Plugins

Arcen has several plugin surfaces. General plugins use PluginManager, memory providers use the memory provider interface, and model providers use lazy ProviderProfile discovery.

General plugins

General plugins can register:

• Lifecycle hooks such as pre_tool_call, post_tool_call, pre_llm_call, and post_llm_call.
• New tools with ctx.register_tool(...).
• CLI subcommands with ctx.register_cli_command(...).

Discovery happens through arcen_cli/plugins.py and is triggered as a side effect of importing model_tools.py.

Memory plugins

Memory plugins implement MemoryProvider and are orchestrated by agent/memory_manager.py.

Built-in memory providers are closed to new in-tree additions. Publish new memory backends as standalone plugin repositories or pip entry points.

Model-provider plugins

Model providers live under plugins/model-providers/<name>. Each plugin registers a ProviderProfile.

Discovery order:

1. Bundled providers in the repo.
2. User providers under $ARCEN_HOME/plugins/model-providers/<name>.
3. Legacy providers under providers/<name>.py.

User plugins of the same name override bundled providers.