gstack/test/fixtures/eng-69193-count-public.json

{
  "source": "69193b9f8ca7e87bd1fb05e235a2e7194c1c437b",
  "originalOutcome": "CANCELLED",
  "qualification": "Exact complete public native decisions and owned report from the cancelled attempt. Free replay cannot grant a paid pass or native ExitPlanMode coverage.",
  "windowStart": "2026-09-16T19:26:31.561Z",
  "windowEnd": "2026-09-16T19:46:44.428Z",
  "calls": [
    {
      "sessionId": "6e59025e-0e69-4ae1-80c3-11ae663e2b96",
      "toolUseId": "toolu_01PaPhx6z6XVzYvwW3NYtjay",
      "questions": [
        {
          "question": "D1 — Keep the Promise.all IDP parallelization inside this refactor, or split it out?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), Scope Challenge deferral gate.\nELI10: The plan promises \"reorganize without changing product behavior\", then also changes how token validation talks to the identity provider: five calls fired at once instead of one after another. That is a behavior change (different timing, five times the burst load on the IDP, different error ordering). Mixing it into a structure-only refactor means if something breaks in production you cannot tell which change caused it, and you cannot roll back one without the other.\nStakes if we pick wrong: bundled = a latency regression or IDP rate-limit outage gets blamed on the refactor and the whole thing gets reverted; split = one extra small PR.\nRecommendation: A because structural and behavioral changes should land separately (Beck), and the Performance review will show caching issuer metadata is the real fix, so the parallelization design may change anyway.\nNote: options differ in kind, not coverage — no completeness score.\nPros / cons:\nA) Defer parallelization to a follow-up PR (recommended) (human: ~0 now / CC: ~0 now)\n  ✅ Refactor stays a pure structural change; a bisect points at exactly one cause if auth breaks\n  ✅ Lets the Performance review pick the right fix (cache discovery/JWKS) instead of committing to Promise.all now\n  ❌ Users keep the 5x sequential latency for one more release cycle\nB) Keep parallelization in this PR as a separate commit\n  ✅ Latency win ships now, in the same review cycle (human: ~1 day incl. load test / CC: ~20 min)\n  ✅ Separate commit still gives some bisectability within the branch\n  ❌ Refactor branch now carries a runtime-behavior change and needs IDP load/rate-limit verification before merge\n  ❌ If the calls are not actually independent (discovery → JWKS → verify usually chain), the \"trivial\" Promise.all is wrong and the refactor PR stalls on it\nNet: trading one release of latency for a refactor you can trust and revert in isolation.",
          "header": "D1 scope",
          "multiSelect": false,
          "options": [
            {
              "label": "A) Defer parallelization (recommended)",
              "description": "Remove the Promise.all change from this refactor. Record it as a follow-up (Performance review will refine what the follow-up should actually be: caching vs parallelizing). Refactor stays behavior-neutral."
            },
            {
              "label": "B) Keep it in this PR",
              "description": "Keep the Promise.all parallelization in this branch as its own commit. Requires verifying the 5 calls are truly independent and adding IDP load/rate-limit checks before merge."
            }
          ]
        }
      ],
      "answered": true,
      "failed": false,
      "answers": {
        "D1 — Keep the Promise.all IDP parallelization inside this refactor, or split it out?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), Scope Challenge deferral gate.\nELI10: The plan promises \"reorganize without changing product behavior\", then also changes how token validation talks to the identity provider: five calls fired at once instead of one after another. That is a behavior change (different timing, five times the burst load on the IDP, different error ordering). Mixing it into a structure-only refactor means if something breaks in production you cannot tell which change caused it, and you cannot roll back one without the other.\nStakes if we pick wrong: bundled = a latency regression or IDP rate-limit outage gets blamed on the refactor and the whole thing gets reverted; split = one extra small PR.\nRecommendation: A because structural and behavioral changes should land separately (Beck), and the Performance review will show caching issuer metadata is the real fix, so the parallelization design may change anyway.\nNote: options differ in kind, not coverage — no completeness score.\nPros / cons:\nA) Defer parallelization to a follow-up PR (recommended) (human: ~0 now / CC: ~0 now)\n  ✅ Refactor stays a pure structural change; a bisect points at exactly one cause if auth breaks\n  ✅ Lets the Performance review pick the right fix (cache discovery/JWKS) instead of committing to Promise.all now\n  ❌ Users keep the 5x sequential latency for one more release cycle\nB) Keep parallelization in this PR as a separate commit\n  ✅ Latency win ships now, in the same review cycle (human: ~1 day incl. load test / CC: ~20 min)\n  ✅ Separate commit still gives some bisectability within the branch\n  ❌ Refactor branch now carries a runtime-behavior change and needs IDP load/rate-limit verification before merge\n  ❌ If the calls are not actually independent (discovery → JWKS → verify usually chain), the \"trivial\" Promise.all is wrong and the refactor PR stalls on it\nNet: trading one release of latency for a refactor you can trust and revert in isolation.": "A) Defer parallelization (recommended)"
      },
      "unansweredQuestionIndices": [],
      "answeredAt": "2026-09-16T19:29:38.092Z"
    },
    {
      "sessionId": "6e59025e-0e69-4ae1-80c3-11ae663e2b96",
      "toolUseId": "toolu_014i5iZBZ3zyeMYNqh321fex",
      "questions": [
        {
          "question": "D2 — Five new classes, or a three-unit arrangement with the same features?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), complexity gate (12 files / 5 new classes). Structure only; D1 (parallelization deferred) is held fixed; error-handling, cache-ownership and test remedies stay pending for later questions.\nELI10: The plan adds five new classes to reorganize one auth flow. Two of them do not earn a class: RequestPolicy has no state, no I/O and no new rules by the plan's own words (PLAN.md:12-13), so it is a function. TokenStore is never described (PLAN.md:44-45 is its only mention) and its name overlaps AuthCache, which already wraps the one real token store (the existing adapter). Every extra class is another file to read at 3am, another seam to mock, another place for the tenant-key rules to drift.\nStakes if we pick wrong: too many parts = slower onboarding and duplicated cache logic between TokenStore and AuthCache; too few = a real boundary gets buried and needs re-extraction later (cheap: extracting a function into a class is a 5-minute CC change).\nRecommendation: B because both dropped classes are either stateless (RequestPolicy) or undefined (TokenStore); the remaining three map one-to-one to real responsibilities: orchestrate (AuthBroker), mint (SessionMint), cache facade (AuthCache).\nCompleteness: A=10/10, B=10/10 — both keep every feature and contract; they differ only in how many boundaries carry them.\nPros / cons:\nA) Original: 5 classes — AuthBroker, TokenStore, SessionMint, AuthCache, RequestPolicy (human: ~1 wk / CC: ~1.5 h)\n  ✅ Matches the plan as written; nothing to re-plan, each concept has a named home\n  ✅ RequestPolicy as a class leaves room for future stateful policy (versioned rule sets) without a later refactor\n  ❌ TokenStore has no defined responsibility in the plan and duplicates AuthCache's role; two token holders means tenant-key rules can drift apart\n  ❌ 12 files / 5 classes for a no-behavior-change reorg is the complexity smell the plan itself flags (PLAN.md:44-45)\nB) Smaller: 3 units — AuthBroker, SessionMint, AuthCache; RequestPolicy becomes a pure exported function `decideAccess(claims, ctx)` in its own module; TokenStore folded into AuthCache (human: ~3-4 days / CC: ~1 h)\n  ✅ One token holder (AuthCache) so the existing tenant/issuer/audience/policy-version key rules live in exactly one place\n  ✅ A pure function is the easiest thing to test exhaustively (input table → allow/deny), no mocks, no lifecycle\n  ✅ Fewer files touched (~8-9), smaller diff to review and revert\n  ❌ If TokenStore was meant to hold something the adapter cannot (e.g. refresh-token secrets with a different lifetime), folding it in is wrong and needs re-splitting\n  ❌ A future stateful policy would need `decideAccess` promoted to a class (5-minute change, but a change)\nNet: trading a speculative future boundary for one owner of the cache rules and a diff half the size today.",
          "header": "D2 structure",
          "multiSelect": false,
          "options": [
            {
              "label": "A) Keep 5 classes",
              "description": "Keep AuthBroker, TokenStore, SessionMint, AuthCache, RequestPolicy as five separate classes across ~12 files. Plan must add a written responsibility for TokenStore distinct from AuthCache."
            },
            {
              "label": "B) 3 units (recommended)",
              "description": "AuthBroker, SessionMint, AuthCache as classes. RequestPolicy becomes a pure function decideAccess(claims, ctx) in its own module. TokenStore folded into AuthCache (one owner of the tenant-key rules). ~8-9 files."
            },
            {
              "label": "C) 4 units: keep TokenStore, drop RequestPolicy class",
              "description": "AuthBroker, TokenStore, SessionMint, AuthCache as classes; RequestPolicy becomes a pure function. Choose this if TokenStore holds something the existing adapter cannot (state the responsibility in the plan)."
            }
          ]
        }
      ],
      "answered": true,
      "failed": false,
      "answers": {
        "D2 — Five new classes, or a three-unit arrangement with the same features?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), complexity gate (12 files / 5 new classes). Structure only; D1 (parallelization deferred) is held fixed; error-handling, cache-ownership and test remedies stay pending for later questions.\nELI10: The plan adds five new classes to reorganize one auth flow. Two of them do not earn a class: RequestPolicy has no state, no I/O and no new rules by the plan's own words (PLAN.md:12-13), so it is a function. TokenStore is never described (PLAN.md:44-45 is its only mention) and its name overlaps AuthCache, which already wraps the one real token store (the existing adapter). Every extra class is another file to read at 3am, another seam to mock, another place for the tenant-key rules to drift.\nStakes if we pick wrong: too many parts = slower onboarding and duplicated cache logic between TokenStore and AuthCache; too few = a real boundary gets buried and needs re-extraction later (cheap: extracting a function into a class is a 5-minute CC change).\nRecommendation: B because both dropped classes are either stateless (RequestPolicy) or undefined (TokenStore); the remaining three map one-to-one to real responsibilities: orchestrate (AuthBroker), mint (SessionMint), cache facade (AuthCache).\nCompleteness: A=10/10, B=10/10 — both keep every feature and contract; they differ only in how many boundaries carry them.\nPros / cons:\nA) Original: 5 classes — AuthBroker, TokenStore, SessionMint, AuthCache, RequestPolicy (human: ~1 wk / CC: ~1.5 h)\n  ✅ Matches the plan as written; nothing to re-plan, each concept has a named home\n  ✅ RequestPolicy as a class leaves room for future stateful policy (versioned rule sets) without a later refactor\n  ❌ TokenStore has no defined responsibility in the plan and duplicates AuthCache's role; two token holders means tenant-key rules can drift apart\n  ❌ 12 files / 5 classes for a no-behavior-change reorg is the complexity smell the plan itself flags (PLAN.md:44-45)\nB) Smaller: 3 units — AuthBroker, SessionMint, AuthCache; RequestPolicy becomes a pure exported function `decideAccess(claims, ctx)` in its own module; TokenStore folded into AuthCache (human: ~3-4 days / CC: ~1 h)\n  ✅ One token holder (AuthCache) so the existing tenant/issuer/audience/policy-version key rules live in exactly one place\n  ✅ A pure function is the easiest thing to test exhaustively (input table → allow/deny), no mocks, no lifecycle\n  ✅ Fewer files touched (~8-9), smaller diff to review and revert\n  ❌ If TokenStore was meant to hold something the adapter cannot (e.g. refresh-token secrets with a different lifetime), folding it in is wrong and needs re-splitting\n  ❌ A future stateful policy would need `decideAccess` promoted to a class (5-minute change, but a change)\nNet: trading a speculative future boundary for one owner of the cache rules and a diff half the size today.": "A) Keep 5 classes"
      },
      "unansweredQuestionIndices": [],
      "answeredAt": "2026-09-16T19:30:10.201Z"
    },
    {
      "sessionId": "6e59025e-0e69-4ae1-80c3-11ae663e2b96",
      "toolUseId": "toolu_01X4EyoaNTRWgaRKH8f6hxte",
      "questions": [
        {
          "question": "D3 — How should AuthBroker and SessionMint get hold of the shared AuthCache?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), Architecture finding A1. Structure (5 classes, D2) is fixed; the invalidation race (R4) and error handling (R5) stay pending.\nELI10: Right now the plan has one cache object created when the module loads, and both new services grab it by importing the module. That works until you need two of them (one per test, one per tenant tier, one for a canary) and discover every file in the auth path secretly depends on that one global. Tests that write to the cache leak into the next test. Passing the cache into each service's constructor from one place makes the dependency visible and swappable.\nStakes if we pick wrong: global = flaky cross-test pollution in the auth suite and monkey-patching to isolate; injection = one small factory function to write.\nRecommendation: A because it is the standard Node/TS pattern [Layer 1], costs one factory function, and is the difference between an auth suite you trust and one you rerun.\nCompleteness: A=10/10, B=3/10, C=6/10\nPros / cons:\nA) Constructor injection from one composition root (recommended) (human: ~half day / CC: ~10 min)\n  ✅ Each service's dependency on the cache is explicit in its constructor signature; nothing hidden behind an import\n  ✅ Tests build a fresh `AuthCache` per case with a fake adapter; zero cross-test state leakage\n  ✅ One place (`createAuthServices()`) owns wiring, so a per-tenant-tier or canary cache later is a wiring change, not a refactor\n  ❌ Callers that today import the flow directly must go through the factory (a few import-site edits)\nB) Keep the module-level global export\n  ✅ Zero extra code; matches the plan as written\n  ✅ Every call site trivially sees the same instance\n  ❌ Test pollution across AuthBroker and SessionMint suites; isolation needs monkey-patching or module cache resets\n  ❌ The two writers to one global are invisible at the type level; nobody reviewing SessionMint sees it can clobber AuthBroker's state\nC) Module-level global + `resetAuthCacheForTests()` hook\n  ✅ Cheap; fixes the test-pollution symptom without touching production wiring\n  ✅ No call-site edits\n  ❌ Test-only API shipped in production code; the hidden coupling remains\n  ❌ Does nothing for per-tenant-tier or canary scenarios; you still end up doing A later\nNet: trading a handful of import-site edits for an auth module whose dependencies are visible and whose tests are isolated.",
          "header": "D3 cache DI",
          "multiSelect": false,
          "options": [
            {
              "label": "A) Constructor injection (recommended)",
              "description": "Create one `AuthCache` in a composition root (`createAuthServices()`) and pass it to `AuthBroker` and `SessionMint` constructors. Remove the module-level mutable export. Still one backing cache."
