Workflows SDK

Installation

This guide will walk you through installing the Vellum Workflows SDK and setting up your development environment.

Prerequisites

The Vellum Workflows SDK requires Python 3.9 or higher. If you don’t have Python installed, you can download it from python.org.

Installation

Install Python (if needed)

If you don’t have Python installed or need to upgrade:

  1. Visit python.org/downloads
  2. Download Python 3.9 or higher for your operating system
  3. Follow the installation instructions for your platform

We recommend using uv for faster package management. If you don’t have uv installed:

$# On macOS and Linux
>curl -LsSf https://astral.sh/uv/install.sh | sh
>
># On Windows
>powershell -c "irm https://astral.sh/uv/install.ps1 | iex"
>
># Or using pip
>pip install uv

Install the Vellum Workflows SDK

$uv add vellum-ai

Environment Setup

Set your Vellum API Key

To use most out-of-the-box Nodes and to push/pull to/from the Vellum UI, you’ll need a Vellum API key.

  1. Get your API key: You can find this at the bottom of the API Keys page in Vellum
  2. Set the environment variable:
$export VELLUM_API_KEY=your-api-key-here

To make this permanent, add it to your shell profile:

$echo 'export VELLUM_API_KEY=your-api-key-here' >> ~/.bashrc
># or for zsh users:
>echo 'export VELLUM_API_KEY=your-api-key-here' >> ~/.zshrc

It’s good practice to create a virtual environment for your project:

$uv venv
>source .venv/bin/activate  # On Windows: .venv\Scripts\activate

Verify Installation

Test that everything is working correctly:

1from vellum.workflows import BaseWorkflow
2from vellum.workflows.nodes import BaseNode
3
4print("Vellum Workflows SDK installed successfully!")

Next Steps

Now that you have the SDK installed, you can:

Need Help?

If you don’t have a Vellum account yet, you can sign up for free here.

For additional support, visit our support page.