Author: Sébastien Helleu

# WeeChat Relay protocol

Sébastien Helleu
flashcode@flashtux.org
version 4.1.2

## 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, macOS ...)
     └────────┘   └──╢           │       ║◄───┘   ┌──────────┐
       ......        ║  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
--- | ---
`handshake` | Handshake: prepare client authentication and set options, before init command.
`init` | Authenticate 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).
`completion` | Request completion of a string.
`sync` | Synchronize buffer(s): get updates for buffer(s).
`desync` | Desynchronize buffer(s): stop updates for buffer(s).
`quit` | Disconnect from relay.

### 3.1. handshake

WeeChat ≥ 2.9, updated in versions 3.5, 4.0.0.

Perform an handshake between the client and WeeChat: this is required in most cases to know the session settings and prepare the authentication with the init command.

Only one handshake is allowed before the init command.

Syntax:

    (id) handshake [<option>=<value>,[<option>=<value>,...]]

Arguments:

- option: one of following options:

  - password_hash_algo: list of hash algorithms supported by the client (separated by colons), allowed values are:

    - plain: plain text password (no hash)

    - sha256: password salted and hashed with SHA256 algorithm

    - sha512: password salted and hashed with SHA512 algorithm

    - pbkdf2+sha256: password salted and hashed with PBKDF2 algorithm (using SHA256 hash)

    - pbkdf2+sha512: password salted and hashed with PBKDF2 algorithm (using SHA512 hash)

  - compression: list of supported compression types supported by the client (separated by colons and sorted from most important to the fallback value); if compression is enabled, messages from relay to client are compressed to save bandwidth; allowed values are:

    - off: no compression (default if option is not given)

    - zlib: compress with zlib ↗ (WeeChat ≥ 0.3.7)

    - zstd: compress with Zstandard ↗: better compression and much faster than zlib for both compression and decompression (WeeChat ≥ 3.5)

  - escape_commands: commands sent by the client to relay must be escaped: all backslashes are interpreted and a single backslash must be escaped (`\\`); this allows for example the client to send multiline messages (chars `\n` are converted to newlines, see input command) (WeeChat ≥ 4.0.0)

Notes about option password_hash_algo:

- If the option is not given (or if the handshake command is not sent by the client), relay uses automatically plain authentication (if allowed on relay side).

- Relay chooses the most secure algorithm available on both client and relay, by order of priority from first (most secure) to last used:

  1. pbkdf2+sha512

  2. pbkdf2+sha256

  3. sha512

  4. sha256

  5. plain

WeeChat replies with a hashtable containing the following keys and values:

- password_hash_algo: the password authentication negotiated: supported by both the client and relay:

  - (empty value): negotiation failed, password authentication is NOT possible; in this case the connection with the client is immediately closed

  - plain

  - sha256

  - sha512

  - pbkdf2+sha256

  - pbkdf2+sha512

- password_hash_iterations: number of iterations for hash (for the PBKDF2 algorithm only)

- totp:

  - on: Time-based One-Time Password (TOTP) is configured and expected in the init command

  - off: Time-based One-Time Password (TOTP) is not enabled and not needed in the init command

- nonce: a buffer of unpredictable bytes, sent as hexadecimal, to prevent replay attacks; if password_hash_algo is a hash algorithm, the client must compute the hash of password on this nonce, concatenated with a client nonce and the user password (the relay nonce + the client nonce is the salt used in the password hash algorithm)

- compression: compression type:

  - off: messages are not compressed

  - zlib: messages are compressed with zlib ↗

  - zstd: messages are compressed with Zstandard ↗

- escape_commands:

  - on: all backslashes are interpreted in the client messages

  - off: backslashes are NOT interpreted in the client messages and used as-is

| With WeeChat ≤ 2.8, the command handshake is not implemented, WeeChat silently ignores this command, even if it is sent before the init command. So it is safe to send this command to any WeeChat version.