            },
            {
              "label": "B) Keep module-level global",
              "description": "Leave the module-level exported `AuthCache` instance as the plan proposes; both services import it directly."
            },
            {
              "label": "C) Global + test reset hook",
              "description": "Keep the module-level export and add an exported `resetAuthCacheForTests()` to clear state between tests. No production wiring change."
            }
          ]
        }
      ],
      "answered": true,
      "failed": false,
      "answers": {
        "D3 — How should AuthBroker and SessionMint get hold of the shared AuthCache?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), Architecture finding A1. Structure (5 classes, D2) is fixed; the invalidation race (R4) and error handling (R5) stay pending.\nELI10: Right now the plan has one cache object created when the module loads, and both new services grab it by importing the module. That works until you need two of them (one per test, one per tenant tier, one for a canary) and discover every file in the auth path secretly depends on that one global. Tests that write to the cache leak into the next test. Passing the cache into each service's constructor from one place makes the dependency visible and swappable.\nStakes if we pick wrong: global = flaky cross-test pollution in the auth suite and monkey-patching to isolate; injection = one small factory function to write.\nRecommendation: A because it is the standard Node/TS pattern [Layer 1], costs one factory function, and is the difference between an auth suite you trust and one you rerun.\nCompleteness: A=10/10, B=3/10, C=6/10\nPros / cons:\nA) Constructor injection from one composition root (recommended) (human: ~half day / CC: ~10 min)\n  ✅ Each service's dependency on the cache is explicit in its constructor signature; nothing hidden behind an import\n  ✅ Tests build a fresh `AuthCache` per case with a fake adapter; zero cross-test state leakage\n  ✅ One place (`createAuthServices()`) owns wiring, so a per-tenant-tier or canary cache later is a wiring change, not a refactor\n  ❌ Callers that today import the flow directly must go through the factory (a few import-site edits)\nB) Keep the module-level global export\n  ✅ Zero extra code; matches the plan as written\n  ✅ Every call site trivially sees the same instance\n  ❌ Test pollution across AuthBroker and SessionMint suites; isolation needs monkey-patching or module cache resets\n  ❌ The two writers to one global are invisible at the type level; nobody reviewing SessionMint sees it can clobber AuthBroker's state\nC) Module-level global + `resetAuthCacheForTests()` hook\n  ✅ Cheap; fixes the test-pollution symptom without touching production wiring\n  ✅ No call-site edits\n  ❌ Test-only API shipped in production code; the hidden coupling remains\n  ❌ Does nothing for per-tenant-tier or canary scenarios; you still end up doing A later\nNet: trading a handful of import-site edits for an auth module whose dependencies are visible and whose tests are isolated.": "A) Constructor injection (recommended)"
      },
      "unansweredQuestionIndices": [],
      "answeredAt": "2026-09-16T19:32:24.144Z"
    },
    {
      "sessionId": "6e59025e-0e69-4ae1-80c3-11ae663e2b96",
      "toolUseId": "toolu_014bftzjrHabGgaQnoJhSMek",
      "questions": [
        {
          "question": "D4 — Should AuthCache stop a late SessionMint write from resurrecting a suspended or revoked tenant's session?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), Architecture finding A2. Cache injection (D3) and 5-class structure (D2) are fixed; error handling (R5) stays pending.\nELI10: Two services write to the same cache and nothing orders their writes (the plan says so at PLAN.md:19). Picture this: an admin suspends a tenant, the adapter wipes that tenant's cached sessions, but a session-mint request that started a moment earlier finishes and writes a fresh session back. The suspended tenant stays logged in until that entry expires. The fix is small: the facade remembers a per-tenant \"generation\" number that goes up on every invalidation, and a write is dropped if the generation moved while the write was in flight. The plan's own code does not touch the adapter, so the guard sits in `AuthCache`.\nStakes if we pick wrong: no guard = a suspension or revocation that silently does not take effect for one token lifetime; guard = a few lines plus one race test.\nRecommendation: A because suspension and revocation are the security boundary of a multi-tenant system, the plan explicitly introduces a second writer, and the cost is a counter and a compare.\nCompleteness: A=10/10, B=n/a (investigation only, approves no implementation), C=3/10\nPros / cons:\nA) Per-tenant invalidation generation check in `AuthCache.put()` (recommended) (human: ~1 day incl. race test / CC: ~15 min)\n  ✅ Closes the resurrect-after-invalidate window without changing the adapter or its key rules\n  ✅ One place to enforce it; both writers go through `AuthCache.put()`, so neither service needs to know\n  ✅ Dropped writes are observable (counter/log), so a real race in prod shows up instead of hiding\n  ❌ It is a behavior tightening inside a \"no behavior change\" refactor; must be called out in the PR and covered by its own test\n  ❌ Generation counter is per-process; a multi-instance deploy with a shared backing cache needs the generation stored alongside the entry (small, but must be designed in)\nB) Investigate the existing adapter first, then decide\n  ✅ Avoids building a guard the adapter may already provide\n  ✅ Surfaces whether suspension bumps policy version (which would make stale entries unreachable by key anyway)\n  ❌ Leaves the window open until the investigation lands and a second decision is made\n  ❌ The two-writer situation is new in this plan; even an existing guard was designed for one writer\nC) No guard; document the window as accepted risk\n  ✅ Zero code; refactor stays strictly behavior-neutral\n  ✅ If the window already exists today with legacyAuthFlow, this is status quo\n  ❌ A suspended tenant can keep a valid session for one token lifetime; that is the kind of thing that ends up in a security incident report\n  ❌ Adding SessionMint as a second writer makes the window more likely to be hit than today\nNet: trading a small, explicit behavior tightening for a suspension/revocation that actually takes effect when the admin clicks it.",
          "header": "D4 race guard",
          "multiSelect": false,
          "options": [
            {
              "label": "A) Generation guard in AuthCache.put() (recommended)",
              "description": "`AuthCache` tracks a per-tenant invalidation generation (bumped by the existing invalidation hooks via the facade). `put()` compares the generation captured before the write with the current one and drops the write with a metric if it advanced. Adapter unchanged. Includes a concurrency test."
            },
            {
              "label": "B) Investigate adapter first",
              "description": "Bounded probe of the existing adapter and invalidation hooks: does it already reject post-invalidation writes, and does tenant suspension bump policy version? No implementation approved; a follow-up decision picks the remedy."
            },
            {
              "label": "C) No guard, document the risk",
              "description": "Leave mutations unserialized. Add a note to the plan and PR describing the resurrect-after-invalidate window as accepted risk."
            }
          ]
        }
      ],
      "answered": true,
      "failed": false,
      "answers": {
        "D4 — Should AuthCache stop a late SessionMint write from resurrecting a suspended or revoked tenant's session?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), Architecture finding A2. Cache injection (D3) and 5-class structure (D2) are fixed; error handling (R5) stays pending.\nELI10: Two services write to the same cache and nothing orders their writes (the plan says so at PLAN.md:19). Picture this: an admin suspends a tenant, the adapter wipes that tenant's cached sessions, but a session-mint request that started a moment earlier finishes and writes a fresh session back. The suspended tenant stays logged in until that entry expires. The fix is small: the facade remembers a per-tenant \"generation\" number that goes up on every invalidation, and a write is dropped if the generation moved while the write was in flight. The plan's own code does not touch the adapter, so the guard sits in `AuthCache`.\nStakes if we pick wrong: no guard = a suspension or revocation that silently does not take effect for one token lifetime; guard = a few lines plus one race test.\nRecommendation: A because suspension and revocation are the security boundary of a multi-tenant system, the plan explicitly introduces a second writer, and the cost is a counter and a compare.\nCompleteness: A=10/10, B=n/a (investigation only, approves no implementation), C=3/10\nPros / cons:\nA) Per-tenant invalidation generation check in `AuthCache.put()` (recommended) (human: ~1 day incl. race test / CC: ~15 min)\n  ✅ Closes the resurrect-after-invalidate window without changing the adapter or its key rules\n  ✅ One place to enforce it; both writers go through `AuthCache.put()`, so neither service needs to know\n  ✅ Dropped writes are observable (counter/log), so a real race in prod shows up instead of hiding\n  ❌ It is a behavior tightening inside a \"no behavior change\" refactor; must be called out in the PR and covered by its own test\n  ❌ Generation counter is per-process; a multi-instance deploy with a shared backing cache needs the generation stored alongside the entry (small, but must be designed in)\nB) Investigate the existing adapter first, then decide\n  ✅ Avoids building a guard the adapter may already provide\n  ✅ Surfaces whether suspension bumps policy version (which would make stale entries unreachable by key anyway)\n  ❌ Leaves the window open until the investigation lands and a second decision is made\n  ❌ The two-writer situation is new in this plan; even an existing guard was designed for one writer\nC) No guard; document the window as accepted risk\n  ✅ Zero code; refactor stays strictly behavior-neutral\n  ✅ If the window already exists today with legacyAuthFlow, this is status quo\n  ❌ A suspended tenant can keep a valid session for one token lifetime; that is the kind of thing that ends up in a security incident report\n  ❌ Adding SessionMint as a second writer makes the window more likely to be hit than today\nNet: trading a small, explicit behavior tightening for a suspension/revocation that actually takes effect when the admin clicks it.": "A) Generation guard in AuthCache.put() (recommended)"
      },
      "unansweredQuestionIndices": [],
      "answeredAt": "2026-09-16T19:33:26.406Z"
    },
    {
      "sessionId": "6e59025e-0e69-4ae1-80c3-11ae663e2b96",
      "toolUseId": "toolu_012Q6MDJPMLkDhaWzr8RQLmy",
      "questions": [
        {
          "question": "D5 — How should validateAndDispatch() handle errors: flat fail-closed pipeline, patched catches, or as written?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), Architecture finding A3 / Code quality finding C1. DI (D3), generation guard (D4) and structure (D2) are fixed.\nELI10: The function that decides whether a request gets in has three nested \"try this, and if it blows up, ignore it\" blocks, each ignoring a different kind of failure. In an auth check, ignoring a failure is the dangerous direction: if the token check fails and gets swallowed, does the request still get dispatched? Nobody can tell from a 60-line nest. The clean shape is a short straight line of steps where any failure stops the line and produces an explicit \"denied because X\" with a log entry. Only the success path can reach dispatch.\nStakes if we pick wrong: keep swallowing = a possible fail-open auth bypass that no test will find because the code hides the error; flat pipeline = an afternoon of restructuring you were doing anyway (this is the refactor).\nRecommendation: A because the whole point of the plan is to reorganize this orchestration, and a fail-closed pipeline is the only shape where \"can a swallowed error reach dispatch?\" is answered by structure instead of by reading every catch.\nCompleteness: A=10/10, B=7/10, C=2/10\nPros / cons:\nA) Flat fail-closed pipeline with typed errors and one top-level handler (recommended) (human: ~1.5 days / CC: ~25 min)\n  ✅ Fail-closed by construction: dispatch is the last step and is only reached when every prior step returned normally\n  ✅ Each step (`validateToken`, `loadClaims`, `decideAccess`, `dispatch`) is 10-15 lines and unit-testable on its own, including its error branch\n  ✅ Every denial carries a reason code and a structured log line, so a 3am on-call can tell \"expired token\" from \"IDP down\" from \"policy deny\"\n  ❌ Introduces a small `AuthError` hierarchy (3-4 classes) that must be kept in sync with the reason codes\n  ❌ Changes the observable error surface (callers now see explicit denials where they may have seen silent success or undefined); must be covered by the regression contract in Test review\nB) Keep the nested try/catch, replace each swallow with log + explicit deny\n  ✅ Smallest diff to the existing shape; each catch gets 2 lines\n  ✅ Fail-closed if every catch is audited and none is missed\n  ❌ Still 60 lines and three nesting levels; the next person adds a fourth catch and swallows again\n  ❌ Correctness depends on a human checking each catch rather than on structure\nC) Keep as written (swallowing catches)\n  ✅ Zero effort now\n  ✅ Matches current production behavior exactly\n  ❌ Unknown whether a swallowed error lets a request through; in an auth path that is a potential bypass\n  ❌ Contradicts the plan's own goal of reorganizing the orchestration\nNet: trading a small typed-error hierarchy for an auth entry point where fail-closed is a property of the code shape, not of reviewer diligence.",
          "header": "D5 error flow",
          "multiSelect": false,
          "options": [
            {
              "label": "A) Flat fail-closed pipeline (recommended)",
              "description": "Restructure `validateAndDispatch()` into `validateToken → loadClaims → decideAccess → dispatch`. Each step throws a typed `AuthError` subclass. One top-level handler maps class → explicit deny with reason code + structured log + per-class counter. Dispatch only reachable on the success path. Unit tests per step incl. error branch."
