add-route-constraint

Create and register custom ASP.NET Core route constraints for string path parameters.

230|29|Updated Dec 25, 2025

Search Tags:#routing #validation #asp.net core #web api #constraint

Ready to run

npx skills add https://github.com/fpindej/netrock --skill add-route-constraint

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: add-route-constraint
Source: https://github.com/fpindej/netrock/tree/main/.claude/skills/add-route-constraint
Command: npx skills add https://github.com/fpindej/netrock --skill add-route-constraint

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This Skill automates the creation and registration of custom route constraints in ASP.NET Core, ensuring that specific URL path parameters meet defined validation criteria directly at the routing layer, preventing invalid requests from reaching controllers.

Core Features & Use Cases

Custom Validation: Define regex patterns to validate string path parameters.
Automatic 404 Responses: Invalid routes automatically return a 404 status code.
Use Case: Ensure that an id parameter in a URL like /api/users/{id} only contains alphanumeric characters and periods, up to 100 characters long.

Quick Start

Add a route constraint named 'myConstraint' that validates string parameters using a regex pattern.

Frequently Asked Questions about add-route-constraint

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I validate URL path parameters in ASP.NET Core Web API?▼

You can validate URL path parameters in ASP.NET Core by creating a custom route constraint class that implements the IRouteConstraint interface and registering it within the routing options in Program.cs.

How do I automatically return a 404 response for invalid URL routes?▼

Adding a custom route constraint automatically returns a 404 status code for invalid routes by validating string path parameters at the routing layer, preventing invalid requests from ever reaching your controllers.

Can I use regex patterns to validate specific string parameters in ASP.NET Core routing?▼

Yes, you can use regex patterns for custom validation of string path parameters by defining the pattern within a custom route constraint and applying it to route definitions using the constraint map.

What is the best way to ensure an id parameter only contains alphanumeric characters in ASP.NET Core?▼

The best way to ensure an id parameter contains only alphanumeric characters is to apply a custom route constraint at the routing layer, which automatically rejects non-matching requests with a 404 status code.

Do I need to modify Program.cs to register a custom route constraint in ASP.NET Core?▼

Yes, registering a custom route constraint in ASP.NET Core requires modifying Program.cs to add the constraint implementation into the routing options before applying it to your route definitions.