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1.3.0 • Public • Published




The @theia/core extension is the main extension for all Theia-based applications, and provides the main framework for all dependent extensions. The extension provides the base APIs for all Theia-based applications, including:

  • Application APIs
  • Shell APIs
  • Base Widgets
  • Contribution Points (ex: commands, menu items, keybindings)

Theia Extension

A Theia extension is a node package declaring theiaExtensions property in package.json:

  "theiaExtensions": [{
      "frontend": "lib/myExtension/browser/myextension-frontend-module",
      "backend": "lib/myExtension/node/myextension-backend-module",
    }, {
      "frontend": "lib/myExtension2/browser/myextension2-browser-module",
      "frontendElectron": "lib/myExtension2/electron-browser/myextension2-electron-browser-module",
      "backend": "lib/myExtension2/node/myextension2-node-module",
      "backendElectron": "lib/myExtension2/electron-main/myextension2-electron-main-module"

Each extension can consist of the following modules:

  • frontend is used in the browser env and as well in the electron if frontendElectron is not provided
  • frontendElectron is used in the electron env
  • backend is used in the node env and as well in the electron env if backendElectron is not provided
  • backendElectron is used in the electron env

An extension module should have a default export of ContainerModule | Promise<ContainerModule> type.

Theia Application

A Theia application is a node package listing Theia extensions as dependencies and managed with Theia CLI.

Logging Configuration

It's possible to change the log level for the entire Theia application by passing it the --log-level={fatal,error,warn,info,debug,trace} option. For more fine-grained adjustment, it's also possible to set the log level per logger (i.e. per topic). The root logger is a special catch-all logger through which go all messages not sent through a particular logger. To change the log level of particular loggers, create a config file such as

  "defaultLevel": "info",
  "levels": {
    "terminal": "debug",
    "task": "error"

where levels contains the logger-to-log-level mapping. defaultLevel contains the log level to use for loggers not specified in levels. This file can then be specified using the --log-config option. Theia will watch that file for changes, so it's possible to change log levels at runtime by modifying this file.

It's unfortunately currently not possible to query Theia for the list of existing loggers. However, each log message specifies from which logger it comes from, which can give an idea, without having to read the code:

root INFO [nsfw-watcher: 10734] Started watching: /Users/captain.future/git/theia/CONTRIBUTING.md
^^^^ ^^^^  ^^^^^^^^^^^^^^^^^^^

Where root is the name of the logger and INFO is the log level. These are optionally followed by the name of a child process and the process ID.

Additional Information



"Theia" is a trademark of the Eclipse Foundation https://www.eclipse.org/theia


npm i @theia/core

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