docs: add env var setup for macOS and Windows GUI (#8181)

* docs: add env var setup for macOS and Windows GUI

* style-and-cleanup

* docs-review

* add-env-vars-to-troubleshooting

* Update docs/docs/Get-Started/get-started-installation.md

* Apply suggestions from code review

Co-authored-by: April I. Murphy <36110273+aimurphy@users.noreply.github.com>

* Apply suggestions from code review

Co-authored-by: April I. Murphy <36110273+aimurphy@users.noreply.github.com>

* docs-review

---------

Co-authored-by: Mendon Kissling <59585235+mendonk@users.noreply.github.com>
Co-authored-by: April I. Murphy <36110273+aimurphy@users.noreply.github.com>

docs/docs/Configuration/environment-variables.md

@@ -388,3 +388,99 @@ To run Langflow using the above VSCode `tasks.json` file, in the VSCode command
 
 </TabItem>
 </Tabs>
+
+## Set environment variables for Langflow Desktop
+
+Environment variables set in your terminal aren't automatically available to GUI-based applications like Langflow Desktop when you launch them from the Windows or macOS GUI.
+
+For Windows, this means any GUI-based app launched from the Start menu, desktop shortcuts, or Windows Explorer.
+
+For macOS, this means any GUI-based app launched from Finder, Spotlight, Launchpad, or the Dock.
+
+To set environment variables for Langflow Desktop, you need to use specific commands or files, depending on your OS.
+
+<Tabs groupId="">
+  <TabItem value="macOS" label="macOS" default>
+
+Langflow Desktop for macOS cannot automatically use variables set in your terminal, such as those in`.zshrc` or `.bash_profile`, when launched from the macOS GUI.
+
+To make environment variables available to GUI apps on macOS, you need to use `launchctl` with a `plist` file:
+
+1. Create the `LaunchAgents` directory if it doesn't exist:
+
+```bash
+mkdir -p ~/Library/LaunchAgents
+```
+
+2. In the `LaunchAgents` directory, create a `.plist` file called `dev.langflow.env`.
+
+3. Add the following content to `dev.langflow.env.plist`, and then add, change, or remove Langflow environment variables as needed for your configuration.
+This example sets the `LANGFLOW_CONFIG_DIR` environment variable for all GUI apps launched from the macOS GUI.
+
+```xml
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN"
+"http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+  <dict>
+    <key>Label</key>
+    <string>dev.langflow.env</string>
+    <key>ProgramArguments</key>
+    <array>
+      <string>launchctl</string>
+      <string>setenv</string>
+      <string>LANGFLOW_CONFIG_DIR</string>
+      <string>/Users/your_user/custom/config</string>
+    </array>
+    <key>RunAtLoad</key>
+    <true/>
+  </dict>
+</plist>
+```
+
+4. Load the file with `launchctl`:
+```bash
+launchctl load ~/Library/LaunchAgents/dev.langflow.env.plist
+```
+
+  </TabItem>
+  <TabItem value="System Properties" label="System Properties">
+
+Langflow Desktop for Windows cannot automatically use variables set in your terminal, such as those defined with `set` in `cmd` or `$env:VAR=...` in PowerShell, when launched from the Windows GUI.
+
+To make environment variables available to the Langflow Desktop app, you must set them at the user or system level using the **System Properties** interface or the Terminal.
+
+To set environment variables using the System Properties interface, do the following:
+
+1. Press <kbd>Win + R</kbd>, enter `SystemPropertiesAdvanced`, and then press <kbd>Enter</kbd>.
+2. Click **Environment Variables**.
+3. Under **User variables**, click **New**.
+:::tip
+To apply the setting to all users, select **System variables**.
+:::
+4. Enter the name of the Langflow variable you want to set, such as `LANGFLOW_CONFIG_DIR`, and the desired value, such as `C:\Users\your_user\.langflow_config`.
+5. Click **OK** to save the variable.
+6. Repeat until you have set all necessary Langflow environment variables.
+7. Launch or restart Langflow Desktop to apply the environment variables.
+
+  </TabItem>
+    <TabItem value="Powershell" label="Powershell">
+
+To define environment variables for Windows using PowerShell, do the following:
+
+1. Enter the name of the Langflow variable you want to set, such as `LANGFLOW_CONFIG_DIR`, and the desired value, such as `C:\Users\your_user\.langflow_config`.
+
+    To set an environment variable for the current user:
+    ```powershell
+    [System.Environment]::SetEnvironmentVariable("LANGFLOW_CONFIG_DIR", "C:\Users\your_user\.langflow_config", "User")
+    ```
+
+   To set an environment variable for all users (you must have Administrator priveleges):
+   ```powershell
+   [System.Environment]::SetEnvironmentVariable("LANGFLOW_CONFIG_DIR", "C:\Langflow\Config", "Machine")
+   ```
+
+2. Repeat until you have set all necessary Langflow environment variables.
+3. Launch or restart Langflow Desktop to apply the environment variables.
+  </TabItem>
+</Tabs>

docs/docs/Support/troubleshooting.md

@@ -112,6 +112,11 @@ There are two possible reasons for this error:
 
 * **Version conflict during installation**: Some version conflicts might have occurred during the installation process. To resolve this issue, reinstall Langflow and its dependencies by running `python -m pip install langflow --pre -U --force-reinstall`.
 
+### Environment variables not available from terminal
+
+Environment variables set in your terminal are not automatically available to GUI-based applications like Langflow Desktop when launched through the Finder or the Start Menu.
+To set environment variables for Langflow Desktop, see [Set environment variables for Langflow Desktop](/environment-variables#set-environment-variables-for-langflow-desktop).
+
 ### Package is not installed
 
 In Langflow OSS, you can follow the error message's instructions to install the missing dependency.