Automate Task & Calendar Management with n8n & OpenAI Agents

1. Opening Problem Statement

Meet Anna, a busy project manager juggling multiple deadlines and meetings every week. Anna spends countless hours manually scheduling appointments in Google Calendar and logging tasks in Notion. With frequent interruptions and constant context switching, she often misses important details or double-books meetings. This mismanagement not only wastes her time—about 5 hours weekly—but also causes project delays and frustrations among her team.

This exact challenge is what the presented n8n workflow addresses: automating task creation in Notion and scheduling events in Google Calendar through a smart AI-powered conversational assistant. Imagine freeing Anna from repetitive scheduling tasks and error-prone manual entries so she can focus on what really matters—leading her projects effectively.

2. What This Automation Does

This n8n workflow uses OpenAI’s advanced GPT-4o model combined with specialized LangChain agents to handle chat inputs for calendar and task management with precision. When a chat message arrives, the workflow intelligently determines whether it’s about scheduling calendar events or creating Notion tasks and routes the request to the appropriate sub-agent.

• Natural Language Understanding: Uses OpenAI Chat Models to comprehend user chat inputs with zero temperature (deterministic responses).
• Contextual Session Memory: Maintains conversation context over 15 turns with LangChain’s Window Buffer Memory to enable smooth, ongoing dialogues.
• Calendar Management: Checks Google Calendar availability, proposes alternate time slots if conflicts exist, drafts events for user approval, and books appointments seamlessly.
• Task Management in Notion: Creates tasks with title, description, and priority. Clarifies missing details by interacting with the user before finalizing the task in Notion’s database.
• Dynamic Tool Routing: A main LangChain agent routes requests accurately between the calendar and task sub-agents based on user intent.
• Webhook Interface: Accepts POST chat message requests securely with header authentication to integrate with external chat clients or platforms.

Altogether, this workflow eliminates manual data entry for scheduling and task tracking, saving an estimated 5 hours weekly for professionals like Anna and reducing costly scheduling conflicts.

3. Prerequisites ⚙️

• n8n Account with access to LangChain nodes
• Google Calendar account with OAuth2 credentials configured in n8n 🔐
• Notion account and database ID for task management 🔐
• OpenAI API key with GPT-4o model enabled 🔐
• Basic knowledge of n8n workflow setup and webhook usage

4. Step-by-Step Guide

Step 1: Setup Webhook to Receive Chat Messages

Navigate to Nodes → Webhook and create a POST webhook node with header authentication. Set a unique path such as 46116445-3b13-48c0-9a38-cd034bee92ac.

After activation, you can send POST requests with JSON body containing prompt and sessionID fields. Example payload:

{
  "prompt": "Schedule a meeting with team",
  "sessionID": "session123"
}

Expected outcome: Receives chat input for processing.

Common mistake: Forgetting to set up header authentication properly, causing unauthorized errors.

Step 2: Map Incoming Chat Data to Workflow Variables

Use Set (Map Fields) node to extract prompt as chatInput and sessionID as sessionId. This cleans and standardizes input for downstream nodes.

Expected outcome: Subsequent nodes receive consistent data keys.

Common mistake: Not matching JSON keys exactly from webhook body.

Step 3: Configure Main LangChain Agent for Routing

The Main Agent node uses a system message explaining its role: to only route requests without modifying inputs or outputs. It uses GPT-4o model with temperature 0 for deterministic, clear routing.

This agent receives the chat input, session context from Window Buffer Memory node, and decides whether to forward to calendarAgent or taskAgent.

Expected outcome: User requests are routed correctly between task creation and calendar event scheduling.

Common mistake: Misconfiguration of sessionKey in memory buffer leading to loss of context.

Step 4: Handle Calendar-Related Requests with calendarAgent Sub-Workflow

The calendarAgent invokes a sub-workflow that includes the Google Calendar Agent LangChain node. This agent:

• Checks calendar availability using Get calendar availability HTTP Request node against Google Calendar API.
• Proposes alternate time slots if conflicts exist.
• Drafts an event in Markdown format and asks user for approval.
• On user approval, books the event via Book appointment HTTP Request node.

Expected outcome: Accurate and conflict-free Google Calendar events.

Common mistake: Incorrect OAuth2 credentials cause API authorization failures.

Step 5: Handle Task-Related Requests with taskAgent Sub-Workflow

The taskAgent node calls another workflow dedicated to Notion task creation. The Notion Task Agent node:

• Interacts via chat to get task title, description, and priority.
• Asks clarifying questions if information is missing.
• Creates tasks in Notion database via HTTP Request node using Notion API.