Examples:

- Nothing offered by the client, authentication password "plain" will be used if allowed on relay side:

    (handshake) handshake

Response:

    id: 'handshake'
    htb: {
        'password_hash_algo': 'plain',
        'password_hash_iterations': '100000',
        'totp': 'on',
        'nonce': '85B1EE00695A5B254E14F4885538DF0D',
        'compression': 'off',
        'escape_commands': 'off',
    }

- Escape of commands enabled by the client (WeeChat ≥ 4.0.0):

    (handshake) handshake escape_commands=on

Response:

    id: 'handshake'
    htb: {
        'password_hash_algo': 'plain',
        'password_hash_iterations': '100000',
        'totp': 'on',
        'nonce': '85B1EE00695A5B254E14F4885538DF0D',
        'compression': 'off',
        'escape_commands': 'on',
    }

- Only "plain" is supported by the client:

    (handshake) handshake password_hash_algo=plain

Response:

    id: 'handshake'
    htb: {
        'password_hash_algo': 'plain',
        'password_hash_iterations': '100000',
        'totp': 'on',
        'nonce': '85B1EE00695A5B254E14F4885538DF0D',
        'compression': 'off',
        'escape_commands': 'off',
    }

- Only "plain", "sha256" and "pbkdf2+sha256" are supported by the client:

    (handshake) handshake password_hash_algo=plain:sha256:pbkdf2+sha256

Response:

    id: 'handshake'
    htb: {
        'password_hash_algo': 'pbkdf2+sha256',
        'password_hash_iterations': '100000',
        'totp': 'on',
        'nonce': '85B1EE00695A5B254E14F4885538DF0D',
        'compression': 'off',
        'escape_commands': 'off',
    }

The client can authenticate with this command (see init command), the salt is the relay nonce + client nonce ("A4B73207F5AAE4" in hexadecimal), the password is "test" in this example:

    init password_hash=pbkdf2+sha256:85b1ee00695a5b254e14f4885538df0da4b73207f5aae4:100000:ba7facc3edb89cd06ae810e29ced85980ff36de2bb596fcf513aaab626876440

- Only "sha256" and "sha512" are supported by the client, enable zstd (preferred) or zlib compression:

    (handshake) handshake password_hash_algo=sha256:sha512,compression=zstd:zlib

Response:

    id: 'handshake'
    htb: {
        'password_hash_algo': 'sha512',
        'password_hash_iterations': '100000',
        'totp': 'on',
        'nonce': '85B1EE00695A5B254E14F4885538DF0D',
        'compression': 'zstd',
        'escape_commands': 'off',
    }

### 3.2. init

Updated in versions 2.4, 2.8, 2.9, 3.5.

Authenticate with relay.

This must be first command sent to relay (only handshake command can be sent before init).
If not sent, relay will close connection on first command received (except handshake), without warning.

Syntax:

    (id) init [<option>=<value>,[<option>=<value>,...]]

Arguments:

- option: one of following options:

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

  - password_hash: hash of password used to authenticate on relay (option relay.network.password in WeeChat), see below for the format (WeeChat ≥ 2.8)

  - totp: Time-based One-Time Password (TOTP) used as secondary authentication factor, in addition to the password (option relay.network.totp_secret in WeeChat) (WeeChat ≥ 2.4)

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

Format of hashed password is one of the following, where hash is the hashed password as hexadecimal:

- `sha256:salt:hash` with:

  - salt: salt (hexadecimal), which must start with the server nonce, concatenated to the client nonce

  - hash: the hashed salt + password (hexadecimal)

- `sha512:salt:hash` with:

  - salt: salt (hexadecimal), which must start with the server nonce, concatenated to the client nonce

  - hash: the hashed salt + password (hexadecimal)

- `pbkdf2+sha256:salt:iterations:hash` with:

  - salt: salt (hexadecimal), which must start with the server nonce, concatenated to the client nonce

  - iterations: number of iterations

  - hash: the hashed salt + password with SHA256 algorithm (hexadecimal)

- `pbkdf2+sha512:salt:iterations:hash` with:

  - salt: salt (hexadecimal), which must start with the server nonce, concatenated to the client nonce

  - iterations: number of iterations

  - hash: the hashed salt + password with SHA512 algorithm (hexadecimal)

| Hexadecimal strings can be lower or upper case, relay can decode both.

