Zapier: ChatGPT Drafts Every Reply, Signatoro Signs It

Updated October 20, 2026. Built against the tool’s current screens and checked step by step. How we check this lesson

Every patient email that waits for a reply is a patient who might book somewhere else. In this free Zapier tutorial you build a four-step Zap that drafts the reply before anyone opens the email: Gmail New Email starts it, ChatGPT Conversation writes a warm reply from the patient's own words, Signatoro's Get Signature step adds the sender's real, current signature, and Gmail Create Draft Reply saves it in the patient's thread for a person to check and send. The AI writes the message and never signs it, so every reply carries the right name, title and phone number.

Start here first: Never Miss a New Client Inquiry using Zapier (module 1 of Zapier Automation Basics)

In the course: Part 7 · Zapier Automation Basics (Module 56 of the full course)

Part of: Email on Autopilot (step 5 of 14). Next up: Add AI to Make.com: ChatGPT Writes a Personal Reply, Gmail Sends It

Part of: Zapier Jump Start (step 4 of 4)

Part of: AI Apps Worth Knowing (step 51 of 62). Next up: Add AI to Make.com: ChatGPT Writes a Personal Reply, Gmail Sends It

What you will build

The example is Brookside Dental, a made-up family dental practice, and Dana Whitfield, its made-up patient coordinator. A parent emails the practice: their 6-year-old needs a first checkup and is nervous about the dentist. A Zap picks the email up, has ChatGPT write a short, warm reply, adds Dana's signature from Signatoro and leaves a draft in the same Gmail thread.

The four steps are: 1. New Email in Gmail (a polling trigger that checks the inbox every few minutes), 2. Conversation in ChatGPT (OpenAI), 3. Get Signature in Signatoro (1.0.0), and 4. Create Draft Reply in Gmail. Signatoro's Zapier app is invite-only while it's in beta, so you join it from Signatoro's invite first.

Who this Zapier tutorial is for

Practice managers, office managers and front-desk teams who answer the same kind of email many times a week and want the first draft written for them, with a person still checking every reply. No coding is needed. It's the Zapier version of the Make.com lesson [Add AI to Make.com: ChatGPT Writes a Personal Reply, Gmail Sends It](/content/make-com-chatgpt-gmail-personalized-reply), with the same practice and the same prompt rules.

What you need to build it for real

• A Zapier account on the free trial or a paid plan. Zapier's free plan runs two-step Zaps, and this one has four.
• An OpenAI account with API credit for the ChatGPT (OpenAI) step. You paste an API key when you sign in; OpenAI bills it separately from a ChatGPT subscription.
• A free Signatoro account with a saved signature, and an API key from Generate API key under For tools and assistants. The free plan includes the API (50 requests a month on 20 October 2026).
• Access to Signatoro's Zapier app. It shows up in Zapier's app search as Signatoro (1.0.0), Invite Only, once you accept the invite.

The prompt

Put the rules first and the email last, so every run gets the same instructions with a different patient. The last rule is the one that makes the signature work: the model ends with a closing line and no name.

You are the front desk at Brookside Dental, a friendly family dental practice. Write a short email reply to a patient who just emailed us. Greet them by first name and thank them. Respond to what they asked in one or two warm sentences. Say we will call within one business day to book a time. No medical advice, no prices, no promises about treatment. End with a short closing line such as "Kind regards," and no name or signature: the signature is added after the email. Write only the email body, as simple HTML with each paragraph in p tags. The patient's email: (insert Body Plain from step 1).

Why the signature comes from Signatoro, not the prompt

A reply signed "The Brookside Dental team" reads like a form letter, and a model asked to sign with a name and phone number can get them wrong. Signatoro keeps each person's signature in one place. The Get Signature step fetches the current version on every run and adds it after the reply, so when Dana's title or number changes, she updates it on Signatoro and the next draft has it, with nothing to edit in the Zap.

