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Spans

A Span represents a single operation within an execution flow, recording input-output data, execution time, and errors. Each span provides insight into specific steps such as:
  • LLM Calls – Capturing model invocation, prompt processing, and response generation.
  • Retrieval Operations – Logging queries made to external databases or indexes.
  • Tool Executions – Tracking API calls and function invocations.
  • Error Handling – Recording failures, timeouts, and system issues.
Spans provide fine-grained visibility into each operation, allowing teams to identify where delays, errors, or inefficiencies originate.

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Traces

A Trace connects multiple spans to represent the full execution flow of a request. It provides a structured view of how different operations interact within an LLM-powered system. Traces help teams:
  • Analyze dependencies between retrieval, inference, and tool execution.
  • Identify performance bottlenecks by measuring latency across spans.
  • Debug unexpected behaviors by tracing execution paths from input to output.
For instance, a trace for an AI-driven search system may include:
  1. A retrieval span fetching relevant documents.
  2. An LLM span generating a response.
  3. A tool execution span calling an external API.
By correlating these spans within a trace, teams can reconstruct the entire request flow, making it easier to analyze system behavior and optimize workflows.

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Projects

A Project provides a structured way to manage multiple traces, ensuring observability is organized across different applications, use cases, or deployments. Projects allow teams to:
  • Segment and categorize observability data for different LLM-powered applications.
  • Compare model versions to track improvements in accuracy and performance.
  • Filter and analyze execution trends across multiple traces.
For example, an organization might maintain separate projects for:
  • Customer Support AI – Handling traces related to automated support queries.
  • Content Generation AI – Managing traces for LLM-powered writing assistants.
  • Legal AI Assistant – Tracking execution flows for contract analysis tasks.
By structuring observability in this way, teams can effectively monitor, compare, and optimize LLM-powered applications at scale.