Session

A session is a chat conversation with message history. When you chat with a knowledge base, each conversation is a session. Context from previous messages is preserved for multi-turn RAG chat, enabling follow-up questions like "What about the second one?" or "Summarize that."

Session Features

Sessions are scoped to a knowledge base. When you start a chat, you select the knowledge base; the session searches only those documents.

Session Lifecycle

1. Create — A new session is created when you start a chat without a session_id, or when you explicitly create one via API
2. Continue — Pass session_id in chat requests to continue an existing session
3. Archive — Sessions can be archived or deleted; history is retained until then

Create or continue a session by passing session_id in chat requests. If omitted, a new session is created. The API returns the session_id in responses so you can persist it and resume later.

Mem0 Compression

DocLD uses memory compression (Mem0) to summarize long conversations, keeping context relevant without exceeding LLM context limits. When a session grows long:

1. Summarize — Older messages are summarized into a compact representation
2. Retain — Recent messages and the summary are kept in context
3. Generate — The LLM receives the summary + recent messages for coherent multi-turn chat

This improves quality for extended chats. Without compression, very long conversations would exceed the context window and lose early context.

API Usage

# Start a new session (omit session_id)
POST /api/chat
{ "message": "What is the total amount?", "knowledge_base_id": "..." }

# Continue a session
POST /api/chat
{ "message": "What about the second invoice?", "session_id": "..." }

The response includes session_id for continuation. Sessions are tied to the knowledge base used when they were created.

Best Practices

• Persist session IDs — Store session_id in your app (e.g., cookie, local storage) to resume conversations
• Scope by use case — Create new sessions when the user switches topics or knowledge bases
• Export for compliance — Use session export for audit trails or compliance records

Related Concepts

Sessions enable multi-turn RAG chat. Knowledge bases scope which documents are searched. The LLM uses session context to generate coherent, contextual answers.