Setup Guide

Send LinkedIn invites from Blue Line in ~10 minutes

Blue Line uses Dux-Soup to dispatch LinkedIn connection requests through your own LinkedIn account. Follow the steps below and your outreach will fire from inside the ATS like every other action.

What you'll need before you start

• Google Chrome (the Dux-Soup extension is Chrome-only)
• A LinkedIn account you log into regularly
• ~10 minutes — most of it spent on the Dux-Soup signup

Dux-Soup Setup

LinkedIn invites + messages, dispatched from your own account

Sign up for Dux-Soup

Dux-Soup is a Chrome extension that sends LinkedIn invites and messages through your own LinkedIn account. Blue Line uses Dux-Soup's Remote Control API to queue invites — Dux-Soup then dispatches them from your browser. 1. Go to dux-soup.com and click "Try for free" 2. Sign up with your work email (use the same one you use for Blue Line if possible) 3. When picking a plan, choose Turbo or higher Why Turbo? Dux-Soup's Remote Control API — the piece Blue Line connects to — is only included on Turbo and above. The Pro plan won't work with Blue Line.

Tip: Dux-Soup offers a free trial of their paid plans. Use the trial to confirm everything works before committing — you can downgrade or cancel later.

Install the Chrome extension

Once your Dux-Soup account is active: 1. Open Chrome (Dux-Soup is Chrome-only — Firefox and Safari aren't supported) 2. Inside your Dux-Soup dashboard, click "Install Chrome Extension" — or grab it from the Chrome Web Store 3. Click "Add to Chrome" and accept the permissions 4. You should see a small dolphin icon in your Chrome toolbar If you don't see the icon, click the puzzle-piece icon in Chrome's toolbar and pin Dux-Soup so it stays visible.

Tip: If you have any other LinkedIn automation extensions (Lemlist, Octopus CRM, Expandi, etc.), disable them. Multiple extensions trying to drive LinkedIn at the same time will collide.

Log in to Dux-Soup, then open LinkedIn

The extension drives LinkedIn from your own browser, so two tabs need to be alive: 1. Click the Dux-Soup dolphin icon and sign in with the account you just created 2. Open linkedin.com in a separate tab and log in to your LinkedIn account 3. Leave the LinkedIn tab open — the extension only dispatches invites while LinkedIn is loaded in your browser If you close the LinkedIn tab, invites queue up but never go out. Re-open LinkedIn and they'll flow through.

Tip: Use your personal LinkedIn, not a company page. Candidates see the invite coming from you personally — that's the whole point of using your own account.

Find your Dux-Soup User ID and Authentication Key

Blue Line needs two values from Dux-Soup to talk to your account: 1. Click the Dux-Soup dolphin icon in Chrome 2. Click the gear icon (Options) in the top right of the popup 3. Click the "Account" tab 4. You'll see two fields — copy both: - User ID — a long number (your LinkedIn member ID) - Authentication Key — an opaque string of letters and numbers Keep this tab open. You'll paste both into Blue Line in the next step.

Tip: If the Account tab doesn't show these fields, your Dux-Soup plan probably doesn't include Remote Control API. Upgrade to Turbo or higher inside Dux-Soup and the fields will appear.

Connect Dux-Soup to Blue Line

Now bring those two values into Blue Line: 1. In Blue Line, go to Settings → LinkedIn Outreach section 2. Pick "I use Dux-Soup for LinkedIn automation" and click Save LinkedIn Preference 3. Scroll down to the Integrations section 4. Find the "Dux-Soup — LinkedIn Outreach" card 5. Paste your User ID into the first field 6. Paste your Authentication Key into the second field 7. Click Connect Dux-Soup You should see a green "Connected as 1114…9318" banner appear (showing the first and last four digits of your User ID).

Tip: Auth keys are case-sensitive and easy to accidentally truncate. If Connect fails, try generating a new Authentication Key in Dux-Soup (Options → Account → regenerate) and pasting the fresh one.

Turn on Noteless mode (temporary)

Right below the green Connected banner you'll see an amber box about "Dux-Soup connect-note bug." LinkedIn recently changed the way their connect modal works, and Dux-Soup's extension hasn't shipped a fix yet — invites that include a personalized note fail to send. Tick the "Noteless mode" checkbox. With Noteless on, Blue Line sends connection requests without a personalized note. They go through cleanly while we wait on Dux-Soup's update. When Dux-Soup ships their fix, come back to this card and uncheck the box. Your invites will start carrying personalized notes again.

Tip: Sending without a note isn't as personalized, but it still works — and an invite that delivers beats a personalized invite that silently fails. Real recruiters routinely send connect-without-note even outside of any bug.

Send a test invite

Verify everything is wired up end-to-end: 1. Open any candidate in your ATS who has a LinkedIn URL on their profile 2. Click Invite to Apply → LinkedIn InMail tab → Generate Message 3. Click the blue "Send via LinkedIn" button 4. You should see a green toast confirming the invite was queued 5. Check the Dux-Soup extension's Activity log — your invite should appear and flip to "Sent" within a few seconds 6. Open https://www.linkedin.com/mynetwork/invitation-manager/sent/ — your invite should show up there within a minute or two Once you've confirmed an invite landed in your LinkedIn Sent Invitations, you're done. Every bulk LinkedIn outreach Blue Line sends from now on will flow through this same connection.

Tip: LinkedIn caps daily connection requests around 100 per week for free accounts. Dux-Soup throttles automatically to stay safe. If you have LinkedIn Premium or Sales Navigator, your limits are higher.

You're ready to send.

From here on, every LinkedIn outreach you run in Blue Line — per candidate or in bulk — flows through your Dux-Soup connection automatically. Match candidates, review the generated messages, hit Send.

Open my ATS

Common Questions

Still stuck?

Email us at support@bluelinesearch.ai or use the Maverick chat in the bottom-right corner of your dashboard. We'll walk you through it.