mirror of
https://github.com/langflow-ai/langflow.git
synced 2026-07-24 13:09:09 +08:00
bc927abef2
* chore: import AGENTS.md from CLAUDE.md so Claude Code loads project instructions Claude Code does not yet natively support AGENTS.md. The previous CLAUDE.md was a human-readable redirect, but the agent never followed it. Using the @AGENTS.md import directive (which Claude Code does support) makes the project instructions auto-load. * chore: clarify dev-deps sync and pre-commit workflow in AGENTS.md - Note that running tests inside a sub-package needs uv sync --group dev --package <name>; the default sync skips sub-package dev deps and leaves things like fakeredis uninstalled. - Tighten the pre-commit workflow section: pre-commit hooks already run ruff/biome on commit, so the previous 5-step manual sequence overstated what's needed.
204 lines
6.9 KiB
Markdown
204 lines
6.9 KiB
Markdown
# AGENTS.md
|
|
|
|
This file provides guidance to AI coding agents when working with code in this repository.
|
|
|
|
## Project Overview
|
|
|
|
Langflow is a visual workflow builder for AI-powered agents. It has a Python/FastAPI backend, React/TypeScript frontend, and a lightweight executor CLI (lfx).
|
|
|
|
## Prerequisites
|
|
|
|
- **Python:** 3.10-3.13
|
|
- **uv:** >=0.4 (Python package manager)
|
|
- **Node.js:** >=20.19.0 (v22.12 LTS recommended)
|
|
- **npm:** v10.9+
|
|
- **make:** For build coordination
|
|
|
|
## Common Commands
|
|
|
|
### Development Setup
|
|
```bash
|
|
make init # Install all dependencies + pre-commit hooks
|
|
make run_cli # Build and run Langflow (http://localhost:7860)
|
|
make run_clic # Clean build and run (use when frontend issues occur)
|
|
```
|
|
|
|
### Development Mode (Hot Reload)
|
|
```bash
|
|
make backend # FastAPI on port 7860 (terminal 1)
|
|
make frontend # Vite dev server on port 3000 (terminal 2)
|
|
```
|
|
|
|
For component development, enable dynamic loading:
|
|
```bash
|
|
LFX_DEV=1 make backend # Load all components dynamically
|
|
LFX_DEV=mistral,openai make backend # Load only specific modules
|
|
```
|
|
|
|
### Code Quality
|
|
```bash
|
|
make format_backend # Format Python (ruff) - run FIRST before lint
|
|
make format_frontend # Format TypeScript (biome)
|
|
make format # Both
|
|
make lint # mypy type checking
|
|
```
|
|
|
|
### Testing
|
|
```bash
|
|
make unit_tests # Backend unit tests (pytest, parallel)
|
|
make unit_tests async=false # Sequential tests
|
|
uv run pytest path/to/test.py # Single test file
|
|
uv run pytest path/to/test.py::test_name # Single test
|
|
|
|
make test_frontend # Jest unit tests
|
|
make tests_frontend # Playwright e2e tests
|
|
```
|
|
|
|
### Database Migrations
|
|
```bash
|
|
make alembic-revision message="Description" # Create migration
|
|
make alembic-upgrade # Apply migrations
|
|
make alembic-downgrade # Rollback one version
|
|
```
|
|
|
|
## Architecture
|
|
|
|
### Monorepo Structure
|
|
```
|
|
src/
|
|
├── backend/
|
|
│ ├── base/langflow/ # Core backend package (langflow-base)
|
|
│ │ ├── api/ # FastAPI routes (v1/, v2/)
|
|
│ │ ├── components/ # Built-in Langflow components
|
|
│ │ ├── services/ # Service layer (auth, database, cache, etc.)
|
|
│ │ ├── graph/ # Flow graph execution engine
|
|
│ │ └── custom/ # Custom component framework
|
|
│ └── tests/ # Backend tests
|
|
├── frontend/ # React/TypeScript UI
|
|
│ └── src/
|
|
│ ├── components/ # UI components
|
|
│ ├── stores/ # Zustand state management
|
|
│ └── icons/ # Component icons
|
|
└── lfx/ # Lightweight executor CLI
|
|
```
|
|
|
|
### Key Packages
|
|
- **langflow**: Main package with all integrations
|
|
- **langflow-base**: Core framework (api, services, graph engine)
|
|
- **lfx**: Standalone CLI for running flows (`lfx serve`, `lfx run`)
|
|
|
|
### Service Layer
|
|
Backend services in `src/backend/base/langflow/services/`:
|
|
- `auth/` - Authentication
|
|
- `database/` - SQLAlchemy models and migrations
|
|
- `cache/` - Caching layer
|
|
- `storage/` - File storage
|
|
- `tracing/` - Observability integrations
|
|
|
|
## Component Development
|
|
|
|
Components live in `src/backend/base/langflow/components/`. To add a new component:
|
|
|
|
1. Create component class inheriting from `Component`
|
|
2. Define `display_name`, `description`, `icon`, `inputs`, `outputs`
|
|
3. Add to `__init__.py` (alphabetical order)
|
|
4. Run with `LFX_DEV=1 make backend` for hot reload
|
|
|
|
**IMPORTANT:** Changing a component's class name is a breaking change and should never be done. The class name serves as an identifier used to match components in saved flows and to flag them for updates in the UI. Renaming it will break existing flows that use that component.
