changed" is sent by WeeChat.

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`number` | integer | Buffer number (≥ 1).
`full_name` | string | Full name (example: irc.freenode.#weechat).
`type` | integer | Buffer type: 0 = formatted (default), 1 = free content.

Example: type of buffer script.scripts changed from formatted (0) to free content (1):

    id: '_buffer_type_changed'
    hda:
      keys: {'number': 'int', 'full_name': 'str', 'type': 'int'}
      path: ['buffer']
      item 1:
        __path: ['0x27c9a70']
        number: 4
        full_name: 'script.scripts'
        type: 1

#### 4.2.11. _buffer_localvar_added

This message is sent to the client when the signal "buffer_localvar_added" is sent by WeeChat.

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`number` | integer | Buffer number (≥ 1).
`full_name` | string | Full name (example: irc.freenode.#weechat).
`local_variables` | hashtable | Local variables.

Example: local variable test added in buffer irc.freenode.#weechat:

    id='_buffer_localvar_added', objects:
    hda:
      keys: {'number': 'int', 'full_name': 'str', 'local_variables': 'htb'}
      path: ['buffer']
      item 1:
        __path: ['0x4a73de0']
        number: 3
        full_name: 'irc.freenode.#weechat'
        local_variables: {'server': 'freenode', 'test': 'value', 'plugin': 'irc',
                          'type': 'channel', 'channel': '#weechat', 'nick': 'test',
                          'name': 'freenode.#weechat'}

#### 4.2.12. _buffer_localvar_changed

This message is sent to the client when the signal "buffer_localvar_changed" is sent by WeeChat.

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`number` | integer | Buffer number (≥ 1).
`full_name` | string | Full name (example: irc.freenode.#weechat).
`local_variables` | hashtable | Local variables.

Example: local variable test updated in buffer irc.freenode.#weechat:

    id='_buffer_localvar_changed', objects:
    hda:
      keys: {'number': 'int', 'full_name': 'str', 'local_variables': 'htb'}
      path: ['buffer']
      item 1:
        __path: ['0x4a73de0']
        number: 3
        full_name: 'irc.freenode.#weechat'
        local_variables: {'server': 'local', 'test': 'value2', 'plugin': 'irc',
                          'type': 'channel', 'channel': '#weechat', 'nick': 'test',
                          'name': 'freenode.#weechat'}

#### 4.2.13. _buffer_localvar_removed

This message is sent to the client when the signal "buffer_localvar_removed" is sent by WeeChat.

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`number` | integer | Buffer number (≥ 1).
`full_name` | string | Full name (example: irc.freenode.#weechat).
`local_variables` | hashtable | Local variables.

Example: local variable test removed from buffer irc.freenode.#weechat:

    id: '_buffer_localvar_removed'
    hda:
      keys: {'number': 'int', 'full_name': 'str', 'local_variables': 'htb'}
      path: ['buffer']
      item 1:
        __path: ['0x4a73de0']
        number: 3
        full_name: 'irc.freenode.#prout'
        local_variables: {'server': 'local', 'plugin': 'irc', 'type': 'channel',
                          'channel': '#weechat', 'nick': 'test', 'name': 'freenode.#weechat'}

#### 4.2.14. _buffer_line_added

This message is sent to the client when the signal "buffer_line_added" is sent by WeeChat.

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`buffer` | pointer | Buffer pointer.
`date` | time | Date of message.
`date_printed` | time | Date when WeeChat displayed message.
`displayed` | char | 1 if message is displayed, 0 if message is filtered (hidden).
`highlight` | char | 1 if line has a highlight, otherwise 0.
`tags_array` | array of strings | List of tags for line.
`prefix` | string | Prefix.
`message` | string | Message.

