Environment variables

import Tabs from '@theme/Tabs'; import TabItem from '@theme/TabItem'; import Link from '@docusaurus/Link';

In general, environment variables, like LANGFLOW_PORT or LANGFLOW_LOG_LEVEL, configure how Langflow runs. These are broad settings that apply to your entire Langflow deployment.

In contrast, global variables are user-defined values stored in Langflow's database for use in flows, such as OPENAI_API_KEY. Langflow can also source global variables from environment variables. For more information, see Langflow global variables.

Configure environment variables for Langflow OSS

Langflow recognizes supported environment variables from the following sources:

• Environment variables set in your terminal.
• Environment variables imported from a .env file when starting Langflow.
• Environment variables set with the Langflow CLI, including the --env-file option and direct options, such as --port.

You can choose to use one or more of these sources.

Precedence {#precedence}

If the same environment variable is set in multiple places, the following hierarchy applies:

1. Langflow CLI options override all other sources.
2. The .env file overrides system environment variables.
3. System environment variables are used only if not set elsewhere. When running a Langflow Docker image, the -e flag can be used to set additional system environment variables.

For example:

• If you set LANGFLOW_PORT=8080 in your system environment and LANGFLOW_PORT=7860 in .env, Langflow uses 7860 from .env.
• If you use the Langflow CLI to run langflow run --env-file .env --port 9000, and you set LANGFLOW_PORT=7860 in .env, then Langflow uses 9000 from the CLI option.

Set environment variables in your terminal {#configure-variables-terminal}

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

export VARIABLE_NAME='VALUE'

set VARIABLE_NAME='VALUE'

docker run -it --rm \
    -p 7860:7860 \
    -e VARIABLE_NAME='VALUE' \
    langflowai/langflow:latest

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 {#configure-variables-env-file}

1. If Langflow is running, quit Langflow.

2. Create a .env file, and then open it in your preferred editor.

3. Define Langflow environment variables in the .env file.

   <details> <summary>Example: .env</summary>
   textCopy

   DO_NOT_TRACK=True
   LANGFLOW_AUTO_LOGIN=False
   LANGFLOW_AUTO_SAVING=True
   LANGFLOW_AUTO_SAVING_INTERVAL=1000
   LANGFLOW_BACKEND_ONLY=False
   LANGFLOW_BUNDLE_URLS=["https://github.com/user/repo/commit/hash"]
   LANGFLOW_CACHE_TYPE=async
   LANGFLOW_COMPONENTS_PATH=/path/to/components/
   LANGFLOW_COMPONENTS_INDEX_PATH=/path/to/component_index.json
   LANGFLOW_CONFIG_DIR=/path/to/config/
   LANGFLOW_DATABASE_URL=postgresql://user:password@localhost:5432/langflow
   LANGFLOW_DEV=False
   LANGFLOW_FALLBACK_TO_ENV_VAR=False
   LANGFLOW_HEALTH_CHECK_MAX_RETRIES=5
   LANGFLOW_HOST=localhost
   LANGFLOW_LANGCHAIN_CACHE=InMemoryCache
   LANGFLOW_MAX_FILE_SIZE_UPLOAD=10000
   LANGFLOW_MAX_ITEMS_LENGTH=100
   LANGFLOW_MAX_TEXT_LENGTH=1000
   LANGFLOW_LOG_LEVEL=error
   LANGFLOW_OPEN_BROWSER=False
   LANGFLOW_PORT=7860
   LANGFLOW_REMOVE_API_KEYS=False
   LANGFLOW_SAVE_DB_IN_CONFIG_DIR=True
   LANGFLOW_SECRET_KEY=somesecretkey
   LANGFLOW_STORE_ENVIRONMENT_VARIABLES=True
   LANGFLOW_SUPERUSER=adminuser
   LANGFLOW_SUPERUSER_PASSWORD=adminpass
   LANGFLOW_WORKER_TIMEOUT=60000
   LANGFLOW_WORKERS=3
   

   For additional examples, see .env.example in the Langflow repository.

   </details>

4. Save and close .env.

5. Start Langflow with your .env file:

   <Tabs> <TabItem value="local" label="Local" default>
   bashCopy

   uv run langflow run --env-file .env
   

   </TabItem> <TabItem value="docker" label="Docker">
   bashCopy

   docker run -it --rm \
       -p 7860:7860 \
       --env-file .env \
       langflowai/langflow:latest
   

   </TabItem> </Tabs>

   If your .env file isn't in the same directory, provide the path to your .env file.

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

Configure environment variables for development

The following examples show how to configure Langflow using environment variables in different development scenarios.

The .env file is a text file that contains key-value pairs of environment variables.

