Depends FastAPI error

Why This Happens

In FastAPI, dependency injection was used incorrectly. This is one of the most common FastAPI errors developers encounter. Understanding the root cause helps you fix it quickly and prevent it from recurring.

The Problem

@app.get('/')
def read(db = get_db()):

The Fix

@app.get('/')
def read(db = Depends(get_db)):

Step-by-Step Fix

1. 1

   Identify the error

   Look at the error message: RuntimeError: Use params for depends. This tells you exactly what went wrong.

2. 2

   Find the cause

   Check the stack trace to find which line of your FastAPI code triggered this error.

3. 3

   Apply the fix

   Use the corrected code pattern shown above. Test to confirm the error is resolved.