main.py

import typing
import strawberry
from strawberry.asgi import GraphQL
from fastapi import FastAPI
import uvicorn


# Pydantic types
@strawberry.type
class ImbeddedPerson:
    id: int
    first_name: str
    last_name: str


@strawberry.type
class Person(ImbeddedPerson):
    person: ImbeddedPerson


# Data set
def get_person():
    return [
        Person(
            person=ImbeddedPerson(
                id=1,
                first_name='John',
                last_name='Doe'
            )
        )
    ]


# Define Query
@strawberry.type
class Query:
    people: typing.List[Person] = strawberry.field(resolver=get_person)


# Instantiate schema
schema = strawberry.Schema(query=Query)

# Create REST api
fastapi_app = FastAPI()


# Default route
@fastapi_app.get("/")
def root_route():
    return {'GraphQLRoute': 'localhost:8000/graphql/'}


# create graphql (strawberry flavor -- see what I did there?) app
gql_qpp = GraphQL(schema)

# pass GraphQL app to it's dedicated route
fastapi_app.add_route('/graphql/', gql_qpp)

if __name__ == '__main__':
    uvicorn.run(fastapi_app, host="localhost", port=8000)

If I try to run the query:

{
  people {
    id
  }
}

I get back:

{
  "data": null,
  "errors": [
    {
      "message": "__init__() missing 3 required positional arguments: 'id', 'first_name', and 'last_name'",
      "locations": [
        {
          "line": 33,
          "column": 3
        }
      ],
      "path": [
        "people"
      ]
    }
  ]
}

Not sure what is going wrong