            },
            {
              "label": "B) Patch each catch: log + explicit deny",
              "description": "Keep the three nested try/catch blocks. Replace each silent swallow with a structured log and an explicit deny return. Function stays ~60 lines."
            },
            {
              "label": "C) Keep as written",
              "description": "Leave the three swallowing catches as described in the plan. No error-handling change in this refactor."
            }
          ]
        }
      ],
      "answered": true,
      "failed": false,
      "answers": {
        "D5 — How should validateAndDispatch() handle errors: flat fail-closed pipeline, patched catches, or as written?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), Architecture finding A3 / Code quality finding C1. DI (D3), generation guard (D4) and structure (D2) are fixed.\nELI10: The function that decides whether a request gets in has three nested \"try this, and if it blows up, ignore it\" blocks, each ignoring a different kind of failure. In an auth check, ignoring a failure is the dangerous direction: if the token check fails and gets swallowed, does the request still get dispatched? Nobody can tell from a 60-line nest. The clean shape is a short straight line of steps where any failure stops the line and produces an explicit \"denied because X\" with a log entry. Only the success path can reach dispatch.\nStakes if we pick wrong: keep swallowing = a possible fail-open auth bypass that no test will find because the code hides the error; flat pipeline = an afternoon of restructuring you were doing anyway (this is the refactor).\nRecommendation: A because the whole point of the plan is to reorganize this orchestration, and a fail-closed pipeline is the only shape where \"can a swallowed error reach dispatch?\" is answered by structure instead of by reading every catch.\nCompleteness: A=10/10, B=7/10, C=2/10\nPros / cons:\nA) Flat fail-closed pipeline with typed errors and one top-level handler (recommended) (human: ~1.5 days / CC: ~25 min)\n  ✅ Fail-closed by construction: dispatch is the last step and is only reached when every prior step returned normally\n  ✅ Each step (`validateToken`, `loadClaims`, `decideAccess`, `dispatch`) is 10-15 lines and unit-testable on its own, including its error branch\n  ✅ Every denial carries a reason code and a structured log line, so a 3am on-call can tell \"expired token\" from \"IDP down\" from \"policy deny\"\n  ❌ Introduces a small `AuthError` hierarchy (3-4 classes) that must be kept in sync with the reason codes\n  ❌ Changes the observable error surface (callers now see explicit denials where they may have seen silent success or undefined); must be covered by the regression contract in Test review\nB) Keep the nested try/catch, replace each swallow with log + explicit deny\n  ✅ Smallest diff to the existing shape; each catch gets 2 lines\n  ✅ Fail-closed if every catch is audited and none is missed\n  ❌ Still 60 lines and three nesting levels; the next person adds a fourth catch and swallows again\n  ❌ Correctness depends on a human checking each catch rather than on structure\nC) Keep as written (swallowing catches)\n  ✅ Zero effort now\n  ✅ Matches current production behavior exactly\n  ❌ Unknown whether a swallowed error lets a request through; in an auth path that is a potential bypass\n  ❌ Contradicts the plan's own goal of reorganizing the orchestration\nNet: trading a small typed-error hierarchy for an auth entry point where fail-closed is a property of the code shape, not of reviewer diligence.": "A) Flat fail-closed pipeline (recommended)"
      },
      "unansweredQuestionIndices": [],
      "answeredAt": "2026-09-16T19:34:38.761Z"
    },
    {
      "sessionId": "6e59025e-0e69-4ae1-80c3-11ae663e2b96",
      "toolUseId": "toolu_01UvARvRSQkCUvRJtEC13iew",
      "questions": [
        {
          "question": "D6 — How do we prove the rewritten auth flow still makes the same allow/deny decisions as legacyAuthFlow()?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), Test review finding T1 (CRITICAL regression risk). DI (D3), generation guard (D4) and fail-closed pipeline (D5) are fixed. This question chooses how to cover the regression, not whether.\nELI10: The plan replaces the code that decides who gets in, and says it will not test that the new code agrees with the old one. The cheap way to make that safe: before touching anything, write a table of inputs (good token, expired, wrong tenant, revoked, suspended tenant, IDP down, cache hit, cache miss...) and record what the old code answers for each. That table becomes a test. The new code must produce the same answers, except for the two changes we chose on purpose (explicit denials, dropped stale writes), which get their own assertions. Ship behind a flag so a surprise is one flip away from undone.\nStakes if we pick wrong: no characterization = a tenant that used to be allowed is denied (or the reverse) and you find out from a support ticket; with it = an afternoon of fixture writing that CC does in minutes.\nRecommendation: A because it protects every behavior class at risk with tests that run in CI, costs minutes with CC, and stays reversible via the flag; B adds real production safety but doubles IDP traffic per request during the bake, which the plan's own 5-sequential-calls finding makes expensive.\nCompleteness: A=9/10, B=10/10, C=4/10\nPros / cons:\nA) Characterization suite + intended-delta assertions + 4 E2E flows + flag cutover (recommended) (human: ~2 days / CC: ~30 min)\n  ✅ Every behavior class at risk (allow/deny matrix, cache hit/miss, three invalidation triggers) has a CI assertion recorded from the real legacy code before it is deleted\n  ✅ Intended deltas from D4/D5 are asserted explicitly, so \"different\" is either expected and tested or a failure\n  ✅ Feature-flag cutover makes a production surprise a flip, not a revert-and-redeploy\n  ❌ Only as good as the fixture matrix; a legacy quirk not in the matrix is not protected\n  ❌ Flag adds a temporary second code path to remove after cutover\nB) Everything in A plus a production shadow-run diff for a bake period\n  ✅ Catches legacy quirks that no fixture author thought of, on real traffic\n  ✅ Highest confidence available before deleting legacyAuthFlow()\n  ❌ Doubles IDP calls per authenticated request during the bake (10 sequential calls with today's flow); latency and IDP rate limits become a rollout risk\n  ❌ Needs decision-compare plumbing and log storage that is thrown away after cutover (human: ~1 week / CC: ~1.5 h)\nC) E2E smoke only against the new flow\n  ✅ Fast to write; proves the happy path works end to end\n  ✅ No legacy fixture recording needed\n  ❌ Does not protect allow/deny parity for denied classes, cache semantics or invalidation; exactly the cases where regressions are silent\n  ❌ Violates the regression rule for a rewrite of the auth decision path\nNet: trading an afternoon of fixture recording for proof that the new gatekeeper answers the same as the old one, with the two intentional differences named.",
          "header": "D6 regression",
          "multiSelect": false,
          "options": [
            {
              "label": "A) Characterization + deltas + E2E + flag (recommended)",
              "description": "Record legacyAuthFlow() outcomes over a fixture matrix (valid, expired, bad signature, wrong issuer, wrong audience, revoked, suspended tenant, IDP timeout/5xx per call, cache hit, cache miss) into `legacyAuthFlow.characterization.test.ts`; run the same matrix against AuthBroker. Assert D4/D5 deltas separately. 4 E2E flows (login/request, logout, suspension, revocation). Cutover behind a feature flag."
            },
            {
              "label": "B) A + production shadow-run diff",
              "description": "All of A, plus run the new flow alongside legacy behind the flag in production, compare decisions, log diffs for a bake period before cutover. Doubles IDP calls per request during the bake."
            },
            {
              "label": "C) E2E smoke only",
              "description": "Login → authorized request → logout E2E against the new flow only. No characterization of legacy behavior; no intended-delta assertions."
            }
          ]
        }
      ],
      "answered": true,
      "failed": false,
      "answers": {
        "D6 — How do we prove the rewritten auth flow still makes the same allow/deny decisions as legacyAuthFlow()?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), Test review finding T1 (CRITICAL regression risk). DI (D3), generation guard (D4) and fail-closed pipeline (D5) are fixed. This question chooses how to cover the regression, not whether.\nELI10: The plan replaces the code that decides who gets in, and says it will not test that the new code agrees with the old one. The cheap way to make that safe: before touching anything, write a table of inputs (good token, expired, wrong tenant, revoked, suspended tenant, IDP down, cache hit, cache miss...) and record what the old code answers for each. That table becomes a test. The new code must produce the same answers, except for the two changes we chose on purpose (explicit denials, dropped stale writes), which get their own assertions. Ship behind a flag so a surprise is one flip away from undone.\nStakes if we pick wrong: no characterization = a tenant that used to be allowed is denied (or the reverse) and you find out from a support ticket; with it = an afternoon of fixture writing that CC does in minutes.\nRecommendation: A because it protects every behavior class at risk with tests that run in CI, costs minutes with CC, and stays reversible via the flag; B adds real production safety but doubles IDP traffic per request during the bake, which the plan's own 5-sequential-calls finding makes expensive.\nCompleteness: A=9/10, B=10/10, C=4/10\nPros / cons:\nA) Characterization suite + intended-delta assertions + 4 E2E flows + flag cutover (recommended) (human: ~2 days / CC: ~30 min)\n  ✅ Every behavior class at risk (allow/deny matrix, cache hit/miss, three invalidation triggers) has a CI assertion recorded from the real legacy code before it is deleted\n  ✅ Intended deltas from D4/D5 are asserted explicitly, so \"different\" is either expected and tested or a failure\n  ✅ Feature-flag cutover makes a production surprise a flip, not a revert-and-redeploy\n  ❌ Only as good as the fixture matrix; a legacy quirk not in the matrix is not protected\n  ❌ Flag adds a temporary second code path to remove after cutover\nB) Everything in A plus a production shadow-run diff for a bake period\n  ✅ Catches legacy quirks that no fixture author thought of, on real traffic\n  ✅ Highest confidence available before deleting legacyAuthFlow()\n  ❌ Doubles IDP calls per authenticated request during the bake (10 sequential calls with today's flow); latency and IDP rate limits become a rollout risk\n  ❌ Needs decision-compare plumbing and log storage that is thrown away after cutover (human: ~1 week / CC: ~1.5 h)\nC) E2E smoke only against the new flow\n  ✅ Fast to write; proves the happy path works end to end\n  ✅ No legacy fixture recording needed\n  ❌ Does not protect allow/deny parity for denied classes, cache semantics or invalidation; exactly the cases where regressions are silent\n  ❌ Violates the regression rule for a rewrite of the auth decision path\nNet: trading an afternoon of fixture recording for proof that the new gatekeeper answers the same as the old one, with the two intentional differences named.": "A) Characterization + deltas + E2E + flag (recommended)"
      },
      "unansweredQuestionIndices": [],
      "answeredAt": "2026-09-16T19:36:38.910Z"
    },
    {
      "sessionId": "6e59025e-0e69-4ae1-80c3-11ae663e2b96",
      "toolUseId": "toolu_01VodwTr58bM8ApViTdyesAs",
      "questions": [
        {
          "question": "D7 — TODO: Cache IDP discovery metadata and JWKS per issuer, then re-evaluate parallelizing what remains?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md). Follow-up to D1 (parallelization deferred) and Performance findings P1/P2.\nELI10: Every token check today makes five trips to the identity provider, one after another. The plan wanted to fire them all at once. But two or three of those trips are almost certainly fetching the provider's public config and signing keys, which change rarely and are meant to be cached for minutes to hours. Cache those and most trips disappear; then see if anything is left worth parallelizing.\nStakes if we pick wrong: skipped = the latency problem D1 deferred is never picked up; added = a captured follow-up with the right shape (cache first, parallelize second).\nRecommendation: A because D1 deferred the latency fix on the promise of capturing it, and this TODO records the corrected approach so the follow-up does not just reimplement Promise.all.\nNote: options differ in kind, not coverage — no completeness score.\nWhat: Add per-issuer caches for OIDC discovery (hours TTL) and JWKS (minutes-hours TTL, refresh on unknown kid, no unbounded refetch loop); then measure remaining IDP calls per validation and parallelize only genuinely independent ones.\nWhy: 5 sequential IDP round trips per cache-miss validation is the dominant auth latency; caching removes most of them and reduces IDP load, unlike Promise.all which increases burst load 5x.\nContext: Deferred from this refactor by D1 to keep it behavior-neutral. Verify first which of the 5 calls are metadata vs per-token. Layer 1 practice per SSOJet / OneUptime references in the review. Start in the validateToken step of AuthBroker once the D5 pipeline lands.\nEffort: M  Priority: P2  Depends on: this refactor landing (D5 pipeline gives a single place to add the cache).\nPros / cons:\nA) Add to TODOS (recommended)\n  ✅ Keeps D1's deferral honest: the latency work has a captured owner and the right approach\n  ✅ Cache-first framing prevents a follow-up that only reimplements Promise.all and 5x IDP burst\n  ❌ One more TODO to groom\nB) Skip — not valuable enough\n  ✅ Nothing to track\n  ✅ Team may already have this on a roadmap elsewhere\n  ❌ The 5x sequential latency deferred by D1 is silently dropped\nC) Build it now in this PR\n  ✅ Users get the latency win in the same release\n  ✅ D5 pipeline is the natural insertion point and is being written anyway\n  ❌ Reintroduces a behavior change into the refactor that D1 explicitly separated; contradicts an approved decision (would need D1 reopened)\nNet: trading one groomed TODO for not losing the latency fix and not doing it the wrong way.",
          "header": "D7 TODO",
          "multiSelect": false,
          "options": [
            {
              "label": "A) Add to TODOS (recommended)",
              "description": "Record the TODO as written (cache discovery + JWKS per issuer, then re-evaluate parallelization). Not persisted to TODOS.md in plan mode; recorded in the report file."
