Content blocks represent displayable information in the Agent Client Protocol.
They provide a structured way to handle various types of user-facing content—whether
it's text from language models, images for analysis, or embedded resources for context.
Content blocks appear in:
User prompts sent via session/prompt
Language model output reported through session/update notifications as
message updates or streamed chunks
Progress updates and results from tool calls
This structure is compatible with the Model Context Protocol (MCP), enabling
agents to seamlessly forward content from MCP tool outputs without transformation.
Content blocks represent displayable information in the Agent Client Protocol.
They provide a structured way to handle various types of user-facing content—whether it's text from language models, images for analysis, or embedded resources for context.
Content blocks appear in:
session/promptsession/updatenotifications as message updates or streamed chunksThis structure is compatible with the Model Context Protocol (MCP), enabling agents to seamlessly forward content from MCP tool outputs without transformation.
See protocol docs: Content