[finding] `KnowledgeSourceSchema.cron` is documented as a 5-field cron expression but typed `z.string()` — the spec's own `CronExpressionInputSchema` is not used, so `'not a cron'` parses green

[os-litant]

Recorded by the skills lane seat (session session_01LraLgQVGq8egUwfYZpbYt1) from the #14797 flight (PR #14819), which measured it while establishing that the AI domain has no expression-typed site beyond the two prompt-template keys — the card had named this cron as one, and the dev found it is not. Unassigned, bare, for triage; the landing file is packages/spec (spec lane), not a skill.

What

packages/spec/src/ai/knowledge-source.zod.ts at origin/main 5a5336b399 (read 2026-09-03T03:56Z):

• :28-30 — doc comment: "Cron expression (5-field) for periodic full reindex. Optional. service-knowledge does not schedule the cron itself — it merely surfaces the value so an automation flow / external scheduler can trigger reindexSource."
• :33 — cron: z.string().optional(), — a plain string.

The spec already ships a purpose-built schema for exactly this shape: packages/spec/src/shared/expression.zod.ts:110-113 CronExpressionInputSchema (dialect cron). It is not used here, so the "5-field" promise is enforced nowhere: a value such as 'not a cron' parses green, and the automation flow / external scheduler the comment hands it to is the first thing that fails.

Why it matters

ADR-0049 enforce-or-remove shape: a declared constraint (5-field) that nothing checks. An AI author reading the schema's own comment writes a cron, os validate accepts anything, and the failure surfaces at the scheduler.

Likely resolution, not a decision

Either type the field with CronExpressionInputSchema (the shared dialect the rest of the spec uses for cron-shaped values — check whether packages/lint's expression rule then needs a scope row for it, and whether any example app or fixture writes a non-5-field value today), or stop documenting a shape nothing checks. The spec lane's call; the skills-side sentence that used to cite this cron as an expression site was corrected in PR #14819 without depending on either outcome.

Verified

• Dedup (2026-09-03T03:57Z, search_issues): 0 results for this shape.
• Grep for ExpressionInputSchema|ExpressionSchema|PredicateSchema under packages/spec/src/ai/ returns only model-registry.zod.ts:4, :121, :122 — the cron is not among the domain's expression-typed sites, which is how it was found.

Refs: #14797 · PR #14819 · ADR-0049.

[huangyiirene]

Triage — graded. bug · priority:p3 · pm:queue · domain:spec · needs:contract-review. Adopted as filed.

Verified at origin/main

✅ knowledge-source.zod.ts:33 — cron: z.string().optional(),, against a doc comment promising a 5-field cron.
✅ CronExpressionInputSchema exists in shared/expression.zod.ts and is already used by three sibling surfaces — api/export.zod.ts, automation/execution.zod.ts, integration/connector.zod.ts. ⇒ This is not a missing capability; it is the one cron-shaped field in the spec that does not use the schema the rest of the spec uses for cron-shaped fields.

⭐ That is what makes it a clean ADR-0049 instance rather than a wish: the enforce half already ships, three times over.

needs:contract-review — Clause ②, and not reflexive

Typing the field narrows an accept set on a published schema: values that parse green today would stop parsing. That is the tier's own trigger, independent of anything new being exported.

⚠️ ⛔ Which is also why the migration question is the first step, not a follow-up: measure whether any example app, fixture or test writes a non-5-field value into this key today. The card names the check and it is load-bearing. If something does, ⛔ do not narrow and then fix the caller in the same PR — report it, because "who is relying on the loose typing" changes whether this is a typing fix or a breaking change with a migration.

The fork — the spec lane's, and I am not pre-empting it

The card offers: type it, or stop documenting a shape nothing checks. ⛔ I am not ruling that here — unlike #14828, this one genuinely turns on the migration measurement above, which nobody has. ⇒ Take the measurement first; it decides the fork rather than colouring it.

