Angular v20 arrives with eyes on generative AI development

Angular v20 is now available. The new version of Google’s web framework stabilizes APIs and features such as incremental hydration, promotes Zoneless (which removes ZoneJS as a dependency) to developer preview, improves debugging, and improves support for AI-powered Angular development with the introduction of an llms.txt file.

Installation instructions for the TypeScript-based framework can be found at angular.dev. Angular v20 was announced May 28.

Advancements in generative AI development in Angular v20 involve helping large language models (LLMs) to produce modern Angular code by maintaining an llms.txt file, and providing guidelines for developers who are building Angular apps with AI features. In introducing Angular v20, Minko Gechev, product and developer relations lead for Angular at Google, said some large language models still produce older Angular syntax using NgModules instead of standalone components, directives, and pipes. Resolving this situation is a multi-step process that has been started with the creation of an llms.txt file that helps LLMs discover the latest Angular documentation and code samples. Future plans call for continuing to provide code samples using the latest Angular syntax and exploring the development of system prompts that hint LLMs to use the correct APIs.

A second effort on the generative AI front the Angular team has started is providing guidelines for developers who are building APIs with AI features. The team ran multiple live streams showing how developers can leverage Genkit and Vertex AI in an Angular app. The team has open-sourced sample apps and listed some best practices on angular.dev/ai.

In Angular v20, debugging of incremental hydration and deferrable views is simplified via the ability to preview them in Angular DevTools directly. Developers can inspect a defer block and the content that it later loads. When using defer blocks with incremental hydration, developers now will see icons that indicate whether Angular has hydrated the current component.

Also in Angular v20, the Angular team has polished the developer experience with style guide updates, type checking and language service support for host bindings, support for untagged template literal expressions in templates, and template hot module replacement by default.

Other improvements in Angular v20:

The Angular CLI has experimental vitest support that has watch mode and browser testing.

Three reactivity APIs have been promoted to stable: effect, which registers an effect to be scheduled whenever the signals it reads change; linkedSignal, which creates a signal to hold a state intrinsically linked to some other state; and toSignal,  which returns a Signalthat provides synchronous reactive access to values produced by the given Observable.

Zoneless, for using Angular without ZoneJS, has been promoted to developer preview status.

An experimental resource API allows for initiating an asynchronous action when a signal changes and exposes the result of this action as a signal.

An experimental  httpResource  API  enables HTTP requests with a Signal-based reactive API.

To solidify Angular on the server, incremental hydration and route-level rendering mode configuration have been promoted to stable.

Angular 20 follows Angular 19, which arrived November 19, 2024, with a developer preview of incremental hydration.