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Version: 1.12.x (Next)

Install LFX

LFX can be installed from PyPI, cloned from the Langflow repository, or run without installing using uvx.

If you have installed Langflow OSS version 1.6 or later, lfx is already included in your environment.

Prerequisites​

Install from PyPI​

  1. Create and activate a virtual environment:

    uv venv lfx-venv
    source lfx-venv/bin/activate

  2. Install LFX:

    uv pip install lfx

    To install the latest nightly (pre-release) version:

    uv pip install --pre lfx

Install with bundle components​

Install the LFX engine and any provider extensions your flows need.

uv pip install langflow installs bundle components automatically.

uv pip install lfx installs the core LFX executor only, with no provider bundles included.

If your flows use bundle components, install the required packages in the same virtual environment.

Some components require an additional torch opt-in installation.

Long-tail bundles are third-party provider integrations like vector stores or model providers that ship together in the lfx-bundles package.

Standalone bundles are graduated providers with their own release cadences, such as OpenAI, Anthropic, and Exa.

To install one long-tail provider:

uv pip install "lfx-bundles[<bundle>]"

To install every long-tail provider:

uv pip install "lfx[bundles]"

lfx[bundles] is equivalent to lfx plus lfx-bundles[all]. It does not install graduated standalone packages such as lfx-openai.

To install a standalone provider package:

uv pip install lfx-<provider>

For example:

uv pip install lfx-openai

For the complete bundle-to-package mapping, see the Bundle list.

Bundle discovery happens at startup. Restart Langflow or your LFX server after installing.

To see the extensions that are currently loaded, run:

lfx extension list

Clone the Langflow repository​

To run LFX from source without a PyPI install:

  1. Clone the Langflow repository:

    git clone https://github.com/langflow-ai/langflow

  2. Change directory to src/lfx:

    cd langflow/src/lfx

  3. Run lfx commands using uv run:

    uv run lfx serve my-flow.json

Running uv run lfx from src/lfx installs the LFX engine only. Bundle components will still need to be installed. To use bundle components, see Install with bundle components, or run make init from the repository root to install the full Langflow development workspace.

Run without installing​

Use uvx to run LFX in a temporary environment without a permanent install:

uvx lfx serve my-flow.json

uvx downloads and caches LFX automatically. This is useful for one-off flow runs or CI pipelines where you do not want to manage a virtual environment.

Verify the installation​

After installing, confirm LFX is available:

lfx --version

To list available commands:

lfx --help

See also​

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