Werk #18600: Preview of upcoming new plug-in APIs

Component Checks & agents
Title Preview of upcoming new plug-in APIs
Date Nov 16, 2025
Level Trivial Change
Class New Feature
Compatibility Compatible - no manual interaction needed
Checkmk versions & editions
2.5.0b1
Not yet released
Checkmk Raw (CRE), Checkmk Enterprise (CEE), Checkmk Cloud (CCE), Checkmk MSP (CME)

Checkmk 2.5 features four new unstable APIs for plugin development. There are three new (versioned) APIs, and a new version of the bakery API. The replaced APIs will be removed in Checkmk 2.7 (details below).

Plugin APIs in general provide means to write own code that interacts with the main application using well defined and stable code libraries.

Over the last versions we gradually replaced more and more of the poorly documented and unversioned APIs. The three new APIs do this for the special agents, active checks and HW/SW inventory views.

All four of these APIs are incuded as an "unstable" version. You can find a detailed technical documentation of the APIs online or in a running sites' "Help" menu, under "Plugin API references".

We would love to receive your feedback via the Checkmk Forum. You can of course also ask for help there.

APIs

cmk.bakery.v2_unstable

This is the successor of cmk.base.cee.plugins.bakery.bakery_api.v1. With version 2 of this API the bakery plugins are included in the new plug-in family layout (at cmk_addons.plugins.<YOUR_NAME_HERE>.bakery).

There's a few other differences that you can read about in the developer documentation.

cmk.inventory_ui.v1_unstable

This is the new API to write user interfaces for HW/SW inventory entries.

cmk.password_store.v1_unstable

This API provides functionality to interact with the password store, mostly to access stored secrets. You will most likely want to use this in your special agents and active checks.

cmk.server_side_programs.v1_unstable

This API provides convenience features to be used in special agents and active checks. The most important ones are decorators to create crash reports and a class that allows to persist some data from one call to another.

Compatibility and timeline

For all these four APIs the same timeline is planned:

Checkmk 2.5

The APIs are released in an "unstable" version. This means that while we intend to release the APIs like this, we are not yet committed to keep them exactly as they are, and might change them in an incompatible manner. This allows us to gather some experience and react to your feedback.

Plug-in developers are encouraged to try out these APIs and give us their feedback via the Checkmk Forum.

Checkmk 2.6

The APIs are released as stable version (their names change accordingly). We strongly recommend users migrate to the new APIs during the lifetime of 2.6.

Checkmk 2.7

All functionality being replaced by the new APIs will be removed. In particular cmk.special_agents, cmk.utils.password_store, cmk.base.cee.plugins.bakery.bakery_api.v1 and cmk.bakery.v1. All plug-ins not migrated to the new APIs will stop working.

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