            },
            {
              "label": "B) Skip",
              "description": "Do not capture. The deferred latency work is dropped from this review's record."
            },
            {
              "label": "C) Build it now in this PR",
              "description": "Include IDP metadata caching in this refactor. Contradicts D1 (behavior-neutral refactor); would require reopening D1 with a new question."
            }
          ]
        }
      ],
      "answered": true,
      "failed": false,
      "answers": {
        "D7 — TODO: Cache IDP discovery metadata and JWKS per issuer, then re-evaluate parallelizing what remains?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md). Follow-up to D1 (parallelization deferred) and Performance findings P1/P2.\nELI10: Every token check today makes five trips to the identity provider, one after another. The plan wanted to fire them all at once. But two or three of those trips are almost certainly fetching the provider's public config and signing keys, which change rarely and are meant to be cached for minutes to hours. Cache those and most trips disappear; then see if anything is left worth parallelizing.\nStakes if we pick wrong: skipped = the latency problem D1 deferred is never picked up; added = a captured follow-up with the right shape (cache first, parallelize second).\nRecommendation: A because D1 deferred the latency fix on the promise of capturing it, and this TODO records the corrected approach so the follow-up does not just reimplement Promise.all.\nNote: options differ in kind, not coverage — no completeness score.\nWhat: Add per-issuer caches for OIDC discovery (hours TTL) and JWKS (minutes-hours TTL, refresh on unknown kid, no unbounded refetch loop); then measure remaining IDP calls per validation and parallelize only genuinely independent ones.\nWhy: 5 sequential IDP round trips per cache-miss validation is the dominant auth latency; caching removes most of them and reduces IDP load, unlike Promise.all which increases burst load 5x.\nContext: Deferred from this refactor by D1 to keep it behavior-neutral. Verify first which of the 5 calls are metadata vs per-token. Layer 1 practice per SSOJet / OneUptime references in the review. Start in the validateToken step of AuthBroker once the D5 pipeline lands.\nEffort: M  Priority: P2  Depends on: this refactor landing (D5 pipeline gives a single place to add the cache).\nPros / cons:\nA) Add to TODOS (recommended)\n  ✅ Keeps D1's deferral honest: the latency work has a captured owner and the right approach\n  ✅ Cache-first framing prevents a follow-up that only reimplements Promise.all and 5x IDP burst\n  ❌ One more TODO to groom\nB) Skip — not valuable enough\n  ✅ Nothing to track\n  ✅ Team may already have this on a roadmap elsewhere\n  ❌ The 5x sequential latency deferred by D1 is silently dropped\nC) Build it now in this PR\n  ✅ Users get the latency win in the same release\n  ✅ D5 pipeline is the natural insertion point and is being written anyway\n  ❌ Reintroduces a behavior change into the refactor that D1 explicitly separated; contradicts an approved decision (would need D1 reopened)\nNet: trading one groomed TODO for not losing the latency fix and not doing it the wrong way.": "A) Add to TODOS (recommended)"
      },
      "unansweredQuestionIndices": [],
      "answeredAt": "2026-09-16T19:38:45.239Z"
    },
    {
      "sessionId": "6e59025e-0e69-4ae1-80c3-11ae663e2b96",
      "toolUseId": "toolu_015SScX8jh3aYbHCJxZ3zYiL",
      "questions": [
        {
          "question": "D8 — TODO: Bound the AuthCache entry count (size limit / LRU) on top of expiry eviction?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md). Performance finding P3 (confidence 5/10, medium: verify the adapter first).\nELI10: The cache throws entries away when they expire, but the plan never says it throws them away when there are too many. Keys combine tenant, issuer, audience and policy version, so a large multi-tenant fleet can grow the cache without limit until the process runs out of memory. This is a follow-up check, not a change to this refactor, because the adapter is explicitly kept unchanged.\nStakes if we pick wrong: skipped = a slow memory leak that shows up as an OOM restart months from now; added = a 30-minute check of the adapter and, if needed, a max-entries setting.\nRecommendation: A because it is cheap to check, the failure mode is silent, and the adapter contract in this plan (unchanged) means it will not get looked at otherwise.\nNote: options differ in kind, not coverage — no completeness score.\nWhat: Verify whether the existing cache adapter bounds entry count; if not, add a max-entries / LRU policy with a metric for evictions-by-size.\nWhy: Expiry-only eviction is unbounded under many tenants x issuers x audiences x policy versions; a policy-version bump orphans every old entry until expiry.\nContext: Raised at confidence 5/10 in the eng review because the adapter source was not available. Start by reading the adapter's eviction code and its tests (PLAN.md:16-22 says both exist). If bounded already, close the TODO with a note.\nEffort: S  Priority: P3  Depends on: None.\nPros / cons:\nA) Add to TODOS (recommended)\n  ✅ Cheap check that closes a silent, slow failure mode before it becomes a 3am OOM page\n  ✅ Keeps the adapter-unchanged contract of this refactor intact\n  ❌ May turn out to be already handled (then it is a 10-minute close)\nB) Skip — not valuable enough\n  ✅ Nothing to track\n  ✅ If the adapter is a bounded store (e.g. Redis with maxmemory), this is moot\n  ❌ If it is unbounded, nobody finds out until memory runs out\nC) Build it now in this PR\n  ✅ Closes the gap in the same release\n  ❌ Changes the adapter, which this plan explicitly keeps unchanged (PLAN.md:21-22); contradicts the retained contract\nNet: trading one small TODO for not discovering the cache's memory ceiling in production.",
          "header": "D8 TODO",
          "multiSelect": false,
          "options": [
            {
              "label": "A) Add to TODOS (recommended)",
              "description": "Record the TODO as written (verify adapter bound; add max-entries/LRU with eviction metric if missing). Not persisted to TODOS.md in plan mode; recorded in the report file."
            },
            {
              "label": "B) Skip",
              "description": "Do not capture."
            },
            {
              "label": "C) Build it now in this PR",
              "description": "Add a size bound to the adapter in this refactor. Contradicts the plan's adapter-unchanged contract."
            }
          ]
        }
      ],
      "answered": true,
      "failed": false,
      "answers": {
        "D8 — TODO: Bound the AuthCache entry count (size limit / LRU) on top of expiry eviction?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md). Performance finding P3 (confidence 5/10, medium: verify the adapter first).\nELI10: The cache throws entries away when they expire, but the plan never says it throws them away when there are too many. Keys combine tenant, issuer, audience and policy version, so a large multi-tenant fleet can grow the cache without limit until the process runs out of memory. This is a follow-up check, not a change to this refactor, because the adapter is explicitly kept unchanged.\nStakes if we pick wrong: skipped = a slow memory leak that shows up as an OOM restart months from now; added = a 30-minute check of the adapter and, if needed, a max-entries setting.\nRecommendation: A because it is cheap to check, the failure mode is silent, and the adapter contract in this plan (unchanged) means it will not get looked at otherwise.\nNote: options differ in kind, not coverage — no completeness score.\nWhat: Verify whether the existing cache adapter bounds entry count; if not, add a max-entries / LRU policy with a metric for evictions-by-size.\nWhy: Expiry-only eviction is unbounded under many tenants x issuers x audiences x policy versions; a policy-version bump orphans every old entry until expiry.\nContext: Raised at confidence 5/10 in the eng review because the adapter source was not available. Start by reading the adapter's eviction code and its tests (PLAN.md:16-22 says both exist). If bounded already, close the TODO with a note.\nEffort: S  Priority: P3  Depends on: None.\nPros / cons:\nA) Add to TODOS (recommended)\n  ✅ Cheap check that closes a silent, slow failure mode before it becomes a 3am OOM page\n  ✅ Keeps the adapter-unchanged contract of this refactor intact\n  ❌ May turn out to be already handled (then it is a 10-minute close)\nB) Skip — not valuable enough\n  ✅ Nothing to track\n  ✅ If the adapter is a bounded store (e.g. Redis with maxmemory), this is moot\n  ❌ If it is unbounded, nobody finds out until memory runs out\nC) Build it now in this PR\n  ✅ Closes the gap in the same release\n  ❌ Changes the adapter, which this plan explicitly keeps unchanged (PLAN.md:21-22); contradicts the retained contract\nNet: trading one small TODO for not discovering the cache's memory ceiling in production.": "A) Add to TODOS (recommended)"
      },
      "unansweredQuestionIndices": [],
      "answeredAt": "2026-09-16T19:39:05.861Z"
    },
    {
      "sessionId": "6e59025e-0e69-4ae1-80c3-11ae663e2b96",
      "toolUseId": "toolu_018ZYEPSYEAXtGbvDbk2XaUj",
      "questions": [
        {
          "question": "D9 — TODO: Remove the `auth.brokerFlow` feature flag and delete legacyAuthFlow() after cutover?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md). Follow-up created by D6 (flag-based cutover).\nELI10: D6 ships the new flow behind a flag so you can flip back if something is wrong. That is the right call, but a flag that never gets removed becomes a permanent second code path that nobody dares delete. This TODO is the reminder to remove the flag and the old flow once the new one has run cleanly.\nStakes if we pick wrong: skipped = two auth flows live forever and every future change has to be made twice; added = a tracked cleanup with a clear trigger.\nRecommendation: A because D6's accepted scope already says the flag and legacyAuthFlow() come out in a follow-up; this gives that follow-up a home and a trigger.\nNote: options differ in kind, not coverage — no completeness score.\nWhat: After the broker flow has been at 100% with no flag flips for an agreed bake window, delete `legacyAuthFlow()`, the `auth.brokerFlow` flag, and the legacy half of the characterization harness (keep the matrix running against AuthBroker only).\nWhy: A permanent flag doubles the maintenance surface of the auth path and keeps dead code that the security team still has to audit.\nContext: Created by D6 (characterization + flag cutover). Trigger: flag at 100% for the bake window with zero `auth_cache.put_dropped_stale` anomalies and zero rollbacks. The characterization matrix stays as the AuthBroker regression suite.\nEffort: S  Priority: P2  Depends on: this refactor shipped and baked at 100%.\nPros / cons:\nA) Add to TODOS (recommended)\n  ✅ Gives D6's promised cleanup a tracked owner and an objective trigger\n  ✅ Prevents the classic permanent-flag outcome for the most security-sensitive path in the codebase\n  ❌ One more TODO to groom\nB) Skip — not valuable enough\n  ✅ Nothing to track\n  ❌ D6's follow-up cleanup has no home; two auth flows likely persist\nC) Build it now in this PR\n  ✅ No cleanup later\n  ❌ Deleting the legacy flow in the same PR removes the flag's whole point (instant rollback); contradicts D6's accepted scope\nNet: trading one groomed TODO for an auth path that ends up with one implementation, not two.",
          "header": "D9 TODO",
          "multiSelect": false,
          "options": [
            {
              "label": "A) Add to TODOS (recommended)",
              "description": "Record the TODO as written (remove flag + legacyAuthFlow after bake). Not persisted to TODOS.md in plan mode; recorded in the report file."
