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Environment Variables

Langflow lets you configure a number of settings using environment variables.

Configure environment variables

Langflow recognizes supported environment variables from the following sources:

  • Environment variables that you've set in your terminal.
  • Environment variables that you've imported from a .env file using the --env-file option in the Langflow CLI.

You can choose to use one source exclusively, or use both sources together. If you choose to use both sources together, be aware that environment variables imported from a .env file take precedence over those set in your terminal.

Set environment variables in your terminal

Run the following commands to set environment variables for your current terminal session:


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export VARIABLE_NAME='VALUE'

When you start Langflow, it looks for environment variables that you've set in your terminal. If it detects a supported environment variable, then it automatically adopts the specified value, subject to precedence rules.

Import environment variables from a .env file

  1. Create a .env file and open it in your preferred editor.

  2. Add your environment variables to the file:


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    VARIABLE_NAME='VALUE'
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    VARIABLE_NAME='VALUE'

    tip

    The Langflow project includes a .env.example file to help you get started. You can copy the contents of this file into your own .env file and replace the example values with your own preferred settings.

  3. Save and close the file.

  4. Start Langflow using the --env-file option to define the path to your .env file:


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    python -m langflow run --env-file .env

On startup, Langflow imports the environment variables from your .env file, as well as any that you set in your terminal, and adopts their specified values.

Precedence

Environment variables defined in the .env file take precedence over those set in your terminal. That means, if you happen to set the same environment variable in both your terminal and your .env file, Langflow adopts the value from the the .env file.

CLI precedence

Langflow CLI options override the value of corresponding environment variables defined in the .env file as well as any environment variables set in your terminal.

Supported environment variables

The following table lists the environment variables supported by Langflow.

VariableFormat / ValuesDefaultDescription
DO_NOT_TRACKBooleanfalseIf enabled, Langflow will not track telemetry.
LANGFLOW_AUTO_LOGINBooleantrueEnable automatic login for Langflow. Set to false to disable automatic login and require the login form to log into the Langflow UI. Setting to false requires LANGFLOW_SUPERUSER and LANGFLOW_SUPERUSER_PASSWORD to be set.
LANGFLOW_AUTO_SAVINGBooleantrueEnable flow auto-saving.
See --auto-saving option.
LANGFLOW_AUTO_SAVING_INTERVALInteger1000Set the interval for flow auto-saving in milliseconds.
See --auto-saving-interval option.
LANGFLOW_BACKEND_ONLYBooleanfalseOnly run Langflow's backend server (no frontend).
See --backend-only option.
LANGFLOW_CACHE_TYPEasync
redis
memory
disk
critical
asyncSet the cache type for Langflow.
If you set the type to redis, then you must also set the following environment variables: LANGFLOW_REDIS_HOST, LANGFLOW_REDIS_PORT, LANGFLOW_REDIS_DB, and LANGFLOW_REDIS_CACHE_EXPIRE.
LANGFLOW_COMPONENTS_PATHStringlangflow/componentsPath to the directory containing custom components.
See --components-path option.
LANGFLOW_CONFIG_DIRStringSet the Langflow configuration directory where files, logs, and the Langflow database are stored.
LANGFLOW_DATABASE_URLStringSet the database URL for Langflow. If you don't provide one, Langflow uses an SQLite database.
LANGFLOW_DEVBooleanfalseRun Langflow in development mode (may contain bugs).
See --dev option.
LANGFLOW_FALLBACK_TO_ENV_VARBooleantrueIf enabled, global variables set in the Langflow UI fall back to an environment variable with the same name when Langflow fails to retrieve the variable value.
LANGFLOW_FRONTEND_PATHString./frontendPath to the frontend directory containing build files. This is for development purposes only.
See --frontend-path option.
LANGFLOW_HEALTH_CHECK_MAX_RETRIESInteger5Set the maximum number of retries for the health check.
See --health-check-max-retries option.
LANGFLOW_HOSTString127.0.0.1The host on which the Langflow server will run.
See --host option.
LANGFLOW_LANGCHAIN_CACHEInMemoryCache
SQLiteCache
InMemoryCacheType of cache to use.
See --cache option.
LANGFLOW_LOG_FILEStringlogs/langflow.logSet the path to the log file for Langflow.
See --log-file option.
LANGFLOW_LOG_LEVELdebug
info
warning
error
critical
criticalSet the logging level.
See --log-level option.
LANGFLOW_MAX_FILE_SIZE_UPLOADInteger100Set the maximum file size for the upload in megabytes.
See --max-file-size-upload option.
LANGFLOW_OPEN_BROWSERBooleantrueOpen the system web browser on startup.
See --open-browser option.
LANGFLOW_PORTInteger7860The port on which the Langflow server will run. The server automatically selects a free port if the specified port is in use.
See --port option.
LANGFLOW_PROMETHEUS_ENABLEDBooleanfalseExpose Prometheus metrics.
LANGFLOW_PROMETHEUS_PORTInteger9090Set the port on which Langflow exposes Prometheus metrics.
LANGFLOW_REDIS_CACHE_EXPIREInteger3600See LANGFLOW_CACHE_TYPE.
LANGFLOW_REDIS_DBInteger0See LANGFLOW_CACHE_TYPE.
LANGFLOW_REDIS_HOSTStringlocalhostSee LANGFLOW_CACHE_TYPE.
LANGFLOW_REDIS_PORTString6379See LANGFLOW_CACHE_TYPE.
LANGFLOW_REMOVE_API_KEYSBooleanfalseRemove API keys from the projects saved in the database.
See --remove-api-keys option.
LANGFLOW_SAVE_DB_IN_CONFIG_DIRBooleanfalseSave the Langflow database in LANGFLOW_CONFIG_DIR instead of in the Langflow package directory. Note, when this variable is set to default (false), the database isn't shared between different virtual environments and the database is deleted when you uninstall Langflow.
LANGFLOW_STOREBooleantrueEnable the Langflow Store.
See --store option.
LANGFLOW_STORE_ENVIRONMENT_VARIABLESBooleantrueStore environment variables as global variables in the database.
LANGFLOW_SUPERUSERStringNot setSet the name for the superuser. Required if LANGFLOW_AUTO_LOGIN is set to false.
See superuser --username option.
LANGFLOW_SUPERUSER_PASSWORDStringNot setSet the password for the superuser. Required if LANGFLOW_AUTO_LOGIN is set to false.
See superuser --password option.
LANGFLOW_VARIABLES_TO_GET_FROM_ENVIRONMENTStringNot setComma-separated list of environment variables to get from the environment and store as global variables.
LANGFLOW_WORKER_TIMEOUTInteger300Worker timeout in seconds.
See --worker-timeout option.
LANGFLOW_WORKERSInteger1Number of worker processes.
See --workers option.

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