apps/behandelportal/src/app/behandeling/application/submit-besluit.ts

@@ -0,0 +1,16 @@
+import { inject } from '@angular/core';
+import { Result } from '@shared/kernel/fp';
+import { Valid } from '@behandeling/domain/besluit.machine';
+import { runSubmit, SUBMIT_FAILED } from '@shared/application/submit';
+import { BesluitAdapter } from '@behandeling/infrastructure/besluit.adapter';
+
+/**
+ * Command factory: binds the besluit adapter in an injection context and returns the
+ * submit function the decision form calls. Same field-initializer shape as
+ * `createStore` — the UI holds an application command, never the network client.
+ */
+export function createSubmitBesluit() {
+  const adapter = inject(BesluitAdapter);
+  return (id: string, data: Valid): Promise<Result<string, void>> =>
+    runSubmit(() => adapter.besluit(id, data), SUBMIT_FAILED);
+}

apps/behandelportal/src/app/behandeling/domain/besluit.machine.spec.ts

@@ -0,0 +1,68 @@
+import { describe, it, expect } from 'vitest';
+import { BesluitState, reduce, initial } from './besluit.machine';
+
+const editingWith = (besluit: string, toelichting = ''): BesluitState => ({
+  tag: 'Editing',
+  draft: { besluit, toelichting },
+  errors: {},
+});
+
+describe('besluit reduce', () => {
+  it('SetField updates the draft while editing', () => {
+    const s = reduce(initial, { tag: 'SetField', key: 'besluit', value: 'Goedkeuren' });
+    expect(s.tag).toBe('Editing');
+    expect((s as Extract<BesluitState, { tag: 'Editing' }>).draft.besluit).toBe('Goedkeuren');
+  });
+
+  it('Submit with no besluit chosen stays Editing and reports a field error', () => {
+    const s = reduce(editingWith(''), { tag: 'Submit' });
+    expect(s.tag).toBe('Editing');
+    expect((s as Extract<BesluitState, { tag: 'Editing' }>).errors.besluit).toBeTruthy();
+  });
+
+  it('Submit Afwijzen without a toelichting stays Editing and reports a field error', () => {
+    const s = reduce(editingWith('Afwijzen'), { tag: 'Submit' });
+    expect(s.tag).toBe('Editing');
+    expect((s as Extract<BesluitState, { tag: 'Editing' }>).errors.toelichting).toBeTruthy();
+  });
+
+  it('Submit Goedkeuren with no toelichting moves to Submitting (optional there)', () => {
+    const s = reduce(editingWith('Goedkeuren'), { tag: 'Submit' });
+    expect(s.tag).toBe('Submitting');
+    expect((s as Extract<BesluitState, { tag: 'Submitting' }>).data).toEqual({
+      besluit: 'Goedkeuren',
+      toelichting: undefined,
+    });
+  });
+
+  it('Submit Afwijzen with a toelichting moves to Submitting with the trimmed value', () => {
+    const s = reduce(editingWith('Afwijzen', '  niet erkend  '), { tag: 'Submit' });
+    expect(s.tag).toBe('Submitting');
+    expect((s as Extract<BesluitState, { tag: 'Submitting' }>).data).toEqual({
+      besluit: 'Afwijzen',
+      toelichting: 'niet erkend',
+    });
+  });
+
+  it('SubmitConfirmed maps Submitting to Submitted', () => {
+    const submitting = reduce(editingWith('Goedkeuren'), { tag: 'Submit' });
+    expect(reduce(submitting, { tag: 'SubmitConfirmed' }).tag).toBe('Submitted');
+  });
+
+  it('SubmitFailed maps Submitting to Failed with the error', () => {
+    const submitting = reduce(editingWith('Goedkeuren'), { tag: 'Submit' });
+    const failed = reduce(submitting, { tag: 'SubmitFailed', error: 'boom' });
+    expect(failed).toMatchObject({ tag: 'Failed', error: 'boom' });
+  });
+
+  it('Retry re-submits a failure', () => {
+    const submitting = reduce(editingWith('Goedkeuren'), { tag: 'Submit' });
+    const failed = reduce(submitting, { tag: 'SubmitFailed', error: 'boom' });
+    expect(reduce(failed, { tag: 'Retry' }).tag).toBe('Submitting');
+  });
+
+  it('Reset returns to the initial editing state', () => {
+    const submitting = reduce(editingWith('Goedkeuren'), { tag: 'Submit' });
+    expect(reduce(submitting, { tag: 'Reset' })).toEqual(initial);
+  });
+});

apps/behandelportal/src/app/behandeling/domain/besluit.machine.ts

@@ -0,0 +1,92 @@
+import { Result, assertNever } from '@shared/kernel/fp';
+
+/** The three actions the beoordeling screen offers a behandelaar (WP-65b) — mirrors the
+    backend's `Besluit` enum member names 1:1 (the wire convention: a string, not a raw
+    enum — see `RecordBesluitRequest`). */
+const BESLUIT_TAGS = ['Goedkeuren', 'Afwijzen', 'MeerInfoOpvragen'] as const;
+export type BesluitTag = (typeof BESLUIT_TAGS)[number];
+
+function isBesluitTag(v: string): v is BesluitTag {
+  return (BESLUIT_TAGS as readonly string[]).includes(v);
+}
+
+/** What the user picked (raw, possibly empty while nothing is selected yet). */
+export interface Draft {
+  besluit: string;
+  toelichting: string;
+}
+
+/** After parsing — besluit is the narrow tag; toelichting is present only when given
+    (required for Afwijzen/MeerInfoOpvragen, optional for Goedkeuren — enforced by validate). */
+export interface Valid {
+  besluit: BesluitTag;
+  toelichting?: string;
+}
+
+export type Errors = Partial<Record<keyof Draft, string>>;
+
+/** The decision form as one tagged union — same idiom as every other form in this
+    house (form-machine skill), single-step. draft/errors exist only while Editing. */
+export type BesluitState =
+  | { tag: 'Editing'; draft: Draft; errors: Errors }
+  | { tag: 'Submitting'; data: Valid }
+  | { tag: 'Submitted'; data: Valid }
+  | { tag: 'Failed'; data: Valid; error: string };
+
+export const initial: BesluitState = {
+  tag: 'Editing',
+  draft: { besluit: '', toelichting: '' },
+  errors: {},
+};
+
+function validate(draft: Draft): Result<Errors, Valid> {
+  if (!isBesluitTag(draft.besluit)) {
+    return {
+      ok: false,
+      error: { besluit: $localize`:@@besluit.error.verplicht:Kies een besluit.` },
+    };
+  }
+  const toelichting = draft.toelichting.trim();
+  if (draft.besluit !== 'Goedkeuren' && toelichting === '') {
+    return {
+      ok: false,
+      error: {
+        toelichting: $localize`:@@besluit.error.toelichtingVerplicht:Geef een toelichting.`,
+      },
+    };
+  }
+  return { ok: true, value: { besluit: draft.besluit, toelichting: toelichting || undefined } };
+}
+
+export type BesluitMsg =
+  | { tag: 'SetField'; key: keyof Draft; value: string }
+  | { tag: 'Submit' }
+  | { tag: 'Retry' }
+  | { tag: 'SubmitConfirmed' }
+  | { tag: 'SubmitFailed'; error: string }
+  | { tag: 'Reset' }
+  | { tag: 'Seed'; state: BesluitState }; // mount a specific state (stories/tests)
+
+export function reduce(s: BesluitState, m: BesluitMsg): BesluitState {
+  switch (m.tag) {
+    case 'SetField':
+      return s.tag === 'Editing' ? { ...s, draft: { ...s.draft, [m.key]: m.value } } : s;
+    case 'Submit': {
+      if (s.tag !== 'Editing') return s;
+      const r = validate(s.draft);
+      return r.ok ? { tag: 'Submitting', data: r.value } : { ...s, errors: r.error };
+    }
+    case 'Retry':
+      return s.tag === 'Failed' ? { tag: 'Submitting', data: s.data } : s;
+    case 'SubmitConfirmed':
+      return s.tag === 'Submitting' ? { tag: 'Submitted', data: s.data } : s;
+    case 'SubmitFailed':
+      return s.tag === 'Submitting' ? { tag: 'Failed', data: s.data, error: m.error } : s;
+    case 'Reset':
+      return initial;
+    case 'Seed':
+      return m.state;
+    default:
+      return assertNever(m);
+  }
+}

