Distillation

Date: Sep 16, 2026

• 🟡 (14:07) Responses stream validation code tracks authoritative content-part values and rejects invalid deltas with throw new Error(\invalid Responses ${event} delta`)`.
• 🟡 (14:07) Responses reasoning-summary handling tracks summaryState.authoritativeValueSeen, validates response.reasoning_summary_part.added, requires finalized summary parts to use type "summary_text", and can throw new Error("invalid Responses reasoning summary part").
• 🟡 (14:07) Function-call lifecycle validation tracks lifecycle.argumentsDone and rejects an output_item.done event that changes finalized arguments with Responses output_item.done changed arguments for index ${outputIndex}.
• 🟡 (14:07) Responses output-item validation checks that item.status, when present, is a string and has special handling for items whose declaredType === "reasoning".
• 🟡 (14:07) Response lifecycle validation marks lifecycle.created = true, requires response.in_progress to have empty output ("response.in_progress must have empty output"), and requires terminal response statuses to be strings contained in terminalStatuses.
• 🟡 (14:07) Streamed-output reconciliation supports an allowedIncompleteIndices: ReadonlySet<number> = new Set() parameter and reconstructs reasoning summaries using { text: summaryState.authoritativeValue }.
• 🟡 (14:07) Reasoning-part processing recognizes "reasoning_text" alongside summary-related content.
• 🟡 (14:07) Terminal-response reconciliation maps response.output, permits sparse streamed placeholders containing only type and id, and rejects terminal output that changes a streamed item with new Error("Responses terminal output changed streamed item").
• 🟡 (14:07) Output reconciliation uses outputIndexForEvent(...), consults acc.rawItems.has(outputIndex), and compares item identity against a reference using item.id !== reference.id.