---
title: Validation
---

Core validation in Arc provides shared TypeScript/JavaScript primitives and generated rules that run before command and query requests.

This page is an overview of validation capabilities. Use the pages below for specific implementation details.

## Capabilities

| Capability | What It Covers | Learn More |
| ---------- | -------------- | ---------- |
| Fluent rules API | Programmatic rule definition, built-in rules, and custom messages | [Rules And Fluent API](/arc/frontend/core/validation/rules/) |
| Command/query integration | Automatic pre-flight validation behavior for commands and queries | [Command And Query Integration](/arc/frontend/core/validation/integration/) |
| Validation payloads | Result shape, severities, and diagnostics | [Validation Results](/arc/frontend/core/validation/results/) |
| Severity-based execution gating | Warning/information filtering and confirmation flows | [Severity Filtering](/arc/frontend/core/validation/severity-filtering/) |

## Related Topics

- [Core Commands](/arc/frontend/core/commands/)
- [Core Queries](/arc/frontend/core/queries/)
- [Backend Command Validation](/arc/backend/commands/validation/)
- [Backend Query Validation](/arc/backend/queries/validation/)
- [Proxy Generation Validation](/arc/backend/proxy-generation/validation/)