TraceStreamEvent

type TraceStreamEvent =
  | {
  agentId: string;
  sessionId: string;
  timestamp: number;
  type: "session:start";
}
  | {
  attributes?: Record<string, unknown>;
  name: string;
  parentId?: string;
  spanId: string;
  timestamp: number;
  type: "span:start";
}
  | {
  durationMs: number;
  spanId: string;
  status: "success" | "error";
  type: "span:end";
}
  | {
  args?: unknown;
  timestamp: number;
  toolName: string;
  type: "tool:call";
}
  | {
  durationMs: number;
  success: boolean;
  toolName: string;
  type: "tool:result";
}
  | {
  from: string;
  timestamp: number;
  to: string;
  type: "flow:transition";
}
  | {
  collected: Record<string, unknown>;
  missing: string[];
  nodeId: string;
  type: "extraction:update";
}
  | {
  cacheReadTokens?: number;
  contextUtilization?: number;
  cumulativeTotalTokens: number;
  inputTokens: number;
  model?: string;
  nodeId?: string;
  outputTokens: number;
  sessionId: string;
  totalTokens: number;
  turn: number;
  type: "tokens:turn";
}
  | {
  durationMs: number;
  sessionId: string;
  success: boolean;
  type: "session:end";
};

Events streamed to Kuralle Studio (or other live trace consumers) during a session. Aligns with the studio WebSocket protocol; keep fields JSON-serializable.