Keep session memory

Use this when a user talks to a model over several requests and each answer should know what was said before. Prerequisites: Call an LLM works for you. This guide matches example 09, which you can run end to end. Add -H "X-API-Key: $YUKTA_API_KEY" if your server has keys.

Steps

Wire load, model, append

A chat turn is a SESSION_MEMORY node in load mode, the model, and a SESSION_MEMORY node in append mode. Save as session.json (this one uses a local Ollama through its OpenAI-compatible endpoint):

session.json

{
  "sessionId": "chat",
  "name": "Chat",
  "workflows": {
    "turn": {
      "workflowId": "turn",
      "description": "One chat turn with memory",
      "nodes": [
        { "nodeId": "trigger", "type": "API_TRIGGER", "config": {} },
        {
          "nodeId": "memory-load",
          "type": "SESSION_MEMORY",
          "config": {
            "mode": "load",
            "sessionId": "${payload.sessionId}",
            "message": "${payload.message}",
            "maxTurns": 20
          }
        },
        {
          "nodeId": "llm",
          "type": "LLM_CALL",
          "config": {
            "provider": "openai",
            "baseUrl": "http://localhost:11434/v1",
            "apiKey": "decrypted:llm-api-key",
            "model": "llama3.2",
            "system": "You are a concise, helpful assistant.",
            "messages": "payload['history']",
            "prompt": "${payload.message}",
            "timeout": 60
          }
        },
        { "nodeId": "memory-append", "type": "SESSION_MEMORY", "config": { "mode": "append", "maxTurns": 20 } },
        { "nodeId": "end", "type": "CONSOLE_TERMINAL", "config": {} }
      ],
      "edges": [
        { "source": "trigger", "target": "memory-load" },
        { "source": "memory-load", "target": "llm" },
        { "source": "llm", "target": "memory-append" },
        { "source": "memory-append", "target": "end" }
      ]
    }
  }
}

load adds history: [{role, content}] to the payload, the newest maxTurns turns (default 20).
append records the user turn and the model’s reply (default ${payload.content}); its sessionId defaults to ${metadata.sessionId}.
messages is an expression on purpose: a ${...} reference would turn the list into text.
With Ollama, set YUKTA_SECRET_LLM_API_KEY to any non-empty value, or drop apiKey.

curl -X POST localhost:9858/api/sessions -H 'Content-Type: application/json' -d @session.json

Send two turns with the same conversation id

curl -X POST localhost:9858/api/workflow/start -H 'Content-Type: application/json' \
  -d '{"sessionId":"chat","workflowId":"turn","payload":{"sessionId":"user-42","message":"My name is Ada. Remember it."}}'
curl -X POST localhost:9858/api/workflow/start -H 'Content-Type: application/json' \
  -d '{"sessionId":"chat","workflowId":"turn","payload":{"sessionId":"user-42","message":"What is my name?"}}'

The conversation id is payload.sessionId here (user-42). It is not the Yukta session chat. Each conversation id has its own history.

Forget a conversation

Use mode: delete with the conversation id to remove its history, for example from a separate workflow wired to a “new chat” button:

{ "nodeId": "forget", "type": "SESSION_MEMORY", "config": { "mode": "delete", "sessionId": "${payload.sessionId}" } }

Verify it worked

Read the result of the second run:

curl -s -H 'Accept: application/json' localhost:9858/api/sessions/chat/executions/$EXEC2/results

payload.content answers along the lines of “Your name is Ada”. If it does not know, the first run did not finish before the second started, or you used a different payload.sessionId.

Variations

Memory is per server process. It lives in memory and a restart clears it. Plan for that if conversations must outlive a restart.
Trim long chats. Lower maxTurns on both memory nodes to bound the prompt size and the token cost: Set token budgets.
Several agents. Give each agent its own conversation id (or a prefix) so they do not share history.

AI plugins reference for SESSION_MEMORY options.
Example 09.

Build workflows

Work with AI

Supervise runs

Run and operate

Extend

Keep session memory

Steps

Verify it worked

Variations

Steps

Verify it worked

Variations

Related