Provider-native structured output fallback detection now uses bounded model-name patterns instead of broad substring checks, reducing false positives for unrelated model IDs. The model examples and test fixtures across OpenAI/OpenRouter-facing code were refreshed around current OpenAI model families while preserving shipped defaults. ## Changes - Tightened `FALLBACK_MODELS_WITH_STRUCTURED_OUTPUT` from loose string fragments to regex patterns, with `_supports_provider_strategy` matching full model-name segments instead of arbitrary substrings. - Expanded structured-output fallback coverage for newer OpenAI, Anthropic, and xAI/Grok model families, including `gpt-5.x`, newer Claude 4/5-style names, and `grok-build`. - Reused `_attempt_infer_model_provider` in provider tool search routing so `_provider_from_model_name` follows the same provider inference behavior as `init_chat_model`. - Suppressed irrelevant provider-inference deprecation warnings during provider tool search registry lookup. - Refreshed OpenAI, Azure OpenAI, OpenRouter, core metadata, and example model references from older fixtures like `gpt-4`, `gpt-4o`, `o1`, and `o4-mini` to current test/profile models such as `gpt-5.5`, `gpt-5-nano`, and `gpt-4.1-mini`. - Removed outdated OpenAI test assumptions around legacy `o1` behavior and narrowed legacy structured-output checks to explicitly legacy model names.
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.