# How to Automate Customer Review Management with n8n, Gmail, and Gemini AI Install an n8n workflow that emails review requests, filters unhappy feedback privately, logs ratings in Google Sheets, and drafts Google review replies with Gemini AI. Published: 2026-06-08 Updated: 2026-06-08 Reading time: 12 min Canonical: https://www.fusionsync.ai/workflow/posts/implement-customer-review-management-n8n Markdown: https://www.fusionsync.ai/workflow/posts/implement-customer-review-management-n8n/markdown Tags: n8n, Google reviews, reputation management, Gmail, Google Sheets, AI agents, Gemini Reviews decide whether a stranger trusts your business, yet asking for them is awkward and chasing them is worse. Send nothing and your happiest customers quietly move on; send a blast and you risk an angry one-star landing on your public Google listing where it sits forever. The naive fix, a manual "please review us" email, gets sent late, to the wrong people, with no way to catch a frustrated customer before they go public. This guide builds a review engine that handles the whole lifecycle in n8n. It emails customers a review form after purchase, filters happy customers toward your public Google listing while routing unhappy ones into a private feedback channel, logs every response in Google Sheets, and uses a Gemini AI agent to draft replies to your public reviews. It covers the same ground as the popular [WhatsApp-based review automation from GrowwStacks](https://growwstacks.com/blog/automate-google-reviews-with-n8n#feedback-filtering), but over email and without the click-tracking step. ## Available resources This build uses three assets you will set up below: 1. **n8n workflow** "Customer Review Management" (email requests, feedback filtering, and AI review replies). 2. **Google Sheet tab** "Customers" (the contact list and send-status tracker). 3. **Google Sheet tab** "Reviews" (the log of every rating, comment, and reply status). [Download workflow JSON: Customer Review Management](/workflows/implement-customer-review-management-n8n.json) ## What you'll need Before you begin, make sure you have: 1. An **n8n account** (cloud or self-hosted) reachable at a public HTTPS webhook URL. 2. A **Google account** with one Google Sheet (two tabs) used as the system of record. 3. A **Gmail account** for sending the review request emails. 4. A **Gemini API key** for the AI agent that drafts review replies (any chat model n8n supports also works). 5. A **hosted review form** (a simple web page) that collects a star rating and posts low ratings to your n8n webhook. 6. A **Google Business Profile** if you want to pull and reply to public Google reviews. ## Overview of the automation The automation runs in three phases that share one Google Sheet. A human decision sits between capturing feedback and replying to it. 1. **Request reviews.** On a schedule, n8n pulls customers who have not been asked yet and emails each one a link to your review form, then marks the row as sent. 2. **Capture and filter feedback.** The form sends 4 and 5 star customers to your public Google listing, while 1 to 3 star customers submit private feedback that posts to an n8n webhook and is logged for follow-up. 3. **Reply to public reviews.** A Google Business Profile trigger feeds each new public review to a Gemini agent, which drafts a short reply for your team to approve before it posts. Review requests sent, status tracked in Sheets Unhappy feedback captured privately, off the public listing AI-drafted replies to Google reviews for human approval The important design decision is the **rating split before anything becomes public**. A delighted customer is one tap from a five-star Google review; a frustrated one is one tap from a private message that reaches your inbox instead of your listing. The filter happens on the form itself, so the unhappy path never touches Google, and you get a chance to fix the problem before it costs you a public star. ## Step-by-step setup ### 1. Set up the Google Sheets Create one Google Sheet with two tabs. The first tab drives who gets emailed; the second is the review log. **Tab one, "Customers"** (the contact list and send tracker): | Column | Purpose | | ----------------- | ------------------------------------------------------------ | | `Name` | Customer display name, used to personalize the email | | `Email` | Where the review request is sent, also the row match key | | `Date of Purchase`| When they bought, so you can delay the ask if you want | | `Review Email` | Send status: `Not Sent` initially, set to `Sent` after email | | `Review msg Status`| Optional guard column the workflow