How to Create Notion Tasks from Slack with n8n

api.slack.com/apps > Your App > Event Subscriptions

Create a Slack App and enable Event Subscriptions

Go to api.slack.com/apps and click 'Create New App'. Choose 'From scratch', name it something like 'Notion Task Bot', and select your workspace. You need a dedicated app here because n8n's webhook URL must be registered with Slack's Event Subscriptions system — you can't do this through a generic OAuth token. Once the app is created, navigate to 'Event Subscriptions' in the left sidebar and toggle 'Enable Events' to On.

1. 1Go to api.slack.com/apps and click 'Create New App'
2. 2Select 'From scratch'
3. 3Enter an app name and select your target workspace
4. 4Click 'Create App'
5. 5In the left sidebar, click 'Event Subscriptions'
6. 6Toggle 'Enable Events' to On — leave the Request URL blank for now

Paste this into the Code node in Step 7. It pulls the message text, formats the Slack timestamp into a human-readable date, builds the Slack deep-link URL from the channel and timestamp, truncates titles over 100 characters so Notion doesn't reject them, and outputs a clean object ready for the Notion node.

// Code node — runs after conversations.history HTTP Request
// Input: HTTP response from Slack API
// Output: structured task object for Notion

// Code node — runs after conversations.history HTTP Request
// Input: HTTP response from Slack API
// Output: structured task object for Notion

const items = $input.all();
const results = [];

for (const item of items) {
  const response = item.json;
  
  // Guard: API call failed
  if (!response.ok || !response.messages || response.messages.length === 0) {
    throw new Error(`Slack API error: ${response.error || 'No messages returned'}`);
  }

  const message = response.messages[0];
  const rawText = message.text || '(no text content)';

  // Truncate long messages — Notion title max is 2000 chars,
  // but over 100 chars makes the task list unreadable
  const taskTitle = rawText.length > 100
    ? rawText.substring(0, 97) + '...'
    : rawText;

  // Pull webhook event data from the trigger node
  const webhookData = $('Webhook').item.json.event;
  const channelId = webhookData.item.channel;
  const slackTs = webhookData.item.ts;
  const userId = webhookData.user;
  const emojiName = webhookData.reaction;

  // Convert Slack epoch timestamp to ISO date string
  // Slack ts format: '1704326400.000200' — take the integer part
  const epochSeconds = parseInt(slackTs.split('.')[0], 10);
  const createdDate = new Date(epochSeconds * 1000).toISOString().split('T')[0];

  // Build Slack deep link URL
  // Format: /archives/CHANNEL_ID/pTIMESTAMP (no dot in timestamp)
  const tsForUrl = slackTs.replace('.', '');
  const workspaceDomain = 'yourworkspace'; // replace with your Slack subdomain
  const messageUrl = `https://${workspaceDomain}.slack.com/archives/${channelId}/p${tsForUrl}`;

  results.push({
    json: {
      taskTitle,
      slackUser: userId,
      channelId,
      slackTimestamp: slackTs,
      messageUrl,
      createdDate,
      emojiUsed: emojiName,
      rawMessageText: rawText
    }
  });
}

return results;

n8n > New Workflow > + Add Node > Webhook

Set up the Slack Webhook node in n8n

Open your n8n instance and create a new workflow. Add a 'Webhook' node as the first node — not the Slack trigger node, because Slack's Event API requires a URL challenge verification that the generic Webhook node handles better. Set the HTTP method to POST and copy the generated webhook URL. You'll paste this into Slack's Event Subscriptions page next.

