How to Add Both File and JSON Body in a Fastapi Post Request

How to add both file and JSON Form in a FastAPI POST request?

You should not define the Content-Type multipart/form-data header yourself. The requests library takes care of this automatically by defining the boundary. If you set this header yourself, requests will not do it and your server will not know what boundary to expect (unless you decide to also set the boundary yourself).

To work your header should be without the content-type:

    headers = {
        'Accept': 'application/json',
        secret: header_secret
    }

I need to send files and data through FastAPI. I'm trying to send requests but couldn't get it to work

You are getting Data in JSON body.

If you want to do it you should do:

@app.post("/uploadfile/")
async def create_file(
    test1: Optional[str] = Form(None),
    test2: Optional[str] = Form(None),
    test3: Optional[str] = Form(None),
    image: bytes = File(...),
):
    # Stuff here ...  

PS: [How to use pydantic model with form data]

POST request to FastAPI using Python Requests with a file and query parameters

To pass query parameters in Python requests, you should use params key instead. Hence:

response = requests.post(url='<your_url_here>', params=payload)

Additionally, there is no need to set the Content-type in the headers, as it will automatically be added, based on the parameters you pass to requests.post(). Doing so, the request will fail, as, in addition to multipart/form-data,"Content-type must include the boundary value used to delineate the parts in the post body. Not setting the Content-Type header ensures that requests sets it to the correct value" (ref). Have a look at this and this. Also, make sure that in files you use the same key name you gave in your endpoint, i.e., file. Thus, in Python requests it should look something like the below:

files = {('file', open('my_file.txt', 'rb'))}
response = requests.post(url='<your_url_here>', files=files, params=payload)

You could also find more options as to how to send additional data along with files at this answer.

How to add multiple body params with fileupload in FastAPI?

From the FastAPI discussion thread--(#657)

if you are receiving JSON data, with application/json, use normal Pydantic models.

This would be the most common way to communicate with an API.

If you are receiving a raw file, e.g. a picture or PDF file to store it in the server, then use UploadFile, it will be sent as form data (multipart/form-data).

If you need to receive some type of structured content that is not JSON but you want to validate in some way, for example, an Excel file, you would still have to upload it using UploadFile and do all the necessary validations in your code. You could use Pydantic in your own code for your validations, but there's no way for FastAPI to do it for you in that case.

So, in your case, the router should be as,

from fastapi import FastAPI, File, UploadFile, Form
app = FastAPI()

@app.post("/predict")
async def predict(
        industry: str = Form(...),
        file: UploadFile = File(...)
):
    # rest of your logic
    return {"industry": industry, "filename": file.filename}

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