Called Fresh

I spend most of my time on Google sheets. I’ve done so for the past 10 years. So, of course, when they dropped the news of =AI( ) as a formula, I was excited.

Here is the cheapest way to bring the power of AI to Google Sheets.

Create custom function in Google Sheets (like =MYAI(B2)) that calls the OpenAI API (or your favourite AI provider) and returns the result directly in the sheet.

Here is an example:

Here I’ve added a function to re-write in the voice of a 5 year old.

And it’s pay as you go.

Here is how you can set it up with OpenAI API

1. Before you start you’ll need to have developer access to openAI. Signup https://platform.openai.com/docs/overview and set up your profile and account.
2. Then get a new API Key that you can use here
3. In your Google Sheet, go to: Extensions → Apps Script
4. Delete the default myFunction code and add the below script:

function MYAI(prompt, instruction) {
  var apiKey = "YOUR_API_KEY";
  var url = "https://api.openai.com/v1/chat/completions";

  var payload = {
    model: "gpt-4o-mini", // cheap & fast
    messages: [
      { role: "system", content: instruction },
      { role: "user", content: prompt }
    ],
    max_tokens: 500
  };

  var options = {
    method: "post",
    contentType: "application/json",
    headers: { Authorization: "Bearer " + apiKey },
    payload: JSON.stringify(payload)
  };

  try {
    var response = UrlFetchApp.fetch(url, options);
    var json = JSON.parse(response.getContentText());
    
    if (!json.choices || !json.choices[0] || !json.choices[0].message) {
      return "No response from AI";
    }
    return json.choices[0].message.content.trim();

  } catch (e) {
    return "Error: " + e;
  }
}

You’ll have to change a couple of things here:

1. Add your API Key
2. Change the name of the function, in the above example it is “REWRITE” given in the first line
3. Change the instruction to the AI

Once all changes have been made:

1. Save the file
2. Go back to the spreadsheet and use the function
3. For adding more functions to the same sheet, add another script file and repeat the process

Got any questions?