diff --git a/.phase2-state.json b/.phase2-state.json
index b094cc5..d480067 100644
--- a/.phase2-state.json
+++ b/.phase2-state.json
@@ -1,11 +1,12 @@
 {
   "completed_features": [],
-  "current_feature": "dashboard-stats",
+  "current_feature": "active-timer-widget",
   "started_at": "2026-05-23T04:42:59.289476",
   "attempted_features": [
     "customers-crud",
     "projects-crud",
     "api-client-extensions",
-    "router-with-new-pages"
+    "router-with-new-pages",
+    "dashboard-stats"
   ]
 }
\ No newline at end of file
diff --git a/GENERATION_LOG.md b/GENERATION_LOG.md
index e9e189c..83f596b 100644
--- a/GENERATION_LOG.md
+++ b/GENERATION_LOG.md
@@ -312,3 +312,33 @@ src/routes/customers.ts(14,49): error TS7006: Parameter 'reply' implicitly has a
 src/routes/customers.ts(22,11): error TS2339: Property 'get' does not exist on type 'FastifyPluginAsync'.
 src/routes/customers.ts(22,27): error TS7006: Parameter 'request' implicitly has an 'any' type.
 src/routes/customers.ts(22,36): error TS7006: Parameter
+- `04:47:04` **INFO**   Committed feature dashboard-stats
+- `04:47:05` **INFO**   Pushed: rc=0
+- `04:47:05` **WARN** ⚠️  Feature dashboard-stats partial — moving on
+
+## Feature: active-timer-widget (2026-05-23 04:47:05)
+
+- `04:47:05` **INFO** Description: Aktiver Timer (start/stop) im Header sichtbar
+- `04:47:05` **INFO** Files: 2
+- `04:47:05` **INFO**   Generating apps/api/src/routes/time-entries.ts (ERWEITERTE time-entries-Routes. Behalte bestehende CRUD. Neu: GET /api…)
+- `04:47:56` **INFO**     wrote 5527 chars in 50.8s (attempt 1)
+- `04:47:56` **INFO**   Generating apps/web/src/components/ActiveTimer.tsx (Live-Timer Widget. useQuery({queryKey:['running-entry'], queryFn: api.…)
+- `04:48:32` **INFO**     wrote 3951 chars in 36.0s (attempt 1)
+- `04:48:32` **INFO** Running tsc --noEmit on api…
+- `04:48:33` **WARN**   tsc errors:
+src/routes/auth.ts(9,11): error TS2339: Property 'post' does not exist on type 'FastifyPluginAsync'.
+src/routes/auth.ts(9,33): error TS7006: Parameter 'request' implicitly has an 'any' type.
+src/routes/auth.ts(9,42): error TS7006: Parameter 'reply' implicitly has an 'any' type.
+src/routes/auth.ts(22,27): error TS2339: Property 'jwt' does not exist on type 'FastifyPluginAsync'.
+src/routes/auth.ts(44,11): error TS2339: Property 'get' does not exist on type 'FastifyPluginAsync'.
+src/routes/auth.ts(44,29): error TS7006: Parameter 'request' implicitly has an 'any' type.
+src/routes/auth.ts(44,38): error TS7006: Parameter 'reply' implicitly has an 'any' type.
+src/routes/auth.ts(70,11): error TS2339: Property 'post' does not exist on type 'FastifyPluginAsync'.
+src/routes/auth.ts(70,34): error TS7006: Parameter 'request' implicitly has an 'any' type.
+src/routes/auth.ts(70,43): error TS7006: Parameter 'reply' implicitly has an 'any' type.
+src/routes/customers.ts(14,11): error TS2339: Property 'addHook' does not exist on type 'FastifyPluginAsync'.
+src/routes/customers.ts(14,40): error TS7006: Parameter 'request' implicitly has an 'any' type.
+src/routes/customers.ts(14,49): error TS7006: Parameter 'reply' implicitly has an 'any' type.
+src/routes/customers.ts(22,11): error TS2339: Property 'get' does not exist on type 'FastifyPluginAsync'.
+src/routes/customers.ts(22,27): error TS7006: Parameter 'request' implicitly has an 'any' type.
+src/routes/customers.ts(22,36): error TS7006: Parameter
diff --git a/apps/api/src/routes/time-entries.ts b/apps/api/src/routes/time-entries.ts
index 439e30f..1fdb63b 100644
--- a/apps/api/src/routes/time-entries.ts
+++ b/apps/api/src/routes/time-entries.ts
@@ -1,7 +1,7 @@
 import { FastifyPluginAsync } from "fastify"
 import { db } from "../db"
 import { timeEntries } from "../db/schema"
-import { eq, and, gte, lte, or } from "drizzle-orm"
+import { eq, and, gte, lte, isNull } from "drizzle-orm"
 import { z } from "zod"
 
