All Strawberry integrations support multipart uploads as described in the
GraphQL multipart request specification.
This includes support for uploading single files as well as lists of files.

Uploads can be used in mutations via the Upload scalar.
The type passed at runtime depends on the integration:

Since these integrations use asyncio for communication, the resolver must be async.

Additionally, these servers rely on the python-multipart package, which is not included by Strawberry by default. It can be installed directly, or, for convenience, it is included in extras: strawberry[asgi] (for ASGI/Starlette) or strawberry[fastapi] (for FastAPI). For example:

• if using Pip, pip install 'strawberry[fastapi]'
• if using Poetry, strawberry = { version = "...", extras = ["fastapi"] } in pyproject.toml.

Example:

import
 typing
import
 strawberry
from




 strawberry
.
file_uploads 
import
 Upload


@strawberry
.
input
class
 
FolderInput
:
    files
:
 typing
.
List
[
Upload
]


@strawberry
.
type
class
 
Mutation
:
    
@strawberry
.
mutation
    
async
 
def
 
read_file
(
self
,
 
file
:
 Upload
)
 
-
>
 
str
:
        
return
 
(
await
 
file
.
read
(
)
)
.
decode
(
"utf-8"
)

    
@strawberry
.
mutation
    
async
 
def
 
read_files
(
self
,
 files
:
 typing
.
List
[
Upload
]
)
 
-
>
 typing
.
List
[
str
]
:
        contents 
=
 
[
]
        
for
 
file
 
in
 files
:
            content 
=
 
(
await
 
file
.
read
(
)
)
.
decode
(
"utf-8"
)
            contents
.
append
(
content
)
        
return
 contents
 
    
@strawberry
.
mutation
    
async
 
def
 
read_folder
(
self
,
 folder
:
 FolderInput
)
 
-
>
 typing
.
List
[
str
]
:
        contents 
=
 
[
]
        
for
 
file
 
in
 folder
.
files
:
            content 
=
 
(
await
 
file
.
read
(
)
)
.
decode
(
"utf-8"
)
            contents
.
append
(
content
)
        
return
 contents

Example:

import
 typing
import
 strawberry
from
 strawberry
.
file_uploads 
import
 Upload


@strawberry
.
input
class
 
FolderInput
:
    files
:
 typing
.
List
[
Upload
]


@strawberry
.
type
class
 
Mutation
:
    
@strawberry
.
mutation
    
def




 
read_file
(
self
,
 
file
:
 Upload
)
 
-
>
 
str
:
        
return
 
file
.
read
(
)
.
decode
(
"utf-8"
)

    
@strawberry
.
mutation
    
def
 
read_files
(
self
,
 files
:
 typing
.
List
[
Upload
]
)
 
-
>
 typing
.
List
[
str
]
:
        contents 
=
 
[
]
        
for
 
file
 
in
 files
:
            content 
=
 
file
.
read
(
)
.
decode
(
"utf-8"
)
            contents
.
append
(
content
)
        
return
 contents
 
    
@strawberry
.
mutation
    
def
 
read_folder
(
self
,
 folder
:
 FolderInput
)
 
-
>
 typing
.
List
[
str
]
:
        contents 
=
 
[
]
        
for
 
file
 
in
 folder
.
files
:
            contents
.
append
(
file
.
read
(
)
.
decode
(
"utf-8"
)
)
        
return
 contents

The tricky part is sending the HTTP request from the client because it must follow the GraphQL multipart request specifications mentioned above.

The multipart/form-data POST request’s data must include:

• operations key for GraphQL request with query and variables
• map key with mapping some multipart-data to exact GraphQL variable
• and other keys for multipart-data which contains binary data of files

Assuming you have your schema up and running, here there are some requests examples:

curl
 localhost:8000/graphql 
\
  
-F
 
operations
=
'{ "query": "mutation($file: Upload!){ readFile(file: $file) }", "variables": { "file": null } }'
 
\
  
-F
 
map
=
'{ "file": ["variables.file"] }'
 
\
  
-F
 
file
=
@a.txt

curl
 localhost:8000/graphql 
\
  
-F
 
operations
=
'{ "query": "mutation($files: [Upload!]!) { readFiles(files: $files) }", "variables": { "files": [null, null] } }'
 
\
  
-F
 
map
=
'{"file1": ["variables.files.0"], "file2": ["variables.files.1"]}'
 
\
  
-F
 
file1
=
@b.txt 
\
  
-F
 
file2
=
@c.txt

curl
 localhost:8000/graphql 
\
  
-F
 
operations
=
'{ "query": "mutation($folder: FolderInput!) { readFolder(folder: $folder) }", "variables": {"folder": {"files": [null, null]}} }'
 
\
  
-F
 
map
=
'{"file1": ["variables.folder.files.0"], "file2": ["variables.folder.files.1"]}'
 
\
  
-F
 
file1
=
@b.txt 
\
  
-F
 
file2
=
@c.txt

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