django-langgraph-agent 0.1.1

A reusable Django package for building streaming AI agents with LangGraph and OpenRouter

django-langgraph-agent

[!WARNING] Beta Release: This project is currently in Beta and is not ready for production use. Features and APIs are subject to change.

A reusable Django package for building streaming AI agents powered by LangGraph and OpenRouter.

Battle-tested in internal workflows at Tathbeet — a Quran memorization platform.

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Features

• ⚙️ Admin-Managed Agents — create and customize agents from the Django Admin UI without code changes
• 🔌 Zero-Boilerplate API — built-in SSE chat & approval endpoints ready out-of-the-box (include("django_langgraph_agent.urls"))
• 🧰 Auto-Included ORM Tools — safe CRUD tools automatically attached and configured via MODEL_WHITELIST in settings.py
• 🎯 Tool Registry (@register_tool) — easily add custom tools (e.g. notifications, emails, external integrations)
• ⚡ Streaming SSE — yields real-time token, tool_approval, done, and error events
• 🛡️ Human-in-the-Loop — pause agents on sensitive actions (e.g. create/update), resume upon user confirmation
• 🧠 Auto Summarization — automatically compresses long conversations to preserve token limits
• 🔄 Multi-Model Fallback — primary model + fallback chain resilient to provider rate limits
• 🗄️ WSGI-Safe Checkpointer — zero idle connection leaks with PostgreSQL NullPool, SQLite, or MemorySaver
• 🧹 Gemini-Safe Turn Sanitizer — prevents strict turn-order errors when using Google AI Studio / Gemini models

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Installation

pip install django-langgraph-agent

# Optional: PostgreSQL checkpointer support
pip install django-langgraph-agent[postgres]

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Quick Start (Zero-Boilerplate Setup)

1. Add to INSTALLED_APPS

INSTALLED_APPS = [
    ...
    "django_langgraph_agent",
]

2. Add Built-in URLs (urls.py)

from django.urls import path, include

urlpatterns = [
    # Adds endpoints: GET /api/agent/, POST /api/agent/chat/, POST /api/agent/chat/approve/
    path("api/agent/", include("django_langgraph_agent.urls")),
]

3. Configure settings.py

DJANGO_LANGGRAPH_AGENT = {
    "OPENROUTER_API_KEY": env("OPENROUTER_API_KEY"),

    # LLM configuration (OpenRouter model IDs)
    "DEFAULT_MODEL": "google/gemini-2.5-flash-preview",
    "FALLBACK_MODELS": ["google/gemini-2.5-flash", "deepseek/deepseek-chat"],

    # Django ORM whitelist — controls accessible models and fields
    "MODEL_WHITELIST": {
        "Product": {
            "app_label": "store",
            "display_name": "Store Product",
            "fields": ["id", "name", "price", "category", "stock", "is_active"],  # allowlist
        },
        "Order": {
            "app_label": "store",
            "display_name": "Customer Order",
            "exclude_fields": ["payment_reference", "internal_notes"],  # blocklist
        },
    },
}

4. Run Migrations & DB Setup

python manage.py migrate
python manage.py setup_agent_db

5. Create an Agent in Django Admin

Navigate to /admin/django_langgraph_agent/agentconfig/add/:

• Name: support
• Display Name: Customer Support Agent
• System Prompt: You are a helpful store assistant. Use {user_id} and {date} context.

💡 Built-in ORM tools (get_model_schema, query_records, add_record, update_record) are automatically attached to every agent based on your MODEL_WHITELIST.

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Adding Custom Tools (@register_tool)

To add external integrations (push notifications, emails, third-party APIs):

# myapp/tools.py
from langchain_core.tools import tool
from django_langgraph_agent import register_tool

@register_tool
@tool
def send_push_notification(user_id: int, title: str, message: str) -> str:
    """Send a push notification to a user's device."""
    # ... your notification code ...
    return f"Notification sent to user #{user_id}"

Import your tools module in your app's AppConfig.ready() so registration runs on startup:

# myapp/apps.py
from django.apps import AppConfig

class MyAppConfig(AppConfig):
    name = "myapp"

    def ready(self):
        import myapp.tools  # noqa: F401

Now send_push_notification will appear in the Django Admin for selection under Extra Custom Tools.

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API Endpoints Reference

1. List Agents (GET /api/agent/)

Returns active agents available for chat.

{
  "agents": [
    { "name": "support", "display_name": "Customer Support Agent" }
  ]
}

2. Chat SSE Endpoint (POST /api/agent/chat/)

Start a conversation turn.

{
  "agent": "support",
  "message": "What products are available under $50?",
  "thread_id": "user-session-123"
}

SSE Events emitted:

• event: token — {"text": "...", "model_name": "..."}
• event: tool_approval — {"tool_calls": [{"id": "tc_1", "name": "add_record", "human_label": "Create record"}]}
• event: done — {"model_name": "..."}
• event: error — {"message": "..."}

3. Tool Approval SSE Endpoint (POST /api/agent/chat/approve/)

Resume execution after the user approves or denies a tool call.

{
  "agent": "support",
  "thread_id": "user-session-123",
  "decisions": {
    "tc_1": "approve"  // or "deny"
  }
}

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Code-Based Agent Definition (Alternative)

If you prefer defining agents directly in Python code instead of Django Admin:

from django_langgraph_agent import DjangoAgent, stream_agent
from django_langgraph_agent.tools import DjangoORMToolkit

toolkit = DjangoORMToolkit(include_write=True)

my_agent = DjangoAgent(
    name="my_agent",
    system_prompt="You are a helpful assistant.",
    tools=toolkit.tools,
    approval_tools=toolkit.approval_tools,
)

# Stream response in a custom view
def my_view(request):
    gen = stream_agent(my_agent, message="Hello", thread_id="t1", user_id=request.user.id)
    return StreamingHttpResponse(gen, content_type="text/event-stream")

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Running the Example Project

cd django-langgraph-agent/
pip install -e ".[test]"
export OPENROUTER_API_KEY=sk-or-...

PYTHONPATH=. python3 example_project/manage.py migrate
PYTHONPATH=. python3 example_project/manage.py setup_agent_db
PYTHONPATH=. python3 example_project/manage.py runserver

Open http://localhost:8000/chat/ for the dark-mode streaming test UI.

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License

MIT