micropython-aioweb

A very minimal asyncio web framework for MicroPython. Doesn't come with all the bells and whistles you might want out of a serious web framework but the goal is just to make asyncio HTTP applications in MicroPython as simple and efficient as possible.

Current features

• minimal overhead in terms of code size or memory use
• easy integration into existing asyncio projects by running as a normal task alongside others
• basic endpoint/method based routing similar to flask (currently doesn't do any pattern matching)
• parses http request line, headers, and query strings
• supports WebSockets!
• supports Server-Sent Events!

Examples

Basic "Hello world!"

import web
import uasyncio as asyncio

app = web.App(host='0.0.0.0', port=80)

# root route handler
@app.route('/')
async def handler(r, w):
    # write http headers
    w.write(b'HTTP/1.0 200 OK\r\n')
    w.write(b'Content-Type: text/html; charset=utf-8\r\n')
    w.write(b'\r\n')
    # write page body
    w.write(b'Hello world!')
    # drain stream buffer
    await w.drain()

# Start event loop and create server task
loop = asyncio.get_event_loop()
loop.create_task(app.serve())
loop.run_forever()

POST request handler

@app.route('/', methods=['POST'])
async def handler(r, w):
    body = await r.read(1024)
    form = web.parse_qs(body.decode())
    name = form.get('name', 'world')
    # write http headers
    w.write(b'HTTP/1.0 200 OK\r\n')
    w.write(b'Content-Type: text/html; charset=utf-8\r\n')
    w.write(b'\r\n')
    # write page body
    w.write(b'Hello {}!'.format(name))
    # drain stream buffer
    await w.drain()

WebSocket handler

# /ws WebSocket route handler
@app.route('/ws')
async def ws_handler(r, w):
    # upgrade connection to WebSocket
    ws = await WebSocket.upgrade(r, w)
    while True:
        evt = await ws.recv()
        if evt is None or evt['type'] == 'close':
            # handle closed stream/close event
            break
        elif evt['type'] == 'text':
            # print received messages and echo them
            print('Received:', evt['data'])
            await ws.send(evt['data'])

SSE (Server-Sent Events) handler

# /events EventSource route handler
@app.route('/events')
async def ws_handler(r, w):
    # upgrade connection to text/event-stream
    sse = await web.EventSource.upgrade(r, w)
    count = 0
    while True:
        count += 1
        try:
            await sse.send('Hello world #{}'.format(count))
        except:
            break
        await asyncio.sleep(1)