checks before sending | **Tab two, "Reviews"** (the log of every response): | Column | Purpose | | -------------------------- | --------------------------------------------------------- | | `Name` | Reviewer name from the form | | `Email` | Reviewer email, for follow-up | | `Rating` | The star rating they submitted | | `Customer Review` | The free-text comment | | `Handle With AI Or Manually`| Who owns the reply: `AI` or `Manually` | | `Replied Or Not` | Reply status: `Not Replied` until handled | ### 2. Connect credentials in n8n Add three credentials so the Sheets, Gmail, and agent nodes can authenticate: 1. **Google Sheets** (OAuth2) with read and write on both tabs. 2. **Gmail** (OAuth2) for sending the review request emails. 3. **Google Gemini** for the chat model behind the review-reply agent. ### 3. Build phase one: email the review request **Trigger the batch.** Add a `Schedule Trigger` named `Schedule Trigger` and set the interval that fits your volume, for example once a day. Leave it disabled while you build and test, then enable it when you go live. **Pull customers who have not been asked.** Add a `Google Sheets` node named `Get row(s) in sheet` pointed at the `Customers` tab. Add a filter so it only returns rows where `Review Email` equals `Not Sent`. That keeps the batch to people who still need the ask. **Guard against double sends.** Add an `If` node that only continues when the send-status field is still empty: ```text ={{ $json['Review msg Status'] }} is empty ``` **Loop and send.** Add a `Loop Over Items` (Split in Batches) node so each customer is handled one at a time, then a `Gmail` node named `Send a message` on the loop output. Set the recipient to the customer email and the body to your review form link: ```text To: ={{ $json.Email }} Subject: Please help us with your valuable review Body: https://your-review-form-url ``` **Mark the row as sent.** After the Gmail node, add a `Google Sheets` node named `Update row in sheet` set to **Update**, matching on `Email`, and write `Review Email` = `Sent`. Wire it back into `Loop Over Items` so the batch advances to the next customer. This is what stops the same person being emailed twice. ### 4. Build phase two: capture and filter the feedback The filtering lives on the review form, not in n8n. Build a small page with a star rating that branches on the score: 4 and 5 stars open your public Google review link, while 1 to 3 stars reveal a short comment box and POST the feedback to your n8n webhook. **Receive the private feedback.** Add a `Webhook` node named `Receiving Customer Review` (POST). Enable CORS for your form origin so the browser can call it. The form should send a JSON body like this: ```json { "rating": 3, "name": "Jane Doe", "email": "jane@example.com", "review": "The product was fine but delivery was slow.", "timestamp": "2026-06-08T06:12:53.691Z" } ``` > **Protect the webhook** > > This endpoint is called from a public browser form, so it cannot send a secret > auth header. Keep the path unguessable, restrict CORS to your form's domain, > and validate the payload shape before writing to Sheets so a random POST cannot > pollute your review log. **Normalize the fields.** Add a `Set` node named `Edit Fields` (Edit Fields) that maps the incoming body into clean top-level fields: ```text rating = {{ $json.body.rating }} name = {{ $json.body.name }} email = {{ $json.body.email }} review = {{ $json.body.review }} ``` **Update the contact row.** Add a `Google Sheets` node named `Update row in sheet1` set to **Update** on the `Customers` tab, matching on `Email`, so you know this person responded. **Log the review.** Add a `Google Sheets` node named `Append row in sheet` set to **Append** on the `Reviews` tab. Map the rating, name, comment, and set the workflow defaults so new feedback lands in a clear queue: ```text Name = {{ $('Edit Fields').item.json.name }} Email = {{ $json.Email }} Rating = {{ $('Edit Fields').item.json.rating }} Customer Review = {{ $('Edit Fields').item.json.review }} Handle With AI Or Manually = Manually Replied Or Not = Not Replied ``` Defaulting private feedback to `Manually` and `Not Replied` is the human gate: a low rating is a service-recovery moment, so a person reads it and decides whether to reply by hand or hand it to the AI agent. ### 5. Build phase three: AI replies to public Google reviews **Trigger on new reviews.** The shipped workflow uses a `Manual Trigger` named "Change this with Google Business Profile Trigger" as a stand-in. Replace it with a Google Business Profile trigger (or a scheduled HTTP request to the Business Profile API) that emits each new public review. **Shape the review.