apps/behandelportal/src/app/behandeling/infrastructure/besluit.adapter.ts

@@ -0,0 +1,18 @@
+import { Injectable, inject } from '@angular/core';
+import { ApiClient } from '@shared/infrastructure/api-client';
+import { Valid } from '@behandeling/domain/besluit.machine';
+
+/**
+ * Infrastructure adapter for recording a behandelaar's decision (WP-65b) — the single
+ * place its HTTP lives. No return value: a successful call means the server accepted
+ * the transition; the caller reloads `BeoordelingStore` to see the new status (the
+ * server, not this adapter, re-validates and is the authority).
+ */
+@Injectable({ providedIn: 'root' })
+export class BesluitAdapter {
+  private client = inject(ApiClient);
+
+  async besluit(id: string, data: Valid): Promise<void> {
+    await this.client.besluit(id, { besluit: data.besluit, toelichting: data.toelichting });
+  }
+}

apps/behandelportal/src/app/behandeling/ui/beoordeling.page.ts

@@ -10,12 +10,13 @@ import { ASYNC } from '@shared/ui/async/async.component';
 import { BeoordelingStore } from '@behandeling/application/beoordeling.store';
 import { detailRows } from '@behandeling/domain/beoordeling-view';
 import { BeoordelingDocumentenComponent } from '@behandeling/ui/beoordeling-documenten/beoordeling-documenten.component';
+import { BesluitFormComponent } from '@behandeling/ui/besluit-form/besluit-form.component';
 
 /**
- * Page: one aanvraag's beoordeling detail (WP-65, read side). The werkvoorraad list
- * (WP-64) links here. Recording a decision is this WP's second half — for now the
- * page only shows status/documents; `canBesluiten` is already carried by the view so
- * the decision form has zero further backend round-trip to add.
+ * Page: one aanvraag's beoordeling detail (WP-65). The werkvoorraad list (WP-64) links
+ * here. `canBesluiten` (server-computed, ADR-0001) gates the decision form (WP-65b) —
+ * the page never recomputes the lifecycle itself. On a recorded decision the form emits
+ * `decided`, and the page just reloads (the server is the authority on the new status).
  */
 @Component({
   selector: 'app-beoordeling-page',
@@ -27,6 +28,7 @@ import { BeoordelingDocumentenComponent } from '@behandeling/ui/beoordeling-docu
     DataBlockComponent,
     DataRowComponent,
     BeoordelingDocumentenComponent,
+    BesluitFormComponent,
     ...ASYNC,
   ],
   template: `
@@ -49,6 +51,11 @@ import { BeoordelingDocumentenComponent } from '@behandeling/ui/beoordeling-docu
             <app-data-block [heading]="documentenHeading" class="app-section">
               <app-beoordeling-documenten [documenten]="v.documenten" />
             </app-data-block>
+            @if (v.canBesluiten) {
+              <div class="app-section">
+                <app-besluit-form [id]="v.id" (decided)="reload()" />
+              </div>
+            }
           }
         </ng-template>
       </app-async>

apps/behandelportal/src/app/behandeling/ui/besluit-form/besluit-form.component.ts

@@ -0,0 +1,140 @@
+import { Component, computed, input, output } from '@angular/core';
+import { FormsModule } from '@angular/forms';
+import { ButtonComponent } from '@shared/ui/button/button.component';
+import { HeadingComponent } from '@shared/ui/heading/heading.component';
+import { AlertComponent } from '@shared/ui/alert/alert.component';
+import { FormFieldComponent } from '@shared/ui/form-field/form-field.component';
+import { TextInputComponent } from '@shared/ui/text-input/text-input.component';
+import { RadioGroupComponent, RadioOption } from '@shared/ui/radio-group/radio-group.component';
+import { createStore } from '@shared/application/store';
+import { whenTag } from '@shared/kernel/fp';
+import { BesluitState, BesluitMsg, initial, reduce } from '@behandeling/domain/besluit.machine';
+import { createSubmitBesluit } from '@behandeling/application/submit-besluit';
+
+/**
+ * Organism: the decision form (WP-65b) — goedkeuren/afwijzen/meer-info-opvragen. Same
+ * idiom as every other form in this house (`change-request-form`): all state in one
+ * signal driven by the pure `reduce` (besluit.machine.ts), submitted via a `submit-*`
+ * command returning `Result`. The server re-validates the transition and is the
+ * authority; on success this only emits `decided` — the page reloads the detail
+ * (BeoordelingStore.reload()), it doesn't guess the new state itself.
+ */
+@Component({
+  selector: 'app-besluit-form',
+  imports: [
+    FormsModule,
+    ButtonComponent,
+    HeadingComponent,
+    AlertComponent,
+    FormFieldComponent,
+    TextInputComponent,
+    RadioGroupComponent,
+  ],
+  template: `
+    @if (state().tag === 'Submitted') {
+      <app-alert type="ok" i18n="@@besluit.success">Het besluit is vastgelegd.</app-alert>
+    } @else {
+      <app-heading [level]="2" i18n="@@besluit.heading">Besluit vastleggen</app-heading>
+
+      <form (ngSubmit)="onSubmit()" class="form-horizontal app-section">
+        <app-form-field
+          i18n-label="@@besluit.besluitLabel"
+          label="Besluit"
+          fieldId="besluit-keuze"
+          required
+          [error]="errors().besluit"
+        >
+          <app-radio-group
+            name="besluit-keuze"
+            [options]="BESLUIT_OPTIONS"
+            [invalid]="!!errors().besluit"
+            [ngModel]="besluit()"
+            (ngModelChange)="dispatch({ tag: 'SetField', key: 'besluit', value: $event })"
+            [ngModelOptions]="{ standalone: true }"
+          />
+        </app-form-field>
+
+        <app-form-field
+          i18n-label="@@besluit.toelichtingLabel"
+          label="Toelichting"
+          fieldId="besluit-toelichting"
+          [error]="errors().toelichting"
+        >
+          <app-text-input
+            inputId="besluit-toelichting"
+            [invalid]="!!errors().toelichting"
+            [ngModel]="toelichting()"
+            (ngModelChange)="dispatch({ tag: 'SetField', key: 'toelichting', value: $event })"
+            name="toelichting"
+            [ngModelOptions]="{ standalone: true }"
+          />
+        </app-form-field>
+
+        @if (failedError()) {
+          <app-alert type="error"
+            ><ng-container i18n="@@besluit.failed">Het vastleggen is niet gelukt:</ng-container>
+            {{ failedError() }}</app-alert
+          >
+        }
+
+        <app-button type="submit" variant="primary" [disabled]="state().tag === 'Submitting'">
+          {{ state().tag === 'Submitting' ? submitBezigLabel : submitLabel }}
+        </app-button>
+      </form>
+    }
+  `,
+})
+export class BesluitFormComponent {
+  private submit = createSubmitBesluit();
+  private store = createStore<BesluitState, BesluitMsg>(initial, reduce);
+
+  id = input.required<string>();
+  decided = output<void>();
+
+  /** Optional seed so Storybook / tests can mount any state directly. */
+  seed = input<BesluitState>(initial);
+
+  readonly state = this.store.model;
+  protected dispatch = this.store.dispatch;
+
+  protected readonly BESLUIT_OPTIONS: RadioOption[] = [
+    { value: 'Goedkeuren', label: $localize`:@@besluit.optie.goedkeuren:Goedkeuren` },
+    { value: 'Afwijzen', label: $localize`:@@besluit.optie.afwijzen:Afwijzen` },
+    {
+      value: 'MeerInfoOpvragen',
+      label: $localize`:@@besluit.optie.meerInfoOpvragen:Meer informatie opvragen`,
+    },
+  ];
+
+  protected readonly submitLabel = $localize`:@@besluit.submit:Besluit vastleggen`;
+  protected readonly submitBezigLabel = $localize`:@@besluit.submitBezig:Bezig met vastleggen…`;
+
+  private editing = computed(() => whenTag(this.state(), 'Editing'));
+  protected errors = computed(() => this.editing()?.errors ?? {});
+  protected failedError = computed(() => whenTag(this.state(), 'Failed')?.error ?? '');
+
+  protected besluit = computed(() => this.editing()?.draft.besluit ?? '');
+  protected toelichting = computed(() => this.editing()?.draft.toelichting ?? '');
+
+  constructor() {
+    queueMicrotask(() => this.dispatch({ tag: 'Seed', state: this.seed() }));
+  }
+
+  onSubmit() {
+    this.dispatch({ tag: 'Submit' });
+    this.runIfSubmitting();
+  }
+
+  /** Effect: when we entered Submitting, call the command, then dispatch the outcome. */
+  private async runIfSubmitting() {
+    const s = this.state();
+    if (s.tag !== 'Submitting') return;
+    const r = await this.submit(this.id(), s.data);
+    if (r.ok) {
+      this.dispatch({ tag: 'SubmitConfirmed' });
+      this.decided.emit();
+    } else {
+      this.dispatch({ tag: 'SubmitFailed', error: r.error });
+    }
+  }
+}

