Perhaps try looking into scripting? You'd retrieve all the fields and then create them programatically
I take it you're trying to create all the fields in the main table and upload the CSV there, and then have it sync over to the synced table in the other base?
Hi,
You can use this very simple script, but it has 2 disadvantages: it creates only fields of the same type, it creates them one-by-one, with approximately 2 fields/sec, so you have to wait 3-4 minutes for all.
let table=base.getTable('Table_1')
let newFields=['Field 1','Second field','And so on']
while(newFields.length) await table.createFieldAsync(newFields.shift(),'singleLineText')
ensure you filled newFields=['....] correct, without empty strings, repeats etc.
ignore linter warning under newfields.shift()
But I would recommend NO-CODE and simple way.
To create a number of fields in bulk, you have to create a new table will all fields together, or you have to import data.
You can't import into synced table, but you do a simple join by paste.
- ensure you have no matching names in the current synced table and new fields to be created.
- create a new table with all your fields by importing CSV
- select first row, press Control+C

(it should react like "450 cells copied")
- switch to your synced table, scroll right to the end, create new field with the name matching first name of your selected fields (I mean in the table you imported from CSV)
- put mouse cursor in the cell, click on it. then press Ctrl+V to paste

If it's OK it will ask you to add more fields. formula fields will be added as text with their values. I guess, some fields like links, lookups will be added as text too.