General Create Condition

Step 1: Define the alias constant

// constants.ts
export const UMB_MY_CONDITION_ALIAS = 'Umb.Condition.MyCondition';

Step 2: Define the config type

// types.ts
import type { UMB_MY_CONDITION_ALIAS } from './constants.js';
import type { UmbConditionConfigBase } from '@umbraco-cms/backoffice/extension-api';

export interface MyConditionConfig extends UmbConditionConfigBase<typeof UMB_MY_CONDITION_ALIAS> {
	/**
	 * The value to match against.
	 * @example "Umb.Section.Content"
	 */
	match?: string;

	/**
	 * One or more values to match against (any match passes).
	 * @example ["Umb.Section.Content", "Umb.Section.Media"]
	 */
	oneOf?: Array<string>;
}

declare global {
	interface UmbExtensionConditionConfigMap {
		UmbMyConditionConfig: MyConditionConfig;
	}
}

Key rules

• Extend UmbConditionConfigBase<typeof ALIAS_CONSTANT> — this types the alias property
• The declare global block on UmbExtensionConditionConfigMap makes the config type-safe when used in extension manifests
• Use a unique key in the map
• Add JSDoc with @example — these feed into JSON schema generation

Common config patterns

Step 3: Implement the condition controller

// my-condition.condition.ts
import type { MyConditionConfig } from './types.js';
import { UMB_MY_CONTEXT } from '../../my-context.token.js';
import type { UmbControllerHost } from '@umbraco-cms/backoffice/controller-api';
import type { UmbConditionControllerArguments, UmbExtensionCondition } from '@umbraco-cms/backoffice/extension-api';
import { UmbConditionBase } from '@umbraco-cms/backoffice/extension-registry';

export class UmbMyCondition
	extends UmbConditionBase<MyConditionConfig>
	implements UmbExtensionCondition
{
	constructor(host: UmbControllerHost, args: UmbConditionControllerArguments<MyConditionConfig>) {
		super(host, args);

		this.consumeContext(UMB_MY_CONTEXT, (context) => {
			this.observe(
				context.someObservable,
				(value) => {
					this.permitted = this.#check(value);
				},
				'_observeConditionValue',
			);
		});
	}

	#check(value: string | undefined): boolean {
		if (!value) return false;

		if (this.config.match) {
			return value === this.config.match;
		}

		if (this.config.oneOf) {
			return this.config.oneOf.includes(value);
		}

		return false;
	}
}

export { UmbMyCondition as api };

Key rules

• Extend UmbConditionBase<ConfigType> — provides permitted property and config access
• Implement UmbExtensionCondition
• Constructor signature: (host: UmbControllerHost, args: UmbConditionControllerArguments<ConfigType>)
• Set this.permitted = true/false — the base class notifies the extension system on change
• Use consumeContext() + observe() for reactive conditions that update as state changes
• Export as api (named export) so the class can be imported by the manifest
• Use an explicit observer alias so re-evaluation replaces the previous subscription

For simple boolean conditions (no config)

export class UmbIsSomethingCondition
	extends UmbConditionBase<UmbConditionConfigBase>
	implements UmbExtensionCondition
{
	constructor(host: UmbControllerHost, args: UmbConditionControllerArguments<UmbConditionConfigBase>) {
		super(host, args);

		this.consumeContext(UMB_SOME_CONTEXT, (context) => {
			this.observe(context.isSomething, (value) => {
				this.permitted = value === true;
			});
		});
	}
}

Step 4: Register the condition manifest

Conditions must load fast — always import the class directly (no lazy () => import()).

// manifests.ts
import { UMB_MY_CONDITION_ALIAS } from './constants.js';
import { UmbMyCondition } from './my-condition.condition.js';

export const manifests: Array<UmbExtensionManifest> = [
	{
		type: 'condition',
		name: 'My Condition',
		alias: UMB_MY_CONDITION_ALIAS,
		api: UmbMyCondition,
	},
];

Add to the parent feature's manifests.ts so it bubbles up to the bundle.

How consumers use the condition

In any extension manifest that supports conditions:

{
	type: 'workspaceAction',
	alias: 'My.WorkspaceAction',
	name: 'My Action',
	conditions: [
		{
			alias: 'Umb.Condition.MyCondition',
			match: 'some-value',
		},
	],
}

All conditions in the array must be permitted for the extension to be active. They are AND-ed together.

Checklist

• Alias constant exported from constants.ts
• Config type extends UmbConditionConfigBase<typeof ALIAS> with the alias constant
• Config type declared on global UmbExtensionConditionConfigMap
• Condition class extends UmbConditionBase<ConfigType> and implements UmbExtensionCondition
• Constructor calls super(host, args) and sets up context observation
• this.permitted is set reactively (via observe()) — not just once in the constructor
• Condition manifest registered with type: 'condition'
• Manifests bubbled up to the package-level manifests.ts
• Compiles: npm run compile