Examples:

- Initialize with password:

    init password=mypass

- Initialize with commas in the password (WeeChat ≥ 1.6):

    init password=mypass\,with\,commas

- Initialize with password and TOTP (WeeChat ≥ 2.4):

    init password=mypass,totp=123456

- Initialize with hashed password "test" (SHA256: salt=relay nonce + client nonce) (WeeChat ≥ 2.9):

    init password_hash=sha256:85b1ee00695a5b254e14f4885538df0da4b73207f5aae4:2c6ed12eb0109fca3aedc03bf03d9b6e804cd60a23e1731fd17794da423e21db

- Initialize with hashed password "test" (SHA512: salt=relay nonce + client nonce) (WeeChat ≥ 2.9):

    init password_hash=sha512:85b1ee00695a5b254e14f4885538df0da4b73207f5aae4:0a1f0172a542916bd86e0cbceebc1c38ed791f6be246120452825f0d74ef1078c79e9812de8b0ab3dfaf598b6ca14522374ec6a8653a46df3f96a6b54ac1f0f8

- Initialize with hashed password "test" (PBKDF2: SHA256, salt=relay nonce + client nonce, 100000 iterations) (WeeChat ≥ 2.9):

    init password_hash=pbkdf2+sha256:85b1ee00695a5b254e14f4885538df0da4b73207f5aae4:100000:ba7facc3edb89cd06ae810e29ced85980ff36de2bb596fcf513aaab626876440

### 3.3. 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 (eg: "0x1234abcd") 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 "number" and "full_name" of all buffers:

    (hdata_buffers) hdata buffer:gui_buffers(*) number,full_name

Response:

    id: 'hdata_buffers'
    hda:
        keys: {
            'number': 'int',
            'full_name': 'str',
        }
        path: ['buffer']
        item 1:
            __path: ['0x558d61ea3e60']
            number: 1
            full_name: 'core.weechat'
        item 2:
            __path: ['0x558d62840ea0']
            number: 1
            full_name: 'irc.server.libera'
        item 3:
            __path: ['0x558d62a9cea0']
            number: 2
            full_name: 'irc.libera.#weechat'

- Request all lines of first buffer:

    (hdata_lines) hdata buffer:gui_buffers/own_lines/first_line(*)/data

Response:

    id: 'hdata_lines'
    hda:
        keys: {
            'buffer': 'ptr',
            'y': 'int',
            'date': 'tim',
            'date_printed': 'tim',
            'str_time': 'str',
            'tags_count': 'int',
            'tags_array': 'arr',
            'displayed': 'chr',
            'notify_level': 'chr',
            'highlight': 'chr',
            'refresh_needed': 'chr',
            'prefix': 'str',
            'prefix_length': 'int',
            'message': 'str',
        }
        path: ['buffer', 'lines', 'line', 'line_data']
        item 1:
            __path: ['0x558d61ea3e60', '0x558d61ea40e0', '0x558d62920d80', '0x558d62abf040']
            buffer: '0x558d61ea3e60'
            y: -1
            date: 1588404926
            date_printed: 1588404926
            str_time: 'F@0025209F@0024535F@0024026'
            tags_count: 0
            tags_array: []
            displayed: 1
            notify_level: 0
            highlight: 0
            refresh_needed: 0
            prefix: ''
            prefix_length: 0
            message: 'this is the first line'
        item 2:
            __path: ['0x558d61ea3e60', '0x558d61ea40e0', '0x558d626779f0', '0x558d62af9700']
            buffer: '0x558d61ea3e60'
            y: -1
            date: 1588404930
            date_printed: 1588404930
            str_time: 'F@0025209F@0024535F@0024030'
            tags_count: 0
            tags_array: []
            displayed: 1
            notify_level: 0
            highlight: 0
            refresh_needed: 0
            prefix: ''
            prefix_length: 0
            message: 'this is the second line'

- Request the hotlist content:

    (hdata_hotlist) hdata hotlist:gui_hotlist(*)

Response:

    id: 'hdata_hotlist'
    hda:
        keys: {
            'priority': 'int',
            'creation_time.tv_sec': 'tim',
            'creation_time.tv_usec': 'lon',
            'buffer': 'ptr',
            'count': 'arr',
            'prev_hotlist': 'ptr',
            'next_hotlist': 'ptr',
        }
        path: ['hotlist']
        item 1:
            __path: ['0x558d629601b0']
            priority: 3
            creation_time.tv_sec: 1588405398
            creation_time.tv_usec: 355383
            buffer: '0x558d62a9cea0'
            count: [1, 1, 0, 1]
            prev_hotlist: '0x0'
            next_hotlist: '0x0'

### 3.4. info

Request an info.

