langchain-ai/langchainjs langchain@1.2.34

on GitHub

Patch Changes

• #10443 ff6822e Thanks @christian-bromann! - fix(langchain): respect version:"v1" in afterModel router's pending tool call path

• #10446 888224c Thanks @hntrl! - fix(agents): propagate store and configurable to ToolNode middleware runtime

• #10444 82d56cb Thanks @christian-bromann! - fix(langchain/agents): dispatch tool calls via Send in afterModel router for version:"v2"

  Breaking change for version: "v2" + afterModel middleware users.

  Previously, when afterModel middleware was present, createAgent always routed all tool calls from an AIMessage to a single ToolNode invocation — regardless of the version option. This meant version: "v2" silently behaved like version: "v1" (parallel via Promise.all in one node) whenever afterModel middleware was used.

  #createAfterModelRouter now correctly respects #toolBehaviorVersion:

  • version: "v1" — routes the full AIMessage to a single ToolNode invocation; all tool calls run concurrently via Promise.all (unchanged behaviour).
  • version: "v2" — dispatches each tool call as a separate Send task, matching the behaviour of #createModelRouter when no afterModel middleware is present, and matching Python LangGraph's post_model_hook_router.

  Migration: If you use version: "v2" (the default) together with afterModel middleware and rely on the previous single-node parallel execution, switch to version: "v1" to preserve that behaviour. See the version JSDoc on CreateAgentParams for guidance on which option to choose.