apps/behandelportal/src/app/behandeling/ui/besluit-form/besluit-form.stories.ts

@@ -0,0 +1,37 @@
+import type { Meta, StoryObj } from '@storybook/angular';
+import { applicationConfig } from '@storybook/angular';
+import { provideHttpClient } from '@angular/common/http';
+import { BesluitFormComponent } from './besluit-form.component';
+import { provideApiClient } from '@shared/infrastructure/api-client.provider';
+import { Valid } from '@behandeling/domain/besluit.machine';
+
+const validData: Valid = { besluit: 'Afwijzen', toelichting: 'Diploma niet erkend' };
+
+const meta: Meta<BesluitFormComponent> = {
+  title: 'Domein/Behandeling/Besluit Form',
+  component: BesluitFormComponent,
+  // The form injects ApiClient (over HttpClient) for the submit command.
+  decorators: [applicationConfig({ providers: [provideHttpClient(), provideApiClient()] })],
+  args: { id: 'aanvraag-1' },
+};
+export default meta;
+type Story = StoryObj<BesluitFormComponent>;
+
+// One render per state of the machine.
+export const Empty: Story = {
+  args: { seed: { tag: 'Editing', draft: { besluit: '', toelichting: '' }, errors: {} } },
+};
+export const WithErrors: Story = {
+  args: {
+    seed: {
+      tag: 'Editing',
+      draft: { besluit: 'Afwijzen', toelichting: '' },
+      errors: { toelichting: 'Geef een toelichting.' },
+    },
+  },
+};
+export const Submitting: Story = { args: { seed: { tag: 'Submitting', data: validData } } };
+export const Submitted: Story = { args: { seed: { tag: 'Submitted', data: validData } } };
+export const Failed: Story = {
+  args: { seed: { tag: 'Failed', data: validData, error: 'Netwerkfout' } },
+};

apps/behandelportal/src/locale/messages.en.xlf

@@ -3020,6 +3020,54 @@
         <source>Opnieuw proberen</source>
         <target datatype="html">Try again</target>
       </trans-unit>
+      <trans-unit id="besluit.error.verplicht" datatype="html">
+        <source>Kies een besluit.</source>
+        <target datatype="html">Choose a decision.</target>
+      </trans-unit>
+      <trans-unit id="besluit.error.toelichtingVerplicht" datatype="html">
+        <source>Geef een toelichting.</source>
+        <target datatype="html">Give an explanation.</target>
+      </trans-unit>
+      <trans-unit id="besluit.success" datatype="html">
+        <source>Het besluit is vastgelegd.</source>
+        <target datatype="html">The decision has been recorded.</target>
+      </trans-unit>
+      <trans-unit id="besluit.heading" datatype="html">
+        <source>Besluit vastleggen</source>
+        <target datatype="html">Record a decision</target>
+      </trans-unit>
+      <trans-unit id="besluit.besluitLabel" datatype="html">
+        <source>Besluit</source>
+        <target datatype="html">Decision</target>
+      </trans-unit>
+      <trans-unit id="besluit.toelichtingLabel" datatype="html">
+        <source>Toelichting</source>
+        <target datatype="html">Explanation</target>
+      </trans-unit>
+      <trans-unit id="besluit.failed" datatype="html">
+        <source>Het vastleggen is niet gelukt:</source>
+        <target datatype="html">Recording the decision failed:</target>
+      </trans-unit>
+      <trans-unit id="besluit.optie.goedkeuren" datatype="html">
+        <source>Goedkeuren</source>
+        <target datatype="html">Approve</target>
+      </trans-unit>
+      <trans-unit id="besluit.optie.afwijzen" datatype="html">
+        <source>Afwijzen</source>
+        <target datatype="html">Reject</target>
+      </trans-unit>
+      <trans-unit id="besluit.optie.meerInfoOpvragen" datatype="html">
+        <source>Meer informatie opvragen</source>
+        <target datatype="html">Request more information</target>
+      </trans-unit>
+      <trans-unit id="besluit.submit" datatype="html">
+        <source>Besluit vastleggen</source>
+        <target datatype="html">Record decision</target>
+      </trans-unit>
+      <trans-unit id="besluit.submitBezig" datatype="html">
+        <source>Bezig met vastleggen…</source>
+        <target datatype="html">Recording…</target>
+      </trans-unit>
       <trans-unit id="beheer.noTables" datatype="html">
         <source>Er is geen stamdata om te beheren.</source>
         <target datatype="html">There is no stamdata to manage.</target>