Example: new message hello! from nick FlashCode on buffer irc.freenode.#weechat:

    id: '_buffer_line_added'
    hda:
      keys: {'buffer': 'ptr', 'date': 'tim', 'date_printed': 'tim', 'displayed': 'chr',
             'highlight': 'chr', 'tags_array': 'arr', 'prefix': 'str', 'message': 'str'}
      path: ['line_data']
      item 1:
        __path: ['0x4a49600']
        buffer: '0x4a715d0'
        date: 1362728993
        date_printed: 1362728993
        displayed: 1
        highlight: 0
        tags_array: ['irc_privmsg', 'notify_message', 'prefix_nick_142', 'nick_FlashCode', 'log1']
        prefix: 'F06@F@00142FlashCode'
        message: 'hello!'

#### 4.2.15. _buffer_closing

This message is sent to the client when the signal "buffer_closing" is sent by WeeChat.

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`number` | integer | Buffer number (≥ 1).
`full_name` | string | Full name (example: irc.freenode.#weechat).

Example: buffer irc.freenode.#weechat is being closed by WeeChat:

    id: '_buffer_closing'
    hda:
      keys: {'number': 'int', 'full_name': 'str'}
      path: ['buffer']
      item 1:
        __path: ['0x4a715d0']
        number: 3
        full_name: 'irc.freenode.#weechat'

#### 4.2.16. _nicklist

This message is sent to the client when large updates are made on a nicklist (groups/nicks added/removed/changed). The message contains full nicklist.

When small updates are made on a nicklist (for example just add one nick), another message with identifier _nicklist_diff is sent (see below).

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`group` | char | 1 for a group, 0 for a nick.
`visible` | char | 1 if group/nick is displayed, otherwise 0.
`level` | integer | Level of group (0 for a nick).
`name` | string | Name of group/nick.
`color` | string | Name color.
`prefix` | string | Prefix (only for a nick).
`prefix_color` | string | Prefix color (only for a nick).

Example: nicklist for buffer irc.freenode.#weechat:

    id: '_nicklist'
    hda:
      keys: {'group': 'chr', 'visible': 'chr', 'level': 'int', 'name': 'str', 'color': 'str',
             'prefix': 'str', 'prefix_color': 'str'}
      path: ['buffer', 'nicklist_item']
      item 1:
        __path: ['0x4a75cd0', '0x31e95d0']
        group: 1
        visible: 0
        level: 0
        name: 'root'
        color: None
        prefix: None
        prefix_color: None
      item 2:
        __path: ['0x4a75cd0', '0x41247b0']
        group: 1
        visible: 1
        level: 1
        name: '000|o'
        color: 'weechat.color.nicklist_group'
        prefix: None
        prefix_color: None
      item 3:
        __path: ['0x4a75cd0', '0x4a60d20']
        group: 0
        visible: 1
        level: 0
        name: 'FlashCode'
        color: '142'
        prefix: '@'
        prefix_color: 'lightgreen'
      item 4:
        __path: ['0x4a75cd0', '0x4aafaf0']
        group: 1
        visible: 1
        level: 1
        name: '001|v'
        color: 'weechat.color.nicklist_group'
        prefix: None
        prefix_color: None
      item 5:
        __path: ['0x4a75cd0', '0x4a48d80']
        group: 1
        visible: 1
        level: 1
        name: '999|...'
        color: 'weechat.color.nicklist_group'
        prefix: None
        prefix_color: None
      item 6:
        __path: ['0x4a75cd0', '0x4a5f560']
        group: 0
        visible: 1
        level: 0
        name: 'test'
        color: 'weechat.color.chat_nick_self'
        prefix: ' '
        prefix_color: ''

#### 4.2.17. _nicklist_diff

WeeChat ≥ 0.4.1.

This message is sent to the client when small updates are made on a nicklist (groups/nicks added/removed/changed). The message contains nicklist differences (between old nicklist and current one).

Data sent as hdata:

Name | Type | Description
--- | --- | ---
`_diff` | char | Type of diff (see below).
`group` | char | 1 for a group, 0 for a nick.
`visible` | char | 1 if group/nick is displayed, otherwise 0.
`level` | integer | Level of group (0 for a nick).
`name` | string | Name of group/nick.
`color` | string | Name color.
`prefix` | string | Prefix (only for a nick).
`prefix_color` | string | Prefix color (only for a nick).

