ae1c9418b5
Closes #38220 --- Users calling `create_agent(..., response_format=<schema>)` with an OpenAI model pinned to a dated snapshot (e.g. `gpt-5.4-2026-03-05`) were silently downgraded from native structured output (`ProviderStrategy`) to tool-calling (`ToolStrategy`). This changes runtime behavior: extra tool-call traces, different token usage, and no provider-side schema enforcement. The cause is in `_supports_provider_strategy`'s fallback patterns: the `gpt-5.2` and `gpt-5.4` base patterns terminated with `($|[/:])`, which — unlike their sibling families — rejected a trailing `-`, so OpenAI's `-YYYY-MM-DD` dated-snapshot suffix matched none of the patterns. The base patterns were deliberately strict to keep `gpt-5.2-pro`/`gpt-5.4-pro` blocked, so rather than allowing any trailing `-` (which would re-admit those `-pro` variants) this change adds an optional dated-snapshot group `(-\d{4}-\d{2}-\d{2})?`. Dated snapshots now resolve to `ProviderStrategy` while `-pro` variants stay blocked. Made by [Open SWE](https://openswe.vercel.app/agents/c5ebcb29-8ce5-dda0-73f6-198e49f0c36c) Co-authored-by: open-swe[bot] <open-swe@users.noreply.github.com>
🦜️🔗 LangChain
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Quick Install
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🤔 What is this?
LangChain is the easiest way to start building agents and applications powered by LLMs. With under 10 lines of code, you can connect to OpenAI, Anthropic, Google, and more. LangChain provides a pre-built agent architecture and model integrations to help you get started quickly and seamlessly incorporate LLMs into your agents and applications.
We recommend you use LangChain if you want to quickly build agents and autonomous applications. Use LangGraph, our low-level agent orchestration framework and runtime, when you have more advanced needs that require a combination of deterministic and agentic workflows, heavy customization, and carefully controlled latency.
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Resources
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