flow/LLM.md

LLM.md - Hanzo Flow

Overview

Hanzo Flow is a powerful platform for building and deploying AI-powered agents and workflows. It provides developers with both a visual authoring experience and built-in API and MCP servers.

Tech Stack

• Backend: Python (FastAPI, SQLModel, Alembic)
• Frontend: TypeScript/React (Next.js)
• Package manager: uv (Python), pnpm (Node.js)

Build & Run

uv sync --all-extras       # Install Python deps
make dev                   # Start dev server
make test                  # Run tests

Package Architecture (2026-03-25)

Three Python packages in a uv workspace:

Package	PyPI name	Dir	Purpose
flow	langflow-base	src/backend/base/flow/	Main backend package (454 files)
flow (root)	hanzoflow	src/backend/flow/	Root package (version only)
lfx	lfx	src/lfx/src/lfx/	Lightweight executor, standalone CLI

Internal package name: flow

• All Python imports use from flow.xxx / import flow.xxx
• Entry point: hanzo-flow = "flow.launcher:main" (root pyproject.toml)
• Entry point: langflow-base = "flow.launcher:main" (base pyproject.toml)
• Hatch build target: packages = ["flow"] (base), packages = ["src/backend/flow"] (root)
• The langflow compat shim package has been removed (was at src/backend/base/langflow/)
• The hanzoflow package dir has been renamed to flow

PyPI package names (unchanged)

• hanzoflow -- root package name in pyproject.toml
• langflow-base -- base package name in pyproject.toml
• lfx -- executor package name

Environment variables (backwards compat)

• LANGFLOW_* env vars are kept for backwards compatibility (e.g. LANGFLOW_DATABASE_URL, LANGFLOW_LOG_LEVEL)
• These are defined in lfx/src/lfx/services/settings/base.py via pydantic-settings

Key classes

• FlowApplication -- Gunicorn application class (flow.server)
• FlowUvicornWorker -- Uvicorn worker class (flow.server)

Key Files

• pyproject.toml -- Root project config (PyPI name: hanzoflow)
• src/backend/base/pyproject.toml -- Base package config (PyPI name: langflow-base)
• src/backend/base/flow/launcher.py -- Main entry point (was langflow_launcher.py)
• src/backend/base/flow/__main__.py -- CLI commands (typer app)
• src/backend/base/flow/main.py -- FastAPI app factory
• src/backend/base/flow/alembic/ -- Database migrations
• Dockerfile -- Production container
• Makefile -- Build automation