 const TimeEntrySchema = z.object({
@@ -13,6 +13,11 @@ const TimeEntrySchema = z.object({
 
 const TimeEntryUpdateSchema = TimeEntrySchema.partial()
 
+const StartEntrySchema = z.object({
+  projectId: z.string().uuid().optional(),
+  description: z.string().min(1)
+})
+
 export default async function timeEntryRoutes(fastify: FastifyPluginAsync) {
   fastify.addHook("preHandler", async (request, reply) => {
     try {
@@ -49,6 +54,27 @@ export default async function timeEntryRoutes(fastify: FastifyPluginAsync) {
     return entries
   })
 
+  fastify.get("/running", async (request, reply) => {
+    const user = request.user as { sub: string }
+
+    const [entry] = await db
+      .select()
+      .from(timeEntries)
+      .where(
+        and(
+          eq(timeEntries.userId, user.sub),
+          isNull(timeEntries.endTime)
+        )
+      )
+      .limit(1)
+
+    if (!entry) {
+      return reply.code(404).send({ message: "No running time entry found" })
+    }
+
+    return entry
+  })
+
   fastify.get("/:id", async (request, reply) => {
     const { id } = request.params as { id: string }
     const user = request.user as { sub: string; role: string }
@@ -71,6 +97,23 @@ export default async function timeEntryRoutes(fastify: FastifyPluginAsync) {
     return entry
   })
 
+  fastify.post("/start", async (request, reply) => {
+    const user = request.user as { sub: string }
+    const body = StartEntrySchema.parse(request.body)
+
+    const [entry] = await db
+      .insert(timeEntries)
+      .values({
+        ...body,
+        userId: user.sub,
+        startTime: new Date(),
+        endTime: null
+      })
+      .returning()
+
+    return reply.code(201).send(entry)
+  })
+
   fastify.post("/", async (request, reply) => {
     const user = request.user as { sub: string }
     const body = TimeEntrySchema.parse(request.body)
@@ -88,6 +131,34 @@ export default async function timeEntryRoutes(fastify: FastifyPluginAsync) {
     return reply.code(201).send(entry)
   })
 
