Skip to content

chore(langchain): bump langgraph to 1.2.4 - #37857

Merged
Nick Hollon (nick-hollon-lc) merged 1 commit into
masterfrom
nh/bump-langgraph-1.2.4
Jun 2, 2026
Merged

chore(langchain): bump langgraph to 1.2.4#37857
Nick Hollon (nick-hollon-lc) merged 1 commit into
masterfrom
nh/bump-langgraph-1.2.4

Conversation

@nick-hollon-lc

@nick-hollon-lc Nick Hollon (nick-hollon-lc) commented Jun 2, 2026

Copy link
Copy Markdown
Contributor
  • Raises the minimum langgraph requirement from >=1.2.2 to >=1.2.4
  • Re-resolves the lockfile off the now-yanked 1.2.3 onto 1.2.4
  • Migrates SubagentTransformer to the 1.2.4 stream-transformer contract

langgraph 1.2.3 was yanked ("unintended merging strategy regression"), and 1.2.4 changes how the base _TasksLifecycleBase hands the triggering cause to its _on_started hook: it no longer passes cause as a keyword argument and instead exposes it via the _pending_cause instance attribute, so overrides predating cause keep working. Our _on_started override still declared a cause keyword and therefore silently received None, dropping the originating tool-call cause on every run.subagents handle. It now reads _pending_cause. The existing test_subagent_transformer regression tests cover the restored behavior.
@nick-hollon-lc
chore(langchain): bump langgraph to 1.2.4
2f015d9 
Move the `langgraph` lower bound to `>=1.2.4` (the lockfile previously
resolved to the now-yanked 1.2.3) and migrate `SubagentTransformer` to the
1.2.4 stream-transformer contract.

In 1.2.4, langgraph's base `_TasksLifecycleBase` stopped passing the
triggering `cause` to `_on_started` as a keyword argument and instead exposes
it via the `self._pending_cause` instance attribute, so overrides predating
`cause` keep working. Our `_on_started` override still declared `*, cause=None`
and therefore silently received `None`, dropping the originating tool-call
`cause` on every `run.subagents` handle. Read `self._pending_cause` instead and
drop the stale kwarg to match the new base signature.
@github-actions github-actions Bot added dependencies Pull requests that update a dependency file (e.g. `pyproject.toml` or `uv.lock`) infra PRs made that include chores, devops, repo meta changes internal langchain `langchain` package issues & PRs size: XS < 50 LOC labels Jun 2, 2026
@nick-hollon-lc
Nick Hollon (nick-hollon-lc) merged commit eb1f731 into master Jun 2, 2026
76 of 79 checks passed
@nick-hollon-lc
Nick Hollon (nick-hollon-lc) deleted the nh/bump-langgraph-1.2.4 branch June 2, 2026 17:36
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

dependencies Pull requests that update a dependency file (e.g. `pyproject.toml` or `uv.lock`) infra PRs made that include chores, devops, repo meta changes internal langchain `langchain` package issues & PRs size: XS < 50 LOC

2 participants

@nick-hollon-lc @sydney-runkle