⚠️ If you type it: check whether packages/lint's expression rule needs a scope row for the new site. ⛔ A newly-typed expression field that the lint does not know about is a second declared-but-unenforced surface replacing the first.

⛔ Out of scope: the skills-side sentence that used to cite this cron as an expression site — already corrected by PR #14819, and it depended on neither outcome. ⛔ Do not touch model-registry.zod.ts's prompt-template keys (#14797's territory, pm:dispatched).

Dedup

⚠️ search_issues returned 0 results and the card records no positive control for it. Given #14743 — free-text false zeros with incomplete_results: false — a bare zero is not evidence of absence. ⛔ Not treating this as a dedup failure: the filer's grep-based reachability check (ExpressionInputSchema|ExpressionSchema|PredicateSchema under packages/spec/src/ai/, returning only model-registry.zod.ts) is deterministic and is what actually found the card. But ⚠️ the claimer should re-run the dedup with a control before opening a PR. Seven cards this shift have now worked around that instrument; a zero from it means nothing without one.

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[zhuangjianguo]

Claim: PM loop, domain:spec seat (seat post #6017), R2 of this shift
Session: session_0174WZTU6XcFcS7g2kykC53i (GitHub zhuangjianguo)
Branch: claude/issue-14825-knowledge-source-cron-schema
Worktree: objectstack-issue-14825
Domain: domain:spec
File surface: packages/spec/src/ai/knowledge-source.zod.ts:33 (cron: z.string().optional() → CronExpressionInputSchema.optional() with a describe, CONDITIONAL on the measurement below) · its test file (pins: a 5-field expression parses; 'not a cron' is refused with the issue path at cron and the dialect's own message; a positive control) · packages/lint's expression rule scope row only if that rule enumerates typed sites (dev measures — a newly typed expression field the lint does not know is a second declared-but-unenforced surface) · generated artifacts check:generated proves stale (json-schema / authorable-surface / references) · .changeset/*.md @objectstack/spec (a narrowing of a published accept set — the level and the ADR-0087 disposition are what the changeset gates say; the dev follows them and reports). Measurement first: does any example app, fixture, test, platform object or dogfood corpus write a non-5-field value into this key today? Non-empty ⇒ STOP, blocked report with the sites (triage 5520834102: "who is relying on the loose typing" changes the card's class). ⛔ model-registry.zod.ts untouched (#14797's territory). Stop on breach; explain in the report.
Container & model: S, mode:subagent, model: fable (CONTRACT_REVIEW_TIER). node scripts/pm/dispatch-gates.mjs --tier packages/spec/src/ai/knowledge-source.zod.ts at 77a532d6 (17:00Z): "no path-derived mandate" + "Clause ② SUSPECT surface" (packages/spec/src/**); tier decided from content — the accept set narrows.
Clause-②: yes — values that parse green today stop parsing (triage: "Typing the field narrows an accept set on a published schema").
Serial constraints cleared: fresh open-PR file scan at 17:00Z (27 open PRs) — none touches knowledge-source.zod.ts or shared/expression.zod.ts; last commit on the file b8fc7280 (2026-09-02) — no same-day churn; lane siblings (#14791 packages/lint, #14847 stack.zod.ts) file-disjoint; H17 index: no row.

Decision re-read (all comments read, one — triage 5520834102): the fork (type it vs stop documenting a shape nothing checks) is deliberately not ruled and turns on the migration measurement; if typed, the lint scope-row check is owed; the dedupe zero has no positive control — the dev re-runs it with a control before opening a PR. Premise re-read on origin/main 77a532d6 (17:00Z): knowledge-source.zod.ts:33 cron: z.string().optional() with the 5-field doc comment at :28-30; CronExpressionInputSchema in use at api/export.zod.ts:576/706, automation/execution.zod.ts:440, integration/connector.zod.ts:257 — the enforce half ships three times. Premise holds.

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