The value of _diff can be:

- `^`: the parent group: group(s) or nick(s) after this one are related to this group

- `+`: group/nick added in the parent group

- `-`: group/nick removed from the parent group

- `*`: group/nick updated in the parent group

Example: nick master added in group 000|o (channel ops on an IRC channel), nicks nick1 and nick2 added in group 999|…​ (standard users on an IRC channel):

    id: '_nicklist_diff'
    hda:
      keys: {'_diff': 'chr', 'group': 'chr', 'visible': 'chr', 'level': 'int', 'name': 'str',
             'color': 'str', 'prefix': 'str', 'prefix_color': 'str'}
      path: ['buffer', 'nicklist_item']
      item 1:
        __path: ['0x46f2ee0', '0x343c9b0']
        _diff: 94 ('^')
        group: 1
        visible: 1
        level: 1
        name: '000|o'
        color: 'weechat.color.nicklist_group'
        prefix: None
        prefix_color: None
      item 2:
        __path: ['0x46f2ee0', '0x47e7f60']
        _diff: 43 ('+')
        group: 0
        visible: 1
        level: 0
        name: 'master'
        color: 'magenta'
        prefix: '@'
        prefix_color: 'lightgreen'
      item 3:
        __path: ['0x46f2ee0', '0x46b8e70']
        _diff: 94 ('^')
        group: 1
        visible: 1
        level: 1
        name: '999|...'
        color: 'weechat.color.nicklist_group'
        prefix: None
        prefix_color: None
      item 4:
        __path: ['0x46f2ee0', '0x3dba240']
        _diff: 43 ('+')
        group: 0
        visible: 1
        level: 0
        name: 'nick1'
        color: 'green'
        prefix: ' '
        prefix_color: ''
      item 5:
        __path: ['0x46f2ee0', '0x3c379d0']
        _diff: 43 ('+')
        group: 0
        visible: 1
        level: 0
        name: 'nick2'
        color: 'lightblue'
        prefix: ' '
        prefix_color: ''

#### 4.2.18. _pong

WeeChat ≥ 0.4.2.

This message is sent to the client when relay receives a "ping" message.

Data sent as string: arguments received in the "ping" message.

The recommended action in client is to measure the response time and disconnect if it is high.

#### 4.2.19. _upgrade

WeeChat ≥ 0.3.8.

This message is sent to the client when WeeChat is starting upgrade process.

There is no data in the message.

The recommended action in client is to desynchronize from WeeChat (send command desync), or to disconnect from WeeChat (because after upgrade, all pointers will change).

| During WeeChat upgrade, the socket remains opened (except if connection uses SSL).

#### 4.2.20. _upgrade_ended

WeeChat ≥ 0.3.8.

This message is sent to the client when WeeChat has finished the upgrade process.

There is no data in the message.

The recommended action in client is to resynchronize with WeeChat: resend all commands sent on startup after the init.

### 4.3. Objects

Objects are identified by 3 letters, called type. Following types are used:

Type | Value | Length
--- | --- | ---
`chr` | Signed char | 1 byte
`int` | Signed integer | 4 bytes
`lon` | Signed long integer | 1 byte + length of integer as string
`str` | String | 4 bytes + length of string (without final \0)
`buf` | Buffer of bytes | 4 bytes + length of data
`ptr` | Pointer | 1 byte + length of pointer as string
`tim` | Time | 1 byte + length of time as string
`htb` | Hashtable | Variable
`hda` | Hdata content | Variable
`inf` | Info: name + content | Variable
`inl` | Infolist content | Variable
`arr` | Array of objects | 3 bytes (type) + number of objects + data

#### 4.3.1. Char

A signed char is stored as 1 byte.

Example:

    ┌────┐
    │ 41 │ ────► 65 (0x41: "A")
    └────┘

#### 4.3.2. Integer

A signed integer is stored as 4 bytes, encoded as big-endian format (most significant byte first).

Range: -2147483648 to 2147483647.

