Crosspulse

Seamless Python ↔ JavaScript Bridge - Bidirectional, fully synchronized cross-language communication library.

Break down language barriers and let Python and JavaScript talk to each other like old friends.

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✨ Features

• ✅ Bidirectional Communication: JS → PY and PY → JS
• ✅ Synchronous Calls: Full Promise/await support
• ✅ Event-Based Architecture: Register, listen, and call methods
• ✅ Error Handling: Exception handling in both languages
• ✅ Type Safe: JSON serialization with validation
• ✅ Simple API: Just 3 core methods: register(), listen(), call()
• ✅ Zero Dependencies: No external packages required
• ✅ Lightweight: Minimal overhead, maximum performance

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🎯 Why Crosspulse?

Ever wanted to combine Python's data processing power with JavaScript's UI capabilities? Or run ML models in Python while displaying results in Node.js? Crosspulse makes it effortless.

// JavaScript
const result = await bridge.call("train_model", data);
console.log("Accuracy:", result.accuracy);

# Python (automatically responds)
bridge.register("train_model", train_ml_model)

That's it. No REST APIs, no HTTP servers, no complexity.

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📦 Installation

Simply copy the files to your project:

crosspulse.py
crosspulse.js

Requirements:

• Python 3.7+
• Node.js 12+

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🚀 Quick Start

Mode 1: JavaScript → Python

Call Python functions from JavaScript.

JavaScript side:

const Crosspulse = require('./crosspulse');

async function main() {
  const bridge = new Crosspulse("connect");
  await bridge.connect("./crosspulse.py");
  
  // Call Python function
  const result = await bridge.call("py_add", 10, 20);
  console.log(result); // 30
  
  bridge.disconnect();
}

main();

Python side:

from crosspulse import Crosspulse

bridge = Crosspulse(mode="listen")

# Register method
bridge.register("py_add", lambda a, b: a + b)

# Start listening
bridge.listen()

Run:

node app.js

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Mode 2: Python → JavaScript

Call JavaScript functions from Python.

Python side:

from crosspulse import Crosspulse

bridge = Crosspulse(mode="connect")
bridge.connect("./crosspulse.js")

# Call JavaScript function
result = bridge.call("js_multiply", 100, 50)
print(result)  # 5000

bridge.disconnect()

JavaScript side:

const Crosspulse = require('./crosspulse');

const bridge = new Crosspulse("listen");

// Register method
bridge.register("js_multiply", (a, b) => a * b);

// Start listening
bridge.listen();

Run:

python3 main.py

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Mode 3: Bidirectional Communication

Both languages can call each other simultaneously!

Python side:

bridge = Crosspulse(mode="connect")

# Register our methods (JS can call these)
bridge.register("py_square", lambda x: x ** 2)
bridge.register("py_reverse", lambda s: s[::-1])

bridge.connect("./app.js")

# Call JS methods
result = bridge.call("js_capitalize", "hello world")
print(result)  # "HELLO WORLD"

# JS can simultaneously call py_square() or py_reverse()

JavaScript side:

const bridge = new Crosspulse("listen");

// Register our methods (Python can call these)
bridge.register("js_capitalize", (str) => str.toUpperCase());
bridge.register("js_length", (str) => str.length);

bridge.listen();

// Python can simultaneously call our methods
// We automatically respond to incoming calls

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📖 API Reference

Python

from crosspulse import Crosspulse

# Create instance
bridge = Crosspulse(mode="listen")   # Listen mode
bridge = Crosspulse(mode="connect")  # Connect mode

# Register method
bridge.register("method_name", callback_function)

# Listen for calls (listen mode)
bridge.listen()

# Connect to target (connect mode)
bridge.connect("target_script.js")

# Call remote method
result = bridge.call("method_name", arg1, arg2)

# Disconnect
bridge.disconnect()

JavaScript

const Crosspulse = require('./crosspulse');

// Create instance
const bridge = new Crosspulse("listen");   // Listen mode
const bridge = new Crosspulse("connect");  // Connect mode

// Register method
bridge.register("method_name", (arg1, arg2) => { 
  return result;
});

// Listen for calls (listen mode)
bridge.listen();

// Connect to target (connect mode)
await bridge.connect("./target_script.py");

// Call remote method
const result = await bridge.call("method_name", arg1, arg2);

// Disconnect
bridge.disconnect();

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🎯 Real-World Examples

Example 1: Data Processing Pipeline

# data_processor.py
import pandas as pd
from crosspulse import Crosspulse

bridge = Crosspulse("connect")
bridge.connect("./visualizer.js")

# Process data in Python
df = pd.read_csv("sales_data.csv")
insights = analyze_sales(df)

# Visualize in JavaScript
chart = bridge.call("create_chart", insights.to_dict())
print(f"Chart created: {chart}")

// visualizer.js
const bridge = new Crosspulse("listen");

bridge.register("create_chart", (data) => {
  // Use Chart.js, D3.js, or any JS library
  const chart = generateChart(data);
  return chart.id;
});

bridge.listen();