apps/behandelportal/src/locale/messages.xlf

@@ -156,6 +156,20 @@
           <context context-type="linenumber">47</context>
         </context-group>
       </trans-unit>
+      <trans-unit id="besluit.error.verplicht" datatype="html">
+        <source>Kies een besluit.</source>
+        <context-group purpose="location">
+          <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/domain/besluit.machine.ts</context>
+          <context context-type="linenumber">46</context>
+        </context-group>
+      </trans-unit>
+      <trans-unit id="besluit.error.toelichtingVerplicht" datatype="html">
+        <source>Geef een toelichting.</source>
+        <context-group purpose="location">
+          <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/domain/besluit.machine.ts</context>
+          <context context-type="linenumber">54</context>
+        </context-group>
+      </trans-unit>
       <trans-unit id="werkvoorraad.row.ingediend" datatype="html">
         <source>ingediend op <x id="datum" equiv-text="formatDatumNl(item.submittedAt)"/></source>
         <context-group purpose="location">
@@ -181,35 +195,105 @@
         <source>Aanvraag</source>
         <context-group purpose="location">
           <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/ui/beoordeling.page.ts</context>
-          <context context-type="linenumber">62</context>
+          <context context-type="linenumber">69</context>
         </context-group>
       </trans-unit>
       <trans-unit id="beoordeling.detail.heading" datatype="html">
         <source>Aanvraaggegevens</source>
         <context-group purpose="location">
           <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/ui/beoordeling.page.ts</context>
-          <context context-type="linenumber">63</context>
+          <context context-type="linenumber">70</context>
         </context-group>
       </trans-unit>
       <trans-unit id="beoordeling.documenten.heading" datatype="html">
         <source>Documenten</source>
         <context-group purpose="location">
           <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/ui/beoordeling.page.ts</context>
-          <context context-type="linenumber">64</context>
+          <context context-type="linenumber">71</context>
         </context-group>
       </trans-unit>
       <trans-unit id="beoordeling.failed" datatype="html">
         <source>De aanvraag kon niet worden geladen.</source>
         <context-group purpose="location">
           <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/ui/beoordeling.page.ts</context>
-          <context context-type="linenumber">65</context>
+          <context context-type="linenumber">72</context>
         </context-group>
       </trans-unit>
       <trans-unit id="beoordeling.retry" datatype="html">
         <source>Opnieuw proberen</source>
         <context-group purpose="location">
           <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/ui/beoordeling.page.ts</context>
-          <context context-type="linenumber">66</context>
+          <context context-type="linenumber">73</context>
+        </context-group>
+      </trans-unit>
+      <trans-unit id="besluit.success" datatype="html">
+        <source>Het besluit is vastgelegd.</source>
+        <context-group purpose="location">
+          <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/ui/besluit-form/besluit-form.component.ts</context>
+          <context context-type="linenumber">35,37</context>
+        </context-group>
+      </trans-unit>
+      <trans-unit id="besluit.heading" datatype="html">
+        <source>Besluit vastleggen</source>
+        <context-group purpose="location">
+          <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/ui/besluit-form/besluit-form.component.ts</context>
+          <context context-type="linenumber">37,39</context>
+        </context-group>
+      </trans-unit>
+      <trans-unit id="besluit.besluitLabel" datatype="html">
+        <source>Besluit</source>
+        <context-group purpose="location">
+          <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/ui/besluit-form/besluit-form.component.ts</context>
+          <context context-type="linenumber">43</context>
+        </context-group>
+      </trans-unit>
+      <trans-unit id="besluit.toelichtingLabel" datatype="html">
+        <source>Toelichting</source>
+        <context-group purpose="location">
+          <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/ui/besluit-form/besluit-form.component.ts</context>
+          <context context-type="linenumber">59,60</context>
+        </context-group>
+      </trans-unit>
+      <trans-unit id="besluit.failed" datatype="html">
+        <source>Het vastleggen is niet gelukt:</source>
+        <context-group purpose="location">
+          <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/ui/besluit-form/besluit-form.component.ts</context>
+          <context context-type="linenumber">75,76</context>
+        </context-group>
+      </trans-unit>
+      <trans-unit id="besluit.optie.goedkeuren" datatype="html">
+        <source>Goedkeuren</source>
+        <context-group purpose="location">
+          <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/ui/besluit-form/besluit-form.component.ts</context>
+          <context context-type="linenumber">101</context>
+        </context-group>
+      </trans-unit>
+      <trans-unit id="besluit.optie.afwijzen" datatype="html">
+        <source>Afwijzen</source>
+        <context-group purpose="location">
+          <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/ui/besluit-form/besluit-form.component.ts</context>
+          <context context-type="linenumber">102</context>
+        </context-group>
+      </trans-unit>
+      <trans-unit id="besluit.optie.meerInfoOpvragen" datatype="html">
+        <source>Meer informatie opvragen</source>
+        <context-group purpose="location">
+          <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/ui/besluit-form/besluit-form.component.ts</context>
+          <context context-type="linenumber">105</context>
+        </context-group>
+      </trans-unit>
+      <trans-unit id="besluit.submit" datatype="html">
+        <source>Besluit vastleggen</source>
+        <context-group purpose="location">
+          <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/ui/besluit-form/besluit-form.component.ts</context>
+          <context context-type="linenumber">109</context>
+        </context-group>
+      </trans-unit>
+      <trans-unit id="besluit.submitBezig" datatype="html">
+        <source>Bezig met vastleggen…</source>
+        <context-group purpose="location">
+          <context context-type="sourcefile">apps/behandelportal/src/app/behandeling/ui/besluit-form/besluit-form.component.ts</context>
+          <context context-type="linenumber">110</context>
         </context-group>
       </trans-unit>
       <trans-unit id="werkvoorraad.heading" datatype="html">
@@ -870,6 +954,20 @@
           <context context-type="linenumber">107</context>
         </context-group>
       </trans-unit>
+      <trans-unit id="common.ja" datatype="html">
+        <source>Ja</source>
+        <context-group purpose="location">
+          <context context-type="sourcefile">libs/shared/src/ui/radio-group/radio-group.component.ts</context>
+          <context context-type="linenumber">12</context>
+        </context-group>
+      </trans-unit>
+      <trans-unit id="common.nee" datatype="html">
+        <source>Nee</source>
+        <context-group purpose="location">
+          <context context-type="sourcefile">libs/shared/src/ui/radio-group/radio-group.component.ts</context>
+          <context context-type="linenumber">13</context>
+        </context-group>
+      </trans-unit>
       <trans-unit id="spinner.aria" datatype="html">
         <source>Bezig met laden</source>
         <context-group purpose="location">

backend/src/BigRegister.Api/Contracts/Dtos.cs

@@ -140,6 +140,15 @@ public sealed record BeoordelingViewDto(
     IReadOnlyList<BeoordelingDocumentDto> Documenten,
     BeoordelingDecisionsDto Decisions);
 
+/// Recording a decision (WP-65b). `Besluit` is the enum member name as a string — same
+/// wire convention as `AanvraagStatusDto.Tag` (this backend never ships a raw C# enum,
+/// it round-trips names via Enum.Parse/.ToString() at the Contracts boundary, no
+/// JsonStringEnumConverter configured). The endpoint 400s an unknown name. Toelichting
+/// is required for Afwijzen/MeerInfoOpvragen, validated server-side.
+public sealed record RecordBesluitRequest(string Besluit, string? Toelichting = null);
+
+public sealed record RecordBesluitResponse(AanvraagStatusDto Status);
+
 // --- Brief (letter composition) contracts ---
 // Rich text is a serialisable node tree; the node union is flattened with a `Type`
 // discriminator + nullable fields, the same wire convention as AanvraagStatusDto.

