@opentelemetry/core breaking changes

3.0.0

19 breaking changes, first published October 20, 2026.

• Removed
  Tools that preferred the esnext entry now fall back to module (ESM) or main (CJS). github.com
• Removed
  An exports map now blocks deep imports such as @opentelemetry/core/build/src/... and fails with ERR_PACKAGE_PATH_NOT_EXPORTED. Import from the package name or a listed subpath instead. github.com
• Removed
  Node.js 18 and 20 are no longer supported. Users must run Node.js 22.15.0 or later. github.com
• Removed _globalThis
  _globalThis was removed. Use globalThis directly. npmjs.com
• Removed @opentelemetry.core.package.json
  Read the package version from your own dependency metadata, or use SDK_INFO from @opentelemetry/core for the SDK version. github.com
• Removed @opentelemetry.core.platform
  The ./platform and ./platform/browser subpath exports were removed. Import from the package root instead. github.com
• Removed getTimeOrigin
  getTimeOrigin() was removed. Use performance.timeOrigin directly. npmjs.com
• Removed otperformance
  otperformance was removed. Use the global performance object directly. npmjs.com
• Removed unrefTimer
  unrefTimer(timer) was removed. Call timer.unref() directly in your own code. npmjs.com
• Behavior changed cleanAttributes
  cleanAttributes() and maybeAddAttribute() now remove undefined properties from object attribute values, so code relying on those keys being kept must change. github.com

And 9 more in this version.

Check your code

These are the changes. To see which of them reach your code, scan a public repository, or have your coding agent call check_code with your manifest or lockfile over MCP. The API reads every change in every version, not only the newest. On Team and up, a fix pull request opens for the changes that reach a connected repository. Nothing merges or deploys.