Example 2: Machine Learning UI

// ml_interface.js
const bridge = new Crosspulse("connect");

async function trainModel(dataset) {
  await bridge.connect("./ml_model.py");
  
  const progress = await bridge.call("train", dataset);
  console.log("Training progress:", progress);
  
  const predictions = await bridge.call("predict", testData);
  displayResults(predictions);
}

# ml_model.py
from sklearn.ensemble import RandomForestClassifier

bridge = Crosspulse("listen")

model = RandomForestClassifier()

def train_model(data):
    X, y = prepare_data(data)
    model.fit(X, y)
    return {"status": "trained", "accuracy": model.score(X, y)}

bridge.register("train", train_model)
bridge.listen()

Example 3: Web Scraping + Frontend

# scraper.py
from crosspulse import Crosspulse
import requests
from bs4 import BeautifulSoup

bridge = Crosspulse("connect")

def scrape_news():
    # Scrape with Python
    data = scrape_website()
    
    # Send to JavaScript for display
    bridge.call("update_ui", data)

bridge.connect("./server.js")
scrape_news()

Example 4: Desktop App (Electron + Python)

// electron_main.js
const bridge = new Crosspulse("connect");

ipcMain.on("process-image", async (event, imagePath) => {
  await bridge.connect("./image_processor.py");
  
  const processed = await bridge.call("enhance_image", imagePath);
  event.reply("image-ready", processed);
});

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🔧 Advanced Usage

Error Handling

try {
  const result = await bridge.call("risky_operation", data);
  console.log("Success:", result);
} catch (error) {
  console.error("Python error:", error.message);
}

try:
    result = bridge.call("risky_operation", data)
    print(f"Success: {result}")
except Exception as e:
    print(f"JavaScript error: {e}")

Multiple Arguments & Complex Data

// JavaScript
const result = await bridge.call("process_user", {
  name: "John",
  age: 30,
  tags: ["developer", "python", "javascript"]
});

# Python
def process_user(user_data):
    return {
        "id": generate_id(),
        "name": user_data["name"],
        "processed": True
    }

bridge.register("process_user", process_user)

Async Operations

# Python
import time

def long_running_task(duration):
    time.sleep(duration)
    return "Task completed"

bridge.register("long_task", long_running_task)

// JavaScript
const result = await bridge.call("long_task", 5);
console.log(result); // "Task completed" (after 5 seconds)

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🎨 Use Cases

Use Case	Python Side	JavaScript Side
Web Scraping	BeautifulSoup, Scrapy	Display in React/Vue
Machine Learning	TensorFlow, PyTorch	Real-time UI updates
Data Analysis	Pandas, NumPy	Chart.js, D3.js
Image Processing	OpenCV, Pillow	Canvas, WebGL
File Processing	Parse Excel/PDF	Electron file picker
API Gateway	Flask/FastAPI alternative	Frontend communication
Desktop Apps	Backend logic	Electron UI
Automation	Selenium, automation	Control panel

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⚡ Performance

• Latency: ~5-10ms per call (local)
• Throughput: 1000+ calls/second
• Memory: Minimal overhead (<5MB)
• Scalability: Single process pair

For high-throughput scenarios, consider batching calls or using WebSocket alternatives.

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🛡️ Security Notes

• Crosspulse uses STDIN/STDOUT for IPC
• Only use with trusted code
• Validate all incoming data
• Don't expose to untrusted networks
• Consider sandboxing for production

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🐛 Troubleshooting

"Method not found" error

# Make sure method is registered before listening
bridge.register("my_method", my_function)
bridge.listen()  # Must be after register

Connection timeout

// Ensure Python script is running
await bridge.connect("./script.py");
// Python should be in listen mode

JSON serialization errors

# Only use JSON-serializable types
# ✅ str, int, float, list, dict, bool, None
# ❌ Custom objects, functions, file handles

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🤝 Contributing

Contributions are welcome! Here's how:

git clone https://github.com/yourusername/crosspulse.git
cd crosspulse

Areas to contribute:

• TypeScript definitions
• More examples
• Performance improvements
• Documentation
• Bug fixes

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📄 License

MIT License - Use it however you want!

MIT License

Copyright (c) 2026 AnarEsgerzade

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

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🌟 Show Your Support

If Crosspulse helps your project, give it a ⭐️ on GitHub!

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📞 Support

• Issues: GitHub Issues
• Discussions: GitHub Discussions
• Email: anardevstudio@gmail.com

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Built with ❤️ by developers who believe languages should work together, not apart.

Crosspulse - Where Python meets JavaScript. 🚀

Make by AnarEsgerzade🌷