diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 2cd720b..4fecb4b 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -12,7 +12,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ["8.3", "8.4"]
+        php: ["8.4"]
     name: PHPUnit (PHP ${{ matrix.php }})
     steps:
       - uses: actions/checkout@v4
diff --git a/CLAUDE.md b/CLAUDE.md
new file mode 100644
index 0000000..1931f4d
--- /dev/null
+++ b/CLAUDE.md
@@ -0,0 +1,26 @@
+<!-- file generated with AI assistance: Claude Code - 2026-06-14 -->
+
+# CLAUDE.md
+
+This is a public open-source package maintained under github.com/dmstr.
+
+## Language policy
+
+**Everything in this repository is in English** — commit messages, code,
+comments, and documentation. Do not write German here, even though related
+company/customer projects (e.g. the consuming application) use German. These
+packages are public and English-only.
+
+## Testing
+
+PHPUnit (^12). Run locally with the bundled CLI-only Docker Compose
+(no host PHP required):
+
+    docker compose run --rm php
+
+This installs dependencies and runs `vendor/bin/phpunit`. The same runs in CI
+via `.github/workflows/tests.yml`.
+
+## Requirements
+
+PHP >= 8.4.
diff --git a/composer.json b/composer.json
index 2330e13..beabd04 100644
--- a/composer.json
+++ b/composer.json
@@ -20,7 +20,7 @@
         }
     ],
     "require": {
-        "php": ">=8.2",
+        "php": ">=8.4",
         "symfony/framework-bundle": "^7.0",
         "symfony/dependency-injection": "^7.0",
         "symfony/config": "^7.0",