File uploads

GQL supports file uploads with the aiohttp transport, the requests transport, the httpx transport, and the httpx async transport, using the GraphQL multipart request spec.

Single File

In order to upload a single file, you need to:

set the file as a variable value in the mutation
create a FileVar object with your file path
provide the FileVar instance to the variable_values attribute of your query
set the upload_files argument to True

from gql import client, gql, FileVar

transport = AIOHTTPTransport(url='YOUR_URL')
# Or transport = RequestsHTTPTransport(url='YOUR_URL')
# Or transport = HTTPXTransport(url='YOUR_URL')
# Or transport = HTTPXAsyncTransport(url='YOUR_URL')

client = Client(transport=transport)

query = gql('''
  mutation($file: Upload!) {
    singleUpload(file: $file) {
      id
    }
  }
''')

query.variable_values = {"file": FileVar("YOUR_FILE_PATH")}

result = client.execute(query, upload_files=True)

Setting the content-type

If you need to set a specific Content-Type attribute to a file, you can set the content_type attribute of FileVar:

# Setting the content-type to a pdf file for example
filevar = FileVar(
    "YOUR_FILE_PATH",
    content_type="application/pdf",
)

Setting the uploaded file name

To modify the uploaded filename, use the filename attribute of FileVar:

# Setting the content-type to a pdf file for example
filevar = FileVar(
    "YOUR_FILE_PATH",
    filename="filename1.txt",
)

File list

It is also possible to upload multiple files using a list.

from gql import client, gql, FileVar

transport = AIOHTTPTransport(url='YOUR_URL')
# Or transport = RequestsHTTPTransport(url='YOUR_URL')
# Or transport = HTTPXTransport(url='YOUR_URL')
# Or transport = HTTPXAsyncTransport(url='YOUR_URL')

client = Client(transport=transport)

query = gql('''
  mutation($files: [Upload!]!) {
    multipleUpload(files: $files) {
      id
    }
  }
''')

f1 = FileVar("YOUR_FILE_PATH_1")
f2 = FileVar("YOUR_FILE_PATH_2")

query.variable_values = {"files": [f1, f2]}

result = client.execute(query, upload_files=True)

Streaming

If you use the above methods to send files, then the entire contents of the files must be loaded in memory before the files are sent. If the files are not too big and you have enough RAM, it is not a problem. On another hand if you want to avoid using too much memory, then it is better to read the files and send them in small chunks so that the entire file contents don’t have to be in memory at once.

We provide methods to do that for two different uses cases:

Sending local files
Streaming downloaded files from an external URL to the GraphQL API

Note

Streaming is only supported with the aiohttp transport

Streaming local files

aiohttp allows to upload files using an asynchronous generator. See Streaming uploads on aiohttp docs.

From gql version 4.0, it is possible to activate file streaming simply by setting the streaming argument of FileVar to True

transport = AIOHTTPTransport(url='YOUR_URL')

client = Client(transport=transport)

query = gql('''
  mutation($file: Upload!) {
    singleUpload(file: $file) {
      id
    }
  }
''')

f1 = FileVar(
    file_name='YOUR_FILE_PATH',
    streaming=True,
)

query.variable_values = {"file": f1}

result = client.execute(query, upload_files=True)

Another option is to use an async generator to provide parts of the file.

You can use aiofiles to read the files in chunks and create this asynchronous generator.

async def file_sender(file_name):
    async with aiofiles.open(file_name, 'rb') as f:
        while chunk := await f.read(64*1024):
            yield chunk

f1 = FileVar(file_sender(file_name='YOUR_FILE_PATH'))
query.variable_values = {"file": f1}

result = client.execute(query, upload_files=True)

Streaming downloaded files

If the file you want to upload to the GraphQL API is not present locally and needs to be downloaded from elsewhere, then it is possible to chain the download and the upload in order to limit the amout of memory used.

Because the content attribute of an aiohttp response is a StreamReader (it provides an async iterator protocol), you can chain the download and the upload together.

In order to do that, you need to:

get the response from an aiohttp request and then get the StreamReader instance from resp.content
provide the StreamReader instance to the variable_values attribute of your query

Example:

# First request to download your file with aiohttp
async with aiohttp.ClientSession() as http_client:
    async with http_client.get('YOUR_DOWNLOAD_URL') as resp:

        # We now have a StreamReader instance in resp.content
        # and we provide it to the variable_values attribute of the query

        transport = AIOHTTPTransport(url='YOUR_GRAPHQL_URL')

        client = Client(transport=transport)

        query = gql('''
          mutation($file: Upload!) {
            singleUpload(file: $file) {
              id
            }
          }
        ''')

        query.variable_values = {"file": FileVar(resp.content)}

        result = client.execute(query, upload_files=True)