            },
            {
              "label": "B) Skip",
              "description": "Do not capture."
            },
            {
              "label": "C) Build it now in this PR",
              "description": "Delete legacyAuthFlow() and skip the flag in this PR. Contradicts D6's flag-based cutover."
            }
          ]
        }
      ],
      "answered": true,
      "failed": false,
      "answers": {
        "D9 — TODO: Remove the `auth.brokerFlow` feature flag and delete legacyAuthFlow() after cutover?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md). Follow-up created by D6 (flag-based cutover).\nELI10: D6 ships the new flow behind a flag so you can flip back if something is wrong. That is the right call, but a flag that never gets removed becomes a permanent second code path that nobody dares delete. This TODO is the reminder to remove the flag and the old flow once the new one has run cleanly.\nStakes if we pick wrong: skipped = two auth flows live forever and every future change has to be made twice; added = a tracked cleanup with a clear trigger.\nRecommendation: A because D6's accepted scope already says the flag and legacyAuthFlow() come out in a follow-up; this gives that follow-up a home and a trigger.\nNote: options differ in kind, not coverage — no completeness score.\nWhat: After the broker flow has been at 100% with no flag flips for an agreed bake window, delete `legacyAuthFlow()`, the `auth.brokerFlow` flag, and the legacy half of the characterization harness (keep the matrix running against AuthBroker only).\nWhy: A permanent flag doubles the maintenance surface of the auth path and keeps dead code that the security team still has to audit.\nContext: Created by D6 (characterization + flag cutover). Trigger: flag at 100% for the bake window with zero `auth_cache.put_dropped_stale` anomalies and zero rollbacks. The characterization matrix stays as the AuthBroker regression suite.\nEffort: S  Priority: P2  Depends on: this refactor shipped and baked at 100%.\nPros / cons:\nA) Add to TODOS (recommended)\n  ✅ Gives D6's promised cleanup a tracked owner and an objective trigger\n  ✅ Prevents the classic permanent-flag outcome for the most security-sensitive path in the codebase\n  ❌ One more TODO to groom\nB) Skip — not valuable enough\n  ✅ Nothing to track\n  ❌ D6's follow-up cleanup has no home; two auth flows likely persist\nC) Build it now in this PR\n  ✅ No cleanup later\n  ❌ Deleting the legacy flow in the same PR removes the flag's whole point (instant rollback); contradicts D6's accepted scope\nNet: trading one groomed TODO for an auth path that ends up with one implementation, not two.": "A) Add to TODOS (recommended)"
      },
      "unansweredQuestionIndices": [],
      "answeredAt": "2026-09-16T19:39:26.488Z"
    },
    {
      "sessionId": "6e59025e-0e69-4ae1-80c3-11ae663e2b96",
      "toolUseId": "toolu_01P9MuCa9P3BcMtKu2YfN3mv",
      "questions": [
        {
          "question": "D10 — Next step after the engineering review?\nProject/branch/task: main — Multi-tenant Auth Refactor, eng review CLEAR with 0 critical gaps.\nELI10: The plan now has every architecture and test decision locked in and written down. The only remaining review lanes (design, DX) are for user-facing UI or developer-tool changes, and this is an internal auth reorg with no UI — so there is nothing else to review before coding starts.\nStakes if we pick wrong: Running an inapplicable review wastes a cycle; skipping straight to coding is safe because the regression contract (D6) gates the rewrite.\nRecommendation: Ready to implement because no UI or developer-facing surface changed and all nine decisions are answered.\nNote: options differ in kind, not coverage — no completeness score.\nNet: proceed to implementation; run /ship when the work is done.",
          "header": "Next step",
          "multiSelect": false,
          "options": [
            {
              "label": "Ready to implement (recommended)",
              "description": "✅ All D1–D9 decisions answered; 0 critical gaps; tasks T1–T9 and lanes written. ✅ Start lanes A (characterization), B (AuthCache guard), C (RequestPolicy) now; run /ship when done. ❌ TokenStore lane stays blocked until you write its one-paragraph responsibility."
            },
            {
              "label": "Run /plan-design-review first",
              "description": "✅ Would catch UI/UX gaps if any screens changed. ❌ Not applicable — this refactor changes no user-facing surface; the review would find nothing to act on."
            }
          ]
        }
      ],
      "answered": true,
      "failed": false,
      "answers": {
        "D10 — Next step after the engineering review?\nProject/branch/task: main — Multi-tenant Auth Refactor, eng review CLEAR with 0 critical gaps.\nELI10: The plan now has every architecture and test decision locked in and written down. The only remaining review lanes (design, DX) are for user-facing UI or developer-tool changes, and this is an internal auth reorg with no UI — so there is nothing else to review before coding starts.\nStakes if we pick wrong: Running an inapplicable review wastes a cycle; skipping straight to coding is safe because the regression contract (D6) gates the rewrite.\nRecommendation: Ready to implement because no UI or developer-facing surface changed and all nine decisions are answered.\nNote: options differ in kind, not coverage — no completeness score.\nNet: proceed to implementation; run /ship when the work is done.": "Ready to implement (recommended)"
      },
      "unansweredQuestionIndices": [],
      "answeredAt": "2026-09-16T19:44:54.473Z"
    }
  ],
  "report": "# Reviewed Plan: Multi-tenant Auth Refactor\n\nReviewed target: `PLAN.md` (`/tmp/g-i9l1d1pe/gstack-paid-shard-E4OT6Q/tmp/gstack-plan-count-VjWQw7/PLAN.md`, branch `main`, commit `70230ec`)\nReview: `/plan-eng-review`, 2026-09-16. Report file chosen per write policy rule 1 (user-requested path).\nEvidence note: the repository holds only `PLAN.md` and `CLAUDE.md`. No source for `validateAndDispatch()`, the cache adapter, or `legacyAuthFlow()` is available here; runtime evidence is **unknown** for every finding. Confidence is calibrated against the plan text.\n\n---\n\n# Plan: Multi-tenant Auth Refactor\n\n## Context supplied by the plan author\nThe goal is to reorganize existing tenant-auth orchestration without changing\nits product behavior. RequestPolicy groups the existing per-request access\ndecision: given already-fetched claims and tenant/request context, it returns\nallow or deny under the existing access policy. AuthBroker.validateAndDispatch()\ncalls it after validation and before dispatch. It adds no policy, network call,\ncache mutation or state. Its separate class boundary remains a proposal to review.\n\n## Existing contracts retained\nThe existing cache adapter keys entries by tenant ID, issuer, audience,\nand policy version. It evicts expired tokens and invalidates entries on\nlogout, token revocation, or tenant suspension. AuthCache retains these\nunchanged validity and tenant-key rules; they do not serialize mutations.\nAuthCache is a service-facing facade over that same existing adapter,\nwith one backing cache. The adapter, its invalidation hooks, and their\nexisting tests remain in use unchanged.\nUnit and integration coverage is planned for the new components and their\nsuccess/error paths. That coverage does not exercise legacyAuthFlow() or\nassert compatibility with its prior behavior.\n\n## Architecture\nTwo new services (`AuthBroker` and `SessionMint`) share a global mutable\n`AuthCache` instance via module-level export. Both services mutate it.\n\n## Code quality\nThe `validateAndDispatch()` function is 60 lines with three nested\ntry/catch blocks; each catch swallows a different error class.\n\n## Tests\nThe existing `legacyAuthFlow()` will get rewritten as part of this work;\nno regression test for the prior behavior is planned.\n\n## Performance\nToken validation issues 5 sequential API calls to the IDP; they could be\nparallelized via Promise.all trivially (calls are independent).\n\n## Architecture (scope smell)\nThis touches 12 files and introduces 5 new classes (AuthBroker, TokenStore,\nSessionMint, AuthCache, RequestPolicy). Worth flagging the complexity check.\n\n---\n\n## Accepted amendments (applied by this review)\n\n### Scope (D1, D2)\n- **Parallelization removed from this refactor (D1 → A).** The `## Performance` item above is out of scope for this branch. The refactor is behavior-neutral: same call sequence to the IDP as today. Follow-up captured in TODOS decisions below.\n- **Structure kept at 5 classes (D2 → A):** `AuthBroker`, `TokenStore`, `SessionMint`, `AuthCache`, `RequestPolicy`, ~12 files. Accepted condition: the plan must state `TokenStore`'s responsibility, distinct from `AuthCache` (`AuthCache` is the facade over the existing adapter; `TokenStore` must not hold a second copy of adapter entries or re-implement the tenant/issuer/audience/policy-version key rules). **Author to fill in** before implementation starts:\n  - `TokenStore` responsibility: _<pending author input>_\n  - Lifetime/ownership of what it holds and why the adapter cannot hold it: _<pending author input>_\n\n### Architecture (D3, D4)\n- **Cache acquisition (D3 → A):** one `AuthCache` is created in a composition root `createAuthServices()` and passed into the `AuthBroker` and `SessionMint` constructors. The module-level mutable export is removed. Still one backing cache (the existing adapter). Import sites that used the flow directly go through the factory.\n- **Post-invalidation write guard (D4 → A):** `AuthCache` keeps a per-tenant invalidation generation, bumped through the facade by the existing logout / revocation / suspension hooks. `AuthCache.put()` captures the generation before the write and drops the write (no-op + `auth_cache.put_dropped_stale` metric/log) if it advanced. Adapter and its key/validity rules unchanged. In multi-instance deployments the generation is stored alongside the entry in the backing cache, not per process. This is the **one intentional behavior tightening** in the refactor; call it out in the PR description.\n- Both `AuthBroker` and `SessionMint` write only through `AuthCache.put()`; neither reimplements tenant/issuer/audience/policy-version key construction.\n\n### Code quality (D5)\n- **`validateAndDispatch()` becomes a fail-closed pipeline (D5 → A):** a ~15-line orchestrator over `validateToken → loadClaims → decideAccess (RequestPolicy) → dispatch`. Each step throws a typed `AuthError` subclass (`TokenInvalidError`, `ClaimsUnavailableError`, `PolicyDeniedError`, `IdpUnavailableError`). One top-level handler maps the class to an explicit deny with reason code, a structured log line and a per-class counter. Unknown errors → deny with `internal` reason. `dispatch()` is reachable only on the success path. No catch swallows.\n- `RequestPolicy` stays a class (D2) but is constructed with no dependencies, so `AuthBroker` tests use the real policy rather than a mock.\n\n### Tests (D6 and required proof for D3–D5)\n- **Regression contract (D6 → A):** `legacyAuthFlow.characterization.test.ts` is recorded against the existing `legacyAuthFlow()` **before any rewrite**, over the matrix: valid; expired; bad signature; wrong issuer; wrong audience; revoked; suspended tenant; IDP timeout and 5xx for each of the 5 calls; cache hit; cache miss. It asserts allow/deny outcome, cache read/write effect and invalidation on logout/revocation/suspension. The identical matrix runs against `AuthBroker.validateAndDispatch()`. Intended deltas asserted separately: explicit deny + reason where legacy swallowed (D5); stale write dropped after invalidation (D4).\n- **Four E2E flows:** login → mint → authorized request → dispatch; logout → next request denied; tenant suspension → in-flight and next request denied; IDP revocation → next request denied.\n- **Cutover behind a feature flag** (`auth.brokerFlow` or project convention). Flag and `legacyAuthFlow()` removed in a follow-up (TODO D9).\n- Required proof of approved behavior (no separate approval needed): per-step unit tests incl. error branch and \"AuthError never reaches dispatch\" (D5); concurrency test for the generation guard, both orderings (D4); services constructed over a fake adapter with a fresh `AuthCache` per test (D3); `RequestPolicy` allow/deny table test.\n- The plan's line \"That coverage does not exercise legacyAuthFlow() or assert compatibility with its prior behavior\" is superseded by D6.\n\n### Performance (D1)\n- No performance change ships in this refactor. IDP call sequence is unchanged. Follow-ups captured as TODOs (D7, D8).