Arc

Full-stack CQRS, typed to the browser

Turn commands and queries into a full-stack CQRS application with generated TypeScript proxies that keep React in lockstep with your C#: no hand-written API client, no DTO duplication. Arc pairs naturally with Chronicle’s event sourcing, and can also run over MongoDB or EF Core when a slice is deliberately current-state only. Build your first slice → · Why Arc? →

Start here

Your first command & query

Build a backend slice end to end: a command with Handle(), the read model it writes, and the live query that serves it.

Wire up the React frontend

Consume the generated proxies from React — a typed query and a command, with the client model generated from C#.

MediatR, MVC, and Arc

Maps controllers, handlers, and DTOs onto Arc’s command/query model so the shift is short.

Explore Arc

Why Arc

The plumbing Arc removes, and why CQRS plus proxy generation keeps a full-stack app honest.

Vertical slices

Why everything for one feature — backend and frontend — lives in a single folder.

CQRS without event sourcing

Use Arc on its own over MongoDB or EF Core when you want the CQRS boundary without an event log.

Integrate with Chronicle

Add Chronicle when a slice needs events, projections, reducers, reactors, history, or aggregate roots.

Backend

Commands, queries, validation, identity, tenancy, persistence, and proxy generation.

Frontend

React integration, command forms, observable queries, and the optional MVVM approach.

Build a full-stack feature

One slice from command to React screen, with full-stack type safety throughout.

Troubleshooting

Answers to the questions that come up most when wiring Arc together.

Arc feeds Components and gives the application its CQRS boundary. In the full Cratis loop it sits on top of Chronicle through the Chronicle integration; for bounded current-state slices it can also run over MongoDB or EF Core. See Why developers choose Cratis for how the pieces fit.