For example I have a DATA_DIR environment variable which points to the directory where disk-data is stored

Okay, so the agent automatically inherits the launching environment's variables?

Depending on where the agent is, the value of DATA_DIR might change

What exactly are you looking to set up?

Hi WackyRabbit7 , how do you run the agent? manually command?

CostlyOstrich36 ?

yep

I guess what I want is a way to define environment variables in agents

you can just running with the env var at the beginning:

YOUR_ENV_VAR_NAME=/path/to/my/data clearml-agent …

so in my code, I'll use this environment variable to read from disk

yep