Branded newsletter writer and sender

What it is

This n8n workflow writes a newsletter from three details typed into a form: the brand’s name, its website and a topic. It then emails the issue to every address on a Google Sheet. Tavily searches the past week’s news on your topic, and an OpenAI agent turns the results into a title and three sub-topics. Each sub-topic gets a search of its own and a section with source links. Meanwhile the brand’s homepage is read for four color codes and a logo, which ConvertAPI converts to a PNG. For each subscriber, a last agent sets the sections into a fixed HTML layout in the brand’s colors, Google Sheets logs the issue and Gmail sends it.

Who it suits

Small brands, clubs and consultancies that send a regular roundup and want each issue to match their site without hiring a designer. Agencies suit it too, with one copy per client and that client’s own sheet.

You need some n8n: importing a file, adding five kinds of credentials and preparing a two-tab sheet. If that is new and you would rather not learn it, skip this one. The page it came from estimates close to 20 minutes, which assumes every account and key already exists.

Where to use it

Any n8n you run will do, as long as it can reach OpenAI, Tavily, ConvertAPI, Google and the brand’s website.

• n8n Cloud: import the file into a new workflow there
• Your own n8n server: the same file, the same steps
• Your subscribers’ inboxes: each issue goes out from the Gmail account you connect
• Another email tool: the finished HTML is kept in the log tab, so you can paste an issue into a tool you prefer

Setup

Get it saves a zip with workflow.json and Mindket’s setup notes in your downloads folder. Have these ready before you import it.

1. In n8n, create a workflow, open its menu, choose Import from File and pick workflow.json.
2. Add an OpenAI credential and select it in OpenAI and in OpenAI Chat Model6.
3. Open Tavily and Tavily1. In each Authorization header, swap <YOUR_TAVILY_KEY> for your key and keep the word Bearer and its space before it.
4. Do the same in Convertor with <YOUR_CONVERTAPI_SECRET>.
5. Add a Google Sheets credential. In Get row(s) in sheet and in Save Newsletter, select it and replace YOUR_SHEET_ID with the long id in your spreadsheet’s address, between /d/ and /edit.
6. In Get row(s) in sheet, replace YOUR_SUBSCRIBERS_TAB_ID with the number after gid= in the Subscribers tab’s address. Save Newsletter writes to the first tab, gid=0.
7. Add a Gmail credential and select it in Sending Emails.
8. Put two or three addresses of your own in the Subscribers tab, save, send a test through the form’s test address, then press Publish.

The logo step expects an ai file. The address in Convertor ends in /convert/ai/to/png. ConvertAPI reads the source and target formats from that address, so a logo that is an SVG or a JPG needs the address changed to match.

How to use it

Open the form from On form submission, fill in Brand Name, Brand Website and Query, all required, and send it. The form confirms at once. The run goes on behind it: the research and the color study first, then a styled issue, a log row and an email for each subscriber. Open the run under Executions to follow it.

Example

A form entry for a coffee roaster:

Brand Name: Harbor Coffee Roasters
Brand Website: https://harborcoffee.example
Query: specialty coffee prices and cafe trends

Generate Topics answers in the parser’s shape, which insists on exactly three topics:

{
  "title": "…",
  "topics": ["…", "…", "…"]
}

Website scrape returns the colors the same way, and Convert Newsletter to HTML returns the issue as a subject and an HTML body:

{
  "primary_color": "…",
  "secondary_color": "…",
  "accent_color": "…",
  "background_color": "…"
}

{
  "subject": "…",
  "content": "<html>…</html>"
}

Each subscriber receives the logo, the title in the primary color, a greeting by name and an introduction that gives the date. Then come three sections with Source links, a sources list sorted by publication, a closing note and a footer.

For newcomers and experts

If you are new. n8n draws a workflow as boxes joined by lines, and each box, a node, does one job. A credential is a key n8n keeps for you and hands to the node you pick it in. Run the form from its test address with a sheet that holds only your own addresses. Open that run under Executions and each node shows what it received and what it sent, so a bad key or a wrong tab turns up there.

For experts. Three inputs meet in Merge: the logo, the color study and the sections, in that order. Convert Newsletter to HTML reads them by position (output[0], output[1], output[2]), so keep the order if you rewire it.

Good to know

Each run costs money and the mail leaves your own account, so test on your own addresses first.

• Billing: OpenAI, Tavily and ConvertAPI each bill their own part. A run makes four searches and one HTML pass for every subscriber
• A long list is a long run: the HTML agent runs again for each address, so the wording can differ a little between readers, and the log gets a row for each
• Sending limits: Gmail caps how many messages one account sends in a day, so a large list needs a sender built for bulk mail
• Unsubscribe: the layout has no unsubscribe line, so add one to the footer if the law where your readers live asks for it
• Open form: once it is published, anyone with the form’s address can start a run on your keys and mail your list. Turn on the form trigger’s basic authentication or keep the address private
• Keys: the Tavily and ConvertAPI keys sit in header fields, not in credentials, so they travel with any export of the workflow
• Sources and logo: the agents are told to cite only real sources, so read the first issues before the list gets them. The logo in each email is a link to the copy ConvertAPI stores, so check how long it keeps it
• A repair: the page’s copy of the file had lost the backslashes of three line breaks. The expressions that join the research and the sections joined them with the letter n. Mindket put them back
• Credentials: the JSON holds none, and nothing from its author’s account