Build a frontend

A frontend reaches your backend through its .axiom contract, the compiled description of every operation, type and error the backend exposes. You can build that frontend in two ways: write the UI itself in Acore, or keep your existing app and call the contract through a client SDK.

Choose a path

Diagram source

flowchart TD
  A[Backend .axiom contract] --> B{Do you already have a frontend?}
  B -->|No| C[Write the UI in .acore]
  C --> D[axiom ui build]
  D --> E[.axiomapp artifact]
  E --> F[UI host: web, Android Emulator, iOS Simulator]
  B -->|Yes| G{Which framework?}
  G -->|Browser or React| H[atmx-web or atmx-react]
  G -->|Flutter| I[axiom_flutter]
  G -->|Anything else| J[Call the HTTP API directly]
  H --> K[axiom pull generates a typed client]
  I --> K

• Acore UI. You write pages, components and styles in .acore. The compiler checks them against target capabilities and a locked backend contract, then a UI host runs the app. A UI host is the signed browser, Android Emulator or iOS Simulator shell that renders compiled Acore UI. The build output is a target-specific .axiomapp artifact.
• Client SDK. Your React, browser or Flutter code stays as it is. axiom pull copies the contract into your project and generates a typed client. A runtime inside the SDK builds requests, validates responses, applies cache policy and attaches credentials.

Physical-device certification and app-store publishing are Coming soon for both paths. See Support and availability.

What every client path needs

1. A pinned .axiom artifact and, for a Cloud release, its signature proof.
2. A target-specific client: generated SDK code or Acore UI source.
3. Runtime configuration: where to load the contract and the backend base URL.
4. Application-owned authentication, error UI, cache privacy and startup order.

The contract is portable. The lifecycle is not. A browser client uses Wasm, browser storage, CORS and cookie rules. Flutter uses a native runtime, bundled contract assets and an optional cache database path. An Acore UI app depends on its UI host version. Test every target you ship, including a release build and a contract integrity failure.

Other frameworks and languages

A framework without a first-party SDK can still call your backend over HTTP. You can keep using the .axiom artifact for review, mocks, tests and change control without routing production calls through an Axiom runtime. The artifact format alone does not imply a client bridge for another stack.

Next steps

• Build your first UI
• Acore UI reference
• App lifecycle and targets
• Client SDKs for an existing frontend