Answer · Agents & Automation
What AI models does LangChain use?
LangChain runs on Bring your own key (Any), Claude Fable 5.1 (Anthropic), Claude Opus 5.5 (Anthropic), Claude Sonnet 5.5 (Anthropic), Gemini 3.7 Flash (Google), Gemini 3.8 Flash (Google), GPT-5.6 Luna (OpenAI), GPT-5.6 Sol (OpenAI), GPT-5.6 Terra (OpenAI), GPT-6 Luna (OpenAI), GPT-6.1-Sol (OpenAI) and LLM Gateway (supports various model providers) (Provider undisclosed).
- Models used
- 12
- Primary model
- Bring your own key
- Public API
- Yes
- Last checked
- 2026-11-08
Model claims are labelled by how we know them: Bring your own key — disclosed, Claude Fable 5.1 — disclosed, Claude Opus 5.5 — disclosed, Claude Sonnet 5.5 — disclosed, Gemini 3.7 Flash — disclosed, Gemini 3.8 Flash — disclosed, GPT-5.6 Luna — disclosed, GPT-5.6 Sol — disclosed, GPT-5.6 Terra — disclosed, GPT-6 Luna — inferred, GPT-6.1-Sol — disclosed and LLM Gateway (supports various model providers) — inferred. "Disclosed" means the vendor says so in public; "inferred" means it was derived from documentation, headers or release notes.
Context window: Depends on chosen model.
Other stack signals: langchain, langgraph and langsmith.
Cite this answer
Tomorrow. “What AI models does LangChain use?” Tomorrow AI & Emerging Tech Index, AlienSquad, updated 2026-11-08. https://tomorrow.aliensquad.ai/q/what-models-does-langchain-use
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