Editing Definitions

The Definitions tab is where you create and configure your feature flags and config rules. It has three panels: a sidebar on the left listing all definitions, an editor in the center for the selected definition, and a preview panel on the right for testing.

Definitions

Creating a definition

Click the New definition button at the bottom of the sidebar. A text field appears - type a key (for example, dark-mode or pricing-tier) and press Enter. The new definition opens in the editor with no variations yet.

Renaming

The definition key is displayed as a heading at the top of the editor. Click it to rename inline.

Description

Below the key is an optional description field - a one-liner that helps your team understand what this definition controls.

Active toggle

Every definition has an Active toggle in the top-right corner. When inactive, the rule engine skips it during resolution and throws a DefinitionInactiveError. Use this to temporarily disable a flag without deleting it.

Deleting

Hover over a definition in the sidebar and click the trash icon. A confirmation dialog will ask you to confirm.

Variations

A variation is a possible value your definition can resolve to. The rule engine evaluates variations top to bottom and returns the first one whose conditions all match.

Adding a variation

Click Add next to the "Variations" heading. A new collapsed card appears. Expand it to see:

Field	Description
Value	The value returned when this variation matches. Supports strings, numbers, booleans, and JSON objects.
Description	An optional label to tell variations apart at a glance.
Conditions	The rules that determine whether this variation matches.

Default fallback

A variation with no conditions always matches - it is a catch-all. Place it last so it serves as the default. If a catch-all appears before other variations, everything below it will never be reached.

Reordering

Grab the drag handle (the grip icon on the left edge of each card) and drag the variation to its new position.

Conditions

Conditions define when a variation should match. Expand a variation card and click Add condition to see the available types:

Type	Description
String	Compare a context field against a string value.
Number	Compare a context field against a numeric value.
Datetime	Compare a context field against a date and time.
Boolean	Check whether a context field is true or false.
Environment	Match against an environment name (shorthand for a string comparison on env).
Start At / End At	Time-window conditions based on context.at.
Custom	A freeform type for app-specific logic that your own evaluator handles.

All conditions on a single variation are combined with AND logic - every condition must pass.

See Conditions for full details on each type, including operators, value formats, and regex.

AND / OR groups

The dropdown also offers AND Group and OR Group for complex rules:

• An AND group requires all inner conditions to pass.
• An OR group requires at least one to pass.

Groups can be nested, so you can build expressions like "environment is production AND (region is sg OR region is us-east-1)". Between each condition in a group, a badge shows the logic (AND or OR) so the evaluation order is always visible.

Preset conditions

If presets are loaded (from a source or custom-defined), they also appear in the "Add condition" dropdown. Preset conditions have their context key pre-filled and locked, and any overridden fields are disabled. See Presets for how to set them up.

Preview panel

The preview panel on the right lets you test the selected definition without leaving the editor.

Context

Enter a JSON object in the Context textarea representing the runtime values your application would provide:

{ "env": "production", "region": "sg" }

Click Resolve. The panel shows which variation matched (or why none did), the returned value, the variation index, and the number of conditions evaluated. If the definition is inactive, you see an "Inactive" badge. If no variation matched, you see "No Match".

Condition simulator

Below the context input is a collapsible Condition Simulator. This handles condition types the built-in engine cannot evaluate - custom or unregistered types that would normally need your application's evaluator.

Enter overrides as one type:true or type:false per line:

tier:true
geo:false

When you resolve, any condition whose type appears here uses your override instead of failing.

Seed annotations

If your conditions use annotations, the preview panel has an annotations input where you can provide seed values as JSON. These are passed to evaluators during resolution, letting you simulate annotation-dependent conditions like checkAnnotations.

Saving and status

Status indicators

Each definition in the sidebar shows a status dot:

Dot colour	Meaning
Green (filled)	Active and saved
Green (hollow)	Active with unsaved changes
Yellow (filled)	Inactive and saved
Yellow (hollow)	Inactive with unsaved changes
Red	Has validation errors

Save and discard

The action bar at the top of the editor has Save and Discard buttons. Save persists your changes to localStorage. Discard reverts to the last saved state (with a confirmation dialog).

Status badge

The status badge in the sidebar header reflects the global state across all definitions:

Badge	Meaning
ready (green)	Everything is saved.
unsaved (amber)	One or more definitions have pending edits. Click the badge to open a confirmation dialog and revert all changes at once.
errors (red)	Validation issues exist.

If you try to close or navigate away from the browser tab while unsaved changes exist, the browser warns you.

Exporting

The Export button in the sidebar header lets you download all saved definitions as YAML or JSON. The exported file includes any file-level presets. Export is disabled when you have unsaved changes or validation errors - save or discard first.

TIP

In split mode (when a split source is loaded), the bulk export button is hidden. Instead, each definition has its own export option for downloading just that definition as a standalone file.

Next steps

• Sources to load definitions from files or remote endpoints
• Presets to define reusable condition shortcuts
• Conditions for full details on each condition type
• Definitions for how definitions work under the hood