A simple custom coded action to check API limits in workflows.

check api limit.js

const axios = require('axios');
exports.main = async (event, callback) => {

  const auth = 'Bearer ' + process.env.CHANGE_THIS_VALUE_TO_MATCH_YOUR_SECRET_NAME;
  const email = event.inputFields['email'];
  
  
  let data = JSON.stringify({
    "filters": [
      {
        "propertyName": "email",
        "operator": "EQ",
        "value": email
      }
    ]
  });

  let config = {
    method: 'post',
    maxBodyLength: Infinity,
    url: 'https://api.hubapi.com/crm/v3/objects/contact/search',
    headers: { 
      'Content-Type': 'application/json', 
      'Authorization': auth
    },
    data : data
  };

  axios.request(config)
  .then((response) => {
    console.log('successhappened');
    console.log(JSON.stringify(response.data));   
    console.log(response.headers['x-hubspot-ratelimit-daily-remaining']);
    let remainder = response.headers['x-hubspot-ratelimit-daily-remaining'];
    callback({
      outputFields: {
        limit_remaining: remainder
      }
    });
  })
  .catch((error) => {
    console.log('errorhappened');
    console.log(error);  
    console.log(error.headers['x-hubspot-ratelimit-daily-remaining']);
  });

  
}