Examples:

    ┌────┬────┬────┬────┐
    │ 00 │ 01 │ E2 │ 40 │ ────► 123456
    └────┴────┴────┴────┘

    ┌────┬────┬────┬────┐
    │ FF │ FE │ 1D │ C0 │ ────► -123456
    └────┴────┴────┴────┘

#### 4.3.3. Long integer

A signed long integer is encoded as a string, with length on one byte.

Range: -9223372036854775808 to 9223372036854775807.

Examples:

    ┌────╥────┬────┬────┬────┬────┬────┬────┬────┬────┬────┐
    │ 0A ║ 31 │ 32 │ 33 │ 34 │ 35 │ 36 │ 37 │ 38 │ 39 │ 30 │ ────► 1234567890
    └────╨────┴────┴────┴────┴────┴────┴────┴────┴────┴────┘
     └──┘ └───────────────────────────────────────────────┘
    length '1'  '2'  '3'  '4'  '5'  '6'  '7'  '8'  '9'  '0'

    ┌────╥────┬────┬────┬────┬────┬────┬────┬────┬────┬────┬────┐
    │ 0B ║ 2D │ 31 │ 32 │ 33 │ 34 │ 35 │ 36 │ 37 │ 38 │ 39 │ 30 │ ────► -1234567890
    └────╨────┴────┴────┴────┴────┴────┴────┴────┴────┴────┴────┘
     └──┘ └────────────────────────────────────────────────────┘
    length '-'  '1'  '2'  '3'  '4'  '5'  '6'  '7'  '8'  '9'  '0'

#### 4.3.4. String

A string is a length (integer on 4 bytes) + content of string (without final \0).

Example:

    ┌────┬────┬────┬────╥────┬────┬────┬────┬────┐
    │ 00 │ 00 │ 00 │ 05 ║ 68 │ 65 │ 6C │ 6C │ 6F │ ────► "hello"
    └────┴────┴────┴────╨────┴────┴────┴────┴────┘
     └─────────────────┘ └──────────────────────┘
           length         'h'  'e'  'l'  'l'  'o'

An empty string has a length of zero:

    ┌────┬────┬────┬────┐
    │ 00 │ 00 │ 00 │ 00 │ ────► ""
    └────┴────┴────┴────┘
     └─────────────────┘
           length

A NULL string (NULL pointer in C) has a length of -1:

    ┌────┬────┬────┬────┐
    │ FF │ FF │ FF │ FF │ ────► NULL
    └────┴────┴────┴────┘
     └─────────────────┘
           length

#### 4.3.5. Buffer

Same format as string; content is just an array of bytes.

#### 4.3.6. Pointer

A pointer is encoded as string (hex), with length on one byte.

Example:

    ┌────╥────┬────┬────┬────┬────┬────┬────┬────┬────┐
    │ 09 ║ 31 │ 61 │ 32 │ 62 │ 33 │ 63 │ 34 │ 64 │ 35 │ ────► 0x1a2b3c4d5
    └────╨────┴────┴────┴────┴────┴────┴────┴────┴────┘
     └──┘ └──────────────────────────────────────────┘
    length '1'  'a'  '2'  'b'  '3'  'c'  '4'  'd'  '5'

A NULL pointer has a length of 1 with value 0:

    ┌────╥────┐
    │ 01 ║ 00 │ ────► NULL (0x0)
    └────╨────┘
     └──┘ └──┘
    length  0

#### 4.3.7. Time

A time (number of seconds) is encoded as a string, with length on one byte.

Example:

    ┌────╥────┬────┬────┬────┬────┬────┬────┬────┬────┬────┐
    │ 0A ║ 31 │ 33 │ 32 │ 31 │ 39 │ 39 │ 33 │ 34 │ 35 │ 36 │ ────► 1321993456
    └────╨────┴────┴────┴────┴────┴────┴────┴────┴────┴────┘
     └──┘ └───────────────────────────────────────────────┘
    length '1'  '3'  '2'  '1'  '9'  '9'  '3'  '4'  '5'  '6'

#### 4.3.8. Hashtable

A hashtable contains type for keys, type for values, number of items in hashtable (integer on 4 bytes), and then keys and values of items.

