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Install Langflow

Langflow can be installed in three ways:

Install and run Langflow OSS​

Before you install and run Langflow OSS, be sure you have the following items.

Install and run Langflow OSS with uv (recommended) or pip.

  1. To install Langflow, use one of the following commands:

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uv pip install langflow

  1. To run Langflow, use one of the following commands:

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uv run langflow run

  1. To confirm that a local Langflow instance starts, go to the default Langflow URL at http://127.0.0.1:7860.

After confirming that Langflow is running, create your first flow with the Quickstart.

Manage Langflow OSS versions​

To upgrade Langflow to the latest version, use one of the following commands:


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uv pip install langflow -U

To install a specific version of the Langflow package, add the required version to the command.


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uv pip install langflow==1.3.2

To reinstall Langflow and all of its dependencies, add the --force-reinstall flag to the command.


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uv pip install langflow --force-reinstall

Install optional dependencies for Langflow OSS​

Langflow OSS provides optional dependency groups that extend its functionality.

These dependencies are listed in the pyproject.toml file under [project.optional-dependencies].

Install dependency groups using pip's [extras] syntax. For example, to install Langflow with the postgresql dependency group, enter one of the following commands:


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uv pip install "langflow[postgresql]"

To install multiple extras, enter one of the following commands:


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uv pip install "langflow[deploy,local,postgresql]"

To add your own custom dependencies, see Install custom dependencies.

Stop Langflow OSS​

To stop Langflow, in the terminal where it's running, enter Ctrl+C.

To deactivate your virtual environment, enter deactivate.

Common OSS installation issues​

This is a list of possible issues that you may encounter when installing and running Langflow.

No langflow.__main__ module​

When you try to run Langflow with the command langflow run, you encounter the following error:


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> No module named 'langflow.__main__'

  1. Run uv run langflow run instead of langflow run.
  2. If that doesn't work, reinstall the latest Langflow version with uv pip install langflow -U.
  3. If that doesn't work, reinstall Langflow and its dependencies with uv pip install langflow --pre -U --force-reinstall.

Langflow runTraceback​

When you try to run Langflow using the command langflow run, you encounter the following error:


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> langflow runTraceback (most recent call last): File ".../langflow", line 5, in <module> from langflow.__main__ import mainModuleNotFoundError: No module named 'langflow.__main__'

There are two possible reasons for this error:

  1. You've installed Langflow using pip install langflow but you already had a previous version of Langflow installed in your system. In this case, you might be running the wrong executable. To solve this issue, run the correct executable by running python -m langflow run instead of langflow run. If that doesn't work, try uninstalling and reinstalling Langflow with uv pip install langflow --pre -U.
  2. Some version conflicts might have occurred during the installation process. Run python -m pip install langflow --pre -U --force-reinstall to reinstall Langflow and its dependencies.

Something went wrong running migrations​


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> Something went wrong running migrations. Please, run 'langflow migration --fix'

Clear the cache by deleting the contents of the cache folder.

This folder can be found at:

  • Linux or WSL2 on Windows: home/<username>/.cache/langflow/
  • MacOS: /Users/<username>/Library/Caches/langflow/

This error can occur during Langflow upgrades when the new version can't override langflow-pre.db in .cache/langflow/. Clearing the cache removes this file but also erases your settings.

If you wish to retain your files, back them up before clearing the folder.

Langflow installation freezes at pip dependency resolution​

Installing Langflow with pip install langflow slowly fails with this error message:


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pip is looking at multiple versions of <<library>> to determine which version is compatible with other requirements. This could take a while.

To work around this issue, install Langflow with uv instead of pip.


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uv pip install langflow

To run Langflow with uv:


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uv run langflow run

Install and run Langflow Desktop​

important

Langflow Desktop is in Alpha. Development is ongoing, and the features and functionality are subject to change.

Langflow Desktop is a desktop version of Langflow that includes all the features of open source Langflow, with an additional version management feature for managing your Langflow version.

important

Langflow Desktop is available only for macOS.

To install Langflow Desktop, follow these steps:

  1. Navigate to Langflow Desktop.
  2. Enter your Name, Email address, and Company, and then click Download.
  3. Open the Finder, and then navigate to Downloads.
  4. Double-click the downloaded *.dmg file.
  5. To install Langflow Desktop, drag and drop the application icon to the Applications folder.
  6. When the installation completes, open the Langflow application.

The application checks uv, your local environment, and the Langflow version, and then starts.

Manage your Langflow version in Langflow Desktop​

When a new version of Langflow is available, Langflow Desktop displays an upgrade message.

To manage your Langflow version in Langflow Desktop, follow these steps:

  1. To access Langflow Desktop's Version Management pane, click your Profile Image, and then select Version Management. Langflow Desktop's current version is displayed, with other version options listed after it. The latest version is always highlighted.
  2. To change your Langflow version, select another version. A confirmation pane containing the selected version's changelog appears.
  3. To change to the selected version, click Confirm. The application restarts with the new version installed.

DataStax Langflow​

DataStax Langflow is a hosted version of Langflow integrated with Astra DB. Be up and running in minutes with no installation or setup required. Sign up for free.

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