Create a new event

Create a new event (span) within a session trace. The request body wraps the event in a JSON-encoded string under the event key. Required properties within the JSON-encoded event string:

• event_type (string) — Must be one of: chain, model, tool, session.
• inputs (object) — Input data for the event. Auto-generated properties (provided by the server when omitted):
• event_id (string, UUID) — Unique identifier for the event.
• session_id (string, UUID) — Session/trace identifier.
• parent_id (string, UUID) — Parent event ID. Defaults to session_id. Optional properties with defaults:
• event_name (string) — Name of the event. Defaults to "unknown".
• source (string) — Source of the event (e.g. sdk-python). Defaults to "unknown". Optional properties:
• config (object) — Configuration data (e.g. model parameters, prompt templates).
• outputs (object) — Output data from the event.
• error (string or null) — Error message if the event failed.
• children_ids (array of strings) — IDs of child events.
• duration (number) — Duration of the event in milliseconds.
• start_time (number) — Unix timestamp in milliseconds for event start.
• end_time (number) — Unix timestamp in milliseconds for event end.
• metadata (object) — Additional metadata (e.g. token counts, cost).
• metrics (object) — Custom metrics.
• feedback (object) — Feedback data (e.g. ratings, ground truth).
• user_properties (object) — User properties associated with the event.