** Add a `Set` node named `Edit Fields1` that pulls the fields the agent needs from the review payload: ```text reviewId = {{ $json.reviewId }} displayName = {{ $json.reviewer.displayName }} comment = {{ $json.comment }} createTime = {{ $json.createTime }} reviewReply = {{ $json.reviewReply }} ``` **Draft the reply.** Add a LangChain `AI Agent` named `AI Agent` with a `Google Gemini Chat Model` attached. Give it a tight system prompt and feed it the review: ```text System: You are a helpful assistant. Write simple and short replies to the customer's feedback. User: This is the customer review: {{ $json.comment }} Customer name: {{ $json.displayName }} ``` **Post the reply.** Add the node that writes the reply back to Google Business Profile. In the shipped file this is a `No Operation` placeholder named `Add Reply to Google Business Profile`; swap it for an HTTP Request to the Business Profile API once your credentials are in place. Keep a human approval in front of the post step until you trust the tone. ### 6. Import the workflow JSON Grab the ready-made workflow with the download button above, or export your own by opening the workflow in n8n and using the menu to **Download** the JSON. On the target instance, import the file, then re-create or re-select the three credentials from Step 2. Finally, update the Google Sheet document id, the two tab names, your Gmail sender, and the review form URL to match your setup. ## Testing the workflow Validate each phase before pointing it at real customers: 1. **Run the request batch.** Add one test row to `Customers` with `Review Email` set to `Not Sent`, run the schedule branch manually, and confirm the email arrives and the row flips to `Sent`. 2. **Submit a happy rating.** Open the form, pick five stars, and confirm it sends you to the Google review link with no row added to `Reviews`. 3. **Submit an unhappy rating.** Pick two stars, type a comment, submit, and confirm a new row appears in `Reviews` with `Handle With AI Or Manually` = `Manually` and `Replied Or Not` = `Not Replied`. 4. **Draft a reply.** Run the review-reply branch with a sample review and confirm the agent returns a short, on-topic reply before any post step. If the webhook never fires, check CORS and the form's POST URL first; a blocked cross-origin request is the most common failure point. ## Customization options - **Delay the ask.** Use `Date of Purchase` in a filter so the request only goes out a few days after the sale, when the experience is fresh but settled. - **Swap the channel.** Replace the Gmail node with WhatsApp, SMS, or Telegram if your customers prefer it; the rest of the flow is identical. - **Swap the model.** Replace Gemini with OpenAI, Anthropic, or any chat model n8n supports. The agent and prompt stay the same. - **Auto-reply to five-star reviews.** Let the AI agent handle clearly positive reviews end to end, and keep critical ones in the manual queue. - **Add a follow-up.** Email customers who were sent a request but never responded a gentle reminder after a few days. ## Common mistakes that quietly break this - **No double-send guard.** If you skip the `If` check and the status update, a customer can get the same request on every run. Always flip `Review Email` to `Sent` after emailing. - **Filtering in n8n instead of the form.** If unhappy customers are routed to Google and only filtered afterward, the bad review is already public. The split has to happen on the form, before the click. - **An open webhook.** Anyone who finds the URL can inject fake reviews into your log. Restrict CORS to your form domain and validate the payload before writing. - **Auto-posting AI replies.** A tone-deaf automated reply to a real complaint makes things worse. Keep a human approval in front of the post step until you trust it. - **Treating Sheets as disposable.** The `Reviews` tab is your audit log and follow-up queue. Match on a stable key (`Email`) and keep the status columns accurate. FusionSync AI builds workflows like this one end-to-end. [Hire FusionSync AI](https://fusionsync.ai/contact) ## Conclusion You now have a review engine that asks at the right moment, protects your public rating, and keeps a human in control of the replies. Happy customers flow to your Google listing, unhappy ones land in a private queue you can actually act on, every response is logged in Google Sheets, and a Gemini agent drafts the replies so your team only has to approve. More five-star reviews, fewer public surprises, and far less manual chasing. Need help setting this up? [Book a call](https://cal.com/fusionsyncai/n8n-hub-call-booking).