# What changed in langchain-classic

> 26 changes in langchain-classic 1 from its official release notes, upgrade guides and advisories: 4 breaking, 4 deprecations, 4 security, 4 new APIs and options. Each one cited. Sources checked 2026-11-09. HTML: https://unstale.sh/pypi/langchain-classic/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## langchain-classic 1

### Breaking changes

- Minimum core versions were bumped, so projects may need to use a newer langchain-core version. (1.0.5) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.5)
- BaseCrossEncoder moved to langchain-core, changing where developers obtain this API. (1.0.3) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.3)
- The prefix keyword is now keyword-only to match BaseStore. (1.0.2) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.2)
- Tigris is removed. (1.0.1) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.1)

### Security

- LangSmith SDK: Public prompt pull deserializes untrusted manifests without trust boundary warning (1.0.7) — [security advisory](https://github.com/advisories/GHSA-3644-Q5CJ-C5C7)
- Deserialization is restricted in this storage module. (1.0.6) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.6)
- The load() function is hardened against untrusted manifests. (1.0.6) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.6)
- A ReDoS vulnerability in the MRKL and ReAct action regex was patched. (1.0.2) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.2)

### Deprecations

- The hub API is deprecated. (1.0.7) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.7)
- Loads and dumps are limited; the notes do not specify the limits. (1.0.7) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.7)
- Deprecation targets now point to create_agent, changing the suggested replacement for deprecated APIs. (1.0.5) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.5)
- Deprecations were added; the notes do not specify which APIs are affected. (1.0.4) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.4)

### New APIs and options

- OpenAI support was added for automatic server-side compaction. (1.0.2) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.2)
- BaseTool gains extras support. (1.0.1) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.1)
- Anthropic support adds the effort option. (1.0.1) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.1)
- The google_genai provider is now supported in init_embeddings. (1.0.1) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.1)

### Behavior and default changes

- Supports state updates from wrap_model_call with command(s). (1.0.2) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.2)
- Improved validation changes how init_chat_model handles its inputs. (1.0.1) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.1)
- Run IDs now use uuid7. (1.0.1) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.1)

### Tooling

- Typing for Runnable.__or__ is improved. (1.0.8) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.8)

### Fixes and other changes

- Callbacks now support content block tokens. (1.0.8) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.8)
- The deprecation for hub.pull uses the langchain-classic version. (1.0.6) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.6)
- Model provider classes were updated for Azure AI Foundry. (1.0.4) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.4)
- Weights are now validated, helping catch invalid ensemble retriever configurations. (1.0.2) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.2)
- Provider prefixes are decoupled from model names when initializing chat models. (1.0.1) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.1)
- The HuggingFace backend helper logic for init_chat_model is fixed. (1.0.1) — [release notes](https://github.com/langchain-ai/langchain/releases/tag/langchain-classic%3D%3D1.0.1)