Keep the Signatoro and OpenAI keys in Zapier's connections, never in the prompt or a note. If you also fill in "Add signature default" in Create Draft Reply, the reply is signed twice, so leave that empty.

Make or Zapier?

Both build the same reply. In Make, an HTTP Make a request module calls Signatoro's API with a bearer token and you map its html after ChatGPT's Result: see the [Make.com version](/content/make-com-chatgpt-gmail-personalized-reply) and its [interactive lesson](/modules/make-add-ai). In Zapier, Signatoro's own app does that work in one Get Signature step, and Create Draft Reply keeps a person in the loop.

Links

• Signatoro: the email signature platform this lesson uses; the forever-free plan includes the API. Thanks to Katya Rozenoer, Signatoro's founder and CEO, who built the Zapier app and invited us to its beta.
• Add your email signature to emails n8n, Zapier and Make send (Signatoro docs): Signatoro's own Make, n8n and Zapier steps.
• The Make.com version of this lesson: the same reply with Make's OpenAI and HTTP modules, plus a downloadable blueprint.

Step by step: Zapier: ChatGPT Drafts Every Reply, Signatoro Signs It

All 35 steps of the interactive module, in order. In the module you watch each one, then do it yourself in a practice copy that checks your work.

1. Why sign it with Signatoro

1. See what the wait costs. Every new patient email at Brookside Dental waits until someone has time to write, sign and send the reply. At 25 emails a week that's about 2.5 hours, and some patients book elsewhere while they wait. Click the last row.

   At Brookside Dental, every new patient email waits until someone has time to answer it. That's hours a week, and some patients book somewhere else while they wait.

2. Let a Zap draft every reply. The fix: a Zap. Gmail starts it, ChatGPT writes the reply, Signatoro adds Dana Whitfield's real signature, and Gmail saves a draft reply for her to check. The AI never signs anything itself. Click the Zapier card.

   Here's the fix. Gmail starts a Zap, ChatGPT writes the reply, Signatoro adds Dana's real signature, and Gmail saves it as a draft for her to check.

2. Save the signature in Signatoro

3. Save the signature. On signatoro.com, the signature page holds the person who signs these replies: Dana Whitfield, Patient Coordinator, Brookside Dental, +1 555 0142. Fill in Your details and click Save signature. The free plan is enough.

   First, the signature. On Signatoro, fill in the person who signs these replies. Here it's Dana Whitfield, patient coordinator.

4. Make an API key for Zapier. Scroll to For tools and assistants. Zapier needs a key to fetch the signature. Click Generate API key and copy the key: it's shown once. You'll paste it when Zapier asks you to sign in to Signatoro.

   Zapier needs a key to fetch this signature. It's shown only once.

3. Gmail starts the Zap

5. Start a new Zap. In Zapier, under Start from scratch, click Zap.

   Under start from scratch, click Zap.

6. Open the trigger. A Zap starts with a trigger, the event that starts it. Click Trigger.

   Every Zap starts with a trigger: the event that starts it.

7. Search for Gmail. In Search 9,000+ apps and tools..., type Gmail.

   Search for Gmail.

8. Pick Gmail. Click Gmail.
9. Open Trigger event. The step opens on the right. Click Trigger event.

   The step opens on the right.

10. Choose New Email. Choose New Email: it starts the Zap when a new email lands in the mailbox you pick. It's a Polling trigger, so Zapier checks for new mail every few minutes.

    Zapier checks the inbox every few minutes, and starts the Zap when a new email lands.

4. ChatGPT writes the reply

11. Add the AI step. The Gmail card now shows 1. New Email. You'll sign in to each app at the end, once every step is in place. Click the Action step.

    The trigger is set. You'll sign in to each app at the end.

12. Search for ChatGPT. Type ChatGPT.
13. Pick ChatGPT (OpenAI). Click ChatGPT (OpenAI).
14. Open Action event. Zapier suggests AI by Zapier instead. That works too, but this lesson uses your own OpenAI account. Click Action event.

