🐛 MyPy MRE — AsyncSession.get() infers type[T] instead of T

[medmoe]

Problem

MyPy incorrectly infers the return type of SQLAlchemy AsyncSession.get() as type[T] | None instead of T | None.

This breaks type narrowing after a None check.

---

Environment

• Python: 3.11
• MyPy: 1.16
• SQLAlchemy: 2.0.41
• OS: Linux

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Code

from sqlalchemy.ext.asyncio import AsyncSession

class WorkerProfile:
pass

async def test(db: AsyncSession) -> None:
worker_profile = await db.get(WorkerProfile, 1)

reveal_type(worker_profile)

if worker_profile is None:
    return

reveal_type(worker_profile)

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Observed MyPy output

First reveal_type:

type[WorkerProfile] | None

Second reveal_type (after narrowing):

type[WorkerProfile]

---

Expected MyPy output

First reveal_type:

WorkerProfile | None

Second reveal_type:

WorkerProfile

---

Impact

This makes MyPy treat ORM instances as class objects (type[T]) instead of instances (T), breaking type narrowing and downstream attribute access.

---

Notes

• Runtime behavior is correct
• worker_profile is an instance of WorkerProfile at runtime
• This only affects static type inference

[A5rocks]

This is a sqlalchemy bug unless you can minimize it to not need sqlalchemy.