Version 1.6.9 released.

Mosquitto 1.6.9 has been released, this is a bugfix release.


  • Fix session expiry with very large expiry intervals. Closes #1525.
  • Check ACL patterns for validity when loading. Closes #1539.
  • Use presence of password file as indicator for whether username checks should take place, not whether usernames are defined in the password file. Closes #1545.
  • Strip whitespace from end of config file string options. Closes #1566.
  • Satisfy valgrind when exiting on error due to not being able to open a listening socket, by calling freeaddrinfo. Closes #1565.
  • Fix config->user not being freed on exit. Closes #1564.
  • Fix trailing whitespace not being trimmed on acl users. Closes #1539.
  • Fix bind_interface not working for the default listener. Closes #1533.
  • Improve password file parsing in the broker and mosquitto_passwd. Closes #1584.
  • Print OpenSSL errors in more situations, like when loading certificates fails. Closes #1552.
  • Fix mosquitto_client_protocol() returning incorrect values.

Client library

  • Set minimum keepalive argument to mosquitto_connect*() to be 5 seconds. Closes #1550.
  • Fix mosquitto_topic_matches_sub() not returning MOSQ_ERR_INVAL if the topic contains a wildcard. Closes #1589.


  • Fix --remove-retained not obeying the -T option for filtering out topics. Closes #1585.
  • Default behaviour for v5 clients using -c is now to use infinite length sessions, as with v3 clients. Closes #1546.

Version 1.6.8 released.

Mosquitto 1.6.8 has been released, this is a bugfix release.


  • Various fixes for allow_zero_length_clientid config, where this option was not being set correctly. Closes #1429.
  • Fix incorrect memory tracking causing problems with memory_limit option. Closes #1437.
  • Fix subscription topics being limited to 200 characters instead of 200 hierarchy levels. Closes #1441.
  • Only a single CRL could be loaded at once. This has been fixed. Closes #1442.
  • Fix problems with reloading config when per_listener_settings was true. Closes #1459.
  • Fix retained messages with an expiry interval not being expired after being restored from persistence. Closes #1464.
  • Fix messages with an expiry interval being sent without an expiry interval property just before they were expired. Closes #1464.
  • Fix TLS Websockets clients not receiving messages after taking over a previous connection. Closes #1489.
  • Fix MQTT 3.1.1 clients using clean session false, or MQTT 5.0 clients using session-expiry-interval set to infinity never expiring, even when the global persistent_client_expiration option was set. Closes #1494.

Client library

  • Fix publish properties not being passed to on_message_v5() callback for QoS 2 messages. Closes #1432.
  • Fix documentation issues in mosquitto.h. Closes #1478.
  • Document mosquitto_connect_srv(). Closes #1499.


  • Fix duplicate cfg definition in rr_client. Closes #1453.
  • Fix mosquitto_pub -l hang when stdin stream ends. Closes #1448.
  • Fix mosquitto_pub -l not sending the final line of stdin if it does not end with a new line. Closes #1473.
  • Make documentation for mosquitto_pub -l match reality - blank lines are sent as empty messages. Closes #1474.
  • Free memory in mosquitto_sub when quiting without having made a successful connection. Closes #1513.


  • Added CLIENT_STATIC_LDADD to makefile builds to allow more libraries to be linked when compiling the clients with a static libmosquitto, as required for e.g. openssl on some systems.


  • Fix mosquitto_rr.exe not being included in Windows installers. Closes #1463.

Streamsheets now open source

The Mosquitto project is sponsored by Cedalo. This week, Cedalo open sourced its core project, Streamsheets, which has Mosquitto as a key part. Streamsheets are real-time web based spreadsheets that can take input from a variety of data sources, process the data, and provide an output.

They are designed to allow non-programmers to build applications in IoT, industrial, or hobbiest environments, reading data from machines, sensors, APIs, and more.

Connectivity includes MQTT, OPC-UA, REST, file, and others.

If you need a front end for Mosquitto or other communication protocol, it would be worth looking at.

streamsheets screenshot

Some examples:

  • Create dynamic charts and dashboards to visualize your processes
  • Build real-time apps for condition monitoring and alerting
  • Merge data streams from different sources to calculate KPIs and enrich your data
  • Map protocols and change data structures to connect your resources
  • Model simple as well as complex control logic to orchestrate your processes