Path Parameters and Numeric Validations

Using Path() for Validation

Use Path() to add numeric constraints:

from justapi import JustAPIApp, Path

app = JustAPIApp()

@app.get("/items/{item_id}")
def get_item(item_id: int = Path(..., ge=1)):
    return {"item_id": item_id}

The ge=1 constraint means item_id must be >= 1. Sending /items/0 returns a validation error.

Validation Options

Parameter	Type	Description
`ge`	`int/float`	Greater than or equal
`le`	`int/float`	Less than or equal
`gt`	`int/float`	Greater than
`lt`	`int/float`	Less than
`multiple_of`	`int/float`	Must be a multiple of this value

Examples

@app.get("/users/{user_id}")
def get_user(user_id: int = Path(..., gt=0)):
    """user_id must be positive"""
    return {"user_id": user_id}

@app.get("/products/{price}")
def get_product(price: float = Path(..., ge=0.01, le=9999.99)):
    """price between 0.01 and 9999.99"""
    return {"price": price}

@app.get("/grid/{position}")
def get_position(position: int = Path(..., multiple_of=10)):
    """position must be a multiple of 10"""
    return {"position": position}

Combining with Type Conversion

@app.get("/items/{item_id}")
def get_item(
    item_id: int = Path(..., ge=1, description="Item ID, must be >= 1"),
):
    return {"item_id": item_id}

The docs will show the constraint alongside the type.

See Also

Path Parameters — basic path params
Query Parameters & String Validations — string constraints
Schema & Validation — validation reference