ChatGPT and Claude
Use MailMergic in ChatGPT and Claude
Connect your MailMergic account and create personalized documents from a chat: pick a template, give it your list, check how one document looks, then download them all.
What you can make
Anything where the same document is filled in for many people or records, one document per row of your list:
- Certificates and awards
- Letters and notices
- Invoices and receipts
- Contracts and agreements
- Labels and name badges
- Filled-in PDF forms
- Tax and HR forms
- Donation receipts
Before you start
A MailMergic account
A free plan is available. Each document you create uses one credit from your plan.
At least one template
Upload a PDF, Word or Excel file in MailMergic and mark where the names, dates and other details go. You do this once, in MailMergic itself.
For test emails: a sender address
To send yourself a test email from the chat, add and confirm a sender address in MailMergic first.
Connect your account
If you find MailMergic in the list of apps or connectors inside ChatGPT or Claude, open it and click Connect. Otherwise add it yourself with this address:
Connector address
https://api.mailmergic.com/v1/mcp
In Claude
- Open Settings, then Connectors.
- Click Add custom connector. Name it MailMergic and paste the connector address.
- Click Connect. A MailMergic page opens: sign in and click Allow.
- Start a new chat and ask: "Which MailMergic templates do I have?"
In ChatGPT
- Open chatgpt.com/plugins.
- Click the plus button, then Add custom MCP server. Name it MailMergic and paste the connector address.
- Keep OAuth as the sign-in method, confirm the notice and click Create as a plugin.
- A MailMergic page opens: sign in and click Allow. Then ask: "Which MailMergic templates do I have?"
Menu names in ChatGPT and Claude change from time to time. If a step looks different, look for "connectors", "apps" or "plugins" in the settings.
What you allow
Before anything is connected, MailMergic shows you which app is asking, where you go back to after you click Allow (claude.ai or chatgpt.com), and what the app will be able to do:
- See your templates and preview generated documents
- Attach recipient data to your templates
- Generate documents and spend credits
- See your sender addresses and send test emails to you
The assistant asks you before it creates documents or sends a test email, because both use credits and an email cannot be taken back.
What you can ask
Talk to it the way you would to a colleague. A few examples:
“What does the certificate template need?”
You see the details each document needs and which ones your list does not have yet.
“Use this spreadsheet for the certificates.”
In ChatGPT, attach the file to your message. In Claude, you get a one-time upload link: open it, drop the file, then tell Claude you are done. A Google Sheets link set to "anyone with the link" works in both.
“Here are the people: Ann Lee, Bo Chen, Cy Diaz.”
The assistant turns what you typed into a table, shows it to you and attaches it once you agree. Good for short lists.
“Show me how the second document looks.”
You see a picture of its first page, filled in with the details from the second row of your list.
“Create all the certificates.”
After you confirm, MailMergic creates one document per person and the assistant gives you a download link.
“Send me a test email with the first certificate.”
One email with one document goes to your own address, from your confirmed sender address.
What stays in MailMergic
Some things you do in MailMergic itself, so you can see everything before it goes out: designing templates, marking where each detail goes, and emailing documents to your whole list. When you ask for one of these, the assistant gives you the link.
Open MailMergicYour data
What the assistant receives
Only what it asks for in your conversation: template names and details, the column names of your list, one preview picture, and download links that stop working after an hour.
Who handles the chat
Your conversation is handled by OpenAI or Anthropic under your own account and settings with them. MailMergic does not use your data to train AI models.
How to disconnect
In MailMergic, open Integrations, then Connected apps, and click Disconnect. Access ends immediately.
Privacy policy: connected AI appsTerms of Service, section 3.6Open Integrations
Questions
Claude says it cannot use the file I attached. What now?
Claude does not pass attached files on to connected apps. Ask it for an upload link instead: open the link, drop your spreadsheet (.xlsx, .xls, .csv, up to 25 MB), then tell Claude you are done. Each link works once and for 30 minutes.
Does using MailMergic in a chat cost extra?
No. It uses the credits of your MailMergic plan, the same as in MailMergic itself: one credit per document. A test email uses one credit too.
The download link does not work any more.
Download links stop working after one hour. Ask the assistant for the documents again and you get a new link. Your documents are kept as long as your account settings say (30 days unless you changed it).
Which templates can I use?
All your MailMergic templates made from a PDF (with or without form fields), a Word file or an Excel file. Word templates can give you Word files or PDFs.
How long can the list be?
A spreadsheet you upload can be as long as your credits allow. A list you type into the chat can have up to 500 rows; for anything longer, upload the spreadsheet instead.
Can it email the documents to everyone on my list?
Not from the chat, on purpose. Open MailMergic to check the email and send it to your list. From the chat you can send one test email to yourself.
How do I stop the connection?
In MailMergic, open Integrations, then Connected apps, and click Disconnect. Access ends immediately. You can also remove MailMergic in the settings of ChatGPT or Claude.
Something not working? Write to support@mailmergic.com