backend/src/BigRegister.Api/Contracts/Mappers.cs

@@ -38,17 +38,25 @@ public static class Mappers
 
   // Aanvraag status is COMPUTED ON READ: an auto-approvable submission reports
   // Goedgekeurd once past the processing window, else In behandeling; a manual case
-  // stays In behandeling forever (awaits the unbuilt backoffice). Pure — testable
-  // by passing different `now` values without waiting for the wall clock.
-  //
-  // Ingediend/MeerInfoGevraagd (AanvraagStatusTag, WP-63) aren't produced here yet — no
-  // behandelaar action exists to reach them (WP-65 adds the transition endpoint).
+  // stays In behandeling until a behandelaar records a decision (WP-65b — before that
+  // WP, it stayed In behandeling forever, awaiting the then-unbuilt backoffice). Pure —
+  // testable by passing different `now` values without waiting for the wall clock.
   public static AanvraagStatusDto ToStatusDto(this Aanvraag a, DateTimeOffset now)
   {
     if (!a.Submitted)
       return new("Concept", StepIndex: a.StepIndex, StepCount: a.StepCount);
     if (a.Reden is not null)
       return new(AanvraagStatusTag.Afgewezen.ToString(), Referentie: a.Referentie, Reden: a.Reden);
+    // A recorded decision (WP-65b) wins over the auto-approve computation below — a
+    // behandelaar's explicit besluit is authoritative once made.
+    if (a.BesluitStatus is { } besluit)
+      return besluit switch
+      {
+        Besluit.Goedkeuren => new(AanvraagStatusTag.Goedgekeurd.ToString(), Referentie: a.Referentie),
+        Besluit.Afwijzen => new(AanvraagStatusTag.Afgewezen.ToString(), Referentie: a.Referentie, Reden: a.BesluitToelichting),
+        Besluit.MeerInfoOpvragen => new(AanvraagStatusTag.MeerInfoGevraagd.ToString(), Referentie: a.Referentie, Reden: a.BesluitToelichting),
+        _ => throw new InvalidOperationException($"Unknown besluit {besluit}"),
+      };
     if (a.AutoApprovable && now > a.SubmittedAt!.Value + ApplicationStore.ProcessingWindow)
       return new(AanvraagStatusTag.Goedgekeurd.ToString(), Referentie: a.Referentie);
     return new(AanvraagStatusTag.InBehandeling.ToString(), Referentie: a.Referentie, Manual: !a.AutoApprovable);

backend/src/BigRegister.Api/Data/ApplicationStore.cs

@@ -13,6 +13,14 @@ namespace BigRegister.Api.Data;
 /// </summary>
 public enum AanvraagStatusTag { Ingediend, InBehandeling, MeerInfoGevraagd, Goedgekeurd, Afgewezen }
 
+/// <summary>
+/// A behandelaar's recorded decision (WP-65b) — the three actions the beoordeling screen
+/// offers, each advancing <see cref="Aanvraag.BesluitStatus"/> and (via
+/// <see cref="BigRegister.Api.Contracts.Mappers.ToStatusDto"/>) the published
+/// <see cref="AanvraagStatusTag"/> the FE renders.
+/// </summary>
+public enum Besluit { Goedkeuren, Afwijzen, MeerInfoOpvragen }
+
 /// <summary>
 /// An application (aanvraag) — the system of record the dashboard reads. A wizard
 /// creates one as a Concept on its first step, syncs its draft snapshot per step,
@@ -50,6 +58,17 @@ public sealed class Aanvraag
   /// is re-findable by <c>identificatie == Referentie</c>. Cleared by a future repair path;
   /// none exists yet (see openzaak-integration.md's "Write resilience" section).</summary>
   public string? ZgwError { get; set; }
+
+  /// <summary>WP-65b: a behandelaar's recorded decision, if any. Non-null wins over the
+  /// auto-approve computation in <see cref="BigRegister.Api.Contracts.Mappers.ToStatusDto"/> —
+  /// "a recorded decision wins". Mutable across <see cref="AanvraagStatusTag.MeerInfoGevraagd"/>
+  /// (a behandelaar may decide again later); frozen once Goedgekeurd/Afgewezen (terminal, per
+  /// <see cref="BigRegister.Domain.Beoordeling.BeoordelingRules.CanDecide"/>).</summary>
+  public Besluit? BesluitStatus { get; set; }
+
+  /// <summary>The behandelaar's toelichting — required for Afwijzen/MeerInfoOpvragen (becomes
+  /// the published status's Reden), optional for Goedkeuren.</summary>
+  public string? BesluitToelichting { get; set; }
 }
 
 /// <summary>
@@ -104,6 +123,17 @@ public static class ApplicationStore
     }
   }
 
+  /// Cross-owner single read (WP-65b) — the behandelaar decision endpoint's counterpart of
+  /// <see cref="Get"/>, same "any owner" shape as <see cref="DeleteAny"/>.
+  public static Aanvraag? GetAny(string id)
+  {
+    lock (_gate)
+    {
+      using var db = Db.Create();
+      return db.Applications.Find(id);
+    }
+  }
+
   /// Admin: every case across all owners (WP-36). The per-owner List is the norm; this
   /// is the deliberate cross-owner read behind the admin-only /admin/cases endpoint.
   public static IReadOnlyList<Aanvraag> ListAll()
@@ -224,4 +254,24 @@ public static class ApplicationStore
       db.SaveChanges();
     }
   }
+
+  /// <summary>Record a behandelaar's decision (WP-65b). The endpoint has already checked
+  /// <see cref="BigRegister.Domain.Beoordeling.BeoordelingRules.CanDecide"/> against the
+  /// freshly-read status before calling this — cross-owner like <see cref="DeleteAny"/>,
+  /// since a behandelaar decides on any citizen's case. Returns null only if the aanvraag
+  /// is gone (shouldn't happen — this runs right after the endpoint's own read found it).</summary>
+  public static Aanvraag? RecordBesluit(string id, Besluit besluit, string? toelichting)
+  {
+    lock (_gate)
+    {
+      using var db = Db.Create();
+      var a = db.Applications.Find(id);
+      if (a is null) return null;
+      a.BesluitStatus = besluit;
+      a.BesluitToelichting = toelichting;
+      a.UpdatedAt = DateTimeOffset.UtcNow;
+      db.SaveChanges();
+      return a;
+    }
+  }
 }

backend/src/BigRegister.Api/Data/Migrations/20260803070817_BesluitStatus.Designer.cs