    Zapier suggests its own AI step. That works too, but we'll use your OpenAI account.

15. Find Conversation. There's a long list. In Search events, type conversation.

    The list is long. Search for conversation.

16. Choose Conversation. Choose Conversation, marked (Recommended): you send ChatGPT a message and it sends a reply back.

    You send ChatGPT a message, and it writes back.

5. Signatoro adds the signature

17. Add a step. Click the + under the ChatGPT step.
18. Search for Signatoro. Type Signatoro.
19. Pick Signatoro. Click Signatoro (1.0.0). Invite Only means it's in beta: you see it after you accept Signatoro's invite to the app.

    It's invite only while it's in beta, so you'll see it once you've joined the beta.

20. Open Action event. Click Action event.
21. Choose Get Signature. Choose Get Signature. It gets the signature saved on Signatoro, as HTML and text, and adds it after your email body. No HTTP step to set up.

    It fetches the saved signature and adds it after your email body. No web request to set up.

6. Gmail saves a draft reply

22. Add the last step. Click the + under 3. Get Signature.
23. Search for Gmail. Type Gmail.
24. Pick Gmail. Click Gmail.
25. Open Action event. Click Action event.
26. Choose Create Draft Reply. Choose Create Draft Reply: a draft in the patient's own thread, not a sent email. Someone still reads every reply first.

    It saves a draft in the patient's thread, so a person checks it before it goes.

27. Sign in. All four steps are in place: 1. New Email, 2. Conversation, 3. Get Signature, 4. Create Draft Reply. Now each one needs your account. Click Sign in.

    All four steps are in place. Now each one needs your account.

7. Connect and fill in

28. Connect your accounts. Sign in on every step: Gmail with Google, ChatGPT with an OpenAI API key, Signatoro with the key you made. Click card 1.

    Sign in on every step. Gmail with Google, ChatGPT with an OpenAI key, and Signatoro with the key you just made.

29. Write the prompt. In ChatGPT's Configure tab, paste the instructions and insert the email's Body Plain from step 1. The last rule matters: a closing line, no name or signature. Click card 2.

    In the ChatGPT step, paste the instructions, then insert the email from step one. The last rule matters: no name, and no signature.

30. Add the signature. In Get Signature's Configure tab, leave Signature on me, pick a Mode (Full or Short) and insert ChatGPT's reply from step 2 into Email Body (HTML). Leave Send Without Signature If Unavailable on. It comes back with Dana's signature after it. Click card 3.

    In Get Signature, insert ChatGPT's reply. It comes back with Dana's signature added.

31. Fill in the draft. In Create Draft Reply, set Thread to the email's Thread Id, Body type to HTML, and Body to Get Signature's Body HTML output. Leave Add signature default empty, so Gmail doesn't add a second signature. Click card 4.

    In Create Draft Reply, pick the email's thread, set body type to HTML, and use the signed body from step three.

32. Test it, keep it off. Send yourself a practice email, then test each step. The draft lands in that thread. Read it, and only then click Publish. Click card 5.

    Send yourself a practice email and test each step. Read the draft. Only publish when every reply looks right.

8. What it saves

33. Read the draft. This is the kind of draft Dana finds in Daniel's thread: a warm reply that ends Kind regards, and then her real signature from Signatoro. Click the draft.

    Here's the draft in Daniel's thread. A warm reply, then Dana's real signature from Signatoro.

34. See what it saves. A draft about two minutes after the email lands, with the right signature, and a person still clicks Send. Click What this saves.

    A draft within minutes, with the right signature, and a person still clicks send.

35. Using Make instead?. The same reply is built in Make in the companion lesson, with an HTTP module. Click the card.

    Using Make instead? The same reply is in the Make lesson.

Screenshots

Frequently asked questions

Does Zapier add my Gmail signature automatically?

