> For the complete documentation index, see [llms.txt](https://ai-os-and-trend-finder.gitbook.io/ai-os-and-trend-finder-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ai-os-and-trend-finder.gitbook.io/ai-os-and-trend-finder-docs/.spec_system/archive/sessions/phase28-session05-signal-aging-half-lives-and-saturation-refinement/implementation_summary.md). # Implementation Summary **Session ID**: `phase28-session05-signal-aging-half-lives-and-saturation-refinement` **Completed**: 2026-06-14 **Duration**: 1 hour *** ## Overview Completed Phase 28 Session 05 by adding source-role half-life recency, bounded per-topic `signalAging`, and refined saturation derivation for Trend Finder. The session keeps the six-factor score weights unchanged, avoids introducing a second lifecycle vocabulary, preserves legacy payload parsing, and exposes the new aging and saturation context through Trend cards, Signal Workbench, tests, fixtures, and documentation. *** ## Deliverables ### Files Created | File | Purpose | Lines | | ------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------ | ----- | | `scripts/lib/ai-runtime/signal-aging.ts` | Pure half-life weighted signal-aging derivation and role contribution helper | 498 | | `scripts/lib/ai-runtime/__tests__/signal-aging.test.ts` | Unit tests for per-role decay, statuses, unavailable states, contribution bounds, and lifecycle threshold fixtures | 137 | | `src/extensions/trend-finder/components/__tests__/trend-card.test.tsx` | Trend card coverage for aging and saturation chips | 49 | | `.spec_system/specs/phase28-session05-signal-aging-half-lives-and-saturation-refinement/spec.md` | Session specification | 401 | | `.spec_system/specs/phase28-session05-signal-aging-half-lives-and-saturation-refinement/tasks.md` | Session task checklist | 98 | | `.spec_system/specs/phase28-session05-signal-aging-half-lives-and-saturation-refinement/implementation-notes.md` | Implementation and validation notes | 655 | | `.spec_system/specs/phase28-session05-signal-aging-half-lives-and-saturation-refinement/security-compliance.md` | Security and GDPR review | 91 | | `.spec_system/specs/phase28-session05-signal-aging-half-lives-and-saturation-refinement/validation.md` | Validation report | 245 | | `.spec_system/specs/phase28-session05-signal-aging-half-lives-and-saturation-refinement/IMPLEMENTATION_SUMMARY.md` | Session closeout summary | 130 | ### Files Modified | File | Changes | | ------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------- | | `scripts/extensions/trend-finder/sources/types.ts` | Added source half-life bounds, role defaults, and optional declaration metadata | | `scripts/extensions/trend-finder/sources/apify-source-config.ts` | Parsed and validated half-life metadata with fallback warnings and role defaults | | `scripts/extensions/trend-finder/sources/__tests__/apify-source-config.test.ts` | Added half-life default, override, invalid metadata, and warning coverage | | `scripts/extensions/trend-finder/sources/apify-adapter.ts` | Forwarded browser-safe source half-life summary metadata | | `scripts/lib/ai-runtime/scoring.ts` | Wired half-life recency into momentum, derived `signalAging`, refined saturation, and bumped scoring version | | `scripts/lib/ai-runtime/__tests__/scoring.test.ts` | Added integration coverage for role-specific recency, aging payloads, saturation, versioning, and no hidden multiplier | | `scripts/lib/ai-runtime/__tests__/scoring-calibration.test.ts` | Updated scoring calibration expectations for `trend-finder-scoring-v28.5` | | `src/extensions/trend-finder/schema.ts` | Added signal-aging enums, default unavailable payloads, contribution schemas, and source summary metadata | | `src/extensions/trend-finder/view-model.ts` | Added signal-aging labels, tones, descriptions, contribution projection, and sort ranks | | `src/extensions/trend-finder/components/trend-card.tsx` | Rendered compact signal-aging and refined-saturation chips | | `src/extensions/trend-finder/signal-workbench-model.ts` | Added aging fields, filters, facets, search text, and deterministic sort keys | | `src/extensions/trend-finder/components/signal-workbench-controls.tsx` | Added the aging filter control | | `src/extensions/trend-finder/components/signal-workbench-table.tsx` | Added a visible sortable Age column and row aging pill | | `src/extensions/trend-finder/fixtures.ts` | Added fresh, active, cooling, stale, and unavailable aging fixture topics | | `src/extensions/trend-finder/__tests__/view-model.test.ts` | Added legacy defaults, labels, unavailable reasons, and contribution coverage | | `src/extensions/trend-finder/__tests__/signal-workbench-model.test.ts` | Added aging filter, facet, search, and sort coverage | | `src/extensions/trend-finder/components/__tests__/trend-sparkline.test.tsx` | Added Workbench table Age column coverage | | `docs/extensions/trend-finder-scoring.md` | Documented half-life aging, unavailable states, refined saturation, and non-goals | | `.spec_system/state.json` | Marked Session 05 complete and cleared the active session | | `.spec_system/PRD/phase_28/PRD_phase_28.md` | Updated Phase 28 progress to 5/15 sessions | | `.spec_system/PRD/phase_28/session_05_signal_aging_half_lives_and_saturation_refinement.md` | Marked the session complete | | `package.json` | Bumped package version from `0.1.322` to `0.1.323` | | `README.md` | Updated version line to `0.1.323` | | `docs/CHANGELOG.md` | Added the Session 05 release entry | *** ## Technical Decisions 1. **Role-level half-lives**: Half-life defaults attach to existing Trend Finder source roles with bounded declaration overrides, avoiding hardcoded Trends-Finderz source names. 2. **Display-derived saturation**: Saturation gains diffusion, density, mainstream pressure, and dominance handling while remaining out of the six-factor score multiplier path. 3. **Scoring version bump**: Recency math changed, so the scoring version moved to `trend-finder-scoring-v28.5` and existing cross-version movement flags remain meaningful. 4. **Legacy-safe browser payloads**: Missing aging fields parse to explicit unavailable defaults rather than requiring generated data migrations. *** ## Test Results | Metric | Value | | -------- | ------------- | | Tests | 3530 | | Passed | 3530 | | Coverage | Not collected | Final validation commands: * `bun run test` - PASS, 290 files / 3530 tests. * `bun run typecheck` - PASS. * `bun run typecheck:scripts` - PASS. * `git diff --check` - PASS. * ASCII and LF scans - PASS. * Local browser smoke at `/extensions/trend-finder/workbench` - PASS. *** ## Lessons Learned 1. Half-life recency needs role-level defaults so new source declarations get a safe value before downstream scoring consumes them. 2. Scoring calibration tests should move with every scoring-version bump, including display-derived math changes that affect ranking through momentum. 3. A visible Workbench Age column is needed alongside filters so operators can understand and verify aging sort behavior. *** ## Future Considerations Items for future sessions: 1. Session 06 should consume `signalAging` and refined saturation through the controlled lifecycle multiplier and named contribution layer. 2. Session 07 should add research-only calibration and cache retention without treating aging status as a raw source payload. 3. Session 08 should use aging, visibility, and quality outputs in action verdict and consistency QA rules. *** ## Session Statistics * **Tasks**: 24 completed * **Files Created**: 9 * **Files Modified**: 24 * **Tests Added**: 8 files * **Blockers**: 0 resolved --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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