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Langfuse

Log LLM traces, spans, generations, and scores to Langfuse, or query traces, prompts, datasets, sessions, and more via the Public API.

Actions28

Ingestion → Trace Create

AI-generated

Summary

Create a new trace record in Langfuse with optional detailed metadata to track and group related events, spans, and scores in a session-based structure.

Inputs

  • Name (required) — Human-readable name for the new trace.
  • Show Advanced Fields — Toggle to reveal additional optional fields for more detailed trace metadata.
  • Trace ID — Optional unique identifier for the trace; if left blank, a new trace ID is autogenerated.
  • Event ID — Optional identifier for event idempotency and deduplication.
  • Timestamp — Optional ISO 8601 timestamp indicating the trace start time; defaults to current time if omitted.
  • User ID — Optional user identifier associated with this trace.
  • Session ID — Optional session identifier for grouping several traces; defaults to the trace ID if not specified.
  • Public — Flag to mark the trace as public in Langfuse.
  • Tags — Comma-separated or JSON array of tags to classify the trace.
  • Environment — Optional environment label for the trace (e.g., production, staging).
  • Input JSON — Optional JSON string with input payload data for the trace.
  • Output JSON — Optional JSON string with output payload data for the trace.
  • Metadata JSON — Optional additional JSON metadata stored with the trace.
  • Version — Optional version string to denote the trace's version.
  • Fail On Batch Errors — Flag to fail the workflow item if Langfuse ingestion returns partial errors.

Output shape

a single record containing at least the created trace's ID and metadata

The trace ID is returned and can be used for attaching subsequent spans or events; if the Trace ID input is left blank, the node supplies an autogenerated trace ID. Partial ingestion errors trigger failures only if 'Fail On Batch Errors' is set to true.

Examples

Example 1: Create a basic trace

Provide a name for the trace; all other fields are optional.

Example 2: Create a trace with detailed metadata

Enable 'Show Advanced Fields' and supply custom Trace ID, User ID, Tags, Environment, Input/Output JSON payloads, and set the trace as public.

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