AI Development: Understanding the Role of Traces as Documentation

Peter Zhang
Jan 10, 2026 17:53

In AI systems, traces replace code as the primary documentation source, reshaping debugging, testing, and collaboration. Learn how this shift impacts AI development.

In the realm of artificial intelligence (AI), the traditional paradigm of software development, where code serves as the primary documentation, is undergoing a significant transformation. According to the LangChain Blog, traces, rather than code, are emerging as the new source of truth for understanding AI systems.

Code vs. Traces in AI Systems

In conventional software development, the codebase is the definitive guide to understanding the functionality and logic of an application. Developers rely on reading and analyzing code to debug, optimize, and improve software. However, in AI systems, particularly those utilizing advanced models like GPT-4, the decision-making process occurs during runtime within the model itself, not in the static code.

AI agents operate using a framework where code merely orchestrates the interactions between various tools and the AI model. The actual logic and decision-making are embedded in the model’s runtime operations, making traditional code insufficient for documenting AI behavior.

The Importance of Traces

Traces capture the sequence of actions an AI agent takes, detailing the logic and reasoning at each step. This includes which tools were utilized, the rationale behind decisions, and the timing of these actions. Thus, traces provide a comprehensive depiction of the AI’s behavior, akin to a real-time operational log.

In AI systems, understanding discrepancies between expected and actual outcomes requires analyzing these traces. For instance, if an AI agent makes an erroneous decision, reviewing the trace can reveal the underlying reasoning error, rather than a bug in the code.

Shifts in AI Development Practices

The shift from code to traces as the primary documentation source necessitates changes in several aspects of AI development:

Debugging

Debugging AI systems involves analyzing traces to pinpoint where reasoning errors occur. Unlike traditional software, where setting breakpoints in code is standard practice, AI debugging requires examining decision points within traces to understand the context and logic used by the AI.

Testing and Evaluation

Testing AI systems involves evaluating traces to ensure consistent and correct behavior. This means continuously assessing traces in production to detect quality issues or deviations from expected performance.

Performance Optimization

Optimizing AI involves analyzing traces to identify inefficient decision patterns, such as unnecessary tool calls or redundant processes. Traces provide insights into the AI’s decision-making pathways, highlighting areas for improvement.

Monitoring and Collaboration

Monitoring AI systems shifts focus from traditional uptime metrics to the quality of decisions made by the AI. Collaboration among developers and stakeholders centers around trace analysis, enabling shared insights into the AI’s logic and performance.

As AI continues to evolve, embracing traces as the primary form of documentation is crucial for effective development and maintenance. This approach ensures that the true logic and behavior of AI systems are transparent and accessible, facilitating better debugging, testing, and optimization practices.

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