Developer overview

OADM is written in C# on .NET 10. Most of what you see in the app is a plugin, built on the same SDK that is open to you. This section explains how OADM is put together, what a plugin can do and how to write one.

Two processes

flowchart TB
    subgraph Client["Client: the Avalonia app on each computer"]
        direction LR
        UI["Devices page, plugin pages,<br/>task dialogs, toolbar"] --- CP["Plugin client parts<br/>*.Client.dll"]
    end
    subgraph Server["Server: one service for the site"]
        direction LR
        Core["Device table, polling, task engine,<br/>event rules, stored passwords"] --- SP["Plugin server parts<br/>*.Server.dll"]
    end
    Devices[("Axis devices: cameras, speakers, I/O, intercoms")]
    Client <-->|"gRPC over TLS"| Server
    Server <-->|"VAPIX over HTTP(S), RTSP, WebSocket"| Devices

• The server owns everything: the device table, the stored passwords, the tasks, discovery, polling and every request to a device. It runs as a service on Windows, Linux and macOS.
• The client is a thin UI. It never talks to a device. It sends requests to the server over gRPC and keeps a live copy of the device and task lists.
• Passwords never leave the server. A plugin gets a VAPIX client that is already logged in, never the password.

A plugin follows the same split: a server part (*.Server.dll) does the device work, an optional client part (*.Client.dll) shows a dialog, a page or a toolbar button.

What a plugin can do

You want to	Build	Example in the repository
Change or read something on many devices from the context menu	Task plugin	Restart, Users, Upgrade firmware
Ask the user first (a form, a file)	Task plugin with a dialog	Date and time, Applications
Run a service or show a page in the navigation rail	Core plugin	NTP server, Edge storage, PKI
Add a button to the Devices toolbar	Toolbar plugin	System report
Do something when an event rule fires	Action	Send email, Set output
Let event rules react to something your plugin sees	Event source	Device triggers

Inside these, the SDK gives you:

• every managed device with its model, firmware, status, tags and API list (Devices and VAPIX);
• a logged-in VAPIX client per device, with WebSockets, RTSP event streams and video source lists;
• tasks with named steps, progress, a log and warnings, one task per device;
• settings per plugin, encrypted secrets, a private data folder;
• live events from the server part to its page, file downloads to the client;
• the shared controls and theme of the app, so a plugin looks like the rest of OADM (UI kit);
• permissions that administrators give per role on the Users page.

Where the code is

Folder	Content
src/Oadm.Sdk	The server SDK: plugin interfaces, devices, VAPIX, tasks, events, actions. No UI
src/Oadm.Sdk.Client	The client SDK: dialog, page and toolbar interfaces, shared controls, validation
src/Oadm.Core	Device model, VAPIX client, discovery, task engine, database
src/Oadm.Server	The server host: gRPC services, plugin loader, polling
src/Oadm.Client	The Avalonia app
src/Oadm.Contracts	The gRPC contracts (.proto)
plugins/	Every built-in plugin, each with its own README.md
tests/	Unit, headless UI, performance and hardware tests

The SDK sources are the reference: every member has a comment that says what it does and what the host guarantees. Start with src/Oadm.Sdk/Plugins/Plugins.cs and src/Oadm.Sdk.Client/ClientPlugins.cs.

Where to go next

1. Build from source: get OADM running from a checkout.
2. Plugin basics: project layout, plugin.json, how plugins load.
3. A tutorial, each on one page with every file: task plugin, plugin page, event rule action. ./manage.sh new task|page|action --name "My plugin" creates the tutorial’s plugin under your name, ready to build and run.
4. The topic pages: Devices and VAPIX, Task plugins, Core plugins and pages, Event rules, UI kit, Testing, Debug a plugin, SDK versions.

Every public type and member, with its signature and comment, is in the SDK reference. The rules and edge cases are in plugins/README.md and the spec, CLAUDE.md.