\n\n### Data flow (added, A5)\n```\n            request(token, tenantCtx)\n                     │\n                     ▼\n  ┌──────────────── AuthBroker.validateAndDispatch() ─────────────────┐\n  │  validateToken ──► loadClaims ──► decideAccess ──► dispatch        │\n  │       │                │          (RequestPolicy)      ▲          │\n  │       │ IDP (5 calls,  │ AuthCache.get()               │ success  │\n  │       │ unchanged)     │ hit ─► claims                 │ only     │\n  │       │                │ miss ─► fetch ─► AuthCache.put()         │\n  │       ▼                ▼                                          │\n  │  any AuthError ──► top-level handler ──► deny(reason) + log + ctr │\n  └───────────────────────────────────────────────────────────────────┘\n\n  SessionMint.mint() ──► AuthCache.put()  ──┐\n                                            ├─► AuthCache (facade) ─► existing adapter\n  logout / revoke / suspend hooks ──────────┘     │ per-tenant generation   (keys: tenant, issuer,\n        (bump generation, invalidate)             │ put() drops stale write  audience, policyVersion)\n                                                  ▼\n                                       auth_cache.put_dropped_stale (metric)\n\n  createAuthServices()  ──constructs──►  AuthCache, AuthBroker(cache, policy), SessionMint(cache)\n  TokenStore: responsibility pending author input (D2 condition)\n```\n\n---\n\n## Decision ledger\n\n### S1: Defer Promise.all parallelization out of this refactor\nFinding: S2, P2, confidence 9/10, PLAN.md:39-41, reviewer: Claude (plan-eng-review)\nPlan baseline: parallelize 5 IDP calls via Promise.all inside this refactor (original proposal)\nRuntime evidence: unknown (no source in repo); plan asserts the 5 calls are independent, unverified\nComparison grid:\n| Choice | Current | A | B |\n|---|---|---|---|\n| S1 parallelization in this branch | included | deferred to follow-up | kept, separate commit + IDP load check |\nQuestion D1: (initial scope selector, asked pre-ledger per Scope Challenge rules) \"Keep the Promise.all IDP parallelization inside this refactor, or split it out?\" Recommendation: A because structural and behavioral changes should land separately.\nHeader: D1 scope\nOptions:\nA) Defer parallelization (recommended)\nRemove the Promise.all change from this refactor. Record it as a follow-up. Refactor stays behavior-neutral.\nB) Keep it in this PR\nKeep the Promise.all parallelization in this branch as its own commit. Requires verifying the 5 calls are truly independent and adding IDP load/rate-limit checks before merge.\n\nState: approved\nActual answer: A (D1 answer, this session)\nAccepted scope: Promise.all parallelization removed from this refactor; follow-up to be captured as a TODO decision.\nHistory: none\n\n### S2: Class arrangement (5 classes vs smaller)\nFinding: S1, P1, confidence 8/10, PLAN.md:44-45, reviewer: Claude (plan-eng-review)\nPlan baseline: 5 new classes across 12 files (original proposal)\nRuntime evidence: unknown; TokenStore has no stated responsibility in the plan\nComparison grid:\n| Choice | Current | A | B | C |\n|---|---|---|---|---|\n| S2 structure | 5 classes | 5 classes + written TokenStore responsibility | 3 units (RequestPolicy → fn, TokenStore folded into AuthCache) | 4 units (RequestPolicy → fn) |\n| S1 parallelization | deferred (D1) | deferred | deferred | deferred |\nQuestion D2: (initial scope selector) \"Five new classes, or a three-unit arrangement with the same features?\" Recommendation: B because RequestPolicy is stateless and TokenStore undefined. Completeness: A=10/10, B=10/10.\nHeader: D2 structure\nOptions:\nA) Keep 5 classes\nKeep AuthBroker, TokenStore, SessionMint, AuthCache, RequestPolicy as five separate classes across ~12 files. Plan must add a written responsibility for TokenStore distinct from AuthCache.\nB) 3 units (recommended)\nAuthBroker, SessionMint, AuthCache as classes. RequestPolicy becomes a pure function decideAccess(claims, ctx) in its own module. TokenStore folded into AuthCache. ~8-9 files.\nC) 4 units: keep TokenStore, drop RequestPolicy class\nAuthBroker, TokenStore, SessionMint, AuthCache as classes; RequestPolicy becomes a pure function.\n\nState: approved\nActual answer: A (D2 answer, this session) — scope reduction rejected by user; not re-argued.\nAccepted scope: 5-class arrangement retained; plan must state TokenStore's responsibility distinct from AuthCache (author input pending, recorded in Accepted amendments).\nHistory: none\n\n### R3: How AuthBroker and SessionMint obtain the shared AuthCache\nFinding: A1, P1, confidence 8/10, PLAN.md:28-29, reviewer: Claude (plan-eng-review)\nPlan baseline: module-level exported global mutable `AuthCache` instance imported by both services (original proposal)\nRuntime evidence: unknown (no source in repo)\nComparison grid:\n| Choice | Current | A | B | C |\n|---|---|---|---|---|\n| R3 cache acquisition | module-level export, imported by both | constructor injection of one `AuthCache` from a composition root (`createAuthServices()`); no module-level mutable export | module-level export kept as-is | module-level export kept + exported `resetAuthCacheForTests()` hook |\n| Number of backing caches | one | one (unchanged) | one | one |\n| S2 structure (approved D2) | 5 classes | 5 classes | 5 classes | 5 classes |\n| R4 invalidation race | pending | pending | pending | pending |\nQuestion D3:\nD3 — How should AuthBroker and SessionMint get hold of the shared AuthCache?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), Architecture finding A1. Structure (5 classes, D2) is fixed; the invalidation race (R4) and error handling (R5) stay pending.\nELI10: Right now the plan has one cache object created when the module loads, and both new services grab it by importing the module. That works until you need two of them (one per test, one per tenant tier, one for a canary) and discover every file in the auth path secretly depends on that one global. Tests that write to the cache leak into the next test. Passing the cache into each service's constructor from one place makes the dependency visible and swappable.\nStakes if we pick wrong: global = flaky cross-test pollution in the auth suite and monkey-patching to isolate; injection = one small factory function to write.\nRecommendation: A because it is the standard Node/TS pattern [Layer 1], costs one factory function, and is the difference between an auth suite you trust and one you rerun.\nCompleteness: A=10/10, B=3/10, C=6/10\nPros / cons:\nA) Constructor injection from one composition root (recommended) (human: ~half day / CC: ~10 min)\n  ✅ Each service's dependency on the cache is explicit in its constructor signature; nothing hidden behind an import\n  ✅ Tests build a fresh `AuthCache` per case with a fake adapter; zero cross-test state leakage\n  ✅ One place (`createAuthServices()`) owns wiring, so a per-tenant-tier or canary cache later is a wiring change, not a refactor\n  ❌ Callers that today import the flow directly must go through the factory (a few import-site edits)\nB) Keep the module-level global export\n  ✅ Zero extra code; matches the plan as written\n  ✅ Every call site trivially sees the same instance\n  ❌ Test pollution across AuthBroker and SessionMint suites; isolation needs monkey-patching or module cache resets\n  ❌ The two writers to one global are invisible at the type level; nobody reviewing SessionMint sees it can clobber AuthBroker's state\nC) Module-level global + `resetAuthCacheForTests()` hook\n  ✅ Cheap; fixes the test-pollution symptom without touching production wiring\n  ✅ No call-site edits\n  ❌ Test-only API shipped in production code; the hidden coupling remains\n  ❌ Does nothing for per-tenant-tier or canary scenarios; you still end up doing A later\nNet: trading a handful of import-site edits for an auth module whose dependencies are visible and whose tests are isolated.\nHeader: D3 cache DI\nOptions:\nA) Constructor injection (recommended)\nCreate one `AuthCache` in a composition root (`createAuthServices()`) and pass it to `AuthBroker` and `SessionMint` constructors. Remove the module-level mutable export. Still one backing cache.\nB) Keep module-level global\nLeave the module-level exported `AuthCache` instance as the plan proposes; both services import it directly.\nC) Global + test reset hook\nKeep the module-level export and add an exported `resetAuthCacheForTests()` to clear state between tests. No production wiring change.\n\nState: approved\nActual answer: A (D3 answer, this session)\nAccepted scope: One `AuthCache` created in a composition root `createAuthServices()` and passed into `AuthBroker` and `SessionMint` constructors; module-level mutable export removed; still one backing cache. Includes the necessary import-site edits and unit tests that construct services with a fresh `AuthCache` over a fake adapter.\nHistory: none\n\n### R4: Guard against SessionMint re-populating a tenant's cache after invalidation\nFinding: A2, P1, confidence 7/10, PLAN.md:19 (\"they do not serialize mutations\") + PLAN.md:28-29 (two writers), reviewer: Claude (plan-eng-review)\nPlan baseline: no guard; AuthCache retains adapter validity/key rules unchanged, mutations unserialized (original proposal)\nRuntime evidence: unknown. Whether the existing adapter already rejects writes after a tenant-level invalidation is unverified (no source in repo). Whether policy version is bumped on suspension is unverified.\nComparison grid:\n| Choice | Current | A | B | C |\n|---|---|---|---|---|\n| R4 post-invalidation write guard | none | `AuthCache` keeps a per-tenant invalidation generation; `put()` captures the generation at read time and rejects (no-op + metric) if the tenant's generation advanced before the write lands | bounded investigation of the existing adapter (does it already guard? does suspension bump policy version?) before choosing; no implementation approved | no guard; document the window as accepted risk |\n| Adapter unchanged (plan contract PLAN.md:21-22) | yes | yes (guard lives in the facade) | yes | yes |\n| R3 cache DI (approved D3) | injection | injection | injection | injection |\nQuestion D4:\nD4 — Should AuthCache stop a late SessionMint write from resurrecting a suspended or revoked tenant's session?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), Architecture finding A2. Cache injection (D3) and 5-class structure (D2) are fixed; error handling (R5) stays pending.\nELI10: Two services write to the same cache and nothing orders their writes (the plan says so at PLAN.md:19). Picture this: an admin suspends a tenant, the adapter wipes that tenant's cached sessions, but a session-mint request that started a moment earlier finishes and writes a fresh session back. The suspended tenant stays logged in until that entry expires. The fix is small: the facade remembers a per-tenant \"generation\" number that goes up on every invalidation, and a write is dropped if the generation moved while the write was in flight. The plan's own code does not touch the adapter, so the guard sits in `AuthCache`.\nStakes if we pick wrong: no guard = a suspension or revocation that silently does not take effect for one token lifetime; guard = a few lines plus one race test.\nRecommendation: A because suspension and revocation are the security boundary of a multi-tenant system, the plan explicitly introduces a second writer, and the cost is a counter and a compare.\nCompleteness: A=10/10, B=n/a (investigation only, approves no implementation), C=3/10\nPros / cons:\nA) Per-tenant invalidation generation check in `AuthCache.put()` (recommended) (human: ~1 day incl. race test / CC: ~15 min)\n  ✅ Closes the resurrect-after-invalidate window without changing the adapter or its key rules\n  ✅ One place to enforce it; both writers go through `AuthCache.put()`, so neither service needs to know\n  ✅ Dropped writes are observable (counter/log), so a real race in prod shows up instead of hiding\n  ❌ It is a behavior tightening inside a \"no behavior change\" refactor; must be called out in the PR and covered by its own test\n  ❌ Generation counter is per-process; a multi-instance deploy with a shared backing cache needs the generation stored alongside the entry (small, but must be designed in)\nB) Investigate the existing adapter first, then decide\n  ✅ Avoids building a guard the adapter may already provide\n  ✅ Surfaces whether suspension bumps policy version (which would make stale entries unreachable by key anyway)\n  ❌ Leaves the window open until the investigation lands and a second decision is made\n  ❌ The two-writer situation is new in this plan; even an existing guard was designed for one writer\nC) No guard; document the window as accepted risk\n  ✅ Zero code; refactor stays strictly behavior-neutral\n  ✅ If the window already exists today with legacyAuthFlow, this is status quo\n  ❌ A suspended tenant can keep a valid session for one token lifetime; that is the kind of thing that ends up in a security incident report\n  ❌ Adding SessionMint as a second writer makes the window more likely to be hit than today\nNet: trading a small, explicit behavior tightening for a suspension/revocation that actually takes effect when the admin clicks it.\nHeader: D4 race guard\nOptions:\nA) Generation guard in AuthCache.put() (recommended)\n`AuthCache` tracks a per-tenant invalidation generation (bumped by the existing invalidation hooks via the facade). `put()` compares the generation captured before the write with the current one and drops the write with a metric if it advanced. Adapter unchanged. Includes a concurrency test.\nB) Investigate adapter first\nBounded probe of the existing adapter and invalidation hooks: does it already reject post-invalidation writes, and does tenant suspension bump policy version? No implementation approved; a follow-up decision picks the remedy.