    ┌───────────┬─────────────┬───────╥───────┬─────────╥─────╥───────┬─────────┐
    │ type_keys │ type_values │ count ║ key 1 │ value 1 ║ ... ║ key N │ value N │
    └───────────┴─────────────┴───────╨───────┴─────────╨─────╨───────┴─────────┘

Example:

    ┌─────┬─────┬───╥──────┬─────╥──────┬─────┐
    │ str │ str │ 2 ║ key1 │ abc ║ key2 │ def │ ────► { 'key1' => 'abc',
    └─────┴─────┴───╨──────┴─────╨──────┴─────┘         'key2' => 'def' }
     └───┘ └───┘ └─┘ └──────────┘ └──────────┘
     type  type count   item 1       item 2
     keys values

#### 4.3.9. Hdata

A hdata contains a path with hdata names, list of keys, number of set of objects, and then set of objects (path with pointers, then objects).

    ┌────────┬──────┬───────╥────────┬─────────────────────╥──
    │ h-path │ keys │ count ║ p-path │ value 1 ... value N ║ ...
    └────────┴──────┴───────╨────────┴─────────────────────╨──

       ──╥────────┬─────────────────────╥─────┐
     ... ║ p-path │ value 1 ... value N ║ ... │
       ──╨────────┴─────────────────────╨─────┘

- h-path (string): path used to reach hdata (example: buffer/lines/line/line_data); the last element in path is the hdata returned

- keys (string): string with list of key:type (separated by commas), example: number:int,name:str

- count (integer): number of set of objects

- p-path: path with pointers to objects (number of pointers here is number of elements in path)

- values: list of values (number of values is number of keys returned for hdata)

Example of hdata with two buffers (weechat core and freenode server) and two keys (number and full_name):

    # command
    hdata buffer:gui_buffers(*) number,full_name

    # response
    ┌────────┬──────────────────────────┬───╥──
    │ buffer │ number:int,full_name:str │ 2 ║ ...
    └────────┴──────────────────────────┴───╨──
     └──────┘ └────────────────────────┘ └─┘
      h-path          keys              count

       ──╥─────────┬───┬──────────────╥─────────┬───┬────────────────────┐
     ... ║ 0x12345 │ 1 │ core.weechat ║ 0x6789a │ 2 │irc.server.freenode │
       ──╨─────────┴───┴──────────────╨─────────┴───┴────────────────────┘
          └──────────────────────────┘ └────────────────────────────────┘
                   buffer 1                        buffer 2

Example of hdata with lines of core buffer:

    # command
    hdata buffer:gui_buffers(*)/lines/first_line(*)/data

    # response
    ┌─────────────────────────────┬─────┬────╥──
    │ buffer/lines/line/line_data │ ... │ 50 ║ ...
    └─────────────────────────────┴─────┴────╨──
     └───────────────────────────┘ └───┘ └──┘
          h-path (hdata names)     keys  count

       ──╥───────────┬───────────┬───────────┬───────╥──
     ... ║ 0x23cf970 │ 0x23cfb60 │ 0x23d5f40 │ ..... ║ ...
       ──╨───────────┴───────────┴───────────┴───────╨──
          └─────────────────────────────────┘ └─────┘
                   p-path (pointers)          objects
          └─────────────────────────────────────────┘
                             line 1

       ──╥───────────┬───────────┬───────────┬───────╥──────────────┐
     ... ║ 0x23cf970 │ 0x23cfb60 │ 0x23d6110 │ ..... ║ ............ │
       ──╨───────────┴───────────┴───────────┴───────╨──────────────┘
          └─────────────────────────────────┘ └─────┘
                   p-path (pointers)          objects
          └─────────────────────────────────────────┘ └────────────┘
                             line 2                     lines 3-50

Example of hdata with nicklist:

    # command
    nicklist

    # response
    ┌───────────────────┬──
    │ buffer/nick_group │ ...
    └───────────────────┴──
     └─────────────────┘
            h-path

       ──╥───────────────────────────────────────────────────────────┬────╥──
     ... ║ group:chr,visible:chr,name:str,color:str,prefix:str,(...) │ 12 ║ ...
       ──╨───────────────────────────────────────────────────────────┴────╨──
          └─────────────────────────────────────────────────────────┘ └──┘
                                     keys                             count

