Distillation

Date: Sep 16, 2026

• 🟡 (19:47) User supplied a continuation of packages/gateway/src/pipeline.ts covering approximately lines 9030-9670 of the Responses stream lifecycle, terminal reconciliation, SSE parsing, and recall-diagnostics implementation.
• 🟡 (19:47) Responses lifecycle validation rejects malformed reasoning-summary items with exact error "invalid Responses reasoning summary item" and reasoning completion without content with Responses reasoning completed without content for index ${outputIndex}.
• 🟡 (19:47) Terminal-event validation rejects events received before response.created with Responses event before response.created: ${event} and rejects response identity changes with exact error "Responses terminal event changed response identity".
• 🟡 (19:47) Terminal reconciliation copies raw.summary when it is an array, updates acc.rawItems only when changed, validates terminal part values through partValue(state.kind, record, \terminal ${description}`), and can synthesize response.output_item.done` events.
• 🟡 (19:47) Item-reference handling validates output_index, throwing exact error "invalid Responses output_index for item_reference", and checks identities against outputIdentities using item.id.
• 🟡 (19:47) SSE processing splits text on "\n\n", parses event data with JSON.parse(data) as Record<string, unknown>, and guards completion with if (completionAttempted) return completed.
• 🟡 (19:47) Recall processing invokes opts.onRecall, handles late or aborted results through onLateResult(), and records successful diagnostics via recallDiagnostics.record(input, result.resultText, result.coverage).
• 🟡 (19:48) User supplied a continuation of packages/gateway/src/pipeline.ts covering approximately lines 9680-10370, including synthetic Responses events, usage accounting, final-output construction, visible-index forwarding, stream cancellation, retries, hidden recall handling, and event accumulation.
• 🟡 (19:48) Synthetic Responses output includes response.content_part.added events and message content shaped as { type: "output_text", text, annotations: [] }.
• 🟡 (19:48) Usage accounting computes inclusiveInputTokens with addUsageTokens(...) and maps ru.cacheCreationInputTokens ?? 0 to cache_write_tokens.
• 🟡 (19:48) Final output is represented as Array<{ index: number; item: Record<string, unknown> }>; construction handles items whose type === "text" and consults state.rawItems.get(index).
• 🟡 (19:48) Stream state tracks principalTransportRetries, a "principal_missing_terminal" condition, forwardedVisibleOutputIndices as new Map<number, number>(), hiddenRecallBaseline, and pendingRecalls as PendingResponsesRecall[].
• 🟡 (19:48) Client-forwarding validation throws exact error "hidden Responses output item reached the client" if a hidden output item is exposed.
• 🟡 (19:48) Responses event processing calls seedImplicitCodexItem(state, normalizationState, event, parsed) and distinguishes recall tools using item.name !== RECALL_TOOL_NAME; resolution state includes resolvingVisibleTool and resolvingRecallTool.
• 🔴 (19:48) User directed that Responses events must always accumulate into the internal state for postResponse.