Install custom dependencies
Langflow provides optional dependency groups and support for custom dependencies to extend Langflow functionality.
Install custom dependencies in Langflow Desktop
To add dependencies to Langflow Desktop, add an entry for the package to the application's requirements.txt
file:
- On macOS, the file is located at
/Users/USER/.langflow/data/requirements.txt
. - On Windows, the file is located at
C:\Users\USER\AppData\Roaming\com.Langflow\data\requirements.txt
.
Add the dependency and version to requirements.txt
on separate lines in the format PACKAGE==VERSION
, such as docling==2.40.0
.
Restart Langflow Desktop to install the dependencies.
If you need to change or uninstall custom dependencies, edit the requirements.txt
file, and then restart Langflow Desktop.
Install custom dependencies in Langflow OSS
To install your own custom dependencies in your Langflow environment, add them with your package manager.
If you're working within a cloned Langflow repository, add dependencies with uv add
because there is already a pyproject.toml
file for uv to reference:
_10uv add langflow DEPENDENCY
Install optional dependency groups
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 the following command:
_10uv pip install "langflow[postgresql]"
To install multiple extras, use commas to separate each dependency group:
_10uv pip install "langflow[deploy,local,postgresql]"
Use a virtual environment to test custom dependencies
When testing locally, use a virtual environment to isolate your dependencies and prevent conflicts with other Python projects.
For example, if you want to experiment with matplotlib
with Langflow:
_10# Create and activate a virtual environment_10uv venv YOUR_LANGFLOW_VENV_10source YOUR_LANGFLOW_VENV/bin/activate_10_10# Install langflow and your additional dependency_10uv pip install langflow matplotlib
If you're working within a cloned Langflow repository, add dependencies with uv add
to reference the existing pyproject.toml
file:
_10uv add langflow matplotlib
Add dependencies to the Langflow codebase
When contributing to the Langflow codebase, you might need to add dependencies to Langflow.
Langflow uses a workspace with two packages:
- The
main
package (root level): For end-user features and main application code - The
base
package (insrc/backend/base
): For core functionality and shared code
Dependencies can be added in different groups:
- Regular dependencies: Core functionality needed to run the package
- Development dependencies: Tools for testing, linting, or debugging are added in the
[dependency-groups.dev]
section - Optional dependencies: Features that users can optionally install are added in the
[project.optional-dependencies]
There are three ways to add a package using make commands:
- Add to main package dependencies (for end-user features):
_10make add main="matplotlib"
- Add to development tools (for testing, linting, debugging):
_10make add devel="matplotlib"
- Add to base package dependencies (for core functionality):
_10make add base="matplotlib"
You can also add these dependencies manually to the pyproject.toml
file:
_10[project]_10dependencies = [_10 "matplotlib>=3.8.0"_10]
- Or as an optional dependency:
_10[project.optional-dependencies]_10plotting = [_10 "matplotlib>=3.8.0",_10]
The make
commands add the dependency with uv add
and update the uv.lock
file in the appropriate location.