Syntax:

    (id) info <name> [<arguments>]

Arguments:

- name: name of info to retrieve

- arguments: arguments (optional)

Examples:

- Request WeeChat version:

    (info_version) info version

Response:

    id: 'info_version'
    inf: ('version', '2.9-dev')

- Request WeeChat version as number:

    (info_version_number) info version_number

Response:

    id: 'info_version_number'
    inf: ('version_number', '34144256')

- Request WeeChat directory:

    (info_weechat_config_dir) info weechat_config_dir

Response:

    id: 'info_weechat_config_dir'
    inf: ('weechat_config_dir', '/home/user/.config/weechat')

### 3.5. infolist

Request an infolist.

| Content of infolist is a duplication of actual data. Wherever possible, use hdata command, 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)

Examples:

- Request infolist "buffer":

    (infolist_buffer) infolist buffer

Response:

    id: 'infolist_buffer'
    inl:
        name: buffer
        item 1:
            pointer: '0x558d61ea3e60'
            current_buffer: 1
            plugin: '0x0'
            plugin_name: 'core'
            number: 1
            layout_number: 1
            layout_number_merge_order: 0
            name: 'weechat'
            full_name: 'core.weechat'
            old_full_name: None
            short_name: 'weechat'
            type: 0
            notify: 3
            num_displayed: 1
            active: 1
            hidden: 0
            zoomed: 0
            print_hooks_enabled: 1
            day_change: 1
            clear: 1
            filter: 1
            closing: 0
            first_line_not_read: 0
            lines_hidden: 0
            prefix_max_length: 0
            time_for_each_line: 1
            nicklist_case_sensitive: 0
            nicklist_display_groups: 1
            nicklist_max_length: 0
            nicklist_count: 0
            nicklist_groups_count: 0
            nicklist_nicks_count: 0
            nicklist_visible_count: 0
            title: 'WeeChat 2.9-dev (C) 2003-2020 - https://weechat.org/'
            input: 1
            input_get_unknown_commands: 0
            input_get_empty: 0
            input_multiline: 0
            input_buffer: ''
            input_buffer_alloc: 256
            input_buffer_size: 0
            input_buffer_length: 0
            input_buffer_pos: 0
            input_buffer_1st_display: 0
            num_history: 0
            text_search: 0
            text_search_exact: 0
            text_search_regex: 0
            text_search_regex_compiled: '0x0'
            text_search_where: 0
            text_search_found: 0
            text_search_input: None
            highlight_words: None
            highlight_disable_regex: None
            highlight_disable_regex_compiled: '0x0'
            highlight_regex: None
            highlight_regex_compiled: '0x0'
            highlight_tags_restrict: None
            highlight_tags: None
            hotlist_max_level_nicks: None
            keys_count: 0
            localvar_name_00000: 'plugin'
            localvar_value_00000: 'core'
            localvar_name_00001: 'name'
            localvar_value_00001: 'weechat'

- Request infolist "window":

    (infolist_window) infolist window

Response:

    id: 'infolist_window'
    inl:
        name: window
        item 1:
            pointer: '0x558d61ddc800'
            current_window: 1
            number: 1
            x: 14
            y: 0
            width: 259
            height: 71
            width_pct: 100
            height_pct: 100
            chat_x: 14
            chat_y: 1
            chat_width: 259
            chat_height: 68
            buffer: '0x558d61ea3e60'
            start_line_y: 0

### 3.6. nicklist

Request a nicklist, for one or all buffers.

Syntax:

    (id) nicklist [<buffer>]

Arguments:

- buffer: pointer (eg: "0x1234abcd") or full name of buffer (for example: core.weechat or irc.libera.#weechat)

Examples:

- Request nicklist for all buffers:

    (nicklist_all) nicklist

Response:

