🔗 n8n-nodes-join

A powerful n8n Community Node for joining parallel workflow branches into a single JSON object. This node waits for all parallel inputs to complete and combines their data with automatic node name detection and intelligent error handling.

✨ Features

🔄 Join Node

• True Parallel Join: Waits for ALL parallel inputs before executing downstream
• Configurable Input Count: Set expected number of inputs (2-99)
• Smart Synchronization: Uses global storage to collect data across executions
• Timeout Protection: Configurable timeout to prevent infinite waiting
• Smart Labeling: Uses input_1, input_2, etc. as keys
• Metadata Support: Optional execution metadata and timing information
• Single Output: Guarantees downstream nodes execute exactly once

🛡️ Quality Assurance

• TypeScript: Full type safety and IntelliSense support
• Professional Error Messages: Clear, actionable error messages
• Timeout Handling: Configurable timeout for parallel operations

📦 Installation

Install the node using n8n's Community Nodes feature:

1. Via n8n Interface:

   • Go to Settings → Community Nodes
   • Install package: @conciso/n8n-nodes-join

2. Via npm (for self-hosted n8n):

   npm install @conciso/n8n-nodes-join

For detailed installation instructions, see the n8n Community Nodes documentation.

🚀 Usage

Problem Solved

In n8n workflows, when you connect multiple parallel nodes to a single downstream node, the downstream node executes multiple times (once for each input). The Join node solves this by:

Before (Multiple Executions):

API Call 1 ──┐
API Call 2 ──┤── Process Data (executes 3 times!)
API Call 3 ──┘

After (Single Execution):

API Call 1 ──┐
API Call 2 ──┤── [JOIN] ──> Process Data (executes 1 time)
API Call 3 ──┘

Basic Usage

1. Add parallel nodes to your workflow (API calls, data processing, etc.)
2. Connect all parallel nodes to the Join node
3. Connect the Join node to your downstream processing node
4. Configure timeout and error handling if needed

Output Structure

The Join node automatically creates a JSON object with input_x keys:

{
  "input_1": {
    "users": [{"id": 1, "name": "John"}, {"id": 2, "name": "Jane"}]
  },
  "input_2": {
    "orders": [{"id": 101, "total": 99.99}]
  },
  "input_3": {
    "processed": true,
    "timestamp": "2025-01-16T21:30:00Z"
  }
}

With Metadata

Enable "Include Metadata" for additional execution information:

{
  "data": {
    "input_1": { "users": [...] },
    "input_2": { "orders": [...] },
    "input_3": { "processed": true }
  },
  "metadata": {
    "input_1": {
      "timestamp": "2025-01-16T21:30:15Z",
      "executionIndex": 1
    },
    "input_2": {
      "timestamp": "2025-01-16T21:30:16Z", 
      "executionIndex": 2
    },
    "input_3": {
      "timestamp": "2025-01-16T21:30:17Z",
      "executionIndex": 3
    },
    "totalInputs": 3,
    "executionTime": "2025-01-16T21:30:17Z",
    "waitTime": "2.1s"
  }
}

⚙️ Configuration

Parameters

Parameter	Type	Default	Description
Expected Inputs	Number	2	Number of parallel inputs to wait for (2-99)
Timeout (seconds)	Number	30	Maximum time to wait for all inputs
Include Metadata	Boolean	false	Include execution metadata in output

💡 Use Cases

1. Parallel API Data Gathering

Get Users API    ──┐
Get Orders API   ──┤── [JOIN] ──> Generate Report
Get Products API ──┘

2. Multi-Source Data Processing

Database Query ──┐
File Processing ──┤── [JOIN] ──> Data Analysis
Web Scraping ──┘

3. Conditional Workflow Merging

IF: Process A ──┐
IF: Process B ──┤── [JOIN] ──> Final Processing
IF: Process C ──┘

🔧 Development

Prerequisites

• Node.js 20+
• npm 8+
• n8n development environment

Setup

# Clone the repository
git clone https://github.com/conciso/n8n-nodes-join.git
cd n8n-nodes-join

# Install dependencies
npm run init

# Build and run in dev mode
npm run dev

Project Structure

n8n-nodes-join/
├── nodes/
│   └── Join/
│       ├── Join.node.ts      # Main node implementation
│       ├── Join.node.json    # Node metadata
│       └── join.svg          # Node icon
├── dist/  
├── test/                    # Test files
├── gulpfile.js              # Build system
└── package.json             # Package configuration

🤝 Contributing

Contributions are welcome!

Development Workflow

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Run build and tests: npm run build:test
5. Submit a pull request

🐛 Troubleshooting

Common Issues

❌ "No input data received" Error

• Ensure all parallel nodes are connected to the Join node
• Check that upstream nodes are producing data

❌ Timeout Issues

• Increase the timeout value in node configuration
• Check for slow upstream operations

❌ Wrong Expected Inputs Configuration

• Ensure "Expected Inputs" matches the actual number of connected parallel nodes
• If you have 4 parallel nodes, set "Expected Inputs" to 4
• The node will timeout if it doesn't receive the expected number of inputs

📚 Resources

• n8n Community Nodes Documentation
• n8n Node Development Guide
• TypeScript Documentation

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• Built for the n8n automation platform
• Inspired by the n8n community's need for better parallel workflow handling

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Made with ❤️ for the n8n community