Expected outcome: Tasks accurately created in Notion DB with user approval.

Common mistake: Incorrect Notion database ID or API token leads to task creation failure.

Step 6: Set Up Contextual Memory for Smooth Conversations

Each agent uses Window Buffer Memory nodes with contextWindowLength set to 15 to keep track of ongoing session context by sessionId. This enables the agents to remember prior chat turns and improve responsiveness over a conversation.

Expected outcome: Conversational continuity and accurate routing.

Common mistake: Using inconsistent session keys causing memory to reset unexpectedly.

Step 7: Format and Respond to User

Exclude Previews from Speech and Format output nodes clean and format the agent responses before sending back through Respond to Webhook node.

Expected outcome: User receives clear text responses without unwanted HTML or partial preview content.

Common mistake: Modifying output improperly can cause confusing responses.

Step 8: Activate and Test Workflow

Activate the main workflow and associated sub-workflows. Send test chat messages via the webhook URL with valid authorization headers. Validate task creation in Notion and event booking in Google Calendar.

Expected outcome: Fully automated, accurate task and event management.

Common mistake: Not activating sub-workflows or configuring credentials correctly.

5. Customizations ✏️

• Change Default Timezone: In the Settings1 node, update the timeZone value to your preferred timezone. This alters calendar event timings to your locale.
• Modify Notion Task Priorities: In the HTTP Request node for Notion, edit the priority field options to add or remove values according to your team’s workflow.
• Increase Context Window Length: Adjust the Window Buffer Memory nodes’ contextWindowLength parameter to track longer conversations if needed.
• Change Chat Model Temperature: In OpenAI Chat Model nodes, tweak the temperature setting for more creative or varied responses, e.g., from 0 to 0.7.
• Add Additional Agents: Create new sub-workflows and link them in the Main Agent node to support new tools beyond calendar and tasks.

6. Troubleshooting 🔧

Problem: “401 Unauthorized” when calling Google Calendar API or Notion API.
Cause: Invalid or expired OAuth2 tokens or API keys.
Solution: Reauthenticate credentials in n8n via your integration settings. Make sure the tokens have sufficient scopes.

Problem: Memory context not persisting between messages.
Cause: Incorrect sessionId configuration or inconsistent session keys across nodes.
Solution: Verify sessionId mapping and ensure the same key is used in all Window Buffer Memory nodes.

Problem: Tasks not created in Notion despite successful chat approvals.
Cause: Incorrect Notion database ID or insufficient permissions.
Solution: Double check the Notion database ID in the Settings node and verify the API token permissions.

7. Pre-Production Checklist ✅

• Confirm n8n has access to Google Calendar & Notion accounts with valid OAuth2 tokens 🔐
• Test webhook URL security and authentication with your chat client 🔌
• Verify sub-workflow IDs assigned to calendarAgent and taskAgent nodes are correct
• Run trial chat scenarios covering scheduling and task creation cases
• Check context memory continuity over multi-turn conversations
• Backup your Notion data and Google Calendar events regularly as a rollback plan

8. Deployment Guide

Once tested, activate your main workflow along with its two sub-workflows for task and calendar management. Make sure credentials remain valid and monitor the webhook for incoming chat requests. Use n8n’s built-in logs to track errors or dropped messages.

Inform your team or users about the chatbot interface and provide instructions for sending chat requests via your webhook endpoint.

9. FAQs

Q: Can I use other calendar services instead of Google Calendar?
A: Currently, this workflow uses Google Calendar API via OAuth2. To integrate other calendars, you’d need to modify the HTTP Request nodes and APIs accordingly.

Q: Does this workflow generate additional API usage costs?
A: OpenAI API calls and Google Calendar/Notion API usage consume credits. Track your usage in the respective platforms to avoid surprises.

Q: Is my chat and task data secure?
A: All API communication uses secure OAuth2 tokens and HTTPS. Header authentication protects webhook access.

Q: Can this handle high volumes of chat requests?
A: This workflow is optimized for individual or team use. Scaling for enterprise requires parallel webhook and processing improvements.

10. Conclusion

By following this comprehensive guide, you have created a powerful n8n automation that connects OpenAI LangChain agents with Google Calendar and Notion. You automated the way Anna manages tasks and appointments, saving her hours of tedious manual entry and reducing scheduling conflicts.

This workflow proves how AI-driven routing and contextual memory enable seamless conversation-driven productivity tools. Next, consider extending this system with more agents for email handling or CRM updates to further boost your team’s efficiency.

Keep experimenting, and happy automating!