diff --git a/swash/config.ini b/swash/config.ini
index 8d6b9e0..ef13eee 100644
--- a/swash/config.ini
+++ b/swash/config.ini
@@ -13,4 +13,6 @@ psize=Psize.dat
 root=cache
 
 [swash]
+input=sws/INPUT.sws
+swashrun=/opt/swash/swash/swashrun
 out=out
diff --git a/swash/processing/swash.py b/swash/processing/swash.py
new file mode 100644
index 0000000..be20683
--- /dev/null
+++ b/swash/processing/swash.py
@@ -0,0 +1,28 @@
+import pathlib
+import subprocess
+import configparser
+import shutil
+import tempfile
+
+
+config = configparser.ConfigParser()
+config.read("config.ini")
+
+inp = pathlib.Path(config.get("swash", "input"))
+out = pathlib.Path(config.get("swash", "out"))
+
+with tempfile.TemporaryDirectory(prefix="swash_") as tmp_raw:
+    tmpdir = pathlib.Path(tmp_raw)
+
+    shutil.copy2(inp, tmpdir)
+    shutil.copytree(
+        pathlib.Path(config.get("out", "root")), tmpdir, dirs_exist_ok=True
+    )
+
+    subprocess.run(
+        (config.get("swash", "swashrun"), "-input", inp.name), cwd=tmpdir
+    )
+
+    if out.exists():
+        shutil.rmtree(out)
+    shutil.copytree(tmpdir, out)