\nC) No guard, document the risk\nLeave mutations unserialized. Add a note to the plan and PR describing the resurrect-after-invalidate window as accepted risk.\n\nState: approved\nActual answer: A (D4 answer, this session)\nAccepted scope: `AuthCache` keeps a per-tenant invalidation generation bumped through the facade by the existing invalidation hooks (logout, revocation, suspension). `AuthCache.put()` captures the generation before the write and drops the write (no-op + `auth_cache.put_dropped_stale` metric/log) if it advanced. Adapter and its key rules unchanged. Multi-instance deployments store the generation alongside the entry in the backing cache rather than per-process. Required proof: a concurrency test (invalidate during in-flight mint → entry absent afterwards; mint completes before invalidate → entry removed by invalidate) and a PR note calling out this as the one intentional behavior tightening.\nHistory: none\n\n### R5: Error handling shape of AuthBroker.validateAndDispatch()\nFinding: A3/C1, P1, confidence 7/10, PLAN.md:32-33 (\"60 lines with three nested try/catch blocks; each catch swallows a different error class\"), reviewer: Claude (plan-eng-review)\nPlan baseline: 60-line function, three nested try/catch, each catch swallows a distinct error class (original proposal / described current shape)\nRuntime evidence: unknown (no source in repo). Whether a swallowed error currently allows control to reach dispatch is unverified; the plan's wording (\"swallows\") is the only evidence.\nComparison grid:\n| Choice | Current | A | B | C |\n|---|---|---|---|---|\n| R5 control flow on error | 3 nested try/catch; swallowed per class; behavior after swallow unspecified | flat pipeline `validateToken → loadClaims → decideAccess → dispatch`; each step throws a typed `AuthError` subclass; ONE handler at the top maps error class → explicit deny with reason code + structured log; no path reaches dispatch after an error (fail-closed) | keep the 3 nested try/catch but replace every silent swallow with `log + return deny(reason)` in place | keep as-is (plan text) |\n| Function length | 60 lines | ~15-line orchestrator + 3-4 small step functions | ~60 lines | 60 lines |\n| Observability of failures | none stated | structured log per denied reason, one counter per error class | log per catch | none |\n| Fail-closed guarantee | unknown | yes, by construction (only the success path reaches dispatch) | yes, if every catch is audited | unknown |\n| R3 DI, R4 guard (approved) | fixed | fixed | fixed | fixed |\nQuestion D5:\nD5 — How should validateAndDispatch() handle errors: flat fail-closed pipeline, patched catches, or as written?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), Architecture finding A3 / Code quality finding C1. DI (D3), generation guard (D4) and structure (D2) are fixed.\nELI10: The function that decides whether a request gets in has three nested \"try this, and if it blows up, ignore it\" blocks, each ignoring a different kind of failure. In an auth check, ignoring a failure is the dangerous direction: if the token check fails and gets swallowed, does the request still get dispatched? Nobody can tell from a 60-line nest. The clean shape is a short straight line of steps where any failure stops the line and produces an explicit \"denied because X\" with a log entry. Only the success path can reach dispatch.\nStakes if we pick wrong: keep swallowing = a possible fail-open auth bypass that no test will find because the code hides the error; flat pipeline = an afternoon of restructuring you were doing anyway (this is the refactor).\nRecommendation: A because the whole point of the plan is to reorganize this orchestration, and a fail-closed pipeline is the only shape where \"can a swallowed error reach dispatch?\" is answered by structure instead of by reading every catch.\nCompleteness: A=10/10, B=7/10, C=2/10\nPros / cons:\nA) Flat fail-closed pipeline with typed errors and one top-level handler (recommended) (human: ~1.5 days / CC: ~25 min)\n  ✅ Fail-closed by construction: dispatch is the last step and is only reached when every prior step returned normally\n  ✅ Each step (`validateToken`, `loadClaims`, `decideAccess`, `dispatch`) is 10-15 lines and unit-testable on its own, including its error branch\n  ✅ Every denial carries a reason code and a structured log line, so a 3am on-call can tell \"expired token\" from \"IDP down\" from \"policy deny\"\n  ❌ Introduces a small `AuthError` hierarchy (3-4 classes) that must be kept in sync with the reason codes\n  ❌ Changes the observable error surface (callers now see explicit denials where they may have seen silent success or undefined); must be covered by the regression contract in Test review\nB) Keep the nested try/catch, replace each swallow with log + explicit deny\n  ✅ Smallest diff to the existing shape; each catch gets 2 lines\n  ✅ Fail-closed if every catch is audited and none is missed\n  ❌ Still 60 lines and three nesting levels; the next person adds a fourth catch and swallows again\n  ❌ Correctness depends on a human checking each catch rather than on structure\nC) Keep as written (swallowing catches)\n  ✅ Zero effort now\n  ✅ Matches current production behavior exactly\n  ❌ Unknown whether a swallowed error lets a request through; in an auth path that is a potential bypass\n  ❌ Contradicts the plan's own goal of reorganizing the orchestration\nNet: trading a small typed-error hierarchy for an auth entry point where fail-closed is a property of the code shape, not of reviewer diligence.\nHeader: D5 error flow\nOptions:\nA) Flat fail-closed pipeline (recommended)\nRestructure `validateAndDispatch()` into `validateToken → loadClaims → decideAccess → dispatch`. Each step throws a typed `AuthError` subclass. One top-level handler maps class → explicit deny with reason code + structured log + per-class counter. Dispatch only reachable on the success path. Unit tests per step incl. error branch.\nB) Patch each catch: log + explicit deny\nKeep the three nested try/catch blocks. Replace each silent swallow with a structured log and an explicit deny return. Function stays ~60 lines.\nC) Keep as written\nLeave the three swallowing catches as described in the plan. No error-handling change in this refactor.\n\nState: approved\nActual answer: A (D5 answer, this session)\nAccepted scope: `validateAndDispatch()` becomes a ~15-line orchestrator over `validateToken → loadClaims → decideAccess (RequestPolicy) → dispatch`. Each step throws a typed `AuthError` subclass (`TokenInvalidError`, `ClaimsUnavailableError`, `PolicyDeniedError`, `IdpUnavailableError` or equivalent). One top-level handler maps class → explicit deny with reason code, structured log, per-class counter. Dispatch is only reachable on the success path (fail-closed). Required proof: unit tests per step incl. its error branch; a test that each `AuthError` class yields a deny and never reaches dispatch; unknown/unexpected error → deny with `internal` reason. The changed error surface (explicit deny where legacy swallowed) is an intended delta to be asserted in the regression contract (R6).\nHistory: none\n\n### R6: Regression contract for the legacyAuthFlow() rewrite (REGRESSION RULE)\nFinding: T1, P1 CRITICAL, confidence 9/10, PLAN.md:36-37 (\"no regression test for the prior behavior is planned\") + PLAN.md:23-25, reviewer: Claude (plan-eng-review)\nPlan baseline: no regression coverage (original proposal)\nRuntime evidence: unknown; legacyAuthFlow() source and its callers are not in this repo. Behavior at risk: allow/deny outcome per input class, cache hit/miss semantics, invalidation on logout/revocation/suspension.\nComparison grid:\n| Choice | Current | A | B | C |\n|---|---|---|---|---|\n| R6 regression coverage method | none | characterization suite recorded against `legacyAuthFlow()` on a fixture matrix, then run unchanged against `AuthBroker`; intended deltas (D4, D5) asserted separately; 4 E2E flows; cutover behind a feature flag | everything in A plus a production shadow-run: new flow executes alongside legacy behind the flag, decisions compared and diffs logged for a bake period before cutover | E2E smoke only (login → request → logout) against the new flow; no characterization of legacy |\n| Behavior preserved | n/a | allow/deny per input class; cache hit/miss; invalidation on logout/revocation/suspension | same | login/request/logout happy path only |\n| Intended deltas asserted | n/a | explicit deny where legacy swallowed (D5); dropped stale write (D4) | same | not asserted |\n| Reversibility | n/a | flag flip | flag flip | none |\n| S1 (deferred), R3, R4, R5 (approved) | fixed | fixed | fixed | fixed |\nQuestion D6:\nD6 — How do we prove the rewritten auth flow still makes the same allow/deny decisions as legacyAuthFlow()?\nProject/branch/task: main — Multi-tenant Auth Refactor (PLAN.md), Test review finding T1 (CRITICAL regression risk). DI (D3), generation guard (D4) and fail-closed pipeline (D5) are fixed. This question chooses how to cover the regression, not whether.\nELI10: The plan replaces the code that decides who gets in, and says it will not test that the new code agrees with the old one. The cheap way to make that safe: before touching anything, write a table of inputs (good token, expired, wrong tenant, revoked, suspended tenant, IDP down, cache hit, cache miss...) and record what the old code answers for each. That table becomes a test. The new code must produce the same answers, except for the two changes we chose on purpose (explicit denials, dropped stale writes), which get their own assertions. Ship behind a flag so a surprise is one flip away from undone.\nStakes if we pick wrong: no characterization = a tenant that used to be allowed is denied (or the reverse) and you find out from a support ticket; with it = an afternoon of fixture writing that CC does in minutes.\nRecommendation: A because it protects every behavior class at risk with tests that run in CI, costs minutes with CC, and stays reversible via the flag; B adds real production safety but doubles IDP traffic per request during the bake, which the plan's own 5-sequential-calls finding makes expensive.\nCompleteness: A=9/10, B=10/10, C=4/10\nPros / cons:\nA) Characterization suite + intended-delta assertions + 4 E2E flows + flag cutover (recommended) (human: ~2 days / CC: ~30 min)\n  ✅ Every behavior class at risk (allow/deny matrix, cache hit/miss, three invalidation triggers) has a CI assertion recorded from the real legacy code before it is deleted\n  ✅ Intended deltas from D4/D5 are asserted explicitly, so \"different\" is either expected and tested or a failure\n  ✅ Feature-flag cutover makes a production surprise a flip, not a revert-and-redeploy\n  ❌ Only as good as the fixture matrix; a legacy quirk not in the matrix is not protected\n  ❌ Flag adds a temporary second code path to remove after cutover\nB) Everything in A plus a production shadow-run diff for a bake period\n  ✅ Catches legacy quirks that no fixture author thought of, on real traffic\n  ✅ Highest confidence available before deleting legacyAuthFlow()\n  ❌ Doubles IDP calls per authenticated request during the bake (10 sequential calls with today's flow); latency and IDP rate limits become a rollout risk\n  ❌ Needs decision-compare plumbing and log storage that is thrown away after cutover (human: ~1 week / CC: ~1.5 h)\nC) E2E smoke only against the new flow\n  ✅ Fast to write; proves the happy path works end to end\n  ✅ No legacy fixture recording needed\n  ❌ Does not protect allow/deny parity for denied classes, cache semantics or invalidation; exactly the cases where regressions are silent\n  ❌ Violates the regression rule for a rewrite of the auth decision path\nNet: trading an afternoon of fixture recording for proof that the new gatekeeper answers the same as the old one, with the two intentional differences named.\nHeader: D6 regression\nOptions:\nA) Characterization + deltas + E2E + flag (recommended)\nRecord legacyAuthFlow() outcomes over a fixture matrix (valid, expired, bad signature, wrong issuer, wrong audience, revoked, suspended tenant, IDP timeout/5xx per call, cache hit, cache miss) into `legacyAuthFlow.characterization.test.ts`; run the same matrix against AuthBroker. Assert D4/D5 deltas separately. 4 E2E flows (login/request, logout, suspension, revocation). Cutover behind a feature flag.\nB) A + production shadow-run diff\nAll of A, plus run the new flow alongside legacy behind the flag in production, compare decisions, log diffs for a bake period before cutover. Doubles IDP calls per request during the bake.\nC) E2E smoke only\nLogin → authorized request → logout E2E against the new flow only. No characterization of legacy behavior; no intended-delta assertions.\n\nState: approved\nActual answer: A (D6 answer, this session)\nAccepted scope: (1) `legacyAuthFlow.characterization.test.ts` recorded against the existing `legacyAuthFlow()` BEFORE any rewrite, over the fixture matrix: valid token; expired; bad signature; wrong issuer; wrong audience; revoked; suspended tenant; IDP timeout and 5xx for each of the 5 calls; cache hit; cache miss. Asserts allow/deny outcome, cache read/write effect, and invalidation on logout/revocation/suspension. (2) The identical matrix run against `AuthBroker.validateAndDispatch()`. (3) Intended deltas asserted separately: explicit deny + reason code where legacy swallowed (D5); stale write dropped after invalidation (D4). (4) Four E2E flows: login → mint → authorized request → dispatch; logout → next request denied; tenant suspension → in-flight and next request denied; IDP revocation → next request denied. (5) Cutover behind a feature flag (`auth.brokerFlow` or project convention); flag and `legacyAuthFlow()` removed in a follow-up after cutover. Completeness 9/10 accepted (above the ≤7 shortcut threshold; no shortcut marker required).