langflow/docs/versioned_docs/version-1.8.0/Develop/configuration-global-variables.mdx

---
title: Global variables
slug: /configuration-global-variables
---

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Use global variables to store and reuse credentials and generic values across all of your flows.
Global variables are typically used by components in flow, and you can use them in any field with the <Icon name="Globe" aria-hidden="true"/> global variable icon.

In contrast, [environment variables](/environment-variables), like `LANGFLOW_PORT` or `LANGFLOW_LOG_LEVEL`, are generally for broader settings that configure how Langflow runs.
However, Langflow can also source global variables from environment variables.

Langflow stores global variables in its internal database, and it encrypts the values using a secret key.

## Create a global variable

To create a new global variable, follow these steps.

1. In the Langflow header, click your profile icon, and then select **Settings**.
2. Click **Global Variables**.

3. Click **Add New**.

4. In the **Create Variable** dialog, enter a name for your variable in the **Variable Name** field.

5. Optional: Select a **Type** for your global variable. The available types are **Generic** (default) and **Credential**.

   Langflow encrypts both **Generic** and **Credential** type global variables.
   However, **Generic** variables aren't masked in the visual editor, whereas **Credential** variables are masked.
   **Session ID** fields don't accept **Credential** (masked) variables.

6. Enter the **Value** for your global variable.

7. Optional: Use the **Apply To Fields** menu to select one or more fields that you want Langflow to automatically apply your global variable to. For example, if you select **OpenAI API Key**, Langflow automatically applies the variable to any **OpenAI API Key** field.

8. Click **Save Variable**.

You can now select your global variable from any text input field that displays the <Icon name="Globe" aria-hidden="true"/> **Globe** icon.

## Edit a global variable

1. In the Langflow header, click your profile icon, and then select **Settings**.

2. Click **Global Variables**.

3. Click on the global variable you want to edit.

4. In the **Update Variable** dialog, you can edit the following fields: **Variable Name**, **Value**, and **Apply To Fields**.

5. Click **Update Variable**.

## Delete a global variable

Deleting a global variable permanently deletes the value from the database.
Flows that reference the deleted global variable will fail.

1. In the Langflow header, click your profile icon, and then select **Settings**.

2. Click **Global Variables**.

3. Click the checkbox next to the global variable that you want to delete.

4. Click <Icon name="Trash2" aria-hidden="true"/> **Delete**.

The global variable is deleted from the database.

## Add custom global variables from the environment {#add-custom-global-variables-from-the-environment}

Langflow can source custom global variables from your runtime environment.
For information about how Langflow detects and applies environment variables, see [Langflow environment variables](/environment-variables).

Langflow automatically generates global variables based on [`constants.py`](https://github.com/langflow-ai/langflow/blob/main/src/lfx/src/lfx/services/settings/constants.py) if it detects any matching environment variables.
For example, if you set `OPENAI_API_KEY` in your runtime environment, Langflow automatically generates a global variable using that value.

You can declare additional variables in `LANGFLOW_VARIABLES_TO_GET_FROM_ENVIRONMENT`.
For example, `LANGFLOW_VARIABLES_TO_GET_FROM_ENVIRONMENT=WATSONX_PROJECT_ID,WATSONX_API_KEY` creates global variables named `WATSONX_PROJECT_ID` and `WATSONX_API_KEY` in Langflow's database.
Then, you can use these variables wherever they are needed in your component settings.

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If you installed Langflow locally, set `LANGFLOW_VARIABLES_TO_GET_FROM_ENVIRONMENT` in your Langflow `.env` file:

1. Create or edit your Langflow `.env` file.

2. Add the `LANGFLOW_VARIABLES_TO_GET_FROM_ENVIRONMENT` environment variable as follows:

   You can specify the variables either as a comma-separated string with no spaces, or as a JSON list:

   ```text
   # Option 1: Comma-separated string (no spaces)
   LANGFLOW_VARIABLES_TO_GET_FROM_ENVIRONMENT=VARIABLE1,VARIABLE2

   # Option 2: JSON list format
   LANGFLOW_VARIABLES_TO_GET_FROM_ENVIRONMENT=["VARIABLE1", "VARIABLE2"]
   ```

   Replace `VARIABLE1,VARIABLE2` with your additional variables that you want Langflow to source from the environment, such as `CUSTOM_API_KEY,INTERNAL_SERVICE_URL` or `["CUSTOM_API_KEY", "INTERNAL_SERVICE_URL"]`.

3. Save and close the file.

4. Start Langflow with the `.env` file:

   ```bash
   uv run langflow run --env-file .env
   ```

   Alternatively, you can set environment variables directly in the command line:

   ```bash
   VARIABLE1="VALUE1" VARIABLE2="VALUE2" uv run langflow run --env-file .env
   ```

   The command-line variables override matching variables in the `.env` file.
   Expose your environment variables to Langflow in a manner that best suits your own environment.

5. Confirm that Langflow successfully sourced the global variables from the environment:

   1. In the Langflow header, click your profile icon, and then select **Settings**.

   2. Click **Global Variables**, and then make sure that your environment variables appear in the **Global Variables** list.

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If you're using Docker, there are two ways that you can set `LANGFLOW_VARIABLES_TO_GET_FROM_ENVIRONMENT`:

* On the command line:

   ```bash
   docker run -it --rm \
      -p 7860:7860 \
      -e LANGFLOW_VARIABLES_TO_GET_FROM_ENVIRONMENT="VARIABLE1,VARIABLE2" \
      -e VARIABLE1="VALUE1" \
      -e VARIABLE2="VALUE2" \
      langflowai/langflow:latest
   ```

* In your `.env` file:

   ```bash
   docker run -it --rm \
      -p 7860:7860 \
      --env-file .env \
      -e VARIABLE1="VALUE1" \
      -e VARIABLE2="VALUE2" \
      langflowai/langflow:latest
   ```

The list in `LANGFLOW_VARIABLES_TO_GET_FROM_ENVIRONMENT` includes only the variable names.
You must ensure that these environment variables are defined in your Docker environment, such as with `-e` or otherwise.

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After starting Langflow, go to your Langflow **Settings** to confirm that the variables were created.

Only the **Name** and **Value** are taken from the environment.
You can edit the variables in your Langflow **Settings** if you want to configure additional options, such as the **Apply To Fields** option.

Global variables sourced from the environment are assigned the **Credential** type, which masks the values in the visual editor.
However, Langflow automatically encrypts _all_ global variables stored in the database.

## Disallow global variables from the environment

If you want to explicitly prevent Langflow from sourcing global variables from the environment, set `LANGFLOW_STORE_ENVIRONMENT_VARIABLES=False` in your `.env` file.

## Use environment variables for missing global variables {#use-environment-variables-for-missing-global-variables}

If you want to automatically set fallback values for your global variables to environment variables, set `LANGFLOW_FALLBACK_TO_ENV_VAR=True` in your `.env` file.
When this setting is enabled, if a global variable isn't found, Langflow attempts to use an environment variable with the same name as a backup.

For example, assume you have the following Langflow `.env` configuration, and your flow has a component that expects a `WATSONX_API_KEY` global variable:

```text
LANGFLOW_FALLBACK_TO_ENV_VAR=True
WATSONX_PROJECT_ID=your_project_id
WATSONX_API_KEY=your_api_key
```

When you run the flow, if there is no global variable named `WATSONX_API_KEY`, Langflow looks for an environment variable named `WATSONX_API_KEY`.
In this example, Langflow uses the `WATSONX_API_KEY` value from the `.env` to run the flow.