What is metronome?

Metronome IM is a lightweight XMPP server that began as a Prosody fork in 2012. It offers a complete XMPP implementation with microblogging (XEP-0277), Multi-User Chat, Publish-Subscribe, HTTP file upload, BOSH and WebSocket support, stream management, and message archiving (MAM). Written in Lua, it uses libevent as its sole backend with a hard dependency on lua-event. Users can compile it from source on Linux or install via the Arch Linux AUR package. The software powers the LW.Org public IM platform and served as the default XMPP server in YunoHost. It meets the XMPP Compliance Suites 2020 Advanced Server level across Core, Web, IM and Mobile categories.

Should you self-host metronome?

metronome scores 47/100 on selfhost.directory (how scoring works) and ranks #61 of 110 in Chat. It has 176 GitHub stars.

It shipped 8 stable releases in the past year. The latest, v4.0.5, came out on 27 November 2025.

Setup is advanced: plan for several services and some ongoing maintenance. It is Other-licensed and written mostly in Lua.

Its closest alternative on selfhost.directory is Zulip (82/100, 26 133 stars). It scores higher overall, so compare the two before you pick. See metronome vs Zulip side by side.

Features

Bidirectional S2S
BOSH Support
Daemon Control Utility
Direct TLS S2S
HTTP API
HTTP File Upload
In-Band Registration
Message Archive Management (MAM)
Microblogging over XMPP
Multi-User Chat (MUC)
Publish-Subscribe (PubSub)
SPIM Prevention
Stream Management
Websocket Support
XMPP Server

How to configure metronome

allowed_sasl_failures3Max times a client can fail authentication
Max times a client can fail authentication
allow_registrationfalseEnable In-Band Registration
Enable In-Band Registration
values: true/false
http_file_quota40 MiBAccount space quota for file uploads
Account space quota for file uploads
http_file_size_limit3 MiBSize limit for uploads in bytes (mod_http_upload)
Size limit for uploads in bytes (mod_http_upload)
mail_hostSMTP server hostname for email notifications
SMTP server hostname for email notifications
mail_port587TCP port to connect to the SMTP server
TCP port to connect to the SMTP server
mam_max_retrievable_results150Max numbers of results which can be retrieved at once
Max numbers of results which can be retrieved at once
mam_stores_cap10000Max number of log entries which each archive can contain
Max number of log entries which each archive can contain
metronome_max_files_hard9216Set hard limit for files which can be opened by the server process
Set hard limit for files which can be opened by the server process
metronome_max_files_soft9216Set soft limit for files which can be opened by the server process
Set soft limit for files which can be opened by the server process
register_max_pass_length30Define the maximum number of characters a password can be composed of
Define the maximum number of characters a password can be composed of
register_min_pass_length8Define the minimum number of characters a password can be composed of
Define the minimum number of characters a password can be composed of
s2s_check_inactivity900Defines in how many seconds Metronome checks if there're idle streams to close down
Defines in how many seconds Metronome checks if there're idle streams to close down
s2s_max_inactivity1800The seconds in which opened s2s streams are considered to be idle
The seconds in which opened s2s streams are considered to be idle
spim_recaptcha_client_keyreCAPTCHA client key for SPIM blocking challenges
reCAPTCHA client key for SPIM blocking challenges
spim_recaptcha_server_keyreCAPTCHA server side secret key for verification
reCAPTCHA server side secret key for verification