How to Send Close Lead Assignments to Slack with n8n

Close > Settings > Integrations > Webhooks > Add Webhook

Create a webhook in Close

Log into Close and go to Settings > Integrations > Webhooks. Click 'Add Webhook'. You'll enter a URL here — leave the tab open because you'll paste n8n's URL in the next step. Set the event to 'Lead Updated' since Close fires assignment changes under that event type, not a dedicated assignment event.

1. 1Click your avatar in the bottom-left corner of Close
2. 2Select 'Settings' from the dropdown
3. 3Click 'Integrations' in the left sidebar
4. 4Click 'Webhooks', then click the blue 'Add Webhook' button
5. 5Select 'Lead Updated' as the event type and leave the URL field blank for now

n8n > New Workflow > + Add Node > Webhook

Set up the n8n Webhook trigger node

In n8n, create a new workflow and add a Webhook node as the trigger. Set the HTTP method to POST. n8n will generate a unique webhook URL — copy it. Switch back to Close and paste this URL into the webhook configuration you started in Step 1. Save the Close webhook.

1. 1Click '+ New Workflow' in the n8n sidebar
2. 2Click the '+' node button and search for 'Webhook'
3. 3Set HTTP Method to 'POST'
4. 4Copy the generated Production URL shown in the node panel
5. 5Paste the URL into the Close webhook URL field and save

n8n > Webhook Node > Listen for Test Event

Test the webhook with a real Close assignment

In n8n, click 'Test Workflow' so the Webhook node starts listening. Go to Close, open any lead, and change the assigned user to someone else. Return to n8n — the Webhook node should show a green execution with a full payload. Inspect the JSON to confirm you can see the 'assigned_to' field and the lead's contact data.

1. 1Click 'Test Workflow' in the top toolbar of your n8n canvas
2. 2Open Close in a separate tab and open any lead record
3. 3Change the 'Assigned To' field to a different user and save
4. 4Return to n8n and click the Webhook node to view the incoming payload

n8n Canvas > + Add Node > IF

Add an IF node to filter assignment changes only

Add an IF node directly after the Webhook node. Close's 'Lead Updated' payload includes a 'changed_fields' array listing which fields changed. Set your IF condition to check whether 'assigned_to' appears in that array. Only route payloads that contain this value down the 'true' branch — everything else hits the 'false' branch and stops.

1. 1Click the '+' connector on the right side of the Webhook node
2. 2Search for 'IF' and add it
3. 3Set Condition to: String, Value 1 = {{ $json.changed_fields.join(',') }}, Operation = 'Contains', Value 2 = 'assigned_to'
4. 4Leave the 'false' branch unconnected — it will simply stop execution

n8n Canvas > + Add Node > HTTP Request

Fetch full lead details from Close API

The webhook payload contains a lead ID but may not include all the fields you want in your Slack message — specifically custom fields like company size. Add an HTTP Request node on the 'true' branch to GET the full lead record from Close's REST API. Use the lead ID from the webhook payload in the URL.

1. 1Click the '+' connector on the 'true' output of the IF node
2. 2Search for 'HTTP Request' and add it
3. 3Set Method to 'GET'
4. 4Set URL to: https://api.close.com/api/v1/lead/{{ $('Webhook').item.json.data.id }}/
5. 5Under Authentication, select 'Basic Auth' and enter your Close API key as the username with a blank password

n8n Canvas > + Add Node > Code

Resolve the assigned user's name and Slack channel

The Close payload gives you an assigned_to value like 'user_abc123' — not a human name and not a Slack channel. Add a Code node to map this user ID to a display name and their Slack channel. Define a static lookup object inside the code. This is the most maintainable approach for teams under 20 reps.

1. 1Click the '+' connector on the HTTP Request node output
2. 2Search for 'Code' and add it
3. 3Select 'Run Once for All Items' mode
4. 4Paste the mapping code (see pro tip) into the JavaScript editor
5. 5Click 'Test Step' to confirm the output includes repName and slackChannel fields

This single Code node handles both the user-to-channel lookup and the Slack Block Kit message assembly. Paste it in Step 6's Code node, replacing the two separate Code nodes if you prefer a single step. Update the 'repLookup' object with your actual Close user IDs and Slack channel names before testing.

// n8n Code Node — Lead Assignment Notification Builder
// Combines user lookup + Block Kit message formatting
// Paste into a Code node connected after the HTTP Request (Close API) node

// n8n Code Node — Lead Assignment Notification Builder
// Combines user lookup + Block Kit message formatting
// Paste into a Code node connected after the HTTP Request (Close API) node

const lead = $('HTTP Request').item.json;
const webhookData = $('Webhook').item.json;

// Map Close user IDs to rep names and Slack channels
// Replace these with your actual Close user IDs
const repLookup = {
  'user_7f3kd92': { name: 'James Okafor', channel: '#leads-james' },
  'user_4a1mn58': { name: 'Sarah Chen', channel: '#leads-sarah' },
  'user_9x2pq71': { name: 'Marcus Webb', channel: '#leads-marcus' },
};

const assignedUserId = webhookData.data.assigned_to;
const rep = repLookup[assignedUserId] || { name: 'Unknown Rep', channel: '#leads-unassigned' };