\nHistory: none\n\n### T7: TODO — cache IDP discovery + JWKS per issuer, then re-evaluate parallelization\nFinding: P1/P2, P2, confidence 8/10 and 6/10, PLAN.md:40-41, reviewer: Claude (plan-eng-review)\nPlan baseline: parallelization deferred (D1); no follow-up captured\nRuntime evidence: unknown which of the 5 IDP calls are metadata\nQuestion D7: TODO question (TODOS-format). Options: A) Add to TODOS (recommended) B) Skip C) Build it now in this PR.\nState: approved\nActual answer: A (D7 answer, this session)\nAccepted scope: TODO recorded in \"TODOS (not persisted)\" below.\nHistory: none\n\n### T8: TODO — bound AuthCache entry count\nFinding: P3, P2, confidence 5/10, PLAN.md:17-18, reviewer: Claude (plan-eng-review)\nPlan baseline: adapter unchanged; expiry-only eviction\nRuntime evidence: unknown\nQuestion D8: TODO question (TODOS-format). Options: A) Add to TODOS (recommended) B) Skip C) Build it now in this PR.\nState: approved\nActual answer: A (D8 answer, this session)\nAccepted scope: TODO recorded in \"TODOS (not persisted)\" below.\nHistory: none\n\n### T9: TODO — remove `auth.brokerFlow` flag and delete legacyAuthFlow() after bake\nFinding: follow-up created by D6, P2, confidence 9/10, reviewer: Claude (plan-eng-review)\nPlan baseline: D6 accepted scope names the follow-up without an owner\nRuntime evidence: n/a\nQuestion D9: TODO question (TODOS-format). Options: A) Add to TODOS (recommended) B) Skip C) Build it now in this PR.\nState: approved\nActual answer: A (D9 answer, this session)\nAccepted scope: TODO recorded in \"TODOS (not persisted)\" below.\nHistory: none\n\n**Approval readiness: PASS** — checked S1 (D1→A), S2 (D2→A), R3 (D3→A), R4 (D4→A), R5 (D5→A), R6 (D6→A), T7 (D7→A), T8 (D8→A), T9 (D9→A). Every accepted remedy cites its own actual answer. Regression contract carried from D6. No pending records. One accepted condition (TokenStore responsibility) awaits author input and is not a decision.\n\n---\n\n## Review output\n\n### Step 0: Scope Challenge\nComplexity gate fired (12 files, 5 classes). D1 → A: parallelization deferred (scope reduced). D2 → A: 5-class structure kept (scope reduction rejected; committed to, not re-argued).\n\n| # | Finding | Disposition |\n|---|---|---|\n| S1 | `[P1] (confidence: 8/10) PLAN.md:44-45` — 5 classes / 12 files for a behavior-neutral reorg; RequestPolicy stateless, TokenStore undefined | rejected reduction (D2 → A); TokenStore responsibility required |\n| S2 | `[P2] (confidence: 9/10) PLAN.md:39-41` — Promise.all is a behavioral change inside a structural refactor | accepted deferral (D1 → A) |\n| S3 | `[P1] (confidence: 9/10) PLAN.md:36-37` — rewrite without regression tests | resolved in Test review (D6 → A) |\n| S4 | Distribution: no new artifact | n/a |\n| S5 | TODOS.md absent; nothing blocking | n/a |\n\nSearch check (WebSearch; Aside unavailable): DI at composition root [Layer 1]; OIDC discovery/JWKS caching [Layer 1]; [EUREKA] candidate: 5 IDP calls per validation means metadata is not cached; caching, not parallelizing, is the real latency fix (captured as TODO D7).\n\n### 1. Architecture review — 7 issues\n| # | Finding | Disposition |\n|---|---|---|\n| A1 | `[P1] (8/10) PLAN.md:28-29` — module-level global mutable AuthCache, two writers | fixed: constructor injection (D3 → A) |\n| A2 | `[P1] (7/10) PLAN.md:19, 28-29` — invalidate-vs-mint race resurrects a suspended tenant's session | fixed: generation guard in `AuthCache.put()` (D4 → A) |\n| A3 | `[P1] (7/10) PLAN.md:32-33` — swallowed errors on the auth path = fail-open risk | fixed: fail-closed pipeline (D5 → A) |\n| A4 | `[P2] (6/10) PLAN.md:44` — TokenStore/AuthCache boundary undefined (medium confidence, verify) | covered by D2 condition; author input pending |\n| A5 | `[P2] (8/10)` — no data-flow diagram | added to plan |\n| A6 | `[P2] (6/10) PLAN.md:40` — IDP timeout/outage path unspecified | covered by D5 (`IdpUnavailableError` → deny) + Failure modes |\n| A7 | `[P3] (5/10) PLAN.md:20-21` — single backing cache is a shared SPOF (pre-existing) | noted, no change |\n\nProduction failure scenarios per new codepath: see Failure modes.\n\n### 2. Code quality review — 5 issues\n| # | Finding | Disposition |\n|---|---|---|\n| C1 | `[P1] (7/10) PLAN.md:32-33` — 60-line function, 3 nested try/catch, swallowing | fixed (D5 → A) |\n| C2 | `[P2] (6/10) PLAN.md:28-29, 44` — DRY: key/validity rules could live in up to 3 places | covered by D4 scope (single write path) + D2 condition |\n| C3 | `[P2] (8/10) PLAN.md:12-13` — RequestPolicy must be dependency-free so tests use the real one | recorded in plan |\n| C4 | `[P3] (8/10)` — no inline diagrams planned for AuthBroker / AuthCache | added to Diagrams |\n| C5 | Existing diagrams in the 12 touched files: unknown here; check and update in the same commit | instruction to implementer |\n\n### 3. Test review — diagram produced, 33 gaps\nFramework unknown (no markers in repo; `*.test.ts` naming assumed). Coverage diagram: see chat record; summary: 0/33 paths covered in this repo (existing adapter tests claimed by the plan, unverifiable here). REGRESSION RULE applied → D6 → A. QA Test Plan artifact: `~/.gstack/projects/gstack-plan-count-VjWQw7/vercel-sandbox-main-eng-review-test-plan-20260916-193707.md`.\n\n| # | Finding | Disposition |\n|---|---|---|\n| T1 | `[P1 CRITICAL] (9/10) PLAN.md:36-37` — legacyAuthFlow rewrite, no regression coverage | approved (D6 → A) |\n| T2 | `[P1] (8/10)` — generation guard concurrency test | required proof of D4 |\n| T3 | `[P1] (8/10)` — pipeline per-step error tests; never-dispatch-after-AuthError | required proof of D5 |\n| T4 | `[P2] (8/10)` — services over fake adapter with fresh cache | required proof of D3 |\n| T5 | `[P2] (7/10) PLAN.md:12-13` — RequestPolicy allow/deny table | specified |\n| T6 | `[P3] (5/10)` — TokenStore tests unknowable until responsibility defined | pending author input |\n\n### 4. Performance review — 4 issues (1 suppressed to appendix)\n| # | Finding | Disposition |\n|---|---|---|\n| P1 | `[P2] (8/10) PLAN.md:40-41` — 5 sequential IDP calls per validation | deferred (D1 → A); follow-up TODO (D7 → A) |\n| P2 | `[P2] (6/10) PLAN.md:40` — IDP discovery/JWKS apparently uncached; [EUREKA] cache first, parallelize second (medium confidence, verify) | TODO (D7 → A) |\n| P3 | `[P2] (5/10) PLAN.md:17-18` — expiry-only eviction, unbounded entry count (medium confidence, verify adapter) | TODO (D8 → A) |\n| P4 | `[P3] (6/10)` — no cold-cache request coalescing (pre-existing) | noted; E2E interaction check in Test Plan |\n\n### Outside Voice\nCodex review skipped (`codex_reviews` disabled). Recorded: `outside_status: disabled`, provider codex, phase plan-review. No native replacement (disabled is an intentional opt-out). Re-enable: `gstack-config set codex_reviews enabled`.\n\n### NOT in scope\n- **Promise.all parallelization of IDP calls** — behavioral change; deferred by D1 to keep the refactor behavior-neutral; superseded by cache-first TODO (D7).\n- **IDP discovery/JWKS caching** — behavioral change; TODO D7.\n- **AuthCache size bound / LRU** — adapter is kept unchanged by the plan; TODO D8.\n- **Production shadow-run diff (D6 option B)** — rejected in favor of characterization + flag; doubles IDP load during bake.\n- **Removing the feature flag and legacyAuthFlow()** — follow-up after bake; TODO D9.\n- **Request coalescing for concurrent cold-cache misses** — pre-existing, not introduced here; not captured as a TODO (low confidence on impact).\n- **Adapter SPOF hardening (A7)** — pre-existing; out of scope.\n- **Distribution/CI pipeline** — no new artifact; nothing to defer.\n\n### What already exists\n- **Cache adapter** with tenant/issuer/audience/policy-version keys, expiry eviction, invalidation hooks and tests (`PLAN.md:16-22`): reused unchanged via the `AuthCache` facade. Correct reuse. The generation guard (D4) sits in the facade, not the adapter.\n- **`legacyAuthFlow()`**: existing orchestration; rewritten. Its behavior is captured by the characterization suite (D6) before deletion, so it is reused as the oracle rather than discarded.\n- **Existing per-request access decision** (`PLAN.md:9-13`): grouped into `RequestPolicy` without new rules. Reuse, not rebuild.\n- **`validateAndDispatch()`**: existing 60-line function; reshaped (D5), not rebuilt from scratch.\n\n### Diagrams\n- Plan: data-flow diagram added under Accepted amendments (A5).\n- Inline ASCII diagram comments to add in code: `AuthBroker.ts` (pipeline: steps, typed errors, single handler, success-only dispatch); `AuthCache.ts` (generation bump on invalidate, put() compare-and-drop, multi-instance storage of generation); `composition.ts` (wiring graph); `legacyAuthFlow.characterization.test.ts` (fixture matrix × two implementations, intended-delta rows).\n- Check the 12 touched files for existing diagrams and update them in the same commit.\n\n### Failure modes\n| Codepath | Realistic failure | Test | Error handling | User sees |\n|---|---|---|---|---|\n| `validateToken` | IDP timeout / 5xx on one of 5 calls | yes (matrix, per call) | yes (`IdpUnavailableError` → deny) | clear \"auth unavailable\"; not dispatched |\n| `validateToken` | expired / bad signature / wrong issuer or audience | yes (matrix) | yes (`TokenInvalidError`) | 401 / re-login |\n| `loadClaims` | malformed or partial claims | yes | yes (`ClaimsUnavailableError`) | explicit deny with reason |\n| `decideAccess` | policy deny | yes | yes (`PolicyDeniedError`) | 403 with reason |\n| top-level handler | unexpected exception type | yes | yes (deny `internal`) | explicit deny, logged |\n| `AuthCache.put()` | mint lands after suspension (race) | yes (concurrency test) | yes (drop + metric) | suspended tenant denied |\n| `AuthCache.put()` | multi-instance: generation per process only | design requirement (D4) | yes if stored with entry | none if implemented; **watch this** |\n| `SessionMint.mint()` | adapter write error | yes (planned error path) | typed error, no partial entry | login fails visibly |\n| cold cache, N concurrent | N×5 IDP calls, possible rate limit | E2E interaction check only | none (pre-existing) | slower login; not silent allow |\n| `TokenStore` | unknown until responsibility defined | pending | pending | pending |\n| flag cutover | flip back to legacy mid-session | E2E check in Test Plan | flag read per request | requests keep working |\n\n**Critical gaps (no test AND no handling AND silent): 0.** Watch item: multi-instance generation storage must be implemented as designed, or the D4 guard is per-process only.\n\n### Worktree parallelization strategy\n| Step | Modules touched | Depends on |\n|---|---|---|\n| T4 characterization suite (record legacy) | tests/auth (legacy fixtures) | — (must precede any rewrite) |\n| T2 AuthCache facade + generation guard + tests | auth/cache | — |\n| T3 AuthBroker pipeline + AuthError + tests | auth/broker, auth/errors | T4 recorded |\n| T8 RequestPolicy + table test | auth/policy | — |\n| T7 TokenStore (define, then implement) | auth/token-store | author input |\n| T1 composition root + import-site edits | auth/composition, callers | T2, T3, T7 |\n| T6 feature flag cutover | auth/composition, callers | T1 |\n| T5 E2E flows | tests/e2e | T6 |\n| T9 diagrams | same modules as above | with each step |\n\nLanes:\n- `Lane A: T4 → T3 (sequential; T3 rewrites what T4 records)`\n- `Lane B: T2 (independent, auth/cache)`\n- `Lane C: T8 (independent, auth/policy)`\n- `Lane D: T7 (blocked on author input, auth/token-store)`\n- `Lane E: T1 → T6 → T5 (sequential; waits for A, B, C, D)`\n\nExecution order: launch A + B + C (+ D when TokenStore is defined) in parallel worktrees. Merge all. Then E.\nConflict flags: Lanes A and E both touch `auth/broker` call sites (constructor signature from T1) — land A before E. Lane D's module boundary with `auth/cache` is undefined until T7's responsibility is written; do not start D in parallel with B until then.\n\n## Implementation Tasks\nSynthesized from this review's findings. Each task derives from a specific finding above. Run with Claude Code or Codex; checkbox as you ship.\n\n- [ ] **T1 (P1, human: ~half day / CC: ~10 min)** — auth/composition — Add `createAuthServices()` composition root; inject one `AuthCache` into `AuthBroker` and `SessionMint`; remove module-level mutable export; update import sites\n  - Surfaced by: Architecture — A1 (D3 → A)\n  - Files: `auth/composition.ts` (new), `auth/AuthBroker.ts`, `auth/SessionMint.ts`, `auth/AuthCache.ts`, callers\n  - Verify: unit tests construct services over a fake adapter with a fresh `AuthCache`; no module-level `AuthCache` instance exported\n- [ ] **T2 (P1, human: ~1 day / CC: ~15 min)** — auth/cache — Add per-tenant invalidation generation to `AuthCache`; `put()` drops stale writes with `auth_cache.put_dