diff --git a/container.yaml b/container.yaml
new file mode 100644
index 0000000..d4f9c71
--- /dev/null
+++ b/container.yaml
@@ -0,0 +1,60 @@
+flatpak:
+    id: org.fedoraproject.Sdk.Extension.llvm21
+    branch: f44
+    build-extension: true
+    runtime: org.fedoraproject.Sdk
+    runtime-version: f44
+    sdk: org.fedoraproject.Sdk
+    name: f44/llvm21
+    component: llvm21-flatpak
+    packages:
+    - clang21
+    - clang21-analyzer
+    - clang21-devel
+    - clang21-libs
+    - clang21-tools-extra
+    - clang21-tools-extra-devel
+    - compiler-rt21
+    - git-clang-format21
+    - libcxx
+    - libcxx-devel
+    - libcxxabi
+    - libcxxabi-devel
+    - libomp21
+    - libomp21-devel
+    - lld21
+    - lld21-devel
+    - lld21-libs
+    - lldb21
+    - lldb21-devel
+    - llvm21
+    - llvm21-cmake-utils
+    - llvm21-devel
+    - llvm21-googletest
+    - llvm21-libs
+    - llvm-libunwind
+    - llvm-libunwind-devel
+    - llvm21-test
+    - python3-clang21
+    - python3-lit
+    - python3-lldb
+    - llvm21-flatpak-config
+    # for cleanup-commands (part of runtime)
+    - coreutils-single
+    - rpm
+    - sed
+    cleanup-commands: |
+        mkdir -p /app/{bin,include,lib64,libexec,share}
+        for f in `rpm -aql clang21* compiler-rt21 git-clang-format21 libcxx* libomp21* lld21* lldb21* llvm21* llvm-libunwind* python3-{clang,lit,lldb}`; do \
+             case $f in /usr/lib/.build-id*|/app/*) continue ;; esac ; \
+             if [ ! -d $f ]; then d=$(echo $f | sed -e 's|^/usr/\(.*\)/[^/]*$|/app/\1|;s|^\(/etc/.*\)/[^/]*|/app/\1|'); mkdir -p $d; mv $f $d; fi; \
+        done
+        mv /app/lib64/llvm21/bin/* /app/bin/
+        mv /app/lib64/llvm21/include/* /app/include/
+        mv /app/lib64/llvm21/lib64/* /app/lib64/
+        mv /app/lib64/llvm21/libexec/* /app/libexec/
+        mv /app/lib64/llvm21/share/* /app/share/
+        for f in /app/bin/*-21; do if [ -L $f -a -f ${f%-21} ]; then rm $f; fi; done
+        ln -sfn ../../../liblldb.so.21.1 /app/lib64/python3.14/site-packages/lldb/_lldb.so
+        ln -sfn ../share/clang/clang-format-diff.py /app/bin/clang-format-diff
+        rm -f /app/bin/ld