diff --git a/src/Squidex/app/shared/services/workflow.service.ts b/src/Squidex/app/shared/services/workflow.service.ts
new file mode 100644
index 000000000..cc2b5e700
--- /dev/null
+++ b/src/Squidex/app/shared/services/workflow.service.ts
@@ -0,0 +1,130 @@
+/*
+ * Squidex Headless CMS
+ *
+ * @license
+ * Copyright (c) Squidex UG (haftungsbeschränkt). All rights reserved.
+ */
+
+import { Model, ResourceLinks } from '@app/shared';
+
+export class WorkflowDto extends Model<WorkflowDto> {
+    public readonly _links: ResourceLinks;
+
+    constructor(links: ResourceLinks,
+        public readonly name: string,
+        public readonly steps: WorkflowStepDto[]
+    ) {
+        super();
+
+        this._links = links;
+    }
+
+    public addStep(name: string, color: string) {
+        let found = this.steps.find(x => x.name === name);
+
+        if (found) {
+            return this;
+        }
+
+        const steps = [...this.steps, new WorkflowStepDto(name, color, [])];
+
+        return this.with({ steps });
+    }
+
+    public changeStepColor(name: string, color: string) {
+        return this.updateStep(name, x => x.changeColor(color));
+    }
+
+    public changeStepName(name: string, newName: string) {
+        return this.updateStep(name, x => x.changeName(newName));
+    }
+
+    public removeStep(name: string) {
+        const steps = this.steps.filter(x => x.name !== name).map(x => x.removeTransition(name));
+
+        return this.with({ steps });
+    }
+
+    private updateStep(name: string, updater: (step: WorkflowStepDto) => WorkflowStepDto) {
+        let found = this.steps.find(x => x.name === name);
+
+        if (!found) {
+            return this;
+        }
+
+        const newStep = updater(found);
+
+        const steps = this.steps.map(x => x.name === name ? newStep : x.replaceTransition(newStep));
+
+        return this.with({ steps });
+    }
+}
+
+export class WorkflowStepDto extends Model<WorkflowStepDto> {
+    constructor(
+        public readonly name: string,
+        public readonly color: string,
+        public readonly transitions: WorkflowTransitionDto[]
+    ) {
+        super();
+    }
+
+    public changeName(name: string) {
+        return this.with({ name });
+    }
+
+    public changeColor(color: string) {
+        return this.with({ color });
+    }
+
+    public addTransition(step: WorkflowStepDto) {
+        let found = this.transitions.find(x => x.step.name === step.name);
+
+        if (found) {
+            return this;
+        }
+
+        const transitions = [...this.transitions, new WorkflowTransitionDto(step) ];
+
+        return this.with({ transitions });
+    }
+
+    public replaceTransition(step: WorkflowStepDto) {
+        const transitions = this.transitions.map(x => x.step.name === step.name ? new WorkflowTransitionDto(step, x.expression) : x);
+
+        return this.with({ transitions });
+    }
+
+    public removeTransition(name: string) {
+        const transitions = this.transitions.filter(x => x.step.name !== name);
+
+        return this.with({ transitions });
+    }
+
+    private updateStep(name: string, updater: (step: WorkflowStepDto) => WorkflowStepDto) {
+        let found = this.steps.find(x => x.name === name);
+
+        if (!found) {
+            return this;
+        }
+
+        const newStep = updater(found);
+
+        const steps = this.steps.map(x => x.name === name ? newStep : x.replaceTransition(newStep));
+
+        return this.with({ steps });
+    }
+}
+
+export class WorkflowTransitionDto extends Model<WorkflowTransitionDto> {
+    constructor(
+        public readonly step: WorkflowStepDto,
+        public readonly expression?: string
+    ) {
+        super();
+    }
+
+    public updateExpression(expression?: string) {
+        return this.with({ expression });
+    }
+}
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