LangChain Unveils Polly: AI Agent Engineer to Enhance Debugging

Peter Zhang
Dec 10, 2025 18:44

LangChain introduces Polly, an AI assistant in LangSmith to aid in debugging and improving agent performance, providing advanced analysis and prompt engineering capabilities.

LangChain has announced the launch of Polly, an AI-powered assistant designed to optimize the debugging and development process for agents within its LangSmith platform. This innovative tool aims to streamline the troubleshooting of complex agent architectures, according to the LangChain Blog.

The Need for AI in Agent Debugging

Agents developed on LangSmith have often faced challenges due to their intricate nature, such as extended prompts and multistep processes that can be difficult to manage manually. Polly addresses these issues by offering a sophisticated analysis of agent executions, which helps developers identify inefficiencies and errors that might otherwise go unnoticed.

LangChain’s experience with thousands of developers has highlighted common obstacles in debugging agents, especially when dealing with lengthy system prompts and comprehensive traces. Polly’s introduction promises to alleviate these concerns by providing a detailed breakdown of agent behaviors and offering solutions in natural language.

Features and Capabilities of Polly

Polly is equipped to debug individual traces, analyze entire conversations, and enhance prompt engineering. In the Trace view, Polly can dissect single agent executions, enabling developers to understand the nuances of agent actions and pinpoint inefficiencies or mistakes.

Moreover, Polly’s ability to analyze entire conversations allows for a comprehensive review of an agent’s performance over time. This feature is particularly useful for identifying patterns and changes in behavior that might impact the agent’s effectiveness.

Polly also excels in prompt engineering by allowing users to describe desired behaviors in natural language, which Polly then translates into optimized prompts. This capability eliminates the need for manual adjustments, making it easier to maintain and improve agent instructions without compromising their functionality.

Integration with LangSmith

Polly’s functionality is enhanced by LangSmith’s robust tracing infrastructure, which captures detailed data on agent runs, traces, and threads. This infrastructure is essential for Polly to perform its analyses and provide actionable insights. Setting up tracing in LangSmith is a straightforward process, enabling users to quickly leverage Polly’s capabilities.

LangChain continues to innovate in the field of agent engineering, and Polly represents a significant advancement in the tools available to developers. As the platform evolves, Polly’s role in optimizing and refining agent performance is expected to expand further.

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