1. 1Click '+ Add first step' in the center of the canvas
2. 2Search for 'Webhook' and select it
3. 3Set HTTP Method to 'POST'
4. 4Set Response Mode to 'Using Respond to Webhook Node' — you'll add that node later
5. 5Click 'Listen for Test Event' to activate the URL
6. 6Copy the Test URL shown at the top of the node panel

api.slack.com/apps > Your App > Event Subscriptions > Subscribe to Bot Events

Register the n8n webhook URL in Slack and subscribe to reaction events

Paste your n8n webhook URL into the 'Request URL' field on Slack's Event Subscriptions page. Slack immediately sends a challenge POST request — n8n must respond with the challenge value within 3 seconds or Slack rejects the URL. To handle this, add a 'Respond to Webhook' node in n8n right after the Webhook node and configure it to return the challenge. Under 'Subscribe to bot events', add the event 'reaction_added'.

1. 1Paste your n8n Test URL into the 'Request URL' field
2. 2In n8n, add a 'Code' node after the Webhook node temporarily to echo back the challenge — use: return [{json: {challenge: $input.first().json.challenge}}]
3. 3Connect it to a 'Respond to Webhook' node set to 'First Incoming Item'
4. 4Wait for Slack to show a green 'Verified' checkmark
5. 5Under 'Subscribe to Bot Events', click 'Add Bot User Event'
6. 6Search for and add 'reaction_added'

api.slack.com/apps > Your App > OAuth & Permissions > Bot Token Scopes

Add required OAuth scopes and install the app

Navigate to 'OAuth & Permissions' in your Slack app settings. Under 'Bot Token Scopes', add three scopes: channels:history (to fetch message content from the reacted message), reactions:read (to receive reaction events), and channels:read (to resolve channel names). After adding scopes, click 'Install to Workspace' and authorize the app. Copy the Bot User OAuth Token — you'll need it in n8n.

1. 1Click 'OAuth & Permissions' in the left sidebar
2. 2Under 'Bot Token Scopes', click 'Add an OAuth Scope'
3. 3Add 'channels:history'
4. 4Add 'reactions:read'
5. 5Add 'channels:read'
6. 6Scroll up and click 'Install to Workspace'
7. 7Click 'Allow' on the authorization screen
8. 8Copy the 'Bot User OAuth Token' (starts with xoxb-)

n8n Workflow Canvas > + Add Node > IF

Filter for the target emoji reaction

The reaction_added event fires for every reaction in every channel the bot can see — thumbs up, heart, everything. Add an 'IF' node in n8n to filter down to just your chosen emoji. The reaction name in Slack's API payload does not include colons — ':clipboard:' is sent as 'clipboard'. Wire the IF node so only matching reactions continue to the next step.

1. 1Click the '+' connector after the Webhook node
2. 2Search for 'IF' and add it
3. 3Set Condition to 'String'
4. 4Set Value 1 to expression: {{ $json.event.reaction }}
5. 5Set Operation to 'Equal'
6. 6Set Value 2 to your chosen emoji name without colons, e.g. clipboard
7. 7Leave the 'False' branch unconnected or connect it to a 'No Operation' node

n8n Workflow Canvas > + Add Node > HTTP Request

Fetch the full Slack message content

The reaction_added event only gives you the message timestamp and channel ID — not the message text. You need to call Slack's conversations.history API to retrieve the actual message. Add an 'HTTP Request' node and configure it to call https://slack.com/api/conversations.history with the channel and timestamp parameters from the webhook payload. Include your Bot User OAuth Token as a Bearer token in the Authorization header.

1. 1Add an 'HTTP Request' node after the IF node's true branch
2. 2Set Method to 'GET'
3. 3Set URL to 'https://slack.com/api/conversations.history'
4. 4Under 'Query Parameters', add 'channel' = {{ $('Webhook').item.json.event.item.channel }}
5. 5Add 'latest' = {{ $('Webhook').item.json.event.item.ts }}
6. 6Add 'limit' = 1
7. 7Add 'inclusive' = true
8. 8Under 'Authentication', select 'Header Auth' and add Authorization: Bearer xoxb-your-token

n8n Workflow Canvas > + Add Node > Code

Parse the message and build the task payload

Add a 'Code' node to extract the message text, sender user ID, channel, and timestamp from the API response. You'll also format the Slack timestamp into a readable date here. The Code node lets you structure exactly the fields you want to send to Notion so the Notion node configuration stays clean.

