> 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/phase29-session07-per-stage-validation-narration/implementation_summary.md). # Implementation Summary **Session ID**: `phase29-session07-per-stage-validation-narration` **Completed**: 2026-06-20 **Duration**: 0.5 hours *** ## Overview Phase 29 Session 07 added bounded per-stage validation narration to Trend Finder. The implementation records retry-once enrichment stage status for Engine Replay, preserves deterministic fallback behavior, sanitizes browser output at trace and model boundaries, and renders compact accessible notices when optional enrichment stages degrade. *** ## Deliverables ### Files Created | File | Purpose | Lines | | -------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------ | ----- | | `scripts/extensions/trend-finder/stage-validation.ts` | Stage validation contract, retry-once wrapper, degraded result helpers, safe issue codes, and message sanitization. | 321 | | `scripts/extensions/trend-finder/__tests__/stage-validation.test.ts` | Unit coverage for first-try success, retry success, retry failure, explicit degradation, abort handling, clamping, and unsafe message stripping. | 152 | ### Files Modified | File | Changes | | ---------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------ | | `scripts/extensions/trend-finder/collector.ts` | Wrapped analyst, source-breakdown, run narrative, and outlier idea enrichment paths with stage validation narration and deterministic fallbacks. | | `scripts/extensions/trend-finder/engine-trace.ts` | Added `stage-validation.recorded` mapping, output caps, deterministic ordering, and unsafe key/value rejection. | | `src/extensions/trend-finder/engine-trace.ts` | Added additive `stageNarrations` types, enums, Zod parsing, caps, sorting, and legacy defaults. | | `src/extensions/trend-finder/engine-replay-model.ts` | Projected stage narration rows into safe labels, tones, retry text, degradation text, and accessible descriptions. | | `src/extensions/trend-finder/views/engine-replay-view.tsx` | Rendered compact stage validation notices with stable empty and legacy behavior. | | `src/extensions/trend-finder/fixtures.ts` | Added accepted, degraded, retry-once, and unsafe-dropped stage narration fixture rows. | | `scripts/extensions/trend-finder/__tests__/collector.test.ts` | Added forced enrichment failure coverage for retry count, deterministic fallback, and private sentinel exclusion. | | `scripts/extensions/trend-finder/__tests__/engine-trace.test.ts` | Added stage narration sanitizer, caps, retry clamp, unsafe row rejection, and legacy default coverage. | | `src/lib/__tests__/trend-finder-engine-replay.test.tsx` | Added Engine Replay model/view coverage for degraded rows, empty legacy payloads, offline tone, accessibility labels, and leak exclusion. | | `scripts/extensions/trend-finder/measure-payload-size.ts` | Added stage narration visibility to payload-size reporting. | | `docs/extensions/trend-finder-pipeline.md` | Documented shipped stage narration behavior and retained privacy boundaries. | | `scripts/lib/ai-runtime/evidence-rationale.ts` | Replaced control-character regex with character-code sanitization during validation lint cleanup. | *** ## Technical Decisions 1. **Single additive trace field**: Published stage narration as `stageNarrations` so legacy payloads parse with an empty default and related state stays in one browser-safe contract. 2. **Retry cap by construction**: Centralized retry-once behavior in the helper so enrichment callers cannot accidentally create unbounded loops. 3. **Boundary-nearest sanitization**: Dropped unsafe trace rows before browser output and sanitized display messages again in the Engine Replay model. 4. **Fallback preservation**: Kept analyst, source-breakdown, narrative, and outlier idea deterministic fallbacks intact while adding visible degraded-state proof. *** ## Test Results | Metric | Value | | -------- | ------------- | | Tests | 3774 | | Passed | 3774 | | Coverage | Not collected | Validation commands passed: * `bun run test` * `bun run typecheck:scripts` * `bun run typecheck` * `bun run lint` * `bun run runtime:check-private` * `bun run scripts/extensions/trend-finder/measure-payload-size.ts src/data/live-data.example.json --threshold-kb=0 --json` * `bunx prettier --check ...` * `git diff --check` *** ## Lessons Learned 1. Trace event sanitizers need to distinguish public enum keys such as `stageId` from unsafe diagnostic key names, otherwise valid rows can be dropped. 2. Stage messages should be generic and short even after helper sanitization because Engine Replay is browser-safe proof, not private diagnostics. 3. Legacy empty-state tests are useful whenever a new trace section is introduced, because replay UI should not show stale rows from earlier payload shapes. *** ## Future Considerations Items for future sessions: 1. Reuse stage narration rows when Session 08 adds the required-derived-field closeout gate. 2. Keep Session 09 source-death baseline alarms private and publish only safe degraded-state proof if they touch Engine Replay. 3. Continue running payload-size and private-runtime checks as Phase 29 adds more trace and Brief richness. *** ## Session Statistics * **Tasks**: 20 completed * **Files Created**: 2 * **Files Modified**: 12 * **Tests Added**: 24 focused tests across 4 focused areas * **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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