[BUG] PUT /profile endpoint bypasses username uniqueness validation and returns IntegrityError

[sujitha-kotyada]

Description of the Bug

The PUT /profile endpoint updates user profile information without validating username uniqueness before committing changes to the database.

When a user attempts to change their username to one that already exists, the database unique constraint is triggered during commit, resulting in an unhandled IntegrityError and a 500 Internal Server Error.

This exposes a database-level failure to the client instead of returning a proper validation error.

As a result, profile updates can fail unexpectedly and produce inconsistent API behavior compared to other user-management endpoints that perform uniqueness checks before updating records.

Steps to Reproduce

1. Create two user accounts:

   • User A with username alice
   • User B with username bob

2. Authenticate as User B.

3. Send a PUT request to:

/api/v1/profile

4. Update the username to:

alice

5. Submit the request.

6. Observe the API response and backend logs.

Expected Behavior

The endpoint should validate username uniqueness before committing changes.

If the requested username already exists, the API should return a user-friendly validation error such as:

HTTP 400 Bad Request

or

HTTP 409 Conflict

with an appropriate error message indicating that the username is already in use.

Screenshots / Logs

No response

Environment

OS: Windows 11 Browser: Google Chrome Backend: FastAPI Database: SQLite/PostgreSQL Python: 3.11

GSSoC '26

• Yes, I am participating in GirlScript Summer of Code and would like to fix this.

[github-actions]

Hi @sujitha-kotyada! 👋

Thanks for opening this issue! We are thrilled to have you contribute to PDF-Assistant-RAG for GSSoC 2026.

📌 Before you start:

• Make sure you have read our Contributing Guidelines.
• Wait for a project admin to assign this issue to you before working on it.
• Remember to branch off dev and not main.

Happy Coding! 🚀