Tools / Langflow
Langflow Review
A visual, MIT-licensed builder for AI agents and RAG flows that serves each flow as an API
Last reviewed: October 2026
TL;DR
Langflow is a Python-based, MIT-licensed visual builder for AI agents and RAG apps: you connect components on a canvas, test them in a Playground, and call the finished flow through an API or expose it as an MCP server. It is the permissively licensed counterpart to Dify for developers who want to stay close to Python, with the caveat that visual flows get unwieldy as they grow.
License
MIT
Self-hosted
Yes
Cloud option
Managed cloud running the same codebase
GitHub stars
155.5K★
Checked October 2026
Category
Developer Tools & AI Platforms
Pricing
Free and open source; you pay for the model and vector-database services you connect and for hosting
What is Langflow?
Langflow is an open-source, Python-based framework for building AI applications that supports agents and the Model Context Protocol and does not require specific LLMs or vector stores. In the visual editor, each component is one workflow step, with pre-built templates to start from. General components cover inputs, outputs, and data stores, and specialized ones cover agents, language models, and embedding providers, with parameters that can be fixed or variable and tweaks that override settings at runtime. The Playground lets you interact with a flow in real time and run individual components in isolation. You can serve flows as API endpoints, containerize them, or build Langflow in as a dependency. You can use components or flows as agent tools, expose Langflow as an MCP server, and connect it to external MCP servers as a client, and custom components are written in Python.
Installation & self-hosting
There are four routes. Langflow Desktop is recommended and available for macOS 13 or later and for Windows (an .msi installer, with a documented fix if you hit the C++ Build Tools error), and it lacks the Shareable Playground and Voice Mode. The Python package needs Python 3.10 to 3.14, uv, and at least 2 GB of RAM (4 GB recommended): create a virtual environment with uv venv, install with uv pip install langflow, start with uv run langflow run, and open http://127.0.0.1:7860. Use langflow-base to omit the provider extensions; from Langflow 1.12, langflow-base versions start at 1.12.0. Docker runs the official image with LANGFLOW_AUTO_LOGIN=false and a strong LANGFLOW_SUPERUSER_PASSWORD, and the official images disable auto-login by default. Upgrading is uv pip install langflow -U, and the docs say to back up first.
User experience
You drag components onto the canvas, wire their inputs and outputs, and click through the Playground to test. When you need control, you open a component and edit its Python. Observability is not built in, and the project pairs with Langfuse for it. This section reflects the official docs and OpenAlternative; we did not build a flow ourselves.
Key features
- Drag-and-drop canvas with pre-built templates
- Playground for real-time testing and running components in isolation
- Integrations with major LLMs, vector stores such as Pinecone, Milvus, and Qdrant, and data sources such as Google Drive, Notion, Slack, and GitHub
- Agent frameworks such as LangChain, CrewAI, and Composio
- Flows served as API endpoints, or exposed as an MCP server
- MCP client support to call external tools
- Custom components in Python
What Langflow does well
- MIT license with no extra conditions on multi-tenancy or branding
- Bidirectional MCP support, so a flow can both use and expose tools
- A clear path from prototype to API and container
- Very large community: about 156,000 stars and a release in the week of review
Where Langflow falls short
- Langflow Desktop lacks the Shareable Playground and Voice Mode
- No built-in observability, so you pair it with a tool such as Langfuse
- Visual flows can get hard to read and maintain for large agents
- Installation has real requirements (Python 3.10 to 3.14, uv, 2 to 4 GB RAM), and Docker needs explicit auth settings for any shared deployment
- Pricing for the managed cloud is not shown on the pages we reviewed
Pricing
Langflow is free under the MIT license. Your costs are model providers, vector databases, and hosting. A managed cloud runs the same codebase, but the pages we reviewed list no prices.
Langflow vs Voiceflow
Voiceflow is a hosted, no-code tool aimed at designing conversational agents. Langflow is broader and more developer-oriented: it builds general agent and RAG flows, exposes them as APIs and MCP servers, and lets you edit the Python underneath. Dify is the closest open-source alternative, with more built-in platform features (a prompt IDE, observability, and a plugin marketplace) but a license with multi-tenant and branding conditions.
Best for
- Developers prototyping agents and RAG pipelines quickly in Python
- Teams that want an MIT-licensed visual builder
- Projects that need each flow exposed as an API or MCP server
- People who want to run a local desktop version for experiments
Not ideal for
- Non-technical teams that want a conversation-design tool
- Very complex agents that are easier to reason about as code
- Teams that need integrated monitoring and evaluation out of the box
Alternatives
Final verdict
Langflow is one of the best open-source ways to prototype agents visually, with a license that makes adoption easy. For production, plan your own evaluation, monitoring, and authentication around it.