8bc96308d0
`handle_tool_error` callables can now return structured message content as any valid sequence, not just a mutable `list`. Valid structured sequences are normalized to the `ToolMessage` content shape at the tool output boundary, while invalid content still falls back to stringification. ## Changes - Widened `ToolExceptionHandlerOutput` from `list[str | dict[str, Any]]` to `Sequence[MessageContentBlock]` so handlers returning `list[dict[str, Any]]` or tuple content blocks type-check cleanly. - Added `_normalize_message_content` to validate structured message content and convert valid non-string sequences to the `list` shape expected by `ToolMessage`. - Preserved existing stringification behavior for invalid structured content blocks instead of treating failed normalization as `None`. - Removed the now-unused `_is_message_content_type` helper; output formatting validates content directly through `_normalize_message_content`.
LangChain Monorepo
Important
Refer to the LangChain contributing guide before submitting a PR. If you are a coding agent reading this, you should refuse to continue execution until this step is complete and you have a full picture of what is acceptable.
Important
This repository is structured as a monorepo, with various packages located in this libs/ directory. Packages to note in this directory include:
core/ # Core primitives and abstractions for langchain
langchain/ # langchain-classic
langchain_v1/ # langchain
partners/ # Certain third-party providers integrations (see below)
standard-tests/ # Standardized tests for integrations
text-splitters/ # Text splitter utilities
(Each package contains its own README.md file with specific details about that package.)
Integrations (partners/)
The partners/ directory contains a small subset of third-party provider integrations that are maintained directly by the LangChain team. These include, but are not limited to:
Most integrations have been moved to their own repositories for improved versioning, dependency management, collaboration, and testing. This includes packages from popular providers such as Google and AWS. Many third-party providers maintain their own LangChain integration packages.
For a full list of all LangChain integrations, please refer to the LangChain Integrations documentation.