diff --git a/package.json b/package.json
index f91e42b..df1678e 100644
--- a/package.json
+++ b/package.json
@@ -19,6 +19,6 @@
     "dev": "vite",
     "build": "vite build",
     "preview": "vite preview",
-    "test": "node --test tests/*.test.mjs"
+    "test": "node --test tests/*.test.mjs tests/unit/*.test.mjs"
   }
 }
diff --git a/src/lib/projectAssign.js b/src/lib/projectAssign.js
new file mode 100644
index 0000000..9f0b7f9
--- /dev/null
+++ b/src/lib/projectAssign.js
@@ -0,0 +1,45 @@
+export const GITEA_ORG = 'WEBklar'
+
+export function isOutsideOrg(repoFullName) {
+  if (!repoFullName) return false
+  const org = repoFullName.split('/')[0] || ''
+  return org.toLowerCase() !== GITEA_ORG.toLowerCase()
+}
+
+export function needsPreviewButton(project) {
+  return !project.previewUrl || project.status !== 'deployed'
+}
+
+export function assignSummary(projectName, result) {
+  if (result && result.error) {
+    return { text: `${projectName}: Zuweisen fehlgeschlagen – ${result.error}`, warnings: [] }
+  }
+
+  const { moved, backfilled, warnings = [] } = result
+  const parts = []
+  if (moved) {
+    parts.push('nach WEBklar verschoben')
+  }
+  if (backfilled === 1) {
+    parts.push('1 Push nachgetragen')
+  } else if (backfilled > 1) {
+    parts.push(`${backfilled} Pushes nachgetragen`)
+  } else {
+    parts.push('keine neuen Pushes')
+  }
+
+  return { text: `${projectName}: ${parts.join(' · ')}`, warnings }
+}
+
+export async function assignSequentially(projectIds, ctx, assignFn) {
+  const results = []
+  for (const projectId of projectIds) {
+    try {
+      const result = await assignFn(projectId, ctx)
+      results.push({ projectId, ok: true, result })
+    } catch (err) {
+      results.push({ projectId, ok: false, error: err.message })
+    }
+  }
+  return results
+}
diff --git a/src/lib/subdomain.js b/src/lib/subdomain.js
new file mode 100644
index 0000000..0a5b2bd
--- /dev/null
+++ b/src/lib/subdomain.js
@@ -0,0 +1,22 @@
+const UMLAUT_MAP = {
+  ä: 'ae',
+  ö: 'oe',
+  ü: 'ue',
+  ß: 'ss',
+}
+
+export function suggestSubdomain(customerName, projectName) {
+  const base = (customerName || '').trim() || (projectName || '').trim()
+  if (!base) return ''
+
+  let value = base.toLowerCase()
+  value = value.replace(/[äöüß]/g, (ch) => UMLAUT_MAP[ch])
+  value = value.normalize('NFD').replace(/[̀-ͯ]/g, '')
+  value = value.replace(/['’‘`]/g, '')
+  value = value.replace(/[^a-z0-9]+/g, '-')
+  value = value.replace(/^-+|-+$/g, '')
+  value = value.slice(0, 63)
+  value = value.replace(/-+$/g, '')
+
+  return value
+}
diff --git a/tests/unit/load.mjs b/tests/unit/load.mjs
new file mode 100644
index 0000000..a174879
--- /dev/null
+++ b/tests/unit/load.mjs
@@ -0,0 +1,20 @@
+import esbuild from 'esbuild'
+import path from 'node:path'
+import { fileURLToPath } from 'node:url'
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url))
+const repoRoot = path.resolve(__dirname, '../..')
