LangSmith now offers full end-to-end OpenTelemetry support, enabling developers to standardize tracing across their stack and send traces to LangSmith's testing and observability platform. This integration provides a unified, vendor-neutral standard for instrumentation that works across different languages, frameworks, and backends, addressing the unique challenges of LLM applications' observability. With this update, users can view their entire application stack in a single, cohesive view, follow requests as they move through their microservices architecture, and connect LangSmith with existing observability tools and infrastructure through the OpenTelemetry standard. The integration unlocks several key benefits, including unified observability, distributed tracing, and interoperability, allowing developers to trace the complete execution path of their LLM applications with detailed visibility into each step along the way.