# What changed in @langchain/classic

> 16 changes in @langchain/classic 0.3 to 1 from its official release notes, upgrade guides and advisories: 3 breaking, 1 security, 6 new APIs and options. Each one cited. Sources checked 2026-10-19. HTML: https://unstale.sh/npm/@langchain/classic/

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

## @langchain/classic 1

### Breaking changes

- The Fireworks provider was extracted into a standalone provider package. (1.0.28) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain/classic%401.0.28)
- A standalone Perplexity provider package was added. (1.0.28) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain/classic%401.0.28)
- Together AI was migrated into a provider package. (1.0.28) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain/classic%401.0.28)

### New APIs and options

- LangChainTracer now supports explicitly setting an agent address. (1.0.53) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain/classic%401.0.53)
- Adds the aws alias to MODEL_PROVIDER_CONFIG so hub/node can auto-detect ChatBedrockConverse from Python-serialized prompts. (1.0.25) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain/classic%401.0.25)
- Accepts an optional modelProvider parameter for direct config lookup, avoiding className collisions when multiple providers share a class name. (1.0.15) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain/classic%401.0.15)
- Adds support for Aurora Postgres DataSource. (1.0.11) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain/classic%401.0.11)
- Prompt pulling now supports secrets. (1.0.8) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain/classic%401.0.8)
- Prompt pulling now supports secretsFromEnv, allowing secrets to be supplied from environment variables. (1.0.8) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain/classic%401.0.8)

### Behavior and default changes

- Project and address destinations are inherited together, and default destination resolution is delegated to the LangSmith SDK. (1.0.53) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain/classic%401.0.53)

### Fixes and other changes

- Prevents local file corruption when using LocalFileStore. (1.0.31) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain/classic%401.0.31)
- Avoids long-lived abort signals. (1.0.14) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain/classic%401.0.14)
- Fixes handling of required fields from nested schemas. (1.0.4) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain/classic%401.0.4)

## @langchain/classic 0.3

### Security

- A fix was made for CVE-2025-12735. (0.3.58) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/0.3.58)

### Fixes and other changes

- node-gyp was added for Vercel builds. (0.3.58) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/0.3.58)
- The default temperature option for v0/anthropic was fixed. (0.3.58) — [release notes](https://github.com/langchain-ai/langchainjs/releases/tag/0.3.58)