FastAPI incompatibility

Context

I get a 500 response code when I try to deploy a simple application.

from fastapi import FastAPI

app = FastAPI()

@app.get("/")
def read_root():
    return {"Hello": "World"}

Zappa tail says [1562665728357] __call__() missing 1 required positional argument: 'send'.

When I go to the api gateway url, I see this message:

“{‘message’: ‘An uncaught exception happened while servicing this request. You can investigate this with the zappa tail command.’, ‘traceback’: [‘Traceback (most recent call last):\n’, ’ File "/var/task/handler.py", line 531, in handler\n with Response.from_app(self.wsgi_app, environ) as response:\n’, ’ File "/var/task/werkzeug/wrappers/base_response.py", line 287, in from_app\n return cls(*_run_wsgi_app(app, environ, buffered))\n’, ’ File "/var/task/werkzeug/test.py", line 1119, in run_wsgi_app\n app_rv = app(environ, start_response)\n’, ’ File "/var/task/zappa/middleware.py", line 70, in call\n response = self.application(environ, encode_response)\n’, "TypeError: call() missing 1 required positional argument: ‘send’\n"]}”

Steps to Reproduce

zappa init
zappa deploy dev
# Error: Warning! Status check on the deployed lambda failed. A GET request to '/' yielded a 500 response code.

Your Environment

• Zappa version used: 0.48.2
• Operating System and Python version: macOS Mojave | Python 3.6.5
• The output of pip freeze:

Package             Version  
------------------- ---------
aiofiles            0.4.0    
aniso8601           6.0.0    
argcomplete         1.9.3    
boto3               1.9.184  
botocore            1.12.184 
certifi             2019.6.16
cfn-flip            1.2.1    
chardet             3.0.4    
Click               7.0      
dataclasses         0.6      
dnspython           1.16.0   
docutils            0.14     
durationpy          0.5      
email-validator     1.0.4    
fastapi             0.31.0   
future              0.16.0   
graphene            2.1.6    
graphql-core        2.2      
graphql-relay       0.4.5    
h11                 0.8.1    
hjson               3.0.1    
httptools           0.0.13   
idna                2.8      
itsdangerous        1.1.0    
Jinja2              2.10.1   
jmespath            0.9.3    
kappa               0.6.0    
lambda-packages     0.20.0   
MarkupSafe          1.1.1    
pip                 19.1.1   
placebo             0.9.0    
promise             2.2.1    
pydantic            0.29     
python-dateutil     2.6.1    
python-multipart    0.0.5    
python-slugify      1.2.4    
PyYAML              5.1.1    
requests            2.22.0   
Rx                  1.6.1    
s3transfer          0.2.1    
setuptools          39.0.1   
six                 1.12.0   
starlette           0.12.0   
toml                0.10.0   
tqdm                4.19.1   
troposphere         2.4.9    
ujson               1.35     
Unidecode           1.1.1    
urllib3             1.25.3   
uvicorn             0.8.3    
uvloop              0.12.2   
websockets          7.0      
Werkzeug            0.15.4   
wheel               0.33.4   
wsgi-request-logger 0.4.6    
zappa               0.48.2

• Your zappa_settings.py:

{
    "dev": {
        "app_function": "app.main.app",
        "aws_region": "ap-northeast-2",
        "profile_name": "default",
        "project_name": "myprojectname",
        "runtime": "python3.6",
        "s3_bucket": "mybucketname"
    }
}

[danielloader]

Has anyone got a zappa deployment working with with FastAPI yet?

[delijati]

I got ASGI running on lambda with magnum here is the code https://github.com/Miserlou/Zappa/issues/649#issuecomment-491625763