> ## Documentation Index
> Fetch the complete documentation index at: https://docs.loadforge.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Load Testing GraphQL Subscriptions

> Guide on load testing real-time GraphQL subscriptions with LoadForge using Locust.

## Overview

GraphQL subscriptions provide real-time data streams over WebSockets. LoadForge supports subscription load testing by leveraging Locust and the `WebSocketUser` from `locust-plugins`.

## Locust Test Script (locust.py)

```python theme={null}
# locust.py
import json
from locust import between, task
from locust_plugins.users import WebSocketUser

class GraphqlSubsUser(WebSocketUser):
    wait_time = between(1, 3)
    host = "wss://api.yourdomain.com/graphql"

    def on_start(self):
        # Open WebSocket connection
        self.connect("/graphql")

        # Initialize the subscription
        init_msg = {"type": "connection_init", "payload": {}}
        self.send(json.dumps(init_msg))
        self.receive()

        # Start subscription
        sub_msg = {
            "id": "1",
            "type": "start",
            "payload": {"query": "subscription { newMessage { content sender } }"}
        }
        self.send(json.dumps(sub_msg))

    @task
    def listen(self):
        # Receive a subscription event
        event = self.receive()
        data = json.loads(event)
        print(data)
```

***

**Notes:**

* Install dependencies: `pip install locust locust-plugins websockets` if you wish to test locally.
* Replace `host` and GraphQL query with your subscription endpoint.