No. Zapier sends through the Gmail API, so the signature in Gmail's settings isn't added unless you pick it in the step. This lesson adds the sender's signature with Signatoro's Get Signature step instead, so it's the same in every tool.

Where do I find the Signatoro app in Zapier?

Search for Signatoro in the app picker. While it's in beta it shows as Signatoro (1.0.0), Invite Only, and you only see it after you accept Signatoro's invite to the app.

Can I build this on Zapier's free plan?

Not as a four-step Zap: Zapier's free plan runs two-step Zaps. Build and test it on the free trial, or use a paid plan.

Why a draft reply and not Send Email?

So a person reads every reply before it goes. Once the drafts have been right for a few weeks, you can switch step 4 to Reply to Email.

Should I use ChatGPT (OpenAI) or AI by Zapier?

Either works. ChatGPT (OpenAI) uses your own OpenAI API key and is billed by OpenAI. AI by Zapier needs no OpenAI account and lets you pick a model inside Zapier. The prompt is the same.

Is Signatoro free?

Yes. Signatoro has a forever-free plan that includes the API, capped at 50 requests a month on 20 October 2026. The Company plan lifts the limit for everyone.

How does the interactive lesson work?

Each step is shown first with a short voice-over, then you do it yourself on real Zapier and Signatoro screens, and every click is checked. Nothing touches your accounts.

Start this module free

Same business, other tools

Brookside Dental shows up in these modules too, built with different tools.

◷Your First Make.com Scenario: Google Forms to Google Sheets

Build your first Make.com scenario: every new Google Forms response becomes a new row in Google Sheets. Trigger, connection, mapping, Run once and a schedule.

Free · Live ~12 min Intermediate

◷Filters and Routers in Make.com: Send Urgent Requests One Way, Routine Ones Another

Add a router to your Make scenario, email the front desk about urgent requests with a filter, and send everything else to Google Sheets with a fallback route.

Free · Live ~12 min Intermediate

◷Add AI to Make.com: ChatGPT Writes a Personal Reply, Gmail Sends It

Connect OpenAI to your Make scenario, have ChatGPT write a personal reply from each patient's form answers, add the sender's real Signatoro signature, and send it with…

Free · Live ~18 min Intermediate

◷On a Schedule: A Daily Summary Email from a Google Sheet in Make.com

Build a Make scenario that runs every day at 5 PM, finds today's rows in Google Sheets, combines them with a Text aggregator and emails one summary with Gmail.

Free · Live ~12 min Intermediate

Webhooks: Connect a Website Form to Make.com

Start a Make scenario with a Custom webhook, paste its URL into your website form's webhook setting, send a test so Make learns the fields, and save every request to…

Free · Live ~12 min Advanced

n8n + Signatoro: AI Drafts Every Reply, Signatoro Signs It

Stop leaving client emails waiting. A Gmail Trigger starts it, OpenAI writes a personal reply, one HTTP Request node fetches the sender's real signature from Signatoro…

Free · Live ~10 min Intermediate

From the blog

Signatoro Use Cases: Signed AI Replies for Office Teams

How office managers, coordinators, client service, recruiting, sales and agencies use Signatoro so AI-drafted emails carry the right signature.

Oct 20, 2026 5 min read

Signatoro FAQ: Signatures for AI Emails in Make and Zapier

Answers about Signatoro for automated emails: why tools skip your Gmail signature, the API, the free plan, Make vs Zapier setup and what to check.

Oct 20, 2026 4 min read

Signatoro in Zapier: 8 AI Draft Reply Mistakes to Avoid

Fix a Zapier AI reply Zap with Signatoro: the invite-only app, the two-step free plan limit, Thread Id, HTML body, double signatures and the prompt.

Oct 20, 2026 5 min read

All blog posts

Terms in this lesson

Plain-English definitions, each with an example from a free lesson.

The full AI glossary

Browse related tutorials