Compatibility

Package

Item	Value
Library version	0.1.0
Distribution	Not on npm. Built from source with npm run build into dist/ngx-sse-resource.
Peer dependencies	@angular/core ^22.0.0, @angular/common ^22.0.0
Runtime dependencies	none
sideEffects	false
License	MIT

The public API uses Angular signals only. The library does not import RxJS.

Toolchain in the repository

These are the versions the repository builds and tests with. They are not requirements for apps that use the package, beyond the Angular peer range.

Tool	Range in package.json	Version in package-lock.json
Angular (@angular/core)	^22.2.0	22.2.3
Angular CLI and @angular/build	^22.2.4
ng-packagr	^22.2.0
TypeScript	~6.0.2	6.0.3
Vitest	^5.0.0	5.0.5
jsdom	^30.0.0
npm (packageManager)	npm@11.20.0

Tests run with the Angular CLI unit-test builder (@angular/build:unit-test) on Vitest. The spec file has 27 tests.

Continuous integration

The GitHub Actions workflow (.github/workflows/ci.yml) runs on pushes to main and on pull requests. It uses ubuntu-latest with Node 24 and runs:

npm ci
npm run lint      # prettier --check .
npm test          # ng test ngx-sse-resource
npm run build     # builds the library into dist/ngx-sse-resource
npx ng build demo

Browser requirements

The library needs a global EventSource, or a constructor provided through the SSE_EVENT_SOURCE token. Where neither exists, the resource stays in status idle and does not throw. On the server (isPlatformServer) it also stays idle.

Known limitations

• GET only, with no custom headers. That is how EventSource works. Use cookies with withCredentials, a token in the URL, or a replacement constructor through SSE_EVENT_SOURCE.
• value() holds the last event only. Collect a history yourself, for example in parse.
• In the default backoff mode the server’s retry: value is not used, and the browser does not send Last-Event-ID. Use lastEventIdParam to resume, or reconnect: 'browser'.
• The backoff has no jitter. Clients that drop at the same moment reconnect at the same moments.
• One resource is one connection. Two resources with the same URL open two connections. Over HTTP/1.1, browsers limit open connections per origin (about six), and each open stream holds one.
• SseConnectionError carries no HTTP status or response body, because EventSource does not expose them.