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Overview

Memory nodes enable stateful conversations by storing and retrieving chat history for LLM nodes.

Chat Memory Node

Store and retrieve conversation history with automatic trimming and summarization

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Chat Memory Node

Purpose: Manage chat history and conversation context Memory nodes store and retrieve conversation history for LLM nodes, enabling stateful conversations.
Memory node visual representation
Memory node visual representation
Node Handles:
Top - Memory HandleConnects to LLM node’s MEMORY handle (bottom) for bidirectional communication.Functionality:
  • Reads: Retrieves existing conversation history for LLM context
  • Writes: Stores new messages after LLM execution
  • Bidirectional: Both input and output through single connection
Data Flow:
  • LLM requests history → Memory provides messages
  • LLM generates response → Memory stores new message
Memory nodes use a special bidirectional connection to the LLM’s MEMORY handle. They don’t have traditional PARALLEL or ERROR output handles - the memory connection handles all data flow.

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Memory Limit Types

Keep last N messages
  • Simple message-based trimming
  • Maintains recent context
  • Predictable memory usage
Example: Keep last 10 messages

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Summarization

When messages are trimmed, enable summarization to condense old context: 
{
  "enable_summarization": true,
  "summarize_prompt": "Summarize the key points from this conversation..."
}
The summarization runs automatically and replaces trimmed messages with a concise summary, preserving important context while reducing token usage.

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External Chat IDs

Memory nodes use external chat IDs to group conversations: 
external_chat_id: "user-{{user_id}}-session-{{session_id}}"
This enables:
  • Multi-user conversations
  • Session management
  • Conversation history across workflow executions
  • Isolated contexts per user/session
Use template variables in external_chat_id to dynamically create isolated conversation contexts for each user or session.

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What’s Next?

AI Nodes

Learn how LLM nodes use memory for context

Variable Mappings

Use templates in chat IDs and prompts

Chats

Explore the Chats feature for end-user conversations

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