Send Message

Send a message to the agent and stream the response.

This endpoint streams Server-Sent Events (SSE) back to the client as the agent processes the message through its workflow.

SSE Event Types

Core Events:

• intent: Intent classification result (emitted first)
  • {intent, confidence, category, reasoning, context_scope}
• thinking: Agent is analyzing/planning
  • {step, message}
• tool_call: Agent is calling a tool
  • {tool_name, tool_call_id, inputs}
• tool_result: Tool execution completed
  • {tool_name, tool_call_id, success, output, latency_ms}
• token: Response token (streaming)
  • {content}
• message: Final response content
  • {content, message_id, is_final}
• session_name: Auto-generated session name (first message only)
  • {session_name}
• done: Processing complete
  • {latency_ms, tool_calls_made, message_id, retriever_summary, data_accessed_via_retriever}
• error: Error occurred
  • {message, recoverable}

Retriever Events (IMPORTANT - Primary Data Pathway):

• retriever_execution: Retriever was used for data access
  • {tool_name, execution_id, retriever_id, is_adhoc, documents_returned, latency_ms, message}
  • Emitted whenever data is accessed via retriever (saved or ad-hoc)
• pipeline_config: Ad-hoc retriever configuration
  • {tool_name, config, message}
  • Contains the exact pipeline config users can save as a named retriever

Retriever Summary in done Event:

{
  "retriever_summary": {
    "used_retrievers": true,
    "retriever_count": 2,
    "saved_retrievers": 1,
    "adhoc_retrievers": 1,
    "total_documents": 25,
    "executions": [...]
  },
  "data_accessed_via_retriever": true
}

Args: request: FastAPI request with tenant context session_id: Session identifier payload: Message request

Returns: StreamingResponse with SSE events

Raises: NotFoundError: If session not found

Example: ```bash curl -N -X POST http://localhost:8000/v1/agents/sessions/ses_abc123/messages
-H "Authorization: Bearer {api_key}"
-H "X-Namespace: {namespace_id}"
-H "Content-Type: application/json"
-d '{ "content": "Find videos about machine learning", "stream": true }'

# SSE Output:
event: intent
data: {"intent": "retriever_search", "confidence": 0.92, "category": "retriever"}

event: thinking
data: {"step": "processing", "message": "Analyzing your request..."}

event: tool_call
data: {"tool_name": "execute_retriever", "tool_call_id": "run_abc", "inputs": {...}}

event: tool_result
data: {"tool_name": "execute_retriever", "success": true, "output": {...}}

event: retriever_execution
data: {"tool_name": "execute_retriever", "is_adhoc": false, "documents_returned": 5}

event: message
data: {"content": "I found 5 videos about machine learning...", "is_final": true}

event: done
data: {"latency_ms": 1250.5, "data_accessed_via_retriever": true, "retriever_summary": {...}}
```