+  fastify.post("/:id/stop", async (request, reply) => {
+    const { id } = request.params as { id: string }
+    const user = request.user as { sub: string; role: string }
+
+    const [entry] = await db
+      .select()
+      .from(timeEntries)
+      .where(
+        and(
+          eq(timeEntries.id, id),
+          user.role === "admin" ? undefined : eq(timeEntries.userId, user.sub)
+        )
+      )
+      .limit(1)
+
+    if (!entry) {
+      return reply.code(404).send({ message: "Time entry not found" })
+    }
+
+    const [updated] = await db
+      .update(timeEntries)
+      .set({ endTime: new Date() })
+      .where(eq(timeEntries.id, id))
+      .returning()
+
+    return updated
+  })
+
   fastify.patch("/:id", async (request, reply) => {
     const { id } = request.params as { id: string }
     const user = request.user as { sub: string; role: string }
diff --git a/apps/web/src/components/ActiveTimer.tsx b/apps/web/src/components/ActiveTimer.tsx
new file mode 100644
index 0000000..0e8233a
--- /dev/null
+++ b/apps/web/src/components/ActiveTimer.tsx
@@ -0,0 +1,103 @@
+import React, { useState, useEffect } from 'react'
+import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query'
+import { api } from '../lib/api'
+import { Loader2, Play, Square } from 'lucide-react'
+
+export const ActiveTimer = () => {
+  const queryClient = useQueryClient()
+  const [description, setDescription] = useState('')
+  const [isInputVisible, setIsInputVisible] = useState(false)
+  const [elapsed, setElapsed] = useState(0)
+
+  const { data: runningEntry, isLoading } = useQuery({
+    queryKey: ['running-entry'],
+    queryFn: () => api.getRunningTimeEntry(),
+    refetchInterval: 30000,
+  })
+
+  const startMutation = useMutation({
+    mutationFn: (desc: string) => api.createTimeEntry({ description, startTime: new Date().toISOString() }),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ['running-entry'] })
+      setIsInputVisible(false)
+      setDescription('')
+    },
+  })
+
+  const stopMutation = useMutation({
+    mutationFn: (id: string) => api.stopTimeEntry(id),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ['running-entry'] })
+    },
+  })
+
+  useEffect(() => {
+    let interval: NodeJS.Timeout
+    if (runningEntry?.startTime) {
+      const update = () => {
+        const start = new Date(runningEntry.startTime).getTime()
+        const now = Date.now()
+        setElapsed(Math.floor((now - start) / 1000))
+      }
+      update()
+      interval = setInterval(update, 1000)
+    } else {
+      setElapsed(0)
+    }
+    return () => clearInterval(interval)
+  }, [runningEntry])
+
+  const formatTime = (seconds: number) => {
+    const h = Math.floor(seconds / 3600)
+    const m = Math.floor((seconds % 3600) / 60)
+    const s = seconds % 60
+    return h > 0 
+      ? `${h}:${m.toString().padStart(2, '0')}:${s.toString().padStart(2, '0')}`
+      : `${m.toString().padStart(2, '0')}:${s.toString().padStart(2, '0')}`
+  }
+
+  if (isLoading) return <div className="h-10 w-10 flex items-center justify-center"><Loader2 className="w-4 h-4 animate-spin" /></div>
+
+  if (runningEntry) {
+    return (
+      <div className="h-10 inline-flex items-center gap-3 px-3 py-1 bg-slate-100 dark:bg-slate-800 rounded-full border border-slate-200 dark:border-slate-700 text-sm font-medium">
+        <span className="text-slate-500 dark:text-slate-400 truncate max-w-[120px]">
+          {runningEntry.description || 'No description'}
+        </span>
+        <span className="tabular-nums font-mono text-blue-600 dark:text-blue-400">
+          {formatTime(elapsed)}
+        </span>
+        <button 
+          onClick={() => stopMutation.mutate(runningEntry.id)}
+          disabled={stopMutation.isPending}
+          className="p-1 hover:bg-red-100 dark:hover:bg-red-900/30 text-red-600 dark:text-red-400 rounded-full transition-colors"
+        >
+          <Square className="w-4 h-4 fill-current" />
+        </button>
+      </div>
+    )
+  }
+
+  return (
+    <div className="h-10 inline-flex items-center gap-2">
+      {isInputVisible && (
+        <input
+          autoFocus
+          className="h-8 px-2 text-sm border rounded-md bg-white dark:bg-slate-900 dark:border-slate-700 outline-none focus:ring-1 ring-blue-500 w-40"
+          placeholder="What are you working on?"
+          value={description}
+          onChange={(e) => setDescription(e.target.value)}
+          onKeyDown={(e) => e.key === 'Enter' && startMutation.mutate(description)}
+        />
+      )}
+      <button
+        onClick={() => isInputVisible ? startMutation.mutate(description) : setIsInputVisible(true)}
+        disabled={startMutation.isPending}
+        className="h-8 px-3 flex items-center gap-2 bg-blue-600 hover:bg-blue-700 text-white text-sm font-medium rounded-md transition-colors"
+      >
+        {startMutation.isPending ? <Loader2 className="w-3 h-3 animate-spin" /> : <Play className="w-3 h-3 fill-current" />}
+        <span>{isInputVisible ? 'Start' : 'Start Timer'}</span>
+      </button>
+    </div>
+  )
+}
\ No newline at end of file