       ──╥─────────┬─────────┬───┬───┬──────┬─┬─┬─┬───╥──
     ... ║ 0x12345 │ 0x6789a │ 1 │ 0 │ root │ │ │ │ 0 ║ ...
       ──╨─────────┴─────────┴───┴───┴──────┴─┴─┴─┴───╨──
          └─────────────────┘ └──────────────────────┘
                 p-path               objects
          └──────────────────────────────────────────┘
                      group (nicklist root)

       ──╥─────────┬─────────┬───┬───┬───────┬─┬─┬─┬───╥──
     ... ║ 0x123cf │ 0x678d4 │ 1 │ 0 │ 000|o │ │ │ │ 1 ║ ...
       ──╨─────────┴─────────┴───┴───┴───────┴─┴─┴─┴───╨──
          └─────────────────┘ └───────────────────────┘
                 p-path                objects
          └───────────────────────────────────────────┘
                        group (channel ops)

       ──╥─────────┬─────────┬───┬───┬──────────┬──────┬───┬────────────┬───╥──
     ... ║ 0x128a7 │ 0x67ab2 │ 0 │ 1 │ ChanServ │ blue │ @ │ lightgreen │ 0 ║ ...
       ──╨─────────┴─────────┴───┴───┴──────────┴──────┴───┴────────────┴───╨──
          └─────────────────┘ └────────────────────────────────────────────┘
                 p-path                          objects
          └────────────────────────────────────────────────────────────────┘
                                   nick (@ChanServ)

Example of empty hdata (hotlist is empty in WeeChat):

    # command
    hdata hotlist:gui_hotlist(*)

    # response
    ┌────────┬────────┬───┐
    │ (NULL) │ (NULL) │ 0 │
    └────────┴────────┴───┘
     └──────┘ └──────┘ └─┘
      h-path    keys  count

#### 4.3.10. Info

A info contains a name and a value (both are strings).

    ┌──────┬───────┐
    │ name │ value │
    └──────┴───────┘

- name (string): name of info

- value (string): value

Example of info version:

    ┌─────────┬───────────────────┐
    │ version │ WeeChat 0.3.7-dev │
    └─────────┴───────────────────┘

#### 4.3.11. Infolist

A infolist contains a name, number of items, and then items (set of variables).

    ┌──────┬───────╥────────╥─────╥────────┐
    │ name │ count ║ item 1 ║ ... ║ item N │
    └──────┴───────╨────────╨─────╨────────┘

An item is:

    ┌───────╥────────┬────────┬─────────╥─────╥────────┬────────┬─────────┐
    │ count ║ name 1 │ type 1 │ value 1 ║ ... ║ name N │ type N │ value N │
    └───────╨────────┴────────┴─────────╨─────╨────────┴────────┴─────────┘

- name (string): name of infolist (buffer, window, bar, …​)

- count (integer): number of items

- item:

  - count: number of variables in item

  - name: name of variable

  - type: type of variable (int, str, …​)

  - value: value of variable

Example of infolist with two buffers (weechat core and freenode server):

    # command
    infolist buffer

    # response
    ┌────────┬───╥────┬─────────┬─────┬─────────┬─────╥──
    │ buffer │ 2 ║ 42 │ pointer │ ptr │ 0x12345 │ ... ║ ...
    └────────┴───╨────┴─────────┴─────┴─────────┴─────╨──
     └──────┘ └─┘ └──────────────────────────────────┘
       name  count              item 1

       ──╥────┬─────────┬─────┬─────────┬─────┐
     ... ║ 42 │ pointer │ ptr │ 0x6789a │ ... │
       ──╨────┴─────────┴─────┴─────────┴─────┘
          └──────────────────────────────────┘
                        item 2

#### 4.3.12. Array

An array is a type (3 bytes) + number of objects (integer on 4 bytes) + data.