@@ -0,0 +1,288 @@
+// <auto-generated />
+using System;
+using BigRegister.Api.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+
+#nullable disable
+
+namespace BigRegister.Api.Data.Migrations
+{
+    [DbContext(typeof(AppDbContext))]
+    [Migration("20260803070817_BesluitStatus")]
+    partial class BesluitStatus
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder.HasAnnotation("ProductVersion", "10.0.9");
+
+            modelBuilder.Entity("BigRegister.Api.Data.Aanvraag", b =>
+                {
+                    b.Property<string>("Id")
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("AutoApprovable")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("BesluitStatus")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("BesluitToelichting")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("CreatedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("DocumentIds")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Draft")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Owner")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Reden")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Referentie")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("StepCount")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("StepIndex")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<bool>("Submitted")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTimeOffset?>("SubmittedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Type")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("UpdatedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ZaakUrl")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ZgwError")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Applications");
+                });
+
+            modelBuilder.Entity("BigRegister.Api.Data.AuditEntry", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Action")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Actor")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("At")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("CategoryId")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("DocumentId")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("AuditEntries");
+                });
+
+            modelBuilder.Entity("BigRegister.Api.Data.AuthzAuditEntry", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Action")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("At")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("CorrelationId")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Decision")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Resource")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Role")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("AuthzAudit");
+                });
+
+            modelBuilder.Entity("BigRegister.Api.Data.BriefEntity", b =>
+                {
+                    b.Property<string>("BriefId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("ArchivedHtml")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Beroep")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("DrafterId")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Owner")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Placeholders")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Sections")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("SentOrgTemplateVersion")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Status")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("SubOrgId")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("TemplateId")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("BriefId");
+
+                    b.HasIndex("Owner")
+                        .IsUnique();
+
+                    b.ToTable("Briefs");
+                });
+
+            modelBuilder.Entity("BigRegister.Api.Data.FeatureFlagEntity", b =>
+                {
+                    b.Property<string>("Key")
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("Enabled")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("Key");
+
+                    b.ToTable("FeatureFlags");
+                });
+
+            modelBuilder.Entity("BigRegister.Api.Data.OrgTemplateEntity", b =>
+                {
+                    b.Property<string>("SubOrgId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Draft")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("History")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("PublishedVersion")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("SubOrgId");
+
+                    b.ToTable("OrgTemplates");
+                });
+
+            modelBuilder.Entity("BigRegister.Api.Data.StoredDocument", b =>
+                {
+                    b.Property<string>("DocumentId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("CategoryId")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<byte[]>("Content")
+                        .IsRequired()
+                        .HasColumnType("BLOB");
+
+                    b.Property<string>("ContentType")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("DrcUrl")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("FileName")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("Linked")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("LocalId")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Owner")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("SizeBytes")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTimeOffset>("UploadedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("WizardId")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("DocumentId");
+
+                    b.ToTable("Documents");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

backend/src/BigRegister.Api/Data/Migrations/20260803070817_BesluitStatus.cs

@@ -0,0 +1,38 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace BigRegister.Api.Data.Migrations
+{
+  /// <inheritdoc />
+  public partial class BesluitStatus : Migration
+  {
+    /// <inheritdoc />
+    protected override void Up(MigrationBuilder migrationBuilder)
+    {
+      migrationBuilder.AddColumn<int>(
+          name: "BesluitStatus",
+          table: "Applications",
+          type: "INTEGER",
+          nullable: true);
+
+      migrationBuilder.AddColumn<string>(
+          name: "BesluitToelichting",
+          table: "Applications",
+          type: "TEXT",
+          nullable: true);
+    }
+
+    /// <inheritdoc />
+    protected override void Down(MigrationBuilder migrationBuilder)
+    {
+      migrationBuilder.DropColumn(
+          name: "BesluitStatus",
+          table: "Applications");
+
+      migrationBuilder.DropColumn(
+          name: "BesluitToelichting",
+          table: "Applications");
+    }
+  }
+}

backend/src/BigRegister.Api/Data/Migrations/AppDbContextModelSnapshot.cs

@@ -25,6 +25,12 @@ namespace BigRegister.Api.Data.Migrations
                     b.Property<bool>("AutoApprovable")
                         .HasColumnType("INTEGER");
 
+                    b.Property<int?>("BesluitStatus")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("BesluitToelichting")
+                        .HasColumnType("TEXT");
+
                     b.Property<DateTimeOffset>("CreatedAt")
                         .HasColumnType("TEXT");
 

backend/src/BigRegister.Api/Program.cs

@@ -442,6 +442,40 @@ api.MapGet("/beoordeling/{id}", (string id, HttpContext ctx, IZaakSource zaken)
 .ProducesProblem(StatusCodes.Status403Forbidden)
 .Produces(StatusCodes.Status404NotFound);
 
+// --- Besluit (WP-65b): record a behandelaar's decision, advancing the WP-63 status
+// lifecycle. Runs against ApplicationStore directly (not the IZaakSource seam) — same
+// reasoning as the GET above: a new seam method would force an OpenZaakZaakSource
+// write now, which is WP-66's surface, not this one's. The transition-legality check
+// (BeoordelingRules.CanDecide) is the SAME function the GET's canBesluiten flag uses,
+// so the two can never drift.
+api.MapPost("/beoordeling/{id}/besluit", (string id, RecordBesluitRequest req, HttpContext ctx) =>
+    Beoordelen(ctx, $"aanvraag/{id}/besluit", () =>
+    {
+      if (!Enum.TryParse<Besluit>(req.Besluit, out var besluit))
+        return Results.Problem(detail: $"Onbekend besluit '{req.Besluit}'.", statusCode: StatusCodes.Status400BadRequest);
+
+      var now = DateTimeOffset.UtcNow;
+      var a = ApplicationStore.GetAny(id);
+      var statusTag = a?.ToStatusDto(now).Tag;
+      if (a is null || statusTag == "Concept") return Results.NotFound();
+      var current = Enum.Parse<AanvraagStatusTag>(statusTag!);
+      if (!BeoordelingRules.CanDecide(current))
+        return Results.Problem(
+            detail: "Deze aanvraag staat geen besluit meer toe in de huidige status.",
+            statusCode: StatusCodes.Status409Conflict);
+      if (besluit != Besluit.Goedkeuren && string.IsNullOrWhiteSpace(req.Toelichting))
+        return Results.Problem(detail: "Toelichting is verplicht bij dit besluit.", statusCode: StatusCodes.Status400BadRequest);
+
+      var updated = ApplicationStore.RecordBesluit(id, besluit, req.Toelichting)!;
+      app.Logger.LogInformation("aanvraag besluit id={Id} besluit={Besluit}", id, besluit);
+      return Results.Ok(new RecordBesluitResponse(updated.ToStatusDto(now)));
+    }))
+.Produces<RecordBesluitResponse>()
+.ProducesProblem(StatusCodes.Status400BadRequest)
+.ProducesProblem(StatusCodes.Status403Forbidden)
+.ProducesProblem(StatusCodes.Status409Conflict)
+.Produces(StatusCodes.Status404NotFound);
+
 // OpenZaak's Notificaties API (NRC) calls this on every zaak event once an `abonnement` is
 // provisioned (WP-52, out-of-band — see openzaak-integration.md, no app code subscribes it).
 // The caller is NRC, not a user: no Principal, so this audits via AuthzAuditStore directly

backend/swagger.json

@@ -840,6 +840,78 @@
         }
       }
     },
+    "/api/v1/beoordeling/{id}/besluit": {
+      "post": {
+        "tags": [
+          "BigRegister.Api, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"
+        ],
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "string"
+            }
+          }
+        ],
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/RecordBesluitRequest"
+              }
+            }
+          },
+          "required": true
+        },
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/RecordBesluitResponse"
+                }
+              }
+            }
+          },
+          "400": {
+            "description": "Bad Request",
+            "content": {
+              "application/problem+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/ProblemDetails"
+                }
+              }
+            }
+          },
+          "403": {
+            "description": "Forbidden",
+            "content": {
+              "application/problem+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/ProblemDetails"
+                }
+              }
+            }
+          },
+          "409": {
+            "description": "Conflict",
+            "content": {
+              "application/problem+json": {
+                "schema": {
+                  "$ref": "#/components/schemas/ProblemDetails"
+                }
+              }
+            }
+          },
+          "404": {
+            "description": "Not Found"
+          }
+        }
+      }
+    },
     "/api/v1/admin/cases/{id}": {
       "delete": {
         "tags": [
@@ -2448,6 +2520,29 @@
         },
         "additionalProperties": false
       },
+      "RecordBesluitRequest": {
+        "type": "object",
+        "properties": {
+          "besluit": {
+            "type": "string",
+            "nullable": true
+          },
+          "toelichting": {
+            "type": "string",
+            "nullable": true
+          }
+        },
+        "additionalProperties": false
+      },
+      "RecordBesluitResponse": {
+        "type": "object",
+        "properties": {
+          "status": {
+            "$ref": "#/components/schemas/AanvraagStatusDto"
+          }
+        },
+        "additionalProperties": false
+      },
       "ReferentieResponse": {
         "type": "object",
         "properties": {

