agents

Send Message Streaming

Changed on

Process a user message and return the agent's response. This endpoint accepts a message from a user and processes it through the agent. It will stream the steps of the response always, and stream the tokens if 'stream_tokens' is set to True.

post/v1/agents/{agent_id}/messages/stream

Request

  • Base URL
    https://app.letta.com
  • URL
    https://app.letta.com/v1/agents/{agent_id}/messages/stream
  • Auth
    HTTP bearer

Path parameters

agent_idstring required

Request body

max_stepsinteger

Maximum number of steps the agent should take to process the request.

use_assistant_messageboolean

Whether the server should parse specific tool call arguments (default send_message) as AssistantMessage objects.

assistant_message_tool_namestring

The name of the designated message tool.

assistant_message_tool_kwargstring

The name of the message argument in the designated message tool.

include_return_message_typesMessageType[] nullable

Only return specified message types in the response. If None (default) returns all messages.

enable_thinkingstring

If set to True, enables reasoning before responses or tool calls from the agent.

stream_tokensboolean

Flag to determine if individual tokens should be streamed, rather than streaming per step.

include_pingsboolean

Whether to include periodic keepalive ping messages in the stream to prevent connection timeouts.

backgroundboolean

Whether to process the request in the background.

Response

Successful response

unknown required

Changes

  • f0554a0bf8b2Revision changes
    • info

      added the new optional request property ///////

    • info

      added the new optional request property ///////

    • info

      added the new optional request property ///////