Example of array with two strings:

    ┌─────╥────┬────┬────┬────╥────┬────┬────┬────╥──
    │ str ║ 00 │ 00 │ 00 │ 02 ║ 00 │ 00 │ 00 │ 03 ║ ...
    └─────╨────┴────┴────┴────╨────┴────┴────┴────╨──
     └───┘ └─────────────────┘ └─────────────────┘
     type   number of strings        length

       ──╥────┬────┬────╥────┬────┬────┬────╥────┬────┐
     ... ║ 61 │ 62 │ 63 ║ 00 │ 00 │ 00 │ 02 ║ 64 │ 65 │ ────► [ "abc", "de" ]
       ──╨────┴────┴────╨────┴────┴────┴────╨────┴────┘
          └────────────┘ └─────────────────┘ └───────┘
           'a'  'b'  'c'       length         'd'  'e'

Example of array with three integers:

    ┌─────╥────┬────┬────┬────╥────┬────┬────┬────╥──
    │ int ║ 00 │ 00 │ 00 │ 03 ║ 00 │ 00 │ 00 │ 7B ║ ...
    └─────╨────┴────┴────┴────╨────┴────┴────┴────╨──
     └───┘ └─────────────────┘ └─────────────────┘
     type   number of integers      123 (0x7B)

       ──╥────┬────┬────┬────╥────┬────┬────┬────┐
     ... ║ 00 │ 00 │ 01 │ C8 ║ 00 │ 00 │ 03 │ 15 │ ────► [ 123, 456, 789 ]
       ──╨────┴────┴────┴────╨────┴────┴────┴────┘
          └─────────────────┘ └─────────────────┘
              456 (0x1C8)         789 (0x315)

A NULL array:

    ┌─────╥────┬────┬────┬────┐
    │ str ║ 00 │ 00 │ 00 │ 00 │ ────► NULL
    └─────╨────┴────┴────┴────┘
     └───┘ └─────────────────┘
     type   number of strings

## 5. Typical session

        ┌────────┐                         ┌───────┐                ┌─────────┐
        │ Client ├ ─ ─ ─ ─(network)─ ─ ─ ─ ┤ Relay ├────────────────┤ WeeChat │
        └────────┘                         └───────┘                └─────────┘
             ║                                 ║                         ║
             ╟───────────────────────────────► ║                         ║
             ║ open socket                     ║ add client              ║
             ║                                 ║                         ║
             ╟───────────────────────────────► ║                         ║
             ║ cmd: init password=xxx,...      ║ init/allow client       ║
             ║                                 ║                         ║
             ╟───────────────────────────────► ║                         ║
             ║ cmd: hdata buffer ...           ╟───────────────────────► ║
             ║      sync ...                   ║ request hdata           ║ read hdata
             ║                                 ║                         ║ values
             ║                                 ║ ◄───────────────────────╢
             ║ ◄───────────────────────────────╢                   hdata ║
      create ║                 msg: hda buffer ║                         ║
     buffers ║                                 ║                         ║
             ║            ........             ║         ........        ║
             ║                                 ║                         ║
             ╟───────────────────────────────► ║                         ║
             ║ cmd: input ...                  ╟───────────────────────► ║
             ║                                 ║ send data to buffer     ║ send data
             ║                                 ║                         ║ to buffer
             ║            ........             ║         ........        ║
             ║                                 ║                         ║ signal
             ║                                 ║ ◄───────────────────────╢ received
             ║ ◄───────────────────────────────╢              signal XXX ║ (hooked by
     update  ║          msg: id: "_buffer_..." ║                         ║ relay)
     buffers ║                                 ║                         ║
             ║            ........             ║         ........        ║
             ║                                 ║                         ║
             ╟───────────────────────────────► ║                         ║
             ║ cmd: ping ...                   ║                         ║
             ║                                 ║                         ║
             ║ ◄───────────────────────────────╢                         ║
     measure ║            msg: id: "_pong" ... ║                         ║
    response ║                                 ║                         ║
        time ║            ........             ║         ........        ║
             ║                                 ║                         ║
             ╟───────────────────────────────► ║                         ║
             ║ cmd: quit                       ║ disconnect client       ║
             ║                                 ║                         ║