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langchain/libs
Mason Daugherty 6b9e22dbbc fix(langchain): tighten structured output model fallbacks (#38042)
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- Removed outdated OpenAI test assumptions around legacy `o1` behavior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.
2026-06-10 21:18:14 -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.