diff --git a/container.yaml b/container.yaml
new file mode 100644
index 0000000..2004765
--- /dev/null
+++ b/container.yaml
@@ -0,0 +1,63 @@
+flatpak:
+    id: org.fedoraproject.Sdk.Extension.llvm21
+    branch: f43
+    build-extension: true
+    runtime: org.fedoraproject.Sdk
+    runtime-version: f43
+    sdk: org.fedoraproject.Sdk
+    name: f43/llvm21
+    component: llvm21-flatpak
+    packages:
+    - clang
+    - clang-analyzer
+    - clang-devel
+    - clang-libs
+    - clang-tools-extra
+    - clang-tools-extra-devel
+    - compiler-rt
+    - flang
+    - git-clang-format
+    - libcxx
+    - libcxx-devel
+    - libcxxabi
+    - libcxxabi-devel
+    - libomp
+    - libomp-devel
+    - lld
+    - lld-devel
+    - lld-libs
+    - lldb
+    - lldb-devel
+    - llvm
+    - name: llvm-bolt
+      platforms:
+          only: [aarch64, x86_64]
+    - llvm-cmake-utils
+    - llvm-devel
+    - llvm-googletest
+    - llvm-libs
+    - llvm-libunwind
+    - llvm-libunwind-devel
+    - llvm-test
+    - mlir
+    - mlir-devel
+    - polly
+    - polly-devel
+    - python3-clang
+    - python3-lit
+    - python3-lldb
+    - python3-mlir
+    - llvm21-flatpak-config
+    # for cleanup-commands (part of runtime)
+    - coreutils-single
+    - rpm
+    - sed
+    cleanup-commands: |
+        for f in `rpm -aql clang* compiler-rt flang* git-clang-format libcxx* libomp* lld* llvm* mlir* polly* python3-{clang,lit,lldb,mlir}`; 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/\/lib64/\/lib}; cp -a $f ${d/\/lib64/\/lib}; fi; \
+        done
+        ln -sfn ../lib/llvm21/bin/llvm-config /app/bin/llvm-config-21
+        ln -sfn llvm-config-21 /app/bin/llvm-config
+        ln -sfn ../share/clang/clang-format-diff.py /app/bin/clang-format-diff
+        rm -f /app/bin/ld