guide/content/en/index.md
.. attrs:: :class: columns is-multiline mt-6
.. attrs::
:class: column is-4
#### Simple and lightweight
Intuitive API with smart defaults and no bloat allows you to get straight to work building your app.
.. attrs::
:class: column is-4
#### Unopinionated and flexible
Build the way you want to build without letting your tooling constrain you.
.. attrs::
:class: column is-4
#### Performant and scalable
Built from the ground up with speed and scalability as a main concern. It is ready to power web applications big and small.
.. attrs::
:class: column is-4
#### Production ready
Out of the box, it comes bundled with a web server ready to power your web applications.
.. attrs::
:class: column is-4
#### Trusted by millions
Sanic is one of the overall most popular frameworks on PyPI, and the top async enabled framework
.. attrs::
:class: column is-4
#### Community driven
The project is maintained and run by the community for the community.
.. attrs:: :class: is-size-3 mt-6
**With the features and tools you'd expect.**
.. attrs:: :class: is-size-3 ml-6
**And some {span:has-text-primary:you wouldn't believe}.**
.. tab:: Production-grade
After installing, Sanic has all the tools you need for a scalable, production-grade server—out of the box!
Including [full TLS support](/en/guide/how-to/tls.md).
```python
from sanic import Sanic
from sanic.response import text
app = Sanic("MyHelloWorldApp")
@app.get("/")
async def hello_world(request):
return text("Hello, world.")
```
```sh
sanic path.to.server:app
[2023-01-31 12:34:56 +0000] [999996] [INFO] Sanic v22.12.0
[2023-01-31 12:34:56 +0000] [999996] [INFO] Goin' Fast @ http://127.0.0.1:8000
[2023-01-31 12:34:56 +0000] [999996] [INFO] mode: production, single worker
[2023-01-31 12:34:56 +0000] [999996] [INFO] server: sanic, HTTP/1.1
[2023-01-31 12:34:56 +0000] [999996] [INFO] python: 3.10.9
[2023-01-31 12:34:56 +0000] [999996] [INFO] platform: SomeOS-9.8.7
[2023-01-31 12:34:56 +0000] [999996] [INFO] packages: sanic-routing==22.8.0
[2023-01-31 12:34:56 +0000] [999997] [INFO] Starting worker [999997]
```
.. tab:: TLS server
Running Sanic with TLS enabled is as simple as passing it the file paths...
```sh
sanic path.to.server:app --cert=/path/to/bundle.crt --key=/path/to/privkey.pem
```
... or the a directory containing `fullchain.pem` and `privkey.pem`
```sh
sanic path.to.server:app --tls=/path/to/certs
```
**Even better**, while you are developing, let Sanic handle setting up local TLS certificates so you can access your site over TLS at [https://localhost:8443](https://localhost:8443)
```sh
sanic path.to.server:app --dev --auto-tls
```
.. tab:: Websockets
Up and running with websockets in no time using the [websockets](https://websockets.readthedocs.io) package.
```python
from sanic import Request, Websocket
@app.websocket("/feed")
async def feed(request: Request, ws: Websocket):
async for msg in ws:
await ws.send(msg)
```
.. tab:: Static files
Serving static files is of course intuitive and easy. Just name an endpoint and either a file or directory that should be served.
```python
app.static("/", "/path/to/index.html")
app.static("/uploads/", "/path/to/uploads/")
```
Moreover, serving a directory has two additional features: automatically serving an index, and automatically serving a file browser.
Sanic can automatically serve `index.html` (or any other named file) as an index page in a directory or its subdirectories.
```python
app.static(
"/uploads/",
"/path/to/uploads/",
index="index.html"
)
```
And/or, setup Sanic to display a file browser.
```python
app.static(
"/uploads/",
"/path/to/uploads/",
directory_view=True
)
```
.. tab:: Lifecycle
Beginning or ending a route with functionality is as simple as adding a decorator.
```python
@app.on_request
async def add_key(request):
request.ctx.foo = "bar"
@app.on_response
async def custom_banner(request, response):
response.headers["X-Foo"] = request.ctx.foo
```
Same with server events.
