@langchain/core reached 1.0 with a reworked API

Announced

22 Oct 2025

Effective

no date announced

Version

1.0.0

Source

the vendor’s own page · last checked 7 Sept 2026

What breaks

Nothing until you bump the major. On the day you do, import paths and agent constructors move, so the build fails before the app runs.

What to do

Migrate to the 1.0 API; expect import paths and agent constructors to move.

What the vendor said

@langchain/core 1.0.0 was published to npm on 17 October 2025 and announced on 22 October 2025, the first stable major after a long 0.x series. The 0.x API surface changes substantially.