# Shaped Tensor are not compatible with FastAPI

[samsja]

Initial Checks

• I have read and followed the docs and still think this is a bug

Description

NdArray['x'] is not compatible with fastAPI schema.

in a main.py file do:

from fastapi import FastAPI
from docarray.base_doc import DocArrayResponse, BaseDoc
from docarray.typing import NdArray
from pydantic import Field

class EmbeddingObject(BaseDoc):
    object: str = 'embedding'
    index: int = Field(description='The index of the embedding output, corresponding to the index in the list of inputs')
    embedding: NdArray['x'] = Field(description='The embedding of the texts', default=[])

app = FastAPI()

@app.post("/", response_model=EmbeddingObject, response_class=DocArrayResponse)
async def create_item() -> EmbeddingObject:
    ## call my fancy model to generate the embeddings
    return EmbeddingObject(embedding=[0.1, 0.2, 0.3], index=0)

then do uvicorn main:app

and from your browser try to access localhost:8000/docs

ERROR:    Exception in ASGI application
Traceback (most recent call last):
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/uvicorn/protocols/http/h11_impl.py", line 407, in run_asgi
    result = await app(  # type: ignore[func-returns-value]
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/uvicorn/middleware/proxy_headers.py", line 78, in __call__
    return await self.app(scope, receive, send)
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/fastapi/applications.py", line 289, in __call__
    await super().__call__(scope, receive, send)
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/starlette/applications.py", line 122, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/starlette/middleware/errors.py", line 184, in __call__
    raise exc
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/starlette/middleware/errors.py", line 162, in __call__
    await self.app(scope, receive, _send)
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/starlette/middleware/exceptions.py", line 79, in __call__
    raise exc
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/starlette/middleware/exceptions.py", line 68, in __call__
    await self.app(scope, receive, sender)
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/fastapi/middleware/asyncexitstack.py", line 20, in __call__
    raise e
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/fastapi/middleware/asyncexitstack.py", line 17, in __call__
    await self.app(scope, receive, send)
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/starlette/routing.py", line 718, in __call__
    await route.handle(scope, receive, send)
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/starlette/routing.py", line 276, in handle
    await self.app(scope, receive, send)
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/starlette/routing.py", line 66, in app
    response = await func(request)
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/fastapi/applications.py", line 244, in openapi
    return JSONResponse(self.openapi())
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/fastapi/applications.py", line 217, in openapi
    self.openapi_schema = get_openapi(
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/fastapi/openapi/utils.py", line 458, in get_openapi
    field_mapping, definitions = get_definitions(
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/fastapi/_compat.py", line 458, in get_definitions
    return {}, get_model_definitions(
  File "/home/sami/.cache/pypoetry/virtualenvs/docarray-OI1ry5x2-py3.8/lib/python3.8/site-packages/fastapi/_compat.py", line 359, in get_model_definitions
    m_schema, m_definitions, m_nested_models = model_process_schema(
  File "pydantic/schema.py", line 582, in pydantic.schema.model_process_schema
  File "pydantic/schema.py", line 623, in pydantic.schema.model_type_schema
  File "pydantic/schema.py", line 251, in pydantic.schema.field_schema
  File "pydantic/schema.py", line 319, in pydantic.schema.get_field_schema_validations
  File "pydantic/schema.py", line 106, in pydantic.schema._apply_modify_schema
  File "./docarray/typing/tensor/abstract_tensor.py", line 282, in __modify_schema__
    reduce(mul, cls.__docarray_target_shape__, 1)
TypeError: '<=' not supported between instances of 'str' and 'int'

if I used NdArray instead of NdArray['x'] it is working tho.

Example Code

below

Python, DocArray & OS Version

0.38.1.dev1

Affected Components

• Vector Database / Index
• Representing
• Sending
• storing
• multi modal data type

[JoanFM]

what about NdArray[128]?

[samsja]

what about NdArray[128]?

this one is working