```python
@app.before_server_start
async def setup_db(app):
app.ctx.db_pool = await db_setup()
@app.after_server_stop
async def setup_db(app):
await app.ctx.db_pool.shutdown()
```
But, Sanic also allows you to tie into a bunch of built-in events (called signals), or create and dispatch your own.
```python
@app.signal("http.lifecycle.complete") # built-in
async def my_signal_handler(conn_info):
print("Connection has been closed")
@app.signal("something.happened.ohmy") # custom
async def my_signal_handler():
print("something happened")
await app.dispatch("something.happened.ohmy")
```
.. tab:: Smart error handling
Raising errors will intuitively result in proper HTTP errors:
```python
raise sanic.exceptions.NotFound # Automatically responds with HTTP 404
```
Or, make your own:
```python
from sanic.exceptions import SanicException
class TeapotError(SanicException):
status_code = 418
message = "Sorry, I cannot brew coffee"
raise TeapotError
```
And, when an error does happen, Sanic's beautiful DEV mode error page will help you drill down to the bug quickly.
Regardless, Sanic comes with an algorithm that attempts to respond with HTML, JSON, or text-based errors as appropriate. Don't worry, it is super easy to setup and customize your error handling to your exact needs.
.. tab:: App Inspector
Check in on your live, running applications (whether local or remote).
```sh
sanic inspect
┌─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ Sanic │
│ Inspecting @ http://localhost:6457 │
├───────────────────────┬─────────────────────────────────────────────────────────────────────────────────────────────┤
│ │ mode: production, single worker │
│ ▄███ █████ ██ │ server: unknown │
│ ██ │ python: 3.10.9 │
│ ▀███████ ███▄ │ platform: SomeOS-9.8.7
│ ██ │ packages: sanic==22.12.0, sanic-routing==22.8.0, sanic-testing==22.12.0, sanic-ext==22.12.0 │
│ ████ ████████▀ │ │
│ │ │
│ Build Fast. Run Fast. │ │
└───────────────────────┴─────────────────────────────────────────────────────────────────────────────────────────────┘
Sanic-Main
pid: 999996
Sanic-Server-0-0
server: True
state: ACKED
pid: 999997
start_at: 2023-01-31T12:34:56.00000+00:00
starts: 1
Sanic-Inspector-0
server: False
state: STARTED
pid: 999998
start_at: 2023-01-31T12:34:56.00000+00:00
starts: 1
```
And, issue commands like `reload`, `shutdown`, `scale`...
```sh
sanic inspect scale 4
```
... or even create your own!
```sh
sanic inspect migrations
```
.. tab:: Extendable
In addition to the tools that Sanic comes with, the officially supported [Sanic Extensions](./plugins/sanic-ext/getting-started.md) provides lots of extra goodies to make development easier.
- **CORS** protection
- Template rendering with **Jinja**
- **Dependency injection** into route handlers
- OpenAPI documentation with **Redoc** and/or **Swagger**
- Predefined, endpoint-specific response **serializers**
- Request query arguments and body input **validation**
- **Auto create** HEAD, OPTIONS, and TRACE endpoints
- Live **health monitor**
.. tab:: Developer Experience
Sanic is **built for building**.
From the moment it is installed, Sanic includes helpful tools to help the developer get their job done.
- **One server** - Develop locally in DEV mode on the same server that will run your PRODUCTION application
- **Auto reload** - Reload running applications every time you save a Python file, but also auto-reload **on any arbitrary directory** like HTML template directories
- **Debugging tools** - Super helpful (and beautiful) [error pages](/en/guide/best-practices/exceptions) that help you traverse the trace stack easily
- **Auto TLS** - Running a localhost website with `https` can be difficult, [Sanic makes it easy](/en/guide/how-to/tls.md)
- **Streamlined testing** - Built-in testing capabilities, making it easier for developers to create and run tests, ensuring the quality and reliability of their services
- **Modern Python** - Thoughtful use of type hints to help the developer IDE experience