API
Open the API keys page by clicking the settings icon and clicking API Keys.
Click the Create New Key button.
Enter your two-factor authentication code if necessary.
Confirm the new API key from the verification email you receive from Poloniex.
Back on Poloniex, deselect the Enable Trading and Enable Withdrawals checkboxes of the new API key.
Paste your API key and secret to TokenTax.
CSV
Instructions for U.S. filers (as Poloniex has shut down for U.S. customers)
Log in to Poloniex (https://poloniex.com/).
You will see a page that says "Withdraw funds to avoid fees" and below that, a link to their FAQ. Click through to the FAQ.
Scroll down to see instructions for "How do I download my history for taxes?" and follow the instructions, and be sure to download the CSV for trade activity.
If you are not a U.S. user:
Log in to your Poloniex account
Click on ‘Activity’ on the right side of the top menu bar
Click ‘Export’ on the right hand side
Select the transaction type and date range, and click download
Navigate to ‘Spot Orders’ in the top left corner, and then click ‘Export’
Select your desired time period, and click ‘Export’
Upload your CSV file to TokenTax