// Pull primary contact details safely
const contacts = lead.contacts || [];
const primaryContact = contacts[0] || {};
const contactName = primaryContact.name || 'No contact listed';
const contactEmail = (primaryContact.emails && primaryContact.emails[0]) ? primaryContact.emails[0].email : 'No email';
const contactPhone = (primaryContact.phones && primaryContact.phones[0]) ? primaryContact.phones[0].phone : 'No phone';

// Pull custom fields — update key to match your Close account
const companySize = lead.custom && lead.custom['cf_company_size'] ? lead.custom['cf_company_size'] : 'Unknown';

const leadUrl = `https://app.close.com/leads/${lead.id}/`;

// Build Slack Block Kit payload
const blocks = [
  {
    type: 'header',
    text: { type: 'plain_text', text: `🎯 New Lead Assigned: ${lead.display_name}`, emoji: true }
  },
  {
    type: 'section',
    fields: [
      { type: 'mrkdwn', text: `*Assigned To:*\n${rep.name}` },
      { type: 'mrkdwn', text: `*Lead Source:*\n${lead.source || 'Not set'}` },
      { type: 'mrkdwn', text: `*Company Size:*\n${companySize}` },
      { type: 'mrkdwn', text: `*Status:*\n${lead.status_label || 'Unknown'}` }
    ]
  },
  {
    type: 'section',
    fields: [
      { type: 'mrkdwn', text: `*Contact:*\n${contactName}` },
      { type: 'mrkdwn', text: `*Phone:*\n${contactPhone}` },
      { type: 'mrkdwn', text: `*Email:*\n${contactEmail}` }
    ]
  },
  {
    type: 'actions',
    elements: [
      {
        type: 'button',
        text: { type: 'plain_text', text: 'Open in Close', emoji: true },
        url: leadUrl,
        style: 'primary'
      }
    ]
  }
];

return [{
  json: {
    slackChannel: rep.channel,
    repName: rep.name,
    blocks: JSON.stringify(blocks),
    fallbackText: `New lead assigned to ${rep.name}: ${lead.display_name} (${contactPhone})`,
    leadId: lead.id,
    leadUrl: leadUrl
  }
}];

n8n Canvas > + Add Node > Code

Format the Slack message with lead details

Add another Code node to build the final Slack Block Kit message. Block Kit gives you structured sections with bold labels, making the lead details scannable at a glance. Pull company name, lead source, company size, primary contact name, and primary phone from the HTTP Request node's output.

1. 1Click the '+' connector on the user-lookup Code node
2. 2Add another Code node
3. 3Build the blocks array with a header block and a fields section block
4. 4Reference lead data using $('HTTP Request').item.json syntax
5. 5Include a fallback text property for Slack clients that don't render Block Kit

n8n Canvas > + Add Node > Slack > Send Message

Add and configure the Slack node

Add the Slack node and connect your Slack account via OAuth. Set the Resource to 'Message' and Operation to 'Send'. Set the Channel field to the dynamic slackChannel value from your Code node output. Set the Message field to the blocks array. Make sure you toggle 'Send as Bot' on so the message comes from your integration bot, not your personal Slack account.

1. 1Click '+' and search for 'Slack', then select the Slack node
2. 2Click 'Create New Credential' and complete the OAuth flow with your Slack workspace
3. 3Set Resource to 'Message' and Operation to 'Send'
4. 4Set Channel to: {{ $json.slackChannel }}
5. 5Enable 'Blocks' toggle and paste in the blocks reference, set Text fallback

n8n > Workflow Settings > Error Workflow

Add error handling with an Error Trigger node

Close does not retry failed webhook deliveries. If your Slack node fails — rate limit, wrong channel, token expiry — the assignment notification is lost silently. Add a separate Error Workflow in n8n's workflow settings that pings a #alerts channel with the failed execution ID. This takes 3 minutes and saves real lead loss.

1. 1Click the three-dot menu at the top of the canvas and select 'Settings'
2. 2Under 'Error Workflow', click 'Select Workflow' and create a new one
3. 3In the new error workflow, add an Error Trigger node and connect it to a Slack node
4. 4Configure the Slack node to post to #alerts with the message: 'Lead notification failed. Execution: {{ $json.executionId }}'
5. 5Save both workflows

n8n > Workflow Canvas > Activate toggle (top right)

Activate the workflow and validate end-to-end

Switch the Webhook node's URL from Test to Production in the Close webhook settings. Toggle the workflow to Active in n8n. Assign a real lead in Close to a real rep and confirm the message appears in their Slack channel within 15 seconds. Check that the company size, lead source, and contact fields are all populated correctly.

1. 1Go back to Close Settings > Integrations > Webhooks and update the URL to the n8n Production URL
2. 2In n8n, click the grey 'Inactive' toggle in the top-right of the canvas to set it to 'Active'
3. 3Open Close and reassign a test lead to a rep whose channel is set up
4. 4Check the rep's Slack channel for the notification within 15 seconds
5. 5Open n8n's Executions log and confirm the run shows green