# Sentry JavaScript SDK Shim [](https://www.npmjs.com/package/@sentry/shim) [](https://www.npmjs.com/package/@sentry/shim) [](https://www.npmjs.com/package/@sentry/shim) A lightweight Sentry SDK shim that uses a configured client when embedded into an application. It allows library authors add support for a Sentry SDK without having to bundle the entire SDK or being dependent on a specific platform. ## Usage To use the shim, you do not have to initialize an SDK. This should be handled by the user of your library. Instead, direcly use the exported functions of `@sentry/shim` to add breadcrumbs or capture events: ```javascript import * as Sentry from '@sentry/shim'; // Add a breadcrumb for future events Sentry.addBreadcrumb({ message: 'My Breadcrumb', // ... }); // Capture exceptions, messages or manual events Sentry.captureMessage('Hello, world!'); Sentry.captureException(new Error('Good bye')); Sentry.captureEvent({ message: 'Manual', stacktrace: [ // ... ], }); ``` Note that while strictly possible, it is discouraged to interfer with the event context. If for some reason your library needs to inject context information, beware that this might override the user's context values: ```javascript // Set user information, as well as tags and further extras Sentry.setExtraContext({ battery: 0.7 }); Sentry.setTagsContext({ user_mode: 'admin' }); Sentry.setUserContext({ id: '4711' }); ```