• Login licensing support: You can now use sidefx.com as the license server instead of installing a local sesinetd. For more information, see hkey.

  • API key support: You can now use api keys instead of an email and password. This is can be used in both hkey and sescitrl allowing for a scripted deployment of licenses. For more information see hkey.

  • Complete rewrite of both the hserver and sesinetd backend based on Django and nginx design. This is the same backend that is used in the new Houdini WebServer. It provides more reliable uptime, better performance, and higher throughput.

  • Complete rewrite of licensing logging system. For more information see sesinetd.

    • Unified logging system across all of our applications.

  • More export options for the peak usage logging system. More interval options, export types, and grouping options. For more information see, sesinetd.

  • Full HTTP support across all of our applications: Houdini, hserver, sesinetd, hkey, and sesictrl.

    • Multiple new options added to aid in debugging an issue and for performance.

    • Faster usage during failure. For example, if hserver wasn’t running, it would cause hkey to spin for at least 30 seconds. It is now instant.

  • Support for direct querying of license information. With HTTP support you can now do a direct call (using your favorite language) to hserver or sesinetd and grab the JSON information from the response. For more information, see sesinetd.

  • License partitioning: Allows you to virtual split your licenses up into different groups based on conditions you set. This is to replace the need to use multiple servers. For more information, see sesinetd.

Supported Versions

Some clients require a certain minimum server version, and some servers only support a certain minimum client version. The following chart shows what client version can talk to what server version.


You should upgrade both hserver and sesinetd to 18.5.


Min server version (http)

Min server version (non http)







Houdini License Administrator (hkey)

18.0.287 (18.5 recommended)



18.0.287 (18.5 recommended)


What’s new in Houdini 18.5