messages/tool

Represents a tool message in a conversation.

Represents a chunk of a tool message, which can be concatenated with other tool message chunks.

Marker parameter for objects that tools can return directly.

If a custom BaseTool is invoked with a ToolCall and the output of custom code is not an instance of DirectToolOutput, the output will automatically be coerced to a string and wrapped in a ToolMessage.

A chunk of a tool call (e.g., as part of a stream). When merging ToolCallChunks (e.g., via AIMessageChunk.add), all string attributes are concatenated. Chunks are only merged if their values of index are equal and not None.