strands.plugins.registry

Plugin registry for managing plugins attached to an agent.

This module provides the _PluginRegistry class for tracking and managing plugins that have been initialized with an agent instance.

_PluginRegistry

class _PluginRegistry()

Defined in: src/strands/plugins/registry.py:21

Registry for managing plugins attached to an agent.

The _PluginRegistry tracks plugins that have been initialized with an agent, providing methods to add plugins and invoke their initialization.

The registry handles:

1. Calling the plugin’s init_agent() method for custom initialization
2. Auto-registering discovered @hook decorated methods with the agent
3. Auto-registering discovered @tool decorated methods with the agent

Example:

registry = _PluginRegistry(agent)

class MyPlugin(Plugin):
    name = "my-plugin"

    @hook
    def on_event(self, event: BeforeModelCallEvent):
        pass  # Auto-registered by registry

    def init_agent(self, agent: Agent) -> None:
        # Custom logic only - no super() needed
        pass

plugin = MyPlugin()
registry.add_and_init(plugin)

__init__

def __init__(agent: "Agent") -> None

Defined in: src/strands/plugins/registry.py:52

Initialize a plugin registry with an agent reference.

Arguments:

• agent - The agent instance that plugins will be initialized with.

add_and_init

def add_and_init(plugin: Plugin) -> None

Defined in: src/strands/plugins/registry.py:61

Add and initialize a plugin with the agent.

This method:

1. Registers the plugin in the registry
2. Calls the plugin’s init_agent method for custom initialization
3. Auto-registers all discovered @hook methods with the agent’s hook registry
4. Auto-registers all discovered @tool methods with the agent’s tool registry

Handles both sync and async init_agent implementations automatically.

Arguments:

• plugin - The plugin to add and initialize.

Raises:

• ValueError - If a plugin with the same name is already registered.