Distillation

Date: Sep 15, 2026

• 🟡 (13:22) Tool displayed a TypeScript session-event module that exports SessionEvent, imports Effect Schema, and defines shared event fields timestamp: DateTimeUtcFromMillis and sessionID: SessionID.
• 🟡 (13:22) The module defines Source with start: NonNegativeInt, end: NonNegativeInt, and text: Schema.String, annotated with identifier "session.next.event.source".
• 🟡 (13:22) Durable session events use aggregate: "sessionID" and version: 1 through options; step-settlement events use aggregate: "sessionID" and version: 2 through stepSettlementOptions.
• 🟡 (13:22) Visible event definitions include AgentSwitched ("session.next.agent.switched", with messageID and agent), Moved ("session.next.moved", with location and optional subdirectory), PromptAdmitted ("session.next.prompt.admitted", using PromptFields), and ContextUpdated ("session.next.context.updated", with messageID and text).
• 🟡 (13:22) Visible streaming event namespaces include Shell, Step, Text, Reasoning, Tool, and Compaction. Text.Delta, Reasoning.Delta, and Tool.Input.Delta are live-only stream fragments; comments identify Text.Ended, Reasoning.Ended, and Tool.Input.Ended as replayable full/raw-value boundaries.
• 🟡 (13:22) Tool.Called records tool, an input string-keyed record, and provider execution state with optional ProviderMetadata; Tool.Success records structured, content: Schema.Array(ToolContent), optional outputPaths, optional result, and the same provider execution metadata.
• 🟡 (13:22) Compaction.Started defines event type "session.next.compaction.started" with messageID and reason restricted to "auto" or "manual"; Compaction.Delta defines "session.next.compaction.delta" with messageID and streamed text.