What is JetBrains Tracy and how does it trace LLM calls?

Tracy is JetBrains' open-source AI observability library for Kotlin/Java. A single annotation (e.g., @TraceAI) automatically traces the full LLM call chain—inputs, outputs, latency, token consumption, and cost—integrating with APM tools like Grafana and Datadog.

What unique advantages does Tracy offer Kotlin/Java developers?

Tracy is designed for the JVM ecosystem with seamless Spring Boot and Micronaut integration. Its annotation-driven approach matches Java development conventions, making it far more suitable for JVM environments than Python-first tools like LangSmith.

Why is AI observability critical for production AI applications?

LLM calls have inherent uncertainty—same inputs may yield different outputs, costs are unpredictable, and latency fluctuates. Tracy's full-chain tracing helps teams identify anomalous outputs, optimize prompts, control costs, and satisfy enterprise security and compliance auditing.

— AI DAILY

Sources

JetBrains Blog
Kotlin Blog
InfoQ