Langflow Base

0.9.1 verified Fri May 01 auth: no python

A Python package with a built-in web application for building AI-powered workflows. Current version 0.9.1, released March 2025. Active development with monthly releases.

pip install langflow-base

Common errors

error ModuleNotFoundError: No module named 'langflow_base' ↓

cause Incorrect package name often confused with 'langflow'.

fix

Install with 'pip install langflow-base' and import as 'import langflow_base'.

error ImportError: cannot import name 'run_flow' from 'langflow_base' ↓

cause Function 'run_flow' removed in 0.9.x.

fix

Use 'from langflow_base import execute_flow' instead.

error RuntimeError: This package requires Python >=3.10 and <3.14 ↓

cause Python version not supported.

fix

Use Python 3.10, 3.11, 3.12, or 3.13.

Warnings

breaking langflow-base 0.9.x renamed several submodules (e.g., 'langflow_base.components' to 'langflow_base.components_v2'). Update imports accordingly. ↓

fix Use new submodule paths as documented in the official changelog.

deprecated The function 'run_flow' is deprecated in 0.8.x and removed in 0.9.x. Use 'execute_flow' instead. ↓

fix Replace 'run_flow(...)' with 'execute_flow(...)'.

gotcha The package requires Python >=3.10 and <3.14. Older Python versions will fail to install. ↓

fix Ensure Python version is 3.10, 3.11, 3.12, or 3.13.

gotcha Web application dependencies (e.g., 'uvicorn', 'fastapi') are not automatically installed. Use 'langflow-base[web]' to include them. ↓

fix Run 'pip install langflow-base[web]' if you need the built-in web app.

Imports

langflow_base
wrong
```
from langflow_base import *
```
correct
```
import langflow_base
```
Wildcard imports not recommended; use specific submodules.

load_flow

wrong

from langflow import load_flow

correct

from langflow_base import load_flow

Incorrect package name; use langflow_base.

Quickstart

Loads a Langflow flow from a JSON file. For authentication, set LANGFLOW_API_KEY environment variable.

import os
from langflow_base import load_flow

# Load a flow from a JSON file
flow = load_flow('path/to/flow.json')
# optional: set API key via env var
api_key = os.environ.get('LANGFLOW_API_KEY', '')
print(f"Flow loaded: {flow}")