|
|
|
|
### Component Structure
|
|
```python
|
|
from langflow.custom import Component
|
|
from langflow.io import MessageTextInput, Output
|
|
|
|
class MyComponent(Component):
|
|
display_name = "My Component"
|
|
description = "What it does"
|
|
icon = "component-icon" # Lucide icon name or custom
|
|
|
|
inputs = [
|
|
MessageTextInput(name="input_value", display_name="Input"),
|
|
]
|
|
outputs = [
|
|
Output(display_name="Output", name="output", method="process"),
|
|
]
|
|
|
|
def process(self) -> Message:
|
|
# Component logic
|
|
return Message(text=self.input_value)
|
|
```
|
|
|
|
### Component Testing
|
|
Tests go in `src/backend/tests/unit/components/`. Use base classes:
|
|
- `ComponentTestBaseWithClient` - Components needing API access
|
|
- `ComponentTestBaseWithoutClient` - Pure logic components
|
|
|
|
Required fixtures: `component_class`, `default_kwargs`, `file_names_mapping`
|
|
|
|
## Frontend Development
|
|
|
|
- **React 19** + TypeScript + Vite
|
|
- **Zustand** for state management
|
|
- **@xyflow/react** for graph visualization
|
|
- **Tailwind CSS** for styling
|
|
|
|
### Custom Icons
|
|
1. Create SVG component in `src/frontend/src/icons/YourIcon/`
|
|
2. Export with `forwardRef` and `isDark` prop support
|
|
3. Add to `lazyIconImports.ts`
|
|
4. Set `icon = "YourIcon"` in Python component
|
|
|
|
## Testing Notes
|
|
|
|
- `@pytest.mark.api_key_required` - Tests requiring external API keys
|
|
- `@pytest.mark.no_blockbuster` - Skip blockbuster plugin
|
|
- Database tests may fail in batch but pass individually
|
|
- Pre-commit hooks require `uv run git commit`
|
|
- Always use `uv run` when running Python commands
|
|
- When running tests inside a sub-package (e.g. `langflow-base`, `lfx`), sync that package's dev group first: `uv sync --group dev --package langflow-base`. The default `uv sync` only resolves the top-level workspace and may leave dev-only test deps (e.g. `fakeredis`) uninstalled.
|
|
|
|
### Graph Testing Pattern
|
|
|
|
Proper Graph tests follow this pattern:
|
|
1. Build graph with connected components
|
|
2. Connect them via `.set()` calls
|
|
3. Call `async_start` and iterate over the results
|
|
4. Validate the results
|
|
|
|
### Testing Best Practices
|
|
|
|
- Avoid mocking in tests when possible
|
|
- Prefer real integrations for more reliable tests
|
|
|
|
## Version Management
|
|
```bash
|
|
make patch v=1.5.0 # Update version across all packages
|
|
```
|
|
|
|
This updates: `pyproject.toml`, `src/backend/base/pyproject.toml`, `src/frontend/package.json`
|
|
|
|
## Pre-commit Workflow
|
|
|
|
Pre-commit hooks run ruff and biome automatically on `git commit`, so manual
|
|
formatting is not required. To avoid an extra commit cycle when you have many
|
|
changes:
|
|
|
|
1. Run `make format_backend` once before staging - fixes most ruff issues up front.
|
|
2. Run `uv run git commit` (the `uv run` ensures pre-commit finds the right Python).
|
|
3. If you touched backend code, run `make unit_tests` locally for faster feedback than CI.
|
|
|
|
## Pull Request Guidelines
|
|
|
|
- Follow [semantic commit conventions](https://www.conventionalcommits.org/)
|
|
- Reference any issues fixed (e.g., `Fixes #1234`)
|
|
- Ensure all tests pass before submitting
|
|
|
|
## Documentation
|
|
|
|
Documentation uses Docusaurus and lives in `docs/`:
|
|
```bash
|
|
cd docs
|
|
yarn install
|
|
yarn start # Dev server on port 3000 (prompts for 3001 if 3000 is in use)
|
|
```
|