Node context

A node can store data within its context object. This context object is reset whenever the node is redeployed and when Node-RED is restarted.

// Access the node's context object
var context = this.context();

var count = context.get('count') || 0;
count += 1;
Flow context

The flow-level context is shared by all nodes on a given tab.

var flowContext = this.context().flow;
var count = flowContext.get('count')||0;
Global context

The global context is shared by, and accessible to all nodes. For example to make the variable foo available globally:

var globalContext = this.context().global;
globalContext.set("foo","bar");  // this is now available to other nodes
Accessing context in a Function node

In the Function node, the flow and global context objects are made available as top-level objects. See this section for more information.