Recover missed calls and book HVAC appointments with GoHighLevel, Twilio, Gemini

Workflow explanation: Watch on YouTube

Automated Missed Call Recovery with Gohighlevel + Twilio + Gemini

Prerequisites for the HVAC n8n Workflow

Before setting up the workflow in n8n, ensure you have completed the following foundational steps:

Twilio Call Status Webhook:** Set the webhook of Sub-workflow 1 in the Twilio Voice section for "Call Status Changes". GoHighLevel Custom Fields:** Create two custom fields in GoHighLevel (GHL): called phone number call sid Twilio API Integration:** Ensure your Twilio API credentials are ready and configured in n8n. GoHighLevel Developer App:** Create a free GoHighLevel Developer App with the following scopes: contacts.readonly, contacts.write, opportunities.readonly, opportunities.write, locations.readonly. Generate the Client ID and Secret within the Developer App. Enter these into the n8n GHL OAuth credentials. Copy the OAuth Redirect URL from n8n to the App OAuth redirection settings and complete the authentication process. GoHighLevel Automation Workflow:** Create a workflow inside GHL that triggers when a "New Appointment is Created" and fires a POST webhook to the URL generated by Sub-workflow 3 in n8n. GoHighLevel Pipeline Setup:** Create a pipeline in GHL named "Missed call to appointment" with the following 3 stages: SMS sent No Reply Engaged | Appointment Link Sent BOOKED Scheduling Link:** Note down your GoHighLevel scheduling link and keep it handy to insert into the Twilio SMS node.

Workflow Breakdown

This n8n architecture is divided into three distinct sub-workflows. Here is the node-by-node explanation.

Sub-Workflow 1: Automated Missed Call Follow-Up Goal: Detect a missed call, log it in GoHighLevel, and immediately text the prospect.

When Webhook Received (n8n-nodes-base.webhook):** Acts as the entry point. It receives incoming POST call data from your telephony provider (Twilio) whenever a call status changes. Filter Valid Call Statuses (n8n-nodes-base.if):** Evaluates the incoming webhook payload. It only allows the workflow to continue if the CallStatus contains busy, no-answer, or canceled. Prepare Lead Data (n8n-nodes-base.set):** Cleans and maps the incoming JSON data. It extracts the caller's phone number, removes the + sign for clean formatting, grabs the called number and CallSid, and attaches specific tags like missed-call-lead. Create Lead in HighLevel (n8n-nodes-base.highLevel):** Pushes the cleaned data into GHL to create a new Contact. It maps the custom fields you created (called phone number and call sid) and assigns the hvac-inbound-missed tag. Create Opportunity in HighLevel (n8n-nodes-base.highLevel):** Creates a pipeline opportunity for the newly generated lead. It names the opportunity dynamically (e.g., "Missed Call.... [Phone].... [Date/Time]"). Send SMS via Twilio (n8n-nodes-base.twilio):** Sends the initial outreach text message to the caller (e.g., "Hi, I believe you missed a call with us... Please state your issue directly here"). Update Opportunity Status (n8n-nodes-base.highLevel):** Updates the GHL opportunity stage to the first stage in your pipeline ("SMS sent No Reply") to track that the initial outreach has occurred.

Sub-Workflow 2: AI-Powered SMS Lead Qualification & Booking Goal: Process replies to the initial SMS, use AI to determine if it's a valid HVAC opportunity, and send a booking link.

When SMS Received (n8n-nodes-base.twilioTrigger):** Listens for incoming SMS messages on your Twilio number. Check If Lead (n8n-nodes-base.highLevel):** Searches GHL to see if the sender's phone number already exists as a contact. Check Pipeline State (n8n-nodes-base.highLevel):** Looks up the specific opportunity associated with this contact in the "Missed call to appointment" pipeline. Lead Analyzer Agent (@n8n/n8n-nodes-langchain.agent):** The core AI brain of this sub-workflow. It consists of three integrated parts: The Agent: Prompted to act as an HVAC Opportunity Finder. It evaluates the user's SMS context to determine if they need HVAC services and if it's appropriate to send a booking link. Gemini Chat Model: Uses Google's gemini-3.1-flash-lite-preview model to process the prompt and context. Parse Structured Output: Forces the AI to return a clean JSON response (e.g., {"HVAC_oppurtunity?": "yes"}). If HVAC Opportunity Found (n8n-nodes-base.if):** Checks the parsed JSON output from the AI. If the AI determined the answer is "yes" or "yeah", the workflow proceeds. Send Response SMS (n8n-nodes-base.twilio):** Sends a text message containing your GHL scheduling link to prompt the prospect to book a visit. Update Lead Opportunity (n8n-nodes-base.highLevel):** Moves the GHL opportunity stage forward to "Engaged | Appointment Link Sent".

Sub-Workflow 3: GoHighLevel Appointment Sync & Pipeline Advancement Goal: Finalize the pipeline sequence once the prospect actually books an appointment through your scheduling link.

When Appointment Booked (n8n-nodes-base.webhook):** Receives the payload triggered by the GHL automation workflow you created in the prerequisites (fired when an appointment is booked). Check Lead SMS Origin (n8n-nodes-base.highLevel):** Queries GHL using the phone number from the appointment payload to ensure it matches up with the correct existing contact record. Check Pipeline State1 (n8n-nodes-base.highLevel):** Retrieves the current opportunity linked to this phone number that is currently sitting in the "Engaged" stage. Update Contact in HighLevel (n8n-nodes-base.highLevel):** Fills in the missing data gaps. Since the initial missed call only gave you a phone number, this node uses the data submitted in the booking form to update the contact's First Name, Last Name, and Email address. Update Opportunity in HighLevel (n8n-nodes-base.highLevel):** Moves the opportunity to its final stage: "BOOKED".