---
title: Queries
---

React queries in Arc provide strongly typed data-access patterns for request/response reads, paged views, and live observable streams.

This page is an overview of capabilities. Detailed behavior is documented on the dedicated pages below.

## Capabilities

| Capability | What It Covers | Learn More |
| ---------- | -------------- | ---------- |
| Arc-level configuration | Query-related `<Arc />` props for transport, headers, and stream transfer mode | [Configuration](/arc/frontend/react/queries/configuration/) |
| Core query usage | `use()` patterns, arguments, and `QueryResultWithState` | [Core Query Usage](/arc/frontend/react/queries/usage/) |
| Paging and sorting | `useWithPaging`, page/sort callbacks, and paging metadata | [Paging](/arc/frontend/react/queries/paging/) |
| Observable streams | Real-time subscriptions, transport selection, and direct mode | [Observable Queries](/arc/frontend/react/queries/observable-queries/) |
| Diagnostics | Live snapshots for cache, transport, and ownership state | [Observable Query Diagnostics](/arc/frontend/react/queries/observable-query-diagnostics/) |
| Suspense integration | `useSuspense()` with query boundaries and error boundaries | [Suspense Queries](/arc/frontend/react/queries/suspense-queries/) |
| Conditional execution | `when(condition)` patterns for safe query activation | [Conditional Queries](/arc/frontend/react/queries/conditional-queries/) |
| Change deltas | `useChangeStream()` and transfer-mode behavior | [Change Stream](/arc/frontend/react/queries/change-stream/) |
| Connection behavior | Multiplexing, connection count, and hub routing | [Observable Query Multiplexing](/arc/frontend/react/queries/observable-query-multiplexing/) |
| Instance lifecycle | Shared query instances and cache behavior | [Query Instance Caching](/arc/frontend/react/queries/query-instance-caching/) |
| Performing state | Track in-flight queries across components and ViewModels | [Query Scope](/arc/frontend/react/queries/scope/) |

## Frontend Layering

For low-level query contracts and non-React runtime behavior, see [Frontend Core Queries](/arc/frontend/core/queries/).

## Backend References

- [Backend Queries Overview](/arc/backend/queries/)
- [Controller-based Queries](/arc/backend/queries/controller-based/)
- [Model-bound Queries](/arc/backend/queries/model-bound/)
- [Query Pipeline](/arc/backend/queries/query-pipeline/)
- [Backend Proxy Generation](/arc/backend/proxy-generation/)