# LangSmith LLM Gateway

Long-running agents previously made every context-management decision with a general-purpose LLM, which is slow and expensive at the volume such agents need. ScaleDown's constrained decoding models (CDMs) are trained for one task and only return answers that task allows, so they can be smaller, faster and cheaper; a new LangChain and Deep Agents integration ships three middlewares for summarization, tool-result compression and structured extraction, and the LangSmith LLM Gateway now lists ScaleDown as a direct model provider so calls are traced and count toward spend and rate limits. ScaleDown reports its models are 200x faster and 467x cheaper than frontier models on these narrow tasks.

Long-running agents previously made every context-management decision with a general-purpose LLM, which is slow and expensive at the volume such agents need. ScaleDown's constrained decoding models (CDMs) are trained for one task and only return answers that task allows, so they can be smaller, faster and cheaper; a new LangChain and Deep Agents integration ships three middlewares for summarization, tool-result compression and structured extraction, and the LangSmith LLM Gateway now lists ScaleDown as a direct model provider so calls are traced and count toward spend and rate limits. ScaleDown reports its models are 200x faster and 467x cheaper than frontier models on these narrow tasks.