---
scope: org
organization: langchain
release_count: 107
last_release: 2026-10-01
generated: 2026-04-21
updated: 2026-10-13
canonical: https://releases.sh/langchain/overview.md
---

Recently shipped mid-conversation model support in the Anthropic and OpenAI integrations, plus a broad LangGraph checkpoint-replay fix pass.

**Model integrations gained mid-conversation support.**

- `langchain-anthropic` 1.7.6 and `langchain-openai` 1.7.1 declare mid-conversation support in their model profiles, alongside a refresh of the profile data.
- `SummarizationMiddleware` now accepts a custom `summarizer`, so summarization no longer depends on the built-in model call.

**MCP adapters 2.0 is a breaking upgrade.** The adapter moved to MCP SDK 2 and serves modern and legacy MCP servers from one place, letting servers ask users for input through LangGraph interrupts. Tool names, configuration, and tool results changed: `MultiServerMCPClient` becomes `MCPAdapter`, and server maps move under `{ servers: { ... } }`. A migration guide covers the rest. A subsequent patch keeps the SSE attempt's SDK error as `cause` after a failed Streamable HTTP connection, so OAuth login handlers checking `UnauthorizedError` work against SSE-only servers.

**LangSmith's MCP server now queries runs the way the SDK does.**

- `query_runs` takes the SDK's `client.runs.query()` parameters, including typed selects for costs, token breakdowns, and full inputs/outputs with cursor pagination; `fetch_runs` is deprecated in its favor.
- Costs resolve for OpenAI models under "All models" and for the open models Vertex AI hosts: DeepSeek, Qwen, GLM, Kimi, MiniMax, and GPT-OSS.
- Public trace and thread share links now require read permission.
- LangSmith Chat offers Claude Sonnet 5.5 (Sonnet 5 stays default), takes roughly 4x more steps per turn, and completes multi-tool turns on Gemini 3.x through Vertex AI.

**Feedback ingest no longer drops runs over bad scores.** A score that violates the workspace feedback-key configuration is accepted and recorded as error feedback on the run with the rejection reason in the comment, instead of a 400 that discarded the run and every other score with it. Annotation-queue feedback is attributed by whichever identity the request resolves.

**LangGraph checkpointing got a correctness pass.**

- An empty `checkpoint_id` now resolves to the latest entry in delta history.
- Delta replay is ordered by task path, and every message written to a `messages` DeltaChannel gets an id.
- Namespace labels are validated before store dispatch, and `ToolNode` no longer swallows invalid resume values.
- Exit runs and `update_state` writes stay on the checkpoints they belong to instead of leaking into newer branches.

**Smaller items.** LangSmith sandboxes accept any JOSE asymmetric algorithm the JWKS key chooses and support customer-managed KMS keys for S3 mounts; `@langchain/core` preserves runtime context across tool calls, nested runnables, and streaming; `langgraph-sdk` percent-encodes `thread_id` and `assistant_id` in thread stream requests.