Config Vars

Configuration variables, often referred to as Config Vars, control how your Nightscout site behaves, what features are enabled, and how information is displayed.

Nightscout Pro automatically manages the vast majority of technical configuration for you. Most users will only ever need to adjust a small number of settings, if any.

This page explains the most commonly used Config Vars, what they do, and which ones are safe to change.

Important note before you continue

For APS users

If you are using an Automated Pancreas System such as Loop, Trio, or iAPS:

• Your APS app usually manages profiles, targets, and many settings
• Changing Config Vars manually may have no effect or may be overwritten
• In some cases, changing Config Vars can cause unexpected behaviour

If your APS setup is working correctly, it is usually best to leave Config Vars unchanged unless you know exactly what you are changing.

For non-APS users

If you are not using an APS system, you may find Config Vars useful for enabling features, adjusting alerts, or customising how Nightscout looks and behaves.

If you are unsure about a setting, it is safe to leave it unchanged.

Understanding Config Vars

Config Vars are key-value settings that control features such as:

• Which plugins are enabled
• How alarms behave
• Authentication and privacy
• Visual appearance

Nightscout Pro applies changes automatically once they are saved. There is no need to restart servers or services.

Essential Config Vars

API_SECRET

Purpose
Provides full access to your Nightscout site.

Important
This is effectively your site’s master password.

Details

• Must be at least 12 characters long
• Case sensitive
• Used by uploaders, apps, and administrative actions

Best practice

• Never share your API_SECRET publicly
• Do not include it in screenshots or social media posts
• Use Nightscout authentication features or tokens to grant viewing access

If you are unsure about this setting, do not change it.

DISPLAY_UNITS

Purpose
Controls how glucose values are displayed across your site.

Options

• mg/dL
• mmol/L

Best practice
This should match the units used by your CGM, uploader, and APS system to avoid confusion.

Feature Configuration

ENABLE

Purpose
Defines which Nightscout plugins and features are active.

Common plugins include:

• careportal – record treatments and events
• boluscalc – bolus calculator
• food – custom food database
• rawbg – raw CGM values
• iob – insulin on board
• cob – carbs on board
• bwp – bolus wizard preview
• cage – cannula age
• sage – sensor age
• iage – insulin age
• basal – basal rate display
• bolus – bolus treatments
• bridge – Dexcom Share integration
• pump – pump information
• openaps – OpenAPS integration
• loop – Loop integration

Best practice
It is generally safe to include plugins you might use later.
Unused plugins do not cause issues, but missing plugins will hide features.

DISABLE

Purpose
Allows disabling specific default features.

Example
direction upbat disables direction arrows and uploader battery display.

Best practice
Only use this if you know exactly what you want to hide.

Alarm Configuration

ALARM_TYPES

Purpose
Controls how alarms behave.

Options

• simple – alarms trigger when thresholds are crossed
• predict – alarms trigger based on predicted glucose trends

Predictive alarms are more advanced and may behave differently from pump or APS alarms.

BG threshold settings

These values define alarm thresholds and must be entered in the units specified by DISPLAY_UNITS:

• BG_HIGH – urgent high
• BG_TARGET_TOP – high
• BG_TARGET_BOTTOM – low
• BG_LOW – urgent low

If you are using an APS system, these values are often managed by the APS app instead.

Authentication and Privacy

AUTH_DEFAULT_ROLES

In Nightscout Pro, this setting is managed through the option:

“Make My Nightscout Site Private”

Behaviour

• Disabled: site is publicly viewable
• Enabled: authentication is required

This controls who can view your site without changing your API_SECRET.

Visual Customisation

THEME

Purpose
Controls the visual appearance of your site.

Options
default, colors, colorblindfriendly, and others.

Safe to experiment with.

CUSTOM_TITLE

Purpose
Sets a custom title displayed at the top of your Nightscout site.

Example
“Alex’s Glucose Monitor”

Time and Display Settings

TIME_FORMAT

Purpose
Controls how time is displayed.

Options

• 12 – 12-hour format
• 24 – 24-hour format

NIGHT_MODE

Purpose
Enables a darker display during nighttime hours.

Options

• on
• off

Advanced Settings

ENABLE_ALERTS

Purpose
Turns the alerting system on or off.

Options

• true
• false

SHOW_PLUGINS

Purpose
Controls which plugins appear in the main interface.

Example
careportal iob cob basal

Modifying Config Vars in Nightscout Pro

To change Config Vars:

1. Log in to your Nightscout Pro account
2. Open your site settings
3. Locate the Config Vars section
4. Make your changes
5. Save your settings

Changes are applied automatically.

Best Practices

• Start with default settings
• Change one thing at a time
• Keep a note of changes you make
• Test your site after each change
• If unsure, leave the setting unchanged

Nightscout Pro handles all infrastructure, hosting, and updates. Your focus should be on configuration only when it provides a clear benefit.

Important Reminder

Config Vars can significantly affect how Nightscout behaves.

If your setup is working correctly, you do not need to change them.

When in doubt, it is always safe to leave Config Vars as they are.