Node-RED Flow Development

This skill provides comprehensive support for Node-RED development, including flow creation, modification, validation, and deployment through the Admin API.

When to Use This Skill

Use this skill when:

Creating or modifying Node-RED flows (flows.json files)
Building MQTT, HTTP API, or data pipeline integrations
Debugging or validating flow configurations
Working with function nodes and context storage
Deploying flows via the Node-RED Admin API
Converting requirements into Node-RED flow implementations

Available Resources

Scripts (scripts/)

Execute these Python scripts for common Node-RED operations:

generate_uuid.py - Generate valid Node-RED node IDs
bash
```
python scripts/generate_uuid.py [count]
```
validate_flow.py - Validate flow JSON structure and wire connections
bash
```
python scripts/validate_flow.py <flow.json>
```

wire_nodes.py - Connect nodes programmatically

bash

python scripts/wire_nodes.py <flow.json> <source_id> <target_id> [output_port]

create_flow_template.py - Generate boilerplate flows

bash

python scripts/create_flow_template.py <mqtt|http-api|data-pipeline|error-handler> [output.json]

References (references/)

Consult these detailed references as needed:

node_schemas.md - Complete schemas for all Node-RED node types
api_reference.md - Node-RED Admin API documentation with examples
function_snippets.md - Reusable function node code patterns

Assets (assets/)

Use these templates and boilerplate files:

templates/mqtt_flow.json - Complete MQTT pub/sub flow with error handling
templates/http_api_flow.json - REST API with CRUD operations and authentication
boilerplate/function_async.js - Async function node patterns
boilerplate/function_context.js - Context storage examples

Core Workflow

Creating a New Flow

Determine the flow type needed (MQTT, HTTP API, data processing, etc.)
Generate a template using
```
scripts/create_flow_template.py
```
Modify the template to match requirements
Validate the flow using
```
scripts/validate_flow.py
```
Deploy via Admin API or save as flows.json

Modifying Existing Flows

Read and parse the flows.json file
Identify nodes by type and ID
Make modifications while preserving:
- Wire connections (arrays of node IDs)
- Tab references (
```
z
```
  property)
- Node coordinates (
```
x
```
  ,
```
y
```
  )
Validate changes before saving
Use
```
scripts/wire_nodes.py
```
to connect nodes if needed

Working with Function Nodes

For function nodes, reference:

```
assets/boilerplate/function_async.js
```
for async operations
```
assets/boilerplate/function_context.js
```
for context storage
```
references/function_snippets.md
```
for specific patterns

Available objects in function nodes:

```
msg
```
- Message object
```
node
```
- Node API (send, done, error, warn, log, status)
```
context
```
- Node-scoped storage
```
flow
```
- Flow-scoped storage
```
global
```
- Global storage
```
RED
```
- Runtime API
```
env
```
- Environment variables

Deploying Flows

To deploy flows via the Admin API:

Retrieve current configuration:
bash
```
GET /flows
```
Modify the configuration as needed

Deploy with appropriate deployment type:

bash

POST /flows
Headers: Node-RED-Deployment-Type: full|nodes|flows|reload

Verify deployment success

Common Patterns

Message Flow Structure

Every Node-RED message follows this pattern:

Primary data in
```
msg.payload
```
Topic/category in
```
msg.topic
```
Unique ID in
```
msg._msgid
```
Additional properties as needed

Error Handling

Implement error handling using:

Try-catch blocks in function nodes
Catch nodes to intercept errors
Status nodes to monitor node states
Dedicated error output wires

Environment Variables

Use environment variables for configuration:

In node properties:
```
$(ENV_VAR_NAME)
```
In function nodes:
```
env.get("ENV_VAR_NAME")
```
Via Docker:
```
-e KEY=value
```

Context Storage Levels

Choose appropriate context level:

Node context: Local to single node
Flow context: Shared within flow/tab
Global context: System-wide sharing
Persistent: Survives restarts (configure in settings.js)

Validation Checklist

Before deploying flows, verify:

JSON syntax is valid
All wire connections reference existing node IDs
Tab references (
```
z
```
property) are correct
Function node JavaScript is syntactically valid
Required configuration nodes exist (MQTT brokers, etc.)
Environment variables are properly referenced
Error handling is implemented

Quick Commands

Generate five Node-RED UUIDs:

bash

python scripts/generate_uuid.py 5

Create an MQTT flow template:

bash

python scripts/create_flow_template.py mqtt my-mqtt-flow.json

Validate a flow file:

bash

python scripts/validate_flow.py flows.json

Wire two nodes together:

bash

python scripts/wire_nodes.py flows.json inject-node-id debug-node-id

Node-RED Configuration

Default File Locations

Flows:
```
~/.node-red/flows_<hostname>.json
```
Settings:
```
~/.node-red/settings.js
```
Custom nodes:
```
~/.node-red/node_modules/
```

Running Node-RED

Normal mode:
```
node-red
```
Safe mode (no flow execution):
```
node-red --safe
```
Custom flow file:
```
node-red myflows.json
```

Best Practices

Use appropriate node types: Prefer change nodes over function nodes for simple transformations
Implement error handling: Always include catch nodes for critical paths
Document flows: Use comment nodes and node descriptions
Organize with tabs: Separate flows by logical function or system
Version control: Store flows.json in git with meaningful commit messages
Test incrementally: Deploy and test small changes frequently
Monitor performance: Use status nodes and debug output wisely

Troubleshooting

For common issues:

Invalid JSON: Use
```
scripts/validate_flow.py
```
to find syntax errors
Broken wires: Check that all wired node IDs exist
Missing configurations: Ensure broker/server configs are included
Function errors: Test JavaScript in isolation first
API deployment fails: Verify authentication and check revision conflicts

Additional Resources

For detailed specifications and examples:

Consult
```
references/node_schemas.md
```
for node property details
Review
```
references/api_reference.md
```
for API operations
Use
```
references/function_snippets.md
```
for tested code patterns
Copy templates from
```
assets/templates/
```
as starting points

node-red

NPX Install

Tags

SKILL.md Content

Node-RED Flow Development

When to Use This Skill

Available Resources

Scripts (scripts/)

References (references/)

Assets (assets/)

Core Workflow

Creating a New Flow

Modifying Existing Flows

Working with Function Nodes

Deploying Flows

Common Patterns

Message Flow Structure

Error Handling

Environment Variables

Context Storage Levels

Validation Checklist

Quick Commands

Node-RED Configuration

Default File Locations

Running Node-RED

Best Practices

Troubleshooting

Additional Resources