diff --git a/AGENTS.md b/AGENTS.md
index 7a311c6..b09b636 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -144,3 +144,9 @@ See `.env.example` for full list. Key variables:
 2. Edit `src/sync.py` for orchestration changes
 3. Update `SPEC.md` if sync behavior changes
 4. Test with a single account first: set `LOG_LEVEL=DEBUG`
+
+## License
+
+MIT License - Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
+- Full text in `LICENSE`
+- License headers in all source code files
diff --git a/Dockerfile b/Dockerfile
index b2d930d..c5e5b53 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -5,6 +5,7 @@ WORKDIR /app
 COPY requirements.txt /app/requirements.txt
 RUN pip install --no-cache-dir -r /app/requirements.txt
 
+COPY LICENSE .
 COPY src/ /app/
 COPY sql/ /app/sql/
 COPY docker/entrypoint.sh /usr/local/bin/entrypoint.sh
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..3556447
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
index a2a488b..9fd62fe 100644
--- a/README.md
+++ b/README.md
@@ -221,3 +221,7 @@ eigenen Accounts.
 ```
 curl -H "Remote-User: mmustermann" http://127.0.0.1:8000/api/contacts
 ```
+
+## License
+
+Licensed under the [MIT License](LICENSE) - Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
diff --git a/docker/entrypoint.sh b/docker/entrypoint.sh
index d42e403..d472403 100644
--- a/docker/entrypoint.sh
+++ b/docker/entrypoint.sh
@@ -1,4 +1,6 @@
 #!/bin/sh
+# Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
+# Licensed under the MIT License. See LICENSE file in project root for details.
 set -e
 
 # Wurde ein alternativer Befehl uebergeben (z.B. uvicorn), fuehre diesen
diff --git a/src/api/__init__.py b/src/api/__init__.py
index e69de29..91f759e 100644
--- a/src/api/__init__.py
+++ b/src/api/__init__.py
@@ -0,0 +1,2 @@
+# Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
+# Licensed under the MIT License. See LICENSE file in project root for details.
diff --git a/src/api/auth.py b/src/api/auth.py
index 0b47d1e..f504336 100644
--- a/src/api/auth.py
+++ b/src/api/auth.py
@@ -1,3 +1,5 @@
+# Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
+# Licensed under the MIT License. See LICENSE file in project root for details.
 """Authelia-Integration: liest den vom Reverse-Proxy weitergereichten
 Remote-User-Header und mappt ihn per accounts.json auf einen internen
 Account-Namen. Kein eigenes Login, Authelia übernimmt die eigentliche
diff --git a/src/api/main.py b/src/api/main.py
index 55964d0..000d14f 100644
--- a/src/api/main.py
+++ b/src/api/main.py
@@ -1,3 +1,5 @@
+# Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
+# Licensed under the MIT License. See LICENSE file in project root for details.
 """FastAPI-App für die interne Web-Ansicht/API der iCloud-Kontakte.
 
 Läuft im selben Image wie der Sync-Container, wird aber über einen
diff --git a/src/api/schemas.py b/src/api/schemas.py
index cc27f02..c8e3f1e 100644
--- a/src/api/schemas.py
+++ b/src/api/schemas.py
@@ -1,3 +1,5 @@
+# Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
+# Licensed under the MIT License. See LICENSE file in project root for details.
 from datetime import date
 from pydantic import BaseModel
 
diff --git a/src/api/templates/contact.html b/src/api/templates/contact.html
index 47d3d0f..724778a 100644
--- a/src/api/templates/contact.html
+++ b/src/api/templates/contact.html
@@ -1,3 +1,5 @@
+<!-- Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de) -->
+<!-- Licensed under the MIT License. See LICENSE file in project root for details. -->
 <!DOCTYPE html>
 <html lang="de">
 <head>
diff --git a/src/api/templates/index.html b/src/api/templates/index.html
index f678e65..11ea19a 100644
--- a/src/api/templates/index.html
+++ b/src/api/templates/index.html
@@ -1,3 +1,5 @@
+<!-- Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de) -->
+<!-- Licensed under the MIT License. See LICENSE file in project root for details. -->
 <!DOCTYPE html>
 <html lang="de">
 <head>
diff --git a/src/carddav_client.py b/src/carddav_client.py
index 92d5c86..81fcc0d 100644
--- a/src/carddav_client.py
+++ b/src/carddav_client.py
@@ -1,3 +1,5 @@
+# Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
+# Licensed under the MIT License. See LICENSE file in project root for details.
 """
 CardDAV-Client für iCloud (RFC 6352) mit Delta-Sync über sync-collection (RFC 6578).
 
diff --git a/src/config.py b/src/config.py
index 246eecd..4bef023 100644
--- a/src/config.py
+++ b/src/config.py
@@ -1,3 +1,5 @@
+# Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
+# Licensed under the MIT License. See LICENSE file in project root for details.
 import os
 import json
 from dotenv import load_dotenv
diff --git a/src/db.py b/src/db.py
index 9871cab..ee9465e 100644
--- a/src/db.py
+++ b/src/db.py
@@ -1,3 +1,5 @@
+# Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
+# Licensed under the MIT License. See LICENSE file in project root for details.
 """MariaDB-Anbindung: Delta-Sync-Strategie (Upsert für Änderungen, gezieltes Löschen für Removals)."""
 import logging
 import os
diff --git a/src/mailer.py b/src/mailer.py
index 7604072..ff2e182 100644
--- a/src/mailer.py
+++ b/src/mailer.py
@@ -1,4 +1,6 @@
 #!/usr/bin/env python3
+# Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
+# Licensed under the MIT License. See LICENSE file in project root for details.
 """Sendet eine tägliche E-Mail mit allen heutigen Geburtstagskindern aus der
 contacts-Tabelle (über alle Accounts hinweg). Wird per Cron einmal täglich
 um MAIL_SEND_HOUR aufgerufen. Verhindert Doppelversand am selben Tag über
diff --git a/src/scheduler.py b/src/scheduler.py
index a1653b2..09c25b1 100644
--- a/src/scheduler.py
+++ b/src/scheduler.py
@@ -1,4 +1,6 @@
 #!/usr/bin/env python3
+# Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
+# Licensed under the MIT License. See LICENSE file in project root for details.
 """Einfacher Cron-Scheduler fuer Sync und Mailer.
 Ersetzt supercronic komplett — keine externe Abhaengigkeit noetig.
 
diff --git a/src/sync.py b/src/sync.py
index 54c8a0d..675f6d4 100644
--- a/src/sync.py
+++ b/src/sync.py
@@ -1,4 +1,6 @@
 #!/usr/bin/env python3
+# Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
+# Licensed under the MIT License. See LICENSE file in project root for details.
 """Einstiegspunkt für einen Sync-Lauf über alle konfigurierten Accounts.
 Für jeden Account wird ein Delta-Sync per CardDAV sync-collection (RFC 6578)
 durchgeführt. Beim allerersten Lauf eines Accounts (kein gespeicherter
diff --git a/src/vcard_parser.py b/src/vcard_parser.py
index 61338ee..ca823f4 100644
--- a/src/vcard_parser.py
+++ b/src/vcard_parser.py
@@ -1,3 +1,5 @@
+# Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
+# Licensed under the MIT License. See LICENSE file in project root for details.
 """Parst rohen vCard-Text in ein flaches dict, passend zum contacts-Schema."""
 import json
 import logging