+
+export async function loadModule(relPathFromRepoRoot) {
+  const entryPoint = path.join(repoRoot, relPathFromRepoRoot)
+  const result = await esbuild.build({
+    entryPoints: [entryPoint],
+    bundle: true,
+    format: 'esm',
+    write: false,
+    platform: 'neutral',
+  })
+  const code = result.outputFiles[0].text
+  const dataUrl = `data:text/javascript;base64,${Buffer.from(code).toString('base64')}`
+  return import(dataUrl)
+}
diff --git a/tests/unit/projectAssign.test.mjs b/tests/unit/projectAssign.test.mjs
new file mode 100644
index 0000000..7a3dfe7
--- /dev/null
+++ b/tests/unit/projectAssign.test.mjs
@@ -0,0 +1,61 @@
+import test from 'node:test'
+import assert from 'node:assert/strict'
+import { loadModule } from './load.mjs'
+
+const { isOutsideOrg, needsPreviewButton, assignSummary, assignSequentially } = await loadModule(
+  'src/lib/projectAssign.js'
+)
+
+function sleep(ms) {
+  return new Promise((resolve) => setTimeout(resolve, ms))
+}
+
+test('isOutsideOrg', () => {
+  assert.equal(isOutsideOrg('JUSN/D-ner-Nation'), true)
+  assert.equal(isOutsideOrg('webklar/x'), false)
+  assert.equal(isOutsideOrg(''), false)
+})
+
+test('needsPreviewButton', () => {
+  assert.equal(needsPreviewButton({ previewUrl: 'https://x', status: 'deployed' }), false)
+  assert.equal(needsPreviewButton({ previewUrl: '', status: 'synced' }), true)
+  assert.equal(needsPreviewButton({ previewUrl: 'https://x', status: 'pending' }), true)
+})
+
+test('assignSummary', () => {
+  assert.deepEqual(
+    assignSummary('Döner Nation', {
+      moved: { from: 'JUSN/D-ner-Nation', to: 'WEBklar/D-ner-Nation' },
+      backfilled: 1,
+      warnings: [],
+    }),
+    { text: 'Döner Nation: nach WEBklar verschoben · 1 Push nachgetragen', warnings: [] }
+  )
+  assert.deepEqual(
+    assignSummary('X', { moved: null, backfilled: 0, warnings: ['Internes Repo, bleibt wo es ist.'] }),
+    { text: 'X: keine neuen Pushes', warnings: ['Internes Repo, bleibt wo es ist.'] }
+  )
+  assert.equal(assignSummary('X', { moved: null, backfilled: 3, warnings: [] }).text, 'X: 3 Pushes nachgetragen')
+  assert.deepEqual(assignSummary('X', { error: 'boom' }), { text: 'X: Zuweisen fehlgeschlagen – boom', warnings: [] })
+})
+
+test('nacheinander und weiter nach Fehler', async () => {
+  const log = []
+  const fn = async (id) => {
+    log.push(id + ':start')
+    await sleep(10)
+    log.push(id + ':end')
+    if (id === 'b') throw new Error('boom')
+    return { backfilled: 0 }
+  }
+  const r = await assignSequentially(['a', 'b', 'c'], { ticketId: 't1' }, fn)
+  assert.deepEqual(log, ['a:start', 'a:end', 'b:start', 'b:end', 'c:start', 'c:end'])
+  assert.deepEqual(
+    r.map((x) => [x.projectId, x.ok, x.error]),
+    [
+      ['a', true, undefined],
+      ['b', false, 'boom'],
+      ['c', true, undefined],
+    ]
+  )
+})
diff --git a/tests/unit/subdomain.test.mjs b/tests/unit/subdomain.test.mjs
new file mode 100644
index 0000000..bff1f6d
--- /dev/null
+++ b/tests/unit/subdomain.test.mjs
@@ -0,0 +1,25 @@
+import test from 'node:test'
+import assert from 'node:assert/strict'
+import { loadModule } from './load.mjs'
+
+const { suggestSubdomain } = await loadModule('src/lib/subdomain.js')
+
+test('Kundenname vor Projektname', () => {
+  assert.equal(suggestSubdomain('Döner Nation', 'D-ner-Nation'), 'doener-nation')
+})
+
+test('Apostroph', () => {
+  assert.equal(suggestSubdomain("Emma's Schatzkiste", ''), 'emmas-schatzkiste')
+})
+
+test('Sonderzeichen', () => {
+  assert.equal(suggestSubdomain('', 'Café Müller & Söhne + Straße'), 'cafe-mueller-soehne-strasse')
+})
+
+test('leer', () => {
+  assert.equal(suggestSubdomain('', ''), '')
+})
+
+test('63 Zeichen ohne Bindestrich am Ende', () => {
+  assert.equal(suggestSubdomain('a'.repeat(62) + ' b', ''), 'a'.repeat(62))
+})