An ad hoc solution for mapping smartsheet columns ids to columns titles and vice-versa given an arbitraty object as input

smartsheet_column_mapper.js

/*
Usage
-----

$ npm init
$ npm install axios

Replace variables "token", "smartsheetId" and "payload"

$ node smartsheet_column_mapper.js

Sample payloads
---------------

Replaces columns IDs by columns titles:
const payload = {
    "foo": 2029574552071291, // => "foo" : "column title A"
    "bar": 8211186521574900, // => "bar" : "column title B"
    "baz": {
        "lorem": 1217136521894920, // "lorem": "column title C"
    }
}

Replaces columns titles by column IDs:
const payload = {
    "foo": "column title A", // => "foo" : 2029574552071291
    "bar": "column title B", // => "bar" : 8211186521574900
    "baz": {
        "lorem": "column title C", // "lorem": "1217136521894920"
    }
}
*/

const axios = require('axios');

const token = '<SMARTSHEET_TOKEN>';
const smartsheetId = '<SMARTSHEET_ID>';
const payload = {};

axios.defaults.headers.common = { 'Authorization': `Bearer ${token}` };

const map = (obj, sheet) => {
    for (const prop in obj) {
        const val = obj[prop];

        if (typeof val === 'object') return map(val, sheet);

        if (typeof val === 'number') {
            const col = sheet.columns.find(c => c.id === val);
            obj[prop] = col ? col.title : '<NOT FOUND>';
        } else {
            const col = sheet.columns.find(c => c.title === val).id;
            obj[prop] = col ? col.id : '<NOT FOUND>';
        }
    }
};

(async () => {
    const { data: sheet } = await axios.get(`https://api.smartsheet.com/2.0/sheets/${smartsheetId}`);
    map(payload, sheet);
    console.log(JSON.stringify(payload, null, 4));
})();