Create or edit a .env file in the root directory of your application or Langflow environment, and then add your configuration variables to the file:

DO_NOT_TRACK=True
LANGFLOW_AUTO_LOGIN=False
LANGFLOW_AUTO_SAVING=True
LANGFLOW_AUTO_SAVING_INTERVAL=1000
LANGFLOW_BACKEND_ONLY=False
LANGFLOW_BUNDLE_URLS=["https://github.com/user/repo/commit/hash"]
LANGFLOW_CACHE_TYPE=async
LANGFLOW_COMPONENTS_PATH=/path/to/components/
LANGFLOW_COMPONENTS_INDEX_PATH=/path/to/component_index.json
LANGFLOW_CONFIG_DIR=/path/to/config/
LANGFLOW_DATABASE_URL=postgresql://user:password@localhost:5432/langflow
LANGFLOW_DEV=False
LANGFLOW_FALLBACK_TO_ENV_VAR=False
LANGFLOW_HEALTH_CHECK_MAX_RETRIES=5
LANGFLOW_HOST=localhost
LANGFLOW_LANGCHAIN_CACHE=InMemoryCache
LANGFLOW_MAX_FILE_SIZE_UPLOAD=10000
LANGFLOW_MAX_ITEMS_LENGTH=100
LANGFLOW_MAX_TEXT_LENGTH=1000
LANGFLOW_LOG_LEVEL=error
LANGFLOW_OPEN_BROWSER=False
LANGFLOW_PORT=7860
LANGFLOW_REMOVE_API_KEYS=False
LANGFLOW_SAVE_DB_IN_CONFIG_DIR=True
LANGFLOW_SECRET_KEY=somesecretkey
LANGFLOW_STORE_ENVIRONMENT_VARIABLES=True
LANGFLOW_SUPERUSER=adminuser
LANGFLOW_SUPERUSER_PASSWORD=adminpass
LANGFLOW_WORKER_TIMEOUT=60000
LANGFLOW_WORKERS=3

A systemd service configuration file configures Linux system services.

To add environment variables, create or edit a service configuration file and add an override.conf file. This file allows you to override the default environment variables for the service.

[Service]
Environment="DO_NOT_TRACK=true"
Environment="LANGFLOW_AUTO_LOGIN=false"
Environment="LANGFLOW_AUTO_SAVING=true"
Environment="LANGFLOW_AUTO_SAVING_INTERVAL=1000"
Environment="LANGFLOW_BACKEND_ONLY=false"
Environment="LANGFLOW_BUNDLE_URLS=[\"https://github.com/user/repo/commit/hash\"]"
Environment="LANGFLOW_CACHE_TYPE=async"
Environment="LANGFLOW_COMPONENTS_PATH=/path/to/components/"
Environment="LANGFLOW_COMPONENTS_INDEX_PATH=/path/to/component_index.json"
Environment="LANGFLOW_CONFIG_DIR=/path/to/config"
Environment="LANGFLOW_DATABASE_URL=postgresql://user:password@localhost:5432/langflow"
Environment="LANGFLOW_DEV=false"
Environment="LANGFLOW_FALLBACK_TO_ENV_VAR=false"
Environment="LANGFLOW_HEALTH_CHECK_MAX_RETRIES=5"
Environment="LANGFLOW_HOST=localhost"
Environment="LANGFLOW_LANGCHAIN_CACHE=InMemoryCache"
Environment="LANGFLOW_MAX_FILE_SIZE_UPLOAD=10000"
Environment="LANGFLOW_MAX_ITEMS_LENGTH=100"
Environment="LANGFLOW_MAX_TEXT_LENGTH=1000"
Environment="LANGFLOW_LOG_ENV=container_json"
Environment="LANGFLOW_LOG_FILE=logs/langflow.log"
Environment="LANGFLOW_LOG_LEVEL=error"
Environment="LANGFLOW_OPEN_BROWSER=false"
Environment="LANGFLOW_PORT=7860"
Environment="LANGFLOW_REMOVE_API_KEYS=false"
Environment="LANGFLOW_SAVE_DB_IN_CONFIG_DIR=true"
Environment="LANGFLOW_SECRET_KEY=somesecretkey"
Environment="LANGFLOW_STORE_ENVIRONMENT_VARIABLES=true"
Environment="LANGFLOW_SUPERUSER=adminuser"
Environment="LANGFLOW_SUPERUSER_PASSWORD=adminpass"
Environment="LANGFLOW_WORKER_TIMEOUT=60000"
Environment="LANGFLOW_WORKERS=3"

For more information on systemd, see the Red Hat documentation.

The tasks.json file located in .vscode/tasks.json is a configuration file for development environments using Visual Studio Code.

Create or edit the .vscode/tasks.json file in your project root.