backend/tests/BigRegister.Tests/BeoordelingTests.cs

@@ -127,4 +127,113 @@ public class BeoordelingTests(TestWebApplicationFactory factory) : IClassFixture
     req.Headers.Add("X-Rollen", "geen");
     Assert.Equal(HttpStatusCode.Forbidden, (await _client.SendAsync(req)).StatusCode);
   }
+
+  private Task<HttpResponseMessage> PostBesluit(string id, object body)
+  {
+    var req = AsBehandelaar(HttpMethod.Post, $"/api/v1/beoordeling/{id}/besluit");
+    req.Content = JsonContent.Create(body);
+    return _client.SendAsync(req);
+  }
+
+  [Fact]
+  public async Task Goedkeuren_advances_status_to_Goedgekeurd()
+  {
+    var (a, _) = await CreateManualCaseWithDocument();
+    try
+    {
+      var res = await PostBesluit(a.Id, new { besluit = "Goedkeuren" });
+      res.EnsureSuccessStatusCode();
+      var body = (await res.Content.ReadFromJsonAsync<RecordBesluitResponse>())!;
+      Assert.Equal("Goedgekeurd", body.Status.Tag);
+
+      var detail = await _client.SendAsync(AsBehandelaar(HttpMethod.Get, $"/api/v1/beoordeling/{a.Id}"));
+      var view = (await detail.Content.ReadFromJsonAsync<BeoordelingViewDto>())!;
+      Assert.Equal("Goedgekeurd", view.Aanvraag.Status.Tag);
+      Assert.False(view.Decisions.CanBesluiten); // terminal — no further decision allowed
+    }
+    finally
+    {
+      await DeleteAsAdmin(a.Id);
+    }
+  }
+
+  [Fact]
+  public async Task Afwijzen_requires_a_toelichting()
+  {
+    var (a, _) = await CreateManualCaseWithDocument();
+    try
+    {
+      var missing = await PostBesluit(a.Id, new { besluit = "Afwijzen" });
+      Assert.Equal(HttpStatusCode.BadRequest, missing.StatusCode);
+
+      var res = await PostBesluit(a.Id, new { besluit = "Afwijzen", toelichting = "Diploma niet erkend" });
+      res.EnsureSuccessStatusCode();
+      var body = (await res.Content.ReadFromJsonAsync<RecordBesluitResponse>())!;
+      Assert.Equal("Afgewezen", body.Status.Tag);
+      Assert.Equal("Diploma niet erkend", body.Status.Reden);
+    }
+    finally
+    {
+      await DeleteAsAdmin(a.Id);
+    }
+  }
+
+  [Fact]
+  public async Task MeerInfoOpvragen_is_still_decidable_afterwards()
+  {
+    var (a, _) = await CreateManualCaseWithDocument();
+    try
+    {
+      var res = await PostBesluit(a.Id, new { besluit = "MeerInfoOpvragen", toelichting = "Stuur een geldig diploma" });
+      res.EnsureSuccessStatusCode();
+      var body = (await res.Content.ReadFromJsonAsync<RecordBesluitResponse>())!;
+      Assert.Equal("MeerInfoGevraagd", body.Status.Tag);
+
+      var detail = await _client.SendAsync(AsBehandelaar(HttpMethod.Get, $"/api/v1/beoordeling/{a.Id}"));
+      var view = (await detail.Content.ReadFromJsonAsync<BeoordelingViewDto>())!;
+      Assert.True(view.Decisions.CanBesluiten); // not terminal — a decision can still follow
+    }
+    finally
+    {
+      await DeleteAsAdmin(a.Id);
+    }
+  }
+
+  [Fact]
+  public async Task Already_decided_case_rejects_a_further_besluit()
+  {
+    var (a, _) = await CreateManualCaseWithDocument();
+    try
+    {
+      (await PostBesluit(a.Id, new { besluit = "Goedkeuren" })).EnsureSuccessStatusCode();
+      var again = await PostBesluit(a.Id, new { besluit = "Afwijzen", toelichting = "te laat" });
+      Assert.Equal(HttpStatusCode.Conflict, again.StatusCode);
+    }
+    finally
+    {
+      await DeleteAsAdmin(a.Id);
+    }
+  }
+
+  [Fact]
+  public async Task Unknown_id_404s_and_zorgverlener_is_forbidden()
+  {
+    var notFound = await PostBesluit("does-not-exist", new { besluit = "Goedkeuren" });
+    Assert.Equal(HttpStatusCode.NotFound, notFound.StatusCode);
+
+    var (a, _) = await CreateManualCaseWithDocument();
+    try
+    {
+      var req = new HttpRequestMessage(HttpMethod.Post, $"/api/v1/beoordeling/{a.Id}/besluit")
+      {
+        Content = JsonContent.Create(new { besluit = "Goedkeuren" }),
+      };
+      req.Headers.Add("X-Role", "admin"); // zorgverlener, no X-Medewerker
+      Assert.Equal(HttpStatusCode.Forbidden, (await _client.SendAsync(req)).StatusCode);
+    }
+    finally
+    {
+      await DeleteAsAdmin(a.Id);
+    }
+  }
 }

docs/project/backlog/WP-65-behandelportal-beoordeling.md

@@ -1,6 +1,6 @@
 # WP-65 — Behandelportal: zaak detail + beoordeling (decision) screen
 
-Status: in progress (65a — detail read — done; 65b — decision write — not started)
+Status: done (65a — detail read — done; 65b — decision write — done)
 Phase: 11 — Behandelportal
 
 ## Why
@@ -80,7 +80,7 @@ one gate for every behandelaar endpoint, `resource` feeding the audit row; the o
 
 **Decision-readiness (`BeoordelingDecisionsDto.canBesluiten`) ships now, not deferred to
 65b:** `BeoordelingRules.CanDecide(AanvraagStatusTag)` only inspects the aanvraag's current
-*computed* status tag (`Ingediend`/`InBehandeling`/`MeerInfoGevraagd` → decidable;
+_computed_ status tag (`Ingediend`/`InBehandeling`/`MeerInfoGevraagd` → decidable;
 `Goedgekeurd`/`Afgewezen` → not) — no persisted "was a decision recorded" field exists yet,
 so this pure rule needed nothing from 65b's eventual migration to be correct today. 65b adds
 the mutation, the `Besluit` enum, and the transition-legality check that reuses this same
@@ -110,14 +110,62 @@ yet — 65a is infrastructure the decision screen needs, not a slice of the AC i
 test, backend test — 197/197 including this WP's 9 new tests). Only the api-client-drift
 step shows the expected pre-commit diff (this WP's own uncommitted endpoint).
 
