diff --git a/.gitignore b/.gitignore
index 3eb56cb..85254da 100644
--- a/.gitignore
+++ b/.gitignore
@@ -150,3 +150,4 @@ cython_debug/
 #  and can be added to the global gitignore or merged into this file.  For a more nuclear
 #  option (not recommended) you can uncomment the following to ignore the entire idea folder.
 .idea/
+data/
diff --git a/api.py b/api.py
new file mode 100644
index 0000000..52e1be5
--- /dev/null
+++ b/api.py
@@ -0,0 +1,90 @@
+import json
+from pathlib import Path
+
+import uvicorn
+from fastapi import FastAPI, Body
+from starlette.responses import RedirectResponse, HTMLResponse
+
+app = FastAPI()
+
+
+links = {}
+last_id = 0
+
+data_path = Path('data')
+links_path = data_path / 'short-links.json'
+last_id_path = data_path / 'last_id.txt'
+
+# Removed lower l
+chars = 'abcdefghijkmnopqrstuvwxyz'
+base = len(chars)
+
+
+def store():
+    data_path.mkdir(parents=True, exist_ok=True)
+    links_path.write_text(json.dumps(links))
+    last_id_path.write_text(str(last_id))
+
+
+def load():
+    global links
+    global last_id
+    links = json.loads(links_path.read_text()) if links_path.is_file() else {}
+    last_id = int(last_id_path.read_text()) if last_id_path.is_file() else 0
+
+
+def encode(plain: int) -> str:
+    cipher = ''
+    while plain != 0:
+        digit = int(plain % base)
+        cipher += chars[digit]
+        plain = (plain - digit) // base
+    return cipher
+
+
+def decode(s: str) -> int:
+    total = 0
+    for i, token in enumerate(s):
+        digit = chars.index(token)
+        assert digit != -1, f'Unknown char: {token}'
+        total += digit * int(base ** i)
+    return total
+
+
+@app.get('/{short}')
+def expand(short: str):
+    print(short)
+    print(links)
+    if short in links:
+        return RedirectResponse(links[short])
+    else:
+        return HTMLResponse('404', status_code=404)
+
+
+@app.get('/')
+def get():
+    return "TODO"
+
+
+@app.put('/')
+def put(name: str | None = None, body: str = Body()):
+    global last_id
+
+    # Generate name
+    while not name:
+        last_id += 1
+        name = encode(last_id)
+        if name in links:
+            name = None
+
+    # Put name
+    links[name] = body
+    store()
+
+    return f'/{name}'
+
+
+if __name__ == '__main__':
+    load()
+    uvicorn.run(app)
+