{
    "version": "2.0.0",
    "options": {
        "env": {
            "DO_NOT_TRACK": "true",
            "LANGFLOW_AUTO_LOGIN": "false",
            "LANGFLOW_AUTO_SAVING": "true",
            "LANGFLOW_AUTO_SAVING_INTERVAL": "1000",
            "LANGFLOW_BACKEND_ONLY": "false",
            "LANGFLOW_BUNDLE_URLS": "[\"https://github.com/user/repo/commit/hash\"]",
            "LANGFLOW_CACHE_TYPE": "async",
            "LANGFLOW_COMPONENTS_PATH": "D:/path/to/components/",
            "LANGFLOW_COMPONENTS_INDEX_PATH": "D:/path/to/component_index.json",
            "LANGFLOW_CONFIG_DIR": "D:/path/to/config/",
            "LANGFLOW_DATABASE_URL": "postgresql://postgres:password@localhost:5432/langflow",
            "LANGFLOW_DEV": "false",
            "LANGFLOW_FALLBACK_TO_ENV_VAR": "false",
            "LANGFLOW_HEALTH_CHECK_MAX_RETRIES": "5",
            "LANGFLOW_HOST": "localhost",
            "LANGFLOW_LANGCHAIN_CACHE": "InMemoryCache",
            "LANGFLOW_MAX_FILE_SIZE_UPLOAD": "10000",
            "LANGFLOW_MAX_ITEMS_LENGTH": "100",
            "LANGFLOW_MAX_TEXT_LENGTH": "1000",
            "LANGFLOW_LOG_ENV": "container_csv",
            "LANGFLOW_LOG_FILE": "langflow.log",
            "LANGFLOW_LOG_LEVEL": "error",
            "LANGFLOW_OPEN_BROWSER": "false",
            "LANGFLOW_PORT": "7860",
            "LANGFLOW_REMOVE_API_KEYS": "true",
            "LANGFLOW_SAVE_DB_IN_CONFIG_DIR": "false",
            "LANGFLOW_SECRET_KEY": "somesecretkey",
            "LANGFLOW_STORE_ENVIRONMENT_VARIABLES": "true",
            "LANGFLOW_SUPERUSER": "adminuser",
            "LANGFLOW_SUPERUSER_PASSWORD": "adminpass",
            "LANGFLOW_WORKER_TIMEOUT": "60000",
            "LANGFLOW_WORKERS": "3"
        }
    },
    "tasks": [
        {
            "label": "langflow backend",
            "type": "shell",
            "command": ". ./langflownightly/Scripts/activate && langflow run",
            "isBackground": true,
            "problemMatcher": []
        }
    ]
}

To run Langflow using the above VSCode tasks.json file, in the VSCode command palette, select Tasks: Run Task > langflow backend.

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.

To modify environment variables for Langflow Desktop, set environment variables in a Desktop .env file, and then restart the app.

To modify the macOS .env file, do the following:

1. Create or edit ~/.langflow/data/.env.

2. Add your Langflow environment variables, for example:

   textCopy

   LANGFLOW_LOG_LEVEL=info
   LANGFLOW_DOCLING=true
   

3. Save the file.

4. Restart Langflow Desktop.

To modify the Windows .env file, do the following:

1. Create or edit %APPDATA%\com.LangflowDesktop\data\.env.

2. Add your Langflow environment variables, for example:

   textCopy

   LANGFLOW_LOG_LEVEL=info
   LANGFLOW_DOCLING=true
   

3. Save the file.

4. Restart Langflow Desktop.

Windows supports two sources for Langflow Desktop environment variables: a Langflow application .env file, and Windows user environment variables.

The .env file at %APPDATA%\com.LangflowDesktop\data\.env is the recommended approach, but Windows user variables are useful for single-sourcing API keys between Langflow and other Windows applications. If the same variable is defined in both the Langflow application .env file and as a Windows user environment variable, the .env file takes precedence.

To modify the Windows user environment variables, do the following:

1. Press <kbd>Win + R</kbd>, enter sysdm.cpl, and then press <kbd>Enter</kbd>.
2. Click the Advanced tab, and then click Environment Variables.
3. In User variables, click New.
4. Enter the variable name, such as OPENAI_API_KEY, and its value.
5. Click OK, and then restart Langflow Desktop.

Supported environment variables {#supported-variables}

The following sections provide information about specific Langflow environment variables.

Authentication and security

See API keys and authentication.

Global variables

For information about the relationship between Langflow global variables and environment variables, as well as environment variables that control handling of global variables, see Global variables.

Logs {#logging}

See Configure log options.

MCP servers {#mcp}

See Use Langflow as an MCP server.

Monitoring and metrics

For environment variables for specific monitoring service providers, see the Langflow monitoring integration guides, such as Langfuse and Best practices for Langflow on Kubernetes.

Server

The following environment variables set base Langflow server configuration, such as where the server is hosted, required files for SSL encryption, and the deployment type (frontend and backend, backend-only, development mode).

For more information about deploying Langflow servers, see Langflow deployment overview.

Storage

For file storage environment variables, see File storage environment variables.

For database environment variables, including PostgreSQL configuration, see Memory management options.

Telemetry

See Telemetry.

Visual editor and Playground behavior