> For the complete documentation index, see [llms.txt](https://docs.flopsar.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.flopsar.com/7/user-guide/plugins.md).

# Plugins

Plugins let you extend what Flopsar does at runtime — adding custom instrumentation and processing — without changing your application's source code. A plugin is uploaded to the server, attached to a monitoring profile, and from then on the agent applies it to the running application alongside Flopsar's built-in instrumentation. 

This page covers how to install, activate, inspect, and manage plugins. If you want to *build* your own plugin, see the *Developer Guide → Agent Extensions*.

## What Plugins Do

Each plugin packages one or more extension classes, and each extension class defines **rules** — the method signatures it attaches to and the custom logic it runs when those methods execute. This lets you capture additional data, react to specific calls, or enrich what Flopsar records, targeted precisely at the methods you care about. 

Flopsar publishes a set of ready-made plugins as open source on GitHub, so you can use them as-is or as a starting point for your own.

## The Plugins Page

Open **Plugins** from the navigation. The page opens with a summary of what is installed and a list of every plugin class on the server.

<figure><img src="/files/qHsOCb9aRAwqwDi0Z1zq" alt=""><figcaption></figcaption></figure>

The summary cards show:

* **Total Plugins** — the number of installed extension classes.
* **Total Size** — their combined size on the server.
* **In Use** — how many are currently referenced by a monitoring profile.
* **Categories** — the number of distinct plugins (groupings) the classes belong to.&#x20;

The plugin list shows one row per extension class:

* **Class Name** — the fully qualified class providing the extension.
* **Category** — the plugin this class belongs to. Click it to see the instrumentation rules the plugin defines.
* **Profiles** — how many monitoring profiles currently use this class. A value of 0 means it is installed but not active anywhere.
* **Size** — the size of the compiled class.
* **Last Edit** / **Edited By** — when it was last changed and by whom.&#x20;

You can search the list by class name, sort by any column, and refresh it. The export action downloads all installed plugins as a single archive for backup or transfer to another server.

## Uploading a Plugin

Use **New Plugin** (or **Add Plugin** in the empty state) to open the upload dialog and add a plugin to the server. This requires the **Manage Extensions** permission.

<figure><img src="/files/oGXo91ifzBbyXLkLO34l" alt="" width="563"><figcaption></figcaption></figure>

Uploading a plugin makes it available on the server, but does **not** activate it on its own — see the next section.

## Activating a Plugin

Plugins take effect through **monitoring profiles**. To activate a plugin, reference it from a profile that is applied to your application; the agent then loads and runs the plugin for instances using that profile. The **Profiles** count on the plugin list reflects this, and the **In Use** card counts plugins that are active in at least one profile. To stop a plugin from running, remove it from the profiles that reference it. See *Setting Up Monitoring → Monitoring Profiles*.

## Inspecting Plugins

**Category rules.** Clicking a plugin's category opens a panel listing the rules it defines, each shown with the method signature it instruments — a quick way to see exactly what a plugin touches before you activate it.

<figure><img src="/files/9evIqjQYUpiSuvKhqo5j" alt=""><figcaption></figcaption></figure>

**View source.** When source is available, you can open it directly in the Workstation. This requires the **Manage Extensions** or **View Plugin Source** permission and is especially useful for reviewing a plugin before trusting it.

## Removing a Plugin

Deleting a plugin class (the trash action on its row) removes it from the server. Make sure it is not referenced by any active profile first; use the **Profiles** count to check. Removal requires the **Manage Extensions** permission.

## Security Considerations

Because plugins execute custom code inside your application's process, only install plugins from sources you trust, and review their rules and source before activating them. For the full risk discussion, see [*Known Risks & Limitations*](/7/security/known-risks-and-limitations.md).