title: Path Parameters and Numeric Validations
description: Add numeric validation constraints to path parameters — ge, le, gt, lt, multiple_of.
keywords: [JustAPI, path parameters, numeric validation, ge, le, gt, lt, Path]

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

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