fix: Move AgentInput to types submodule

Author: Unshure

src/strands/agent/agent.py

@@ -22,7 +22,6 @@
     Mapping,
     Optional,
     Type,
-    TypeAlias,
     TypeVar,
     Union,
     cast,
@@ -51,7 +50,7 @@
 from ..tools.executors._executor import ToolExecutor
 from ..tools.registry import ToolRegistry
 from ..tools.watcher import ToolWatcher
-from ..types.content import ContentBlock, Message, Messages
+from ..types.content import AgentInput, ContentBlock, Message, Messages
 from ..types.exceptions import ContextWindowOverflowException
 from ..types.tools import ToolResult, ToolUse
 from ..types.traces import AttributeValue
@@ -67,8 +66,6 @@
 # TypeVar for generic structured output
 T = TypeVar("T", bound=BaseModel)
 
-AgentInput: TypeAlias = str | list[ContentBlock] | Messages | None
-
 
 # Sentinel class and object to distinguish between explicit None and default parameter value
 class _DefaultCallbackHandlerSentinel:

src/strands/types/content.py

@@ -6,7 +6,7 @@
 - Bedrock docs: https://docs.aws.amazon.com/bedrock/latest/APIReference/API_Types_Amazon_Bedrock_Runtime.html
 """
 
-from typing import Dict, List, Literal, Optional
+from typing import Dict, List, Literal, Optional, TypeAlias
 
 from typing_extensions import TypedDict
 
@@ -186,3 +186,6 @@ class Message(TypedDict):
 
 Messages = List[Message]
 """A list of messages representing a conversation."""
+
+
+AgentInput: TypeAlias = str | list[ContentBlock] | Messages | None