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langchain/libs
Mason Daugherty 43880362d8 feat(standard-tests): validate tool call chunks during streaming (#34707)
As a LangChain user streaming a tool-calling model, I expect each
streamed chunk to expose structured `tool_call_chunk` content blocks so
I can render or process tool calls live, instead of waiting for the
final aggregated message.

This adds `tool_call_streaming` to `ModelProfile` and uses it in the
standard chat-model tool-calling tests. When a model profile opts in,
`test_tool_calling` and `test_tool_calling_async` now validate that at
least one streamed chunk includes a `tool_call_chunk` block via
`content_blocks`, while preserving the existing final-message
validation.

This keeps the contract profile-gated so providers can opt in once their
streaming chunk shape is verified. This PR opts in the providers
verified by smoke testing with straightforward profile coverage: OpenAI,
Anthropic, Fireworks, HuggingFace, OpenRouter, DeepSeek, and xAI. The
generated profile artifacts are refreshed so runtime profiles expose the
new capability flag.

Perplexity Responses also passed the smoke test, but its current profile
data is for the `sonar` family while the Responses smoke path used a
routed model string. That profile strategy is left as follow-up.
MistralAI currently streams `.tool_call_chunks`, but its content-block
translator exposes a complete `tool_call` block instead of
`tool_call_chunk`, so it also stays out of this flag until that
integration is fixed.
2026-06-10 22:29:02 -04:00
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LangChain Monorepo

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Important

View all LangChain integrations packages

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.