+## Progress notes (65b — done)
+
+**Backend (`POST /beoordeling/{id}/besluit`):** runs against `ApplicationStore` directly
+(not the `IZaakSource` seam) — same reasoning as 65a's GET: a new seam method would force
+an `OpenZaakZaakSource` write now, which stays WP-66's surface. A new `Besluit` enum
+(`Goedkeuren | Afwijzen | MeerInfoOpvragen`) backs a nullable `Aanvraag.BesluitStatus` +
+`Aanvraag.BesluitToelichting` column pair (EF migration `BesluitStatus`). Like every other
+enum in this backend, `Besluit` never crosses the wire as a raw C# enum — no
+`JsonStringEnumConverter` is configured, so `RecordBesluitRequest.Besluit` is a plain
+`string`, parsed with `Enum.TryParse` (400 on an unknown name) — the same wire convention
+`AanvraagStatusDto.Tag` already established. The endpoint reuses
+`BeoordelingRules.CanDecide` — the SAME function the read side's `canBesluiten` flag calls
+— as the transition-legality check, so the two can never drift (409 on an illegal
+transition, e.g. deciding an already-`Goedgekeurd` case again). Toelichting is required
+(400) for Afwijzen/MeerInfoOpvragen, optional for Goedkeuren — enforced server-side because
+the published `AanvraagStatusDto`'s `Reden` field is non-optional on those two tags (the
+FE's existing `parseBeoordelingStatus` already required it). `Mappers.ToStatusDto` gained
+"a recorded decision wins" between the submit-time `Reden` check and the auto-approve
+computation — the two never collide in practice (a submit-time-rejected case is already
+terminal and never reaches the werkvoorraad/beoordeling screens, so no behandelaar ever
+records a besluit on one). `MeerInfoGevraagd` is not terminal: `CanDecide` still allows a
+further besluit afterwards, so a behandelaar can ask for info, then later approve/reject
+once it arrives — the same `BesluitStatus` column is simply overwritten.
+
+**FE:** `besluit.machine.ts` is the same single-step Editing/Submitting/Submitted/Failed
+union as `change-request.machine.ts` (form-machine skill) — `Draft.besluit` stays a raw
+string (parsed into the narrow `BesluitTag` union only in `validate`, "parse, don't
+validate"), so the generic `SetField` reducer case needs no per-field typing gymnastics.
+`besluit-form` (organism) composes `RadioGroupComponent` (the three actions) +
+`FormFieldComponent`/`TextInputComponent` (toelichting, plain single-line — no textarea
+atom exists and this form doesn't justify adding one) — no new shared atom. On a
+successful decision it emits `decided`, and `BeoordelingPage` just calls
+`BeoordelingStore.reload()` — the server is the authority on the new status, the page
+never guesses it. The form only renders when the server's `canBesluiten` flag is true
+(ADR-0001: render the decision, don't recompute the lifecycle).
+
+Re-ran the full acceptance-criteria smoke by hand against `LocalZaakSource`: created a
+manual registratie case, opened it via werkvoorraad → beoordeling, recorded Afwijzen with a
+toelichting (status → Afgewezen, reason shown), confirmed a further besluit on that same
+case now 409s. `npm run ci` green (lint, dep:check ×2, format:check, check:tokens, all four
+projects' test suites, both apps' localized `nl`+`en` builds, backend `dotnet format
+--verify-no-changes` + `dotnet test` — 201/201 including this WP's 5 new tests, api-client
+regenerated). One pre-existing, unrelated finding: `format:check` was already red on this
+branch before this session touched anything — `docs/project/backlog/README.md` has a
+long-standing prettier drift (a big markdown table) untouched by this WP; fixed the same
+class of drift in this file's own body (`*computed*` → `_computed_`) since this WP was
+already editing it, left `README.md` alone as out of scope.
+
 ## Acceptance criteria
 
-- [ ] A medewerker can view one aanvraag's detail and record a decision that advances its
+- [x] A medewerker can view one aanvraag's detail and record a decision that advances its
       status.
-- [ ] Illegal transitions are rejected server-side (tested).
-- [ ] End-to-end smoke: werkvoorraad → detail → decision → status change reflected back
+- [x] Illegal transitions are rejected server-side (tested).
+- [x] End-to-end smoke: werkvoorraad → detail → decision → status change reflected back
       in the queue.
-- [ ] `npm run ci` (behandelportal app) + `dotnet test` green.
+- [x] `npm run ci` (behandelportal app) + `dotnet test` green.
 
 ## Verification
 

libs/shared/src/infrastructure/api-client.ts

@@ -1165,6 +1165,71 @@ export class ApiClient {
         return Promise.resolve<BeoordelingViewDto>(null as any);
     }
 
+    /**
+     * @return OK
+     */
+    besluit(id: string, body: RecordBesluitRequest): Promise<RecordBesluitResponse> {
+        let url_ = this.baseUrl + "/api/v1/beoordeling/{id}/besluit";
+        if (id === undefined || id === null)
+            throw new globalThis.Error("The parameter 'id' must be defined.");
+        url_ = url_.replace("{id}", encodeURIComponent("" + id));
+        url_ = url_.replace(/[?&]$/, "");
+
+        const content_ = JSON.stringify(body);
+
+        let options_: RequestInit = {
+            body: content_,
+            method: "POST",
+            headers: {
+                "Content-Type": "application/json",
+                "Accept": "application/json"
+            }
+        };
+
+        return this.http.fetch(url_, options_).then((_response: Response) => {
+            return this.processBesluit(_response);
+        });
+    }
+
+    protected processBesluit(response: Response): Promise<RecordBesluitResponse> {
+        const status = response.status;
+        let _headers: any = {}; if (response.headers && response.headers.forEach) { response.headers.forEach((v: any, k: any) => _headers[k] = v); };
+        if (status === 200) {
+            return response.text().then((_responseText) => {
+            let result200: any = null;
+            result200 = _responseText === "" ? null : JSON.parse(_responseText, this.jsonParseReviver) as RecordBesluitResponse;
+            return result200;
+            });
+        } else if (status === 400) {
+            return response.text().then((_responseText) => {
+            let result400: any = null;
+            result400 = _responseText === "" ? null : JSON.parse(_responseText, this.jsonParseReviver) as ProblemDetails;
+            return throwException("Bad Request", status, _responseText, _headers, result400);
+            });
+        } else if (status === 403) {
+            return response.text().then((_responseText) => {
+            let result403: any = null;
+            result403 = _responseText === "" ? null : JSON.parse(_responseText, this.jsonParseReviver) as ProblemDetails;
+            return throwException("Forbidden", status, _responseText, _headers, result403);
+            });
+        } else if (status === 404) {
+            return response.text().then((_responseText) => {
+            return throwException("Not Found", status, _responseText, _headers);
+            });
+        } else if (status === 409) {
+            return response.text().then((_responseText) => {
+            let result409: any = null;
+            result409 = _responseText === "" ? null : JSON.parse(_responseText, this.jsonParseReviver) as ProblemDetails;
+            return throwException("Conflict", status, _responseText, _headers, result409);
+            });
+        } else if (status !== 200 && status !== 204) {
+            return response.text().then((_responseText) => {
+            return throwException("An unexpected server error occurred.", status, _responseText, _headers);
+            });
+        }
+        return Promise.resolve<RecordBesluitResponse>(null as any);
+    }
+
     /**
      * @return No Content
      */
@@ -2248,6 +2313,15 @@ export interface PublishOrgTemplateResponse {
     affectedUnsentBriefs?: number;
 }
 
+export interface RecordBesluitRequest {
+    besluit?: string | undefined;
+    toelichting?: string | undefined;
+}
+
+export interface RecordBesluitResponse {
+    status?: AanvraagStatusDto;
+}
+
 export interface ReferentieResponse {
     referentie?: string | undefined;
 }