How to Sync Client Messages from Basecamp to Slack with n8n

n8n Workflow > + > Trigger > Webhook

Set up Basecamp webhook in n8n

Create a new workflow in n8n and add a Webhook trigger node. Copy the webhook URL from the node settings. In Basecamp, go to your project settings and find the webhooks section. Add the n8n webhook URL and select message events as your trigger type.

1. 1Click the + button in n8n and select Webhook trigger
2. 2Copy the generated webhook URL from the node panel
3. 3Open your Basecamp project settings
4. 4Navigate to Webhooks and paste the n8n URL
5. 5Select 'Message posted' from the event types

Credentials > + > Basecamp 3

Add Basecamp credentials to n8n

Create new Basecamp 3 credentials in n8n using OAuth2. You'll need to authorize n8n to access your Basecamp account. The credential setup requires your Basecamp account ID and user agent string. Use your company name as the user agent.

1. 1Click Credentials in the left sidebar
2. 2Select + and choose Basecamp 3
3. 3Click 'Connect my account' for OAuth setup
4. 4Authorize n8n in the Basecamp popup
5. 5Enter your company name as User Agent

Workflow > + > Basecamp 3

Add message details node

Insert a Basecamp 3 node after your webhook trigger to fetch full message details. Set the operation to 'Get' and resource to 'Message'. The webhook payload contains basic info but you need the full message content and author details for your Slack notification.

1. 1Click + after the webhook trigger node
2. 2Search for and select Basecamp 3
3. 3Set Resource to 'Message' and Operation to 'Get'
4. 4Map Project ID from webhook: {{$node.Webhook.json.recording.bucket.id}}
5. 5Map Message ID from webhook: {{$node.Webhook.json.recording.id}}

Workflow > + > IF

Filter internal team messages

Add an IF node to skip notifications when your internal team posts messages. Create a condition that checks if the message author's email domain matches your company domain. This prevents notification spam when team members post updates in client projects.

1. 1Add an IF node after the Basecamp node
2. 2Set condition to 'String' and 'Not contains'
3. 3First value: {{$node['Basecamp 3'].json.creator.email_address}}
4. 4Second value: @yourcompany.com (replace with your domain)
5. 5Connect the 'true' output to continue the workflow

Workflow > + > Basecamp 3

Add project name lookup

Insert another Basecamp 3 node to get the project name for your Slack notification. Set operation to 'Get' and resource to 'Project'. You'll use the project ID from the original webhook to fetch the full project details including the name.

1. 1Add Basecamp 3 node after the IF node
2. 2Set Resource to 'Project' and Operation to 'Get'
3. 3Set Project ID to {{$node.Webhook.json.recording.bucket.id}}
4. 4Leave other fields empty

Workflow > + > Code

Create project-to-channel mapping

Add a Code node to map specific Basecamp projects to their corresponding Slack channels. Create a lookup object that matches project IDs to channel names. This ensures messages from different clients go to the right private channels.

1. 1Insert a Code node after the project lookup
2. 2Select 'Run Once for All Items' mode
3. 3Paste the channel mapping code in the editor
4. 4Update the projectChannelMap with your actual project IDs
5. 5Set fallback channel for unmapped projects

Credentials > + > Slack OAuth2 API

Set up Slack credentials

Create Slack OAuth2 credentials in n8n with the required scopes. You need chat:write, channels:read, and groups:read permissions to send messages to private channels. Generate the credentials through your Slack app settings in the Slack API console.

1. 1Go to api.slack.com and create a new app
2. 2Add OAuth scopes: chat:write, channels:read, groups:read
3. 3Install the app to your workspace
4. 4Copy the Bot User OAuth Token
5. 5Create new Slack OAuth2 credentials in n8n with this token

Workflow > + > Slack > Post Message

Build Slack notification

Add a Slack node to send the formatted message notification. Set the operation to 'Post Message' and configure the channel from your mapping code. Create a message template that includes the client name, project name, message preview, and link back to Basecamp.

1. 1Add Slack node and select 'Post Message' operation
2. 2Set Channel to {{$node.Code.json.slackChannel}}
3. 3Set Text to your formatted message template
4. 4Enable 'Link Names' to mention users if needed
5. 5Set Username to 'Basecamp Bot'

Workflow > Execute Workflow

Test with client message

Activate your workflow and post a test message in Basecamp as if you were a client. Check that the notification appears in the correct Slack channel within 10 seconds. Verify that internal team messages don't trigger notifications by posting one from your company email.

1. 1Click the workflow toggle to activate it
2. 2Post a message in Basecamp using a non-company email
3. 3Check the target Slack channel for the notification
4. 4Post another message using your company email
5. 5Confirm this second message doesn't create a notification

This code maps Basecamp projects to Slack channels and creates formatted notifications. Paste it in the Code node after the project lookup step.

const projectChannelMap = {
  '12345678': '#client-acme',
  '23456789': '#client-techstart', 

const projectChannelMap = {
  '12345678': '#client-acme',
  '23456789': '#client-techstart', 
  '34567890': 'C01ABC123DE' // private channel ID
};

const webhookData = $node.Webhook.json;
const messageData = $node['Basecamp 3'].json;
const projectData = $node['Basecamp 3_1'].json;

const projectId = webhookData.recording.bucket.id.toString();
const slackChannel = projectChannelMap[projectId] || '#general';

const clientName = messageData.creator.name;
const projectName = projectData.name;
const messageContent = messageData.content.length > 200 
  ? messageData.content.substring(0, 197) + '...'
  : messageData.content;

const basecampUrl = messageData.app_url;
const timestamp = new Date(messageData.created_at).toLocaleString();

const slackMessage = `🔔 New message from ${clientName} in ${projectName}\n\n"${messageContent}"\n\n📅 ${timestamp}\nView in Basecamp: ${basecampUrl}`;

return [{
  json: {
    slackChannel: slackChannel,
    formattedMessage: slackMessage,
    clientName: clientName,
    projectName: projectName,
    isClientMessage: !messageData.creator.email_address.includes('@yourcompany.com')
  }
}];