How to disable automatic activation of the Conda base environment

A terminal that opens directly in Conda's base environment can hide which Python and package manager a command is using. Disabling auto activation keeps new shells in the system environment until an environment is activated deliberately.

Conda controls this startup behavior through the auto_activate configuration setting. The older auto_activate_base name is an alias, and default_activation_env remains base unless it has been changed.

The setting affects new shell sessions. If (base) is already active in the current terminal, deactivate it or open a new terminal after saving the setting; Conda can still activate base manually when it is needed.

Steps to disable Conda base environment auto activation:

Check the current Conda auto-activation setting.
```
$ conda config --show auto_activate
auto_activate: True
```
True means Conda activates the configured default environment when the shell initializes. On most installations, that environment is base.
Disable automatic Conda environment activation.
```
$ conda config --set auto_activate false
```
Older examples may use auto_activate_base for the same setting. Current Conda records the value under auto_activate.

Confirm the saved setting.

$ conda config --show auto_activate
auto_activate: False

Deactivate base in the current terminal if it is still active.
```
(base) $ conda deactivate
```
Skip this step if the prompt does not show (base). The config change controls future shell startup; it does not remove the current active environment from an already-open terminal.
Open a new terminal session.
Verify Conda did not auto-activate an environment in the new session.
```
$ printf 'CONDA_DEFAULT_ENV=%s\n' "${CONDA_DEFAULT_ENV:-unset}"
CONDA_DEFAULT_ENV=unset
```
If the shell prompt hides environment names, the CONDA_DEFAULT_ENV check is more direct than looking for (base) in the prompt.
Activate base manually when needed.
```
$ conda activate base
```

Confirm manual activation still works.

(base) $ printf 'CONDA_DEFAULT_ENV=%s\n' "$CONDA_DEFAULT_ENV"
CONDA_DEFAULT_ENV=base