# Tip: Cylc 7 Compatibility Mode Retirement

**URL:** <https://cylc.discourse.group/t/tip-cylc-7-compatibility-mode-retirement/1353>\
**Category:** Tips\
**Created:** [October 14, 2026, 11:49am UTC](https://cylc.discourse.group/t/tip-cylc-7-compatibility-mode-retirement/1353 "2026-10-14T11:49:02Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![oliver.sanders](https://yyz2.discourse-cdn.com/free1/user_avatar/cylc.discourse.group/oliver.sanders/32/110_2.png) [@oliver.sanders](https://cylc.discourse.group/u/oliver.sanders)\
**Post date:** [October 14, 2026, 11:49am UTC](https://cylc.discourse.group/t/tip-cylc-7-compatibility-mode-retirement/1353/1 "2026-10-14T11:49:02Z")

</div>

The Cylc 7 compatibility mode (which allowed workflows to run under both Cylc 7 and 8) has now been removed in Cylc 8.7.0.

See [Cylc 7 Compatibility Mode](https://cylc.github.io/cylc-doc/stable/html/7-to-8/major-changes/compatibility-mode.html#cylc-7-compat-mode) for more details.

As part of this change, the version of Jinja2 that Cylc uses has increased From 3.0 to 3.1+. As a result, any use of deprecated Jinja2 interfaces may break with this Cylc release.

Additionally, support has been removed for reading Cylc 7 workflow databases in the `cylc workflow-state` command and `workflow_state` xtrigger.

Deprecated Cylc 7 configuration syntax remains supported, though deprecation messages have been updated to announce the intended removal of support in Cylc 8.9.