    id: 'nicklist_all'
    hda:
        keys: {
            'group': 'chr',
            'visible': 'chr',
            'level': 'int',
            'name': 'str',
            'color': 'str',
            'prefix': 'str',
            'prefix_color': 'str',
        }
        path: ['buffer', 'nicklist_item']
        item 1:
            __path: ['0x558d61ea3e60', '0x558d61ea4120']
            group: 1
            visible: 0
            level: 0
            name: 'root'
            color: None
            prefix: None
            prefix_color: None
        item 2:
            __path: ['0x558d62840ea0', '0x558d61e75f90']
            group: 1
            visible: 0
            level: 0
            name: 'root'
            color: None
            prefix: None
            prefix_color: None
        item 3:
            __path: ['0x558d62a9cea0', '0x558d62abf2e0']
            group: 1
            visible: 0
            level: 0
            name: 'root'
            color: None
            prefix: None
            prefix_color: None
        item 4:
            __path: ['0x558d62a9cea0', '0x558d62afb9d0']
            group: 1
            visible: 1
            level: 1
            name: '000|o'
            color: 'weechat.color.nicklist_group'
            prefix: None
            prefix_color: None
        item 5:
            __path: ['0x558d62a9cea0', '0x558d62aff930']
            group: 0
            visible: 1
            level: 0
            name: 'FlashCode'
            color: 'weechat.color.chat_nick_self'
            prefix: '@'
            prefix_color: 'lightgreen'
        item 6:
            __path: ['0x558d62a9cea0', '0x558d62af9930']
            group: 1
            visible: 1
            level: 1
            name: '001|v'
            color: 'weechat.color.nicklist_group'
            prefix: None
            prefix_color: None
        item 7:
            __path: ['0x558d62a9cea0', '0x558d62afc510']
            group: 1
            visible: 1
            level: 1
            name: '999|...'
            color: 'weechat.color.nicklist_group'
            prefix: None
            prefix_color: None
        item 8:
            __path: ['0x558d62a9cea0', '0x558d6292c290']
            group: 0
            visible: 1
            level: 0
            name: 'flashy'
            color: '142'
            prefix: ' '
            prefix_color: 'lightblue'
        item 9:
            __path: ['0x558d62914680', '0x558d62afc4b0']
            group: 1
            visible: 0
            level: 0
            name: 'root'
            color: None
            prefix: None
            prefix_color: None

- Request nicklist for buffer "irc.libera.#weechat":

    (nicklist_weechat) nicklist irc.libera.#weechat

Response:

    id: 'nicklist_weechat'
    hda:
        keys: {
            'group': 'chr',
            'visible': 'chr',
            'level': 'int',
            'name': 'str',
            'color': 'str',
            'prefix': 'str',
            'prefix_color': 'str',
        }
        path: ['buffer', 'nicklist_item']
        item 1:
            __path: ['0x558d62a9cea0', '0x558d62abf2e0']
            group: 1
            visible: 0
            level: 0
            name: 'root'
            color: None
            prefix: None
            prefix_color: None
        item 2:
            __path: ['0x558d62a9cea0', '0x558d62afb9d0']
            group: 1
            visible: 1
            level: 1
            name: '000|o'
            color: 'weechat.color.nicklist_group'
            prefix: None
            prefix_color: None
        item 3:
            __path: ['0x558d62a9cea0', '0x558d62aff930']
            group: 0
            visible: 1
            level: 0
            name: 'FlashCode'
            color: 'weechat.color.chat_nick_self'
            prefix: '@'
            prefix_color: 'lightgreen'
        item 4:
            __path: ['0x558d62a9cea0', '0x558d62af9930']
            group: 1
            visible: 1
            level: 1
            name: '001|v'
            color: 'weechat.color.nicklist_group'
            prefix: None
            prefix_color: None
        item 5:
            __path: ['0x558d62a9cea0', '0x558d62afc510']
            group: 1
            visible: 1
            level: 1
            name: '999|...'
            color: 'weechat.color.nicklist_group'
            prefix: None
            prefix_color: None
        item 6:
            __path: ['0x558d62a9cea0', '0x558d6292c290']
            group: 0
            visible: 1
            level: 0
            name: 'flashy'
            color: '142'
            prefix: ' '
            prefix_color: 'lightblue'

### 3.7. input

Send data to a buffer.

Syntax:

    (id) input <buffer> <data>

Arguments:

- buffer: pointer (eg: "0x1234abcd") or full name of buffer (for example: core.weechat or irc.libera.#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:

- Send command "/help filter" on WeeChat core bufer:

    input core.weechat /help filter

- Send message "hello!" to #weechat channel:

    input irc.libera.#weechat hello!

- Send multiline message to #test channel (option escape_commands must have been enabled in handshake command and requires WeeChat ≥ 4.0.0):

    input irc.ergo.#test this message has\n2 lines

### 3.8. completion

WeeChat ≥ 2.9.

Request completion of a string: list of possible words at a given position in a string for a given buffer.

