Realtime Notion-Todoist 2-way Sync

• Bidirectional sync: Changes made in Notion are reflected in Todoist, and vice-versa.
• Project and section mapping: Configure specific Notion databases and Todoist projects for synchronization.
• Status synchronization: Tasks can be marked as complete or incomplete across platforms.
• Task creation and updates: New tasks in Notion can be created in Todoist, and existing tasks can be updated.
• OAuth integration for Todoist: Securely connect your Todoist account.
• Setup helper: Guides you through the initial configuration process.

Workflow Setup:

1. **Initial Setup (Form Triggers):

   • Notion-Todoist Sync Setup Helper: Start by clicking 'Begin'.
   • Choose Notion Database: Select the Notion database you want to sync from the dropdown.
   • Choose Todoist Project: Select the Todoist project you want to sync from the dropdown.

2. **Todoist OAuth Authentication (for Webhook setup):

   • Todoist Webhook Setup Helper: Enter your Todoist Developer App 'Client ID' and 'Client secret'.
   • The workflow will then redirect you to Todoist to authorize the connection. This step is crucial for enabling webhooks, which facilitate real-time updates.

3. **Configuration Output:

   • Return config JSON: After the setup steps, this node will output a JSON configuration. Copy this JSON.

4. **Global Variables:

   • Navigate to your n8n workflow editor.
   • Click on 'Globals' in the left-hand sidebar.
   • Paste the copied JSON into the 'Globals' section. This makes the database_id and project_id available to the main sync nodes.

Synchronization Logic:

1. Fetch Data: The workflow fetches all relevant tasks from both your selected Notion database (Notion node) and Todoist project (Todoist node).

2. Compare Datasets: The Compare Datasets node merges and identifies differences between the Notion and Todoist tasks.

3. Process Differences: Based on the comparison, the workflow determines which tasks need to be created, updated, or marked as completed/incomplete.

   • New Tasks (Notion to Todoist): If a task exists in Notion but not in Todoist (identified by the absence of a 'Todoist ID' in Notion), a new task is created in Todoist.
   • Updated Tasks (Notion to Todoist): If a task exists in both but has been updated in Notion, the corresponding Todoist task is updated.
   • Completed Tasks (Notion to Todoist): If a task's status in Notion is 'Done', the corresponding Todoist task is marked as completed.
   • Incomplete Tasks (Todoist to Notion): If a task's status in Todoist changes (e.g., reopened), the corresponding Notion task is updated to reflect its current status.

Important Notes:

• 'Todoist ID' Property in Notion: Ensure your Notion database has a text property named exactly 'Todoist ID' (case-sensitive) to store the Todoist task ID. This is crucial for linking tasks and enabling bidirectional sync.
• Filtering in Notion Node: The Notion node has specific filters to only pull tasks that are not 'Done' or 'Obsolete', and are either 'Focused' or have a 'Due' date. Adjust these filters if your workflow requires different criteria.
• Credentials: Ensure you have set up the correct n8n credentials for both Notion and Todoist.
• Webhook Setup: For true real-time sync, ensure your Todoist Developer App is correctly set up with a webhook URL pointing to your n8n instance's webhook. This workflow includes a helper for this OAuth authentication process.