diff --git a/requirements.txt b/requirements.txt
index d7d8990..dbed088 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,7 +2,9 @@
 # This file is autogenerated by pip-compile with Python 3.11
 # by the following command:
 #
+
 #    pip-compile --output-file=requirements.txt requirements.in
+
 #
 annotated-types==0.7.0
     # via pydantic
diff --git a/src/ssoss/api.py b/src/ssoss/api.py
new file mode 100644
index 0000000..0a377f6
--- /dev/null
+++ b/src/ssoss/api.py
@@ -0,0 +1,37 @@
+from fastapi import FastAPI, UploadFile, File, HTTPException
+from pathlib import Path
+import shutil
+
+app = FastAPI()
+
+UPLOAD_DIR = Path("uploads")
+UPLOAD_DIR.mkdir(parents=True, exist_ok=True)
+
+
+def _save_upload(upload: UploadFile, allowed_exts: set[str]):
+    ext = Path(upload.filename).suffix.lower()
+    if ext not in allowed_exts:
+        raise HTTPException(status_code=400, detail="Invalid file type")
+    dest = UPLOAD_DIR / upload.filename
+    with dest.open("wb") as buffer:
+        shutil.copyfileobj(upload.file, buffer)
+    return {"filename": upload.filename}
+
+
+@app.post("/upload/csv")
+async def upload_csv(file: UploadFile = File(...)):
+    """Accept a CSV file upload."""
+    return _save_upload(file, {".csv"})
+
+
+@app.post("/upload/gpx")
+async def upload_gpx(file: UploadFile = File(...)):
+    """Accept a GPX file upload."""
+    return _save_upload(file, {".gpx"})
+
+
+@app.post("/upload/video")
+async def upload_video(file: UploadFile = File(...)):
+    """Accept a video file upload."""
+    # Accept a few common video extensions
+    return _save_upload(file, {".mp4", ".mov", ".avi", ".mkv"})