Syntax:

    (id) completion <buffer> <position> [<data>]

Arguments:

- buffer: pointer (eg: "0x1234abcd") or full name of buffer (for example: core.weechat or irc.libera.#weechat)

- position: position for completion in string (starts to 0); if the value is -1, the position is the length of data (so the completion is made at the end of data)

- data: the input string; if not given, completion is performed on an empty string

WeeChat replies with a hdata:

Name | Type | Description
--- | --- | ---
`context` | string | Completion context: "null" (no completion), "command", "command_arg", "auto".
`base_word` | string | The base word used for completion.
`pos_start` | integer | Index of first char to replace (starts to 0).
`pos_end` | integer | Index of last char to replace (starts to 0).
`add_space` | integer | 1 if a space must be added after words, 0 otherwise.
`list` | array of strings | List of words found; empty if nothing was found to complete at asked position.

| In case of error, for example invalid buffer or internal error on WeeChat side, an empty hdata is returned.

Examples:

- Completion of a command argument:

    (completion_help) completion core.weechat -1 /help fi

Response:

    id: 'completion_help'
    hda:
        keys: {
            'context': 'str',
            'base_word': 'str',
            'pos_start': 'int',
            'pos_end': 'int',
            'add_space': 'int',
            'list': 'arr',
        }
        path: ['completion']
        item 1:
          __path: ['0x55d0ccc842c0']
          context: 'command_arg'
          base_word: 'fi'
          pos_start: 6
          pos_end: 7
          add_space: 0
          list: [
              'fifo',
              'fifo.file.enabled',
              'fifo.file.path',
              'filter',
          ]

- Completion of a command in the middle of a word:

    (completion_query) completion core.weechat 5 /quernick

Response:

    id: 'completion_query'
    hda:
        keys: {
            'context': 'str',
            'base_word': 'str',
            'pos_start': 'int',
            'pos_end': 'int',
            'add_space': 'int',
            'list': 'arr',
        }
        path: ['completion']
        item 1:
            __path: ['0x55d0ccc88470']
            context: 'command'
            base_word: 'quer'
            pos_start: 1
            pos_end: 4
            add_space: 1
            list: ['query']

- Nothing to complete:

    (completion_abcdefghijkl) completion core.weechat -1 abcdefghijkl

Response:

    id: 'completion_abcdefghijkl'
    hda:
        keys: {
            'context': 'str',
            'base_word': 'str',
            'pos_start': 'int',
            'pos_end': 'int',
            'add_space': 'int',
            'list': 'arr',
        }
        path: ['completion']
        item 1:
            __path: ['0x55d0ccc88470']
            context: 'auto'
            base_word: 'abcdefghijkl'
            pos_start: 0
            pos_end: 11
            add_space: 1
            list: []

- Completion on an invalid buffer:

    (completion_help) completion buffer.does.not.exist -1 /help fi

Response:

    id: 'completion_help'
    hda:
        keys: {}
        path: ['completion']

### 3.9. 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:

    (id) sync [<buffer>[,<buffer>...] <option>[,<option>...]]

Arguments:

- buffer: pointer (eg: "0x1234abcd") or full name of buffer (for example: core.weechat or irc.libera.#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 WeeChat core buffer:

    sync core.buffer

- Synchronize #weechat channel, without nicklist:

    sync irc.libera.#weechat buffer

- Get general signals + all signals for #weechat channel:

    sync * buffers,upgrade
    sync irc.libera.#weechat

### 3.10. 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:

    (id) desync [<buffer>[,<buffer>...] <option>[,<option>...]]

Arguments:

- buffer: pointer (eg: "0x1234abcd") or full name of buffer (for example: core.weechat or irc.libera.#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 sync command for values

| When using buffer "*", the other buffers synchronized (using a name) are kept. So if you send: "sync *", then "sync irc.libera.#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.libera.#weechat nicklist

- Desynchronize #weechat channel:

    desync irc.libera.#weechat

### 3.11. test

Test command: WeeChat will reply with various different objects.

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

Syntax:

    (id) test

Returned objects (in this order):

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

| 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.

Example:

    (test) test

Response:

    id: 'test'
    chr: 65
    int: 123456
    int: -123456
    lon: 1234567890
    lon: -1234567890
    str: 'a string'
    str: ''
    str: None
    buf: 'buffer'
    buf: None
    ptr: '0x1234abcd'
    ptr: '0x0'
    tim: 1321993456
    arr: ['abc', 'de']
    arr: [123, 456, 789]

### 3.12. 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:

    (id) ping [<arguments>]

Example:

    ping 1370802127000

Response:

    id:'_pong'
    str: '1370802127000'

### 3.13. quit

Disconnect from relay.