1. 1Add a 'Code' node after the HTTP Request node
2. 2Set Language to 'JavaScript'
3. 3Paste the transformation code from the Pro Tip section below
4. 4Click 'Test Step' to verify the output fields look correct

n8n Workflow Canvas > + Add Node > Notion > Create Database Page

Connect Notion and create the database entry

Add a 'Notion' node and connect it with your Notion credentials (OAuth or Internal Integration Token). Set the operation to 'Create' and resource to 'Database Page'. Select your target Notion database from the dropdown — n8n will load all your accessible databases. Map each field from the Code node output to the corresponding Notion database property. At minimum, map the task title to the database's title property.

1. 1Add a 'Notion' node after the Code node
2. 2Click 'Credential for Notion API' and add your Internal Integration Token
3. 3Set Resource to 'Database Page'
4. 4Set Operation to 'Create'
5. 5In the Database ID field, select your task database from the dropdown
6. 6Click 'Add Property' for each field and map: Title = {{ $json.taskTitle }}, Status = 'To Do', Source = 'Slack'
7. 7Add a 'Text' property for Slack Message URL mapped to {{ $json.messageUrl }}

n8n Workflow Canvas > + Add Node > HTTP Request

Add a Slack confirmation reaction back to the message

Add an HTTP Request node to post a reaction back to the original Slack message confirming the task was created. This closes the loop for the person who added the emoji — they see a ✅ appear on the message within seconds and know it was captured. Call the reactions.add API endpoint with the channel, timestamp, and your confirmation emoji.

1. 1Add a second 'HTTP Request' node after the Notion node
2. 2Set Method to 'POST'
3. 3Set URL to 'https://slack.com/api/reactions.add'
4. 4Set Body Content Type to 'JSON'
5. 5Set Body to: { "channel": "{{ $('Code').item.json.channelId }}", "timestamp": "{{ $('Code').item.json.slackTimestamp }}", "name": "white_check_mark" }
6. 6Use the same Bearer token Authorization header as in Step 6

n8n Workflow Canvas > IF Node > Respond to Webhook

Handle the Slack URL verification challenge permanently

Replace the temporary challenge-echo Code node from Step 3 with a proper IF node that detects whether the incoming request is a challenge verification or a real event. Slack sends challenge requests during URL registration and occasionally for verification checks. Route challenge requests to a Respond to Webhook node that returns the challenge value, and route real events through your main workflow logic.

1. 1Add an IF node immediately after the Webhook trigger node
2. 2Set Condition: check if {{ $json.type }} equals 'url_verification'
3. 3On the 'true' branch, add a 'Respond to Webhook' node
4. 4Set its Response Body to: { "challenge": "{{ $json.challenge }}" }
5. 5On the 'false' branch, wire in your existing reaction filter IF node from Step 5
6. 6Delete the temporary Code node you added in Step 3

n8n Workflow > Activate Toggle | api.slack.com > Event Subscriptions > Request URL

Switch to Production URL and activate the workflow

Go back to your Webhook trigger node and copy the Production URL (not the Test URL). Update the Request URL in Slack's Event Subscriptions page with this production URL. Slack will re-verify it — your workflow must be active for this to succeed. Click 'Active' toggle at the top of your n8n workflow to turn it on, then go to Slack and react to any message with your target emoji to do a live test.

1. 1In n8n, click the Webhook node and copy the Production URL
2. 2Go to api.slack.com/apps > your app > Event Subscriptions
3. 3Replace the Test URL with your Production URL
4. 4Wait for the green 'Verified' checkmark
5. 5In n8n, click the 'Inactive' toggle in the top right to set it to 'Active'
6. 6Go to Slack, find any message, and react with your chosen emoji
7. 7Check your Notion database — the task should appear within 10 seconds