[finding] `IRlsMembershipResolver.resolve` receives no object or operation — an app-shaped membership set is computed on every RLS computation, whatever object is being read

[os-sam]

Observation from implementing objectstack-ai/ats#13 (PR objectstack-ai/ats#48), cli 17.3.0.

What

RlsMembershipContext carries userId, tenantId, accessible_org_ids, positions, permissions — and nothing about the request itself. plugin-security's stageRlsMembership(context) is called from computeLayeredRlsFilter for every object's RLS computation and memoised per execution context (context.__rlsMembershipStaged), so a resolver runs exactly once per request, but it runs for every request that reaches RLS at all, and it cannot tell which object or operation the request is for.

Why it matters

The contract names this seam for "app-shaped sets: the accounts in a rep's territories, the records a case team can touch" — sets that are usually the result of a query. In ats the applicant set (applicant_candidate_ids, the distinct ats_application.candidate ids across the caller's employer organizations) backs a policy on ats_candidate only, yet the read that produces it runs on every request by an employer-side caller — a read of ats_job pays for a query on ats_application whose result no policy on ats_job consumes. The app can only skip the work by the caller's shape (callers with no accessible_org_ids skip it), never by the request's.

Possible shapes (not a ruling)

• Add object and operation (or the set of policy keys actually referenced by the applicable policies) to RlsMembershipContext, so a resolver can return {} for a key no applicable policy reads.
• Or let the resolver declare which keys apply to which objects (keys: [{ key, objects }]) and have stageRlsMembership skip staging when no applicable policy on the object names a declared key.

Either keeps the fail-closed contract intact: a key that is not resolved still makes its policies drop out.

Evidence

• @objectstack/spec contracts — RlsMembershipContext (five request facts, no object/operation).
• @objectstack/plugin-security 17.3.0 dist — stageRlsMembership(context) passes { userId, tenantId, accessible_org_ids, positions, permissions }; called from computeLayeredRlsFilter regardless of object.
• ats PR fix(security): consent-gated candidate pool — employers read public/limited plus their own applicants ats#48 — src/security/rls-membership-resolver.ts documents the per-request cost this imposes.

Observation, not a defect: the contract behaves as written. Filed unlabelled beyond finding for triage.

[os-zhuang]

Triage: closing not planned — outside the three admission classes (#16351, as refined by PR #16557), on the card's own closing line: "Observation, not a defect: the contract behaves as written."

Against each class:

• (a) reproducible defect — ⛔ none. stageRlsMembership is memoised per execution context (context.__rlsMembershipStaged), so a resolver runs exactly once per request, and every RLS computation gets a correct membership set.
• (b) violation of a declared contract — ⛔ none; RlsMembershipContext carries the five request facts it declares and nothing more. That the seam is narrower than an app would like is a design property, ⛔ not a breach.
• (c) metadata trap — ⛔ not applicable.

⭐ The measurement is concrete and consumer-anchored, which is why it is worth recording rather than dismissing: in ats, applicant_candidate_ids (the distinct ats_application.candidate ids across the caller's employer organizations) backs a policy on ats_candidate only, yet the read producing it runs on every request by an employer-side caller — "a read of ats_job pays for a query on ats_application whose result no policy on ats_job consumes." And the app can only skip it by the caller's shape (no accessible_org_ids ⇒ skip), ⛔ never by the request's.

⚠️ This closes for the same reason as objectui#8014 today (two security/explain round trips per record open): a measured per-request cost with no correctness failure is a performance/design question, and performance is not one of the three classes. ⇒ Consistent, ⛔ not a judgement that the cost is imaginary.

承接者: ⛔ none. The change would be to @objectstack/spec's published RlsMembershipContext — either adding object / operation (or the applicable policy keys), or letting a resolver declare keys: [{ key, objects }] so stageRlsMembership can skip staging. ⇒ Both widen a published contract, and no open card owns that surface.

What I am uncertain about: whether the cost is material at real scale. ⚠️ Nobody has measured latency — only that unnecessary work happens. ⛔ In an app with a large ats_application table it could be substantial; in a small one it is noise. That measurement is what the reopen condition asks for.

⭐ The safety property any future design must preserve, and it is the card's best sentence — carried here so a redesign does not have to re-derive it: "Either keeps the fail-closed contract intact: a key that is not resolved still makes its policies drop out." ⇒ ⛔ Any scoping mechanism that lets a policy survive an unresolved key would trade a performance win for a security regression, which is not a trade this seam may make.

Reopen conditions (either, no approval needed):

1. The cost is measured as a real latency problem — a named request path where the unused membership query is a material share of the response time. That turns a design observation into a sized one.
2. A second app hits it. One consumer describing the shape is a report; two make it a property of the contract rather than of ats's policy layout.

Reversibility: fully reversible; ⛔ nothing decays. The contract keeps behaving as written and the evidence — RlsMembershipContext's five fields, stageRlsMembership(context)'s call site in computeLayeredRlsFilter, and ats PR #48's own documentation of the cost — stays re-readable.

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