Syntax:

    (id) 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        4 + str      3        ??                 3        ??
     └────────────────────┘ └───────────────────────────────────────────────────────┘
           header (5)                          compressed data (??)
     └──────────────────────────────────────────────────────────────────────────────┘
                                   'length' bytes

- length (unsigned integer, 4 bytes): 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 ↗

  - 0x02: following data is compressed with Zstandard ↗

- id (string, 4 bytes + content): 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 or 0x02, then all data after is compressed with zlib ↗ or Zstandard ↗, 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.

#### _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.libera.#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 libera, new buffer irc.libera.#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.libera.#weechat'
            short_name: None
            nicklist: 0
            title: None
            local_variables: {
                'plugin': 'irc',
                'name': 'libera.#weechat',
            }
            prev_buffer: '0x34e7400'
            next_buffer: '0x0'

#### _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.libera.#weechat).
`prev_buffer` | pointer | Pointer to previous buffer.
`next_buffer` | pointer | Pointer to next buffer.

Example: buffer irc.libera.#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.libera.#weechat'
            prev_buffer: '0x347b9f0'
            next_buffer: '0x3471bc0'

#### _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.libera.#weechat).
`prev_buffer` | pointer | Pointer to previous buffer.
`next_buffer` | pointer | Pointer to next buffer.

Example: buffer irc.libera.#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.libera.#weechat'
            prev_buffer: '0x4cef9b0'
            next_buffer: '0x0'

#### _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.libera.#weechat).
`prev_buffer` | pointer | Pointer to previous buffer.
`next_buffer` | pointer | Pointer to next buffer.

Example: buffer irc.libera.#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.libera.#weechat'
            prev_buffer: '0x4cef9b0'
            next_buffer: '0x0'

#### _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.libera.#weechat).
`prev_buffer` | pointer | Pointer to previous buffer.
`next_buffer` | pointer | Pointer to next buffer.

Example: buffer irc.libera.#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.libera.#weechat'
            prev_buffer: '0x4cef9b0'
            next_buffer: '0x0'

#### _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.libera.#weechat).
`prev_buffer` | pointer | Pointer to previous buffer.
`next_buffer` | pointer | Pointer to next buffer.

Example: buffer irc.libera.#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.libera.#weechat'
            prev_buffer: '0x4cef9b0'
            next_buffer: '0x0'

#### _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.libera.#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.libera.Flash2'
            short_name: 'Flash2'
            local_variables: {
                'server': 'libera',
                'plugin': 'irc',
                'type': 'private',
                'channel': 'FlashCode',
                'nick': 'test',
                'name': 'libera.Flash2',
            }

#### _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.libera.#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.libera.#weechat'
            title: 'Welcome on #weechat!  https://weechat.org/'

#### _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.libera.#weechat).

Example: buffer irc.libera.#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.libera.#weechat'

#### _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.libera.#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

#### _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.libera.#weechat).
`local_variables` | hashtable | Local variables.

Example: local variable test added in buffer irc.libera.#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.libera.#weechat'
            local_variables: {
                'server': 'libera',
                'test': 'value',
                'plugin': 'irc',
                'type': 'channel',
                'channel': '#weechat',
                'nick': 'test',
                'name': 'libera.#weechat',
            }

#### _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.libera.#weechat).
`local_variables` | hashtable | Local variables.

Example: local variable test updated in buffer irc.libera.#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.libera.#weechat'
            local_variables: {
                'server': 'local',
                'test': 'value2',
                'plugin': 'irc',
                'type': 'channel',
                'channel': '#weechat',
                'nick': 'test',
                'name': 'libera.#weechat',
            }

#### _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.libera.#weechat).
`local_variables` | hashtable | Local variables.

Example: local variable test removed from buffer irc.libera.#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.libera.#prout'
            local_variables: {
                'server': 'local',
                'plugin': 'irc',
                'type': 'channel',
                'channel': '#weechat',
                'nick': 'test',
                'name': 'libera.#weechat',
            }

#### _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).
`notify_level` | char | Notify level: -1 = notify disabled, 0 = low, 1 = message, 2 = private, 3 = highlight.
`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.libera.#weechat:

    id: '_buffer_line_added'
    hda:
        keys: {
            'buffer': 'ptr',
            'date': 'tim',
            'date_printed': 'tim',
            'displayed': 'chr',
            'notify_level': '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
            notify_level: 1
            highlight: 0
            tags_array: [
                'irc_privmsg',
                'notify_message',
                'prefix_nick_142',
                'nick_FlashCode',
                'log1',
            ]
            prefix: 'F06@F@00142FlashCode'
            message: 'hello!'

#### _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.libera.#weechat).

Example: buffer irc.libera.#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.libera.#weechat'

#### _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.libera.#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: ''

#### _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: ''

#### _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.

#### _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 TLS).

#### _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

#### Char

A signed char is stored as 1 byte.

Example:

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

#### 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
    └────┴────┴────┴────┘

#### 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'

#### 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

#### Buffer

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

#### 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 ║ 30 │ ────► NULL (0x0)
    └────╨────┘
     └──┘ └──┘
    length '0'

#### 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'

#### 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

#### 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 libera server) and two keys (number and full_name):

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

    # response
    ┌────────┬──────────────────────────┬───╥─────────┬───┬──────────────╥─────────┬───┬───────────────────┐
    │ buffer │ number:int,full_name:str │ 2 ║ 0x12345 │ 1 │ core.weechat ║ 0x6789a │ 2 │ irc.server.libera │
    └────────┴──────────────────────────┴───╨─────────┴───┴──────────────╨─────────┴───┴───────────────────┘
     └──────┘ └────────────────────────┘ └─┘ └──────────────────────────┘ └───────────────────────────────┘
      h-path          keys              count          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 │ 0x23d8a10 │ ..... ║ ...
       ──╨───────────┴───────────┴───────────┴───────────┴───────╨──
          └─────────────────────────────────────────────┘ └─────┘
                        p-path (pointers)                 objects
          └─────────────────────────────────────────────────────┘
                                  line 1

       ──╥───────────┬───────────┬───────────┬───────────┬───────╥──────────────┐
     ... ║ 0x23cf970 │ 0x23cfb60 │ 0x23d6110 │ 0x23d9420 │ ..... ║ ............ │
       ──╨───────────┴───────────┴───────────┴───────────┴───────╨──────────────┘
          └─────────────────────────────────────────────┘ └─────┘
                        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

#### 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 │
    └─────────┴───────────────────┘

#### 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 libera server):

    # command
    infolist buffer

    # response
    ┌────────┬───╥────┬─────────┬─────┬─────────┬─────╥────┬─────────┬─────┬─────────┬─────┐
    │ buffer │ 2 ║ 42 │ pointer │ ptr │ 0x12345 │ ... ║ 42 │ pointer │ ptr │ 0x6789a │ ... │
    └────────┴───╨────┴─────────┴─────┴─────────┴─────╨────┴─────────┴─────┴─────────┴─────┘
     └──────┘ └─┘ └──────────────────────────────────┘ └──────────────────────────────────┘
       name  count              item 1                               item 2

#### 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 ║ 61 │ 62 │ 63 ║ 00 │ 00 │ 00 │ 02 ║ 64 │ 65 │ ────► [ "abc", "de" ]
    └─────╨────┴────┴────┴────╨────┴────┴────┴────╨────┴────┴────╨────┴────┴────┴────╨────┴────┘
     └───┘ └─────────────────┘ └─────────────────┘ └────────────┘ └─────────────────┘ └───────┘
     type   number of strings        length         'a'  'b'  'c'       length         'd'  'e'

Example of array with three integers:

    ┌─────╥────┬────┬────┬────╥────┬────┬────┬────╥────┬────┬────┬────╥────┬────┬────┬────┐
    │ int ║ 00 │ 00 │ 00 │ 03 ║ 00 │ 00 │ 00 │ 7B ║ 00 │ 00 │ 01 │ C8 ║ 00 │ 00 │ 03 │ 15 │ ────► [ 123, 456, 789 ]
    └─────╨────┴────┴────┴────╨────┴────┴────┴────╨────┴────┴────┴────╨────┴────┴────┴────┘
     └───┘ └─────────────────┘ └─────────────────┘ └─────────────────┘ └─────────────────┘
     type   number of integers      123 (0x7B)         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: handshake ...              ║ negotiate algos         ║
             ║                                 ║ and options             ║
             ║ ◄───────────────────────────────╢                         ║
             ║        msg: id: "handshake" ... ║                         ║
             ║                                 ║                         ║
             ╟───────────────────────────────► ║                         ║
             ║ cmd: init password=xxx,...      ║ authenticate 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       ║
             ║                                 ║                         ║