diff --git a/README.md b/README.md
index 470f584..685a8cb 100644
--- a/README.md
+++ b/README.md
@@ -52,10 +52,11 @@ to know what they do:
 
 Run it:
 ```sh
-python -m uvicorn app:app --port 5051
+python -m anonstream
 ```
 
-This will start a webserver listening on the local host at port 5051.
+This will start a webserver listening on the local host at port 5051 (use
+`--port PORT` to override).
 
 If you go to `http://localhost:5051` in a web browser now you should see
 the site.  When you started the webserver some credentials were printed
@@ -68,6 +69,24 @@ setting up OBS Studio and a Tor onion service.  If you want to use
 different streaming software and put your stream on the Internet some
 other way, read those instructions and copy the gist.
 
+## Running
+
+Start anonstream like this:
+```sh
+python -m anonstream
+```
+The default port is 5051. Append `--help` to see options.
+
+If you want to use a different ASGI server, point it to the app factory
+at `asgi:create_app()`.  For example with `uvicorn`:
+```sh
+python -m uvicorn asgi:create_app --factory --port 5051
+```
+
+In either case you can explicitly set the location of the config file
+using the `ANONSTREAM_CONFIG` environment variable.
+
+
 ## Hacking
 
 anonstream has APIs for accessing internal state and hooking into
diff --git a/anonstream/__main__.py b/anonstream/__main__.py
new file mode 100644
index 0000000..f3801bc
--- /dev/null
+++ b/anonstream/__main__.py
@@ -0,0 +1,32 @@
+import argparse
+import os
+
+import uvicorn
+
+from anonstream import create_app
+
+formatter = lambda prog: argparse.HelpFormatter(prog, max_help_position=26)
+parser = argparse.ArgumentParser(
+    'python -m anonstream',
+    description='Start the anonstream webserver locally.',
+    formatter_class=formatter,
+)
+parser.add_argument(
+    '--config', '-c',
+    metavar='FILE',
+    default=os.environ.get('ANONSTREAM_CONFIG', 'config.toml'),
+    help=(
+        'location of config.toml '
+        '(default: $ANONSTREAM_CONFIG or ./config.toml)'
+    ),
+)
+parser.add_argument(
+    '--port', '-p',
+    type=int,
+    default=5051,
+    help='bind webserver to this port (default: 5051)',
+)
+args = parser.parse_args()
+
+app = create_app(args.config)
+uvicorn.run(app, port=args.port)
diff --git a/app.py b/app.py
deleted file mode 100644
index 45f5b90..0000000
--- a/app.py
+++ /dev/null
@@ -1,11 +0,0 @@
-# SPDX-FileCopyrightText: 2022 n9k <https://git.076.ne.jp/ninya9k>
-# SPDX-License-Identifier: AGPL-3.0-or-later
-
-import os
-import anonstream
-
-config_file = os.path.join(os.path.dirname(__file__), 'config.toml')
-app = anonstream.create_app(config_file)
-
-if __name__ == '__main__':
-    app.run(port=5051, debug=True)
diff --git a/asgi.py b/asgi.py
new file mode 100644
index 0000000..4034f64
--- /dev/null
+++ b/asgi.py
@@ -0,0 +1,23 @@
+# SPDX-FileCopyrightText: 2022 n9k <https://git.076.ne.jp/ninya9k>
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+if __name__ == '__main__':
+    import sys
+    message = (
+        'To start anonstream, run one of:\n'
+        ' $ python -m anonstream\n'
+        ' $ python -m uvicorn asgi:create_app --factory --port 5051\n'
+    )
+    print(message, file=sys.stderr, end='')
+    exit(1)
+
+import os
+import anonstream
+
+config = os.environ.get(
+    'ANONSTREAM_CONFIG',
+    os.path.join(os.path.dirname(__file__), 'config.toml'),
+)
+
+def create_app():
+    return anonstream.create_app(config)