Netscript Miscellaneous

Netscript Ports

Netscript Ports are endpoints that can be used to communicate between scripts. A port is implemented as a sort of serialized queue, where you can only write and read one element at a time from the port. When you read data from a port, the element that is read is removed from the port.

The read(), write(), tryWrite(), clear(), and peek() Netscript functions can be used to interact with ports.

Right now, there are only 20 ports for Netscript, denoted by the number 1 through 20. When using the functions above, the ports are specified by passing the number as the first argument.

IMPORTANT: The data inside ports are not saved! This means if you close and re-open the game, or reload the page then you will lose all of the data in the ports!

Example Usage

Here’s a brief example of how ports work. For the sake of simplicity we’ll only deal with port 1.

Let’s assume Port 1 starts out empty (no data inside). We’ll represent the port as such:


Now assume we ran the following simple script:

for (i = 0; i < 10; ++i) {
    writePort(1, i); //Writes the value of i to port 1

After this script executes, our script will contain every number from 0 through 9, as so:

[0, 1, 2, 3, 4, 5, 6, 7 , 8, 9]

Then, assume we run the following script:

for (i = 0; i < 3; ++i) {
    print(readPort(1)); //Reads a value from port 1 and then prints it

This script above will read the first three values from port 1 and then print them to the script’s log. The log will end up looking like:


And the data in port 1 will look like:

[3, 4, 5, 6, 7, 8, 9]


In NS2, do not trying writing base Promises to a port.

Port Handles

WARNING: Port Handles only work in NS2. They do not work in Netscript 1.0

The getPortHandle() Netscript function can be used to get a handle to a Netscript Port. This handle allows you to access several new port-related functions. The functions are:

  • data – Data to write to the port

If the port is full, the item that is removed from the port is returned. Otherwise, null is returned.

Writes data to the port. Works the same as the Netscript function write.

  • data – Data to try to write to the port

True if the data is successfully written to the port, and false otherwise.

Attempts to write data to the Netscript port. If the port is full, the data will not be written. Otherwise, the data will be written normally.

Returns:True if the Netscript Port is full, and false otherwise
Returns:True if the Netscript Port is empty, and false otherwise

Clears all data from the port. Works the same as the Netscript function clear

Port Handle Example:

port = getPortHandle(5);
back =; //Get and remove last element in port

//Wait for port data before reading
while(port.empty()) {
res =;

//Wait for there to be room in a port before writing
while (!port.tryWrite(5)) {

//Successfully wrote to port!


Netscript supports comments using the same syntax as Javascript comments. Comments are not evaluated as code, and can be used to document and/or explain code:

//This is a comment and will not get executed even though its in the code
/* Multi
 * line
 * comment */
print("This code will actually get executed");

Importing Functions

In Netscript you can import functions that are declared in other scripts. The script will incur the RAM usage of all imported functions. There are two ways of doing this:

import * as namespace from "script filename"; //Import all functions from script
import {fn1, fn2, ...} from "script filename"; //Import specific functions from script

Suppose you have a library script called testlibrary.script:

function foo1(args) {
    //function definition...

function foo2(args) {
    //function definition...

function foo3(args) {
    //function definition...

function foo4(args) {
    //function definition...

Then, if you wanted to use these functions in another script, you can import them like so:

import * as testlib from "testlibrary.script";

values = [1,2,3];

//The imported functions must be specified using the namespace
someVal1 = testlib.foo3(values);
someVal2 = testlib.foo1(values);
if (someVal1 > someVal2) {
} else {

If you only wanted to import certain functions, you can do so without needing to specify a namespace for the import:

import {foo1, foo3} from "testlibrary.script"; //Saves RAM since not all functions are imported!

values = [1,2,3];

//No namespace needed
someVal1 = foo3(values);
someVal2 = foo1(values);
if (someVal1 > someVal2) {
} else {


For those who are experienced with JavaScript, note that the export keyword should NOT be used in Netscript 1.0, as this will break the script. It can, however, be used in NS2 (but it’s not required).

Standard, Built-In JavaScript Objects

Standard built-in JavaScript objects such as Math, Date, Number, and others are supported as expected based on which version of Netscript you use (i.e. Netscript 1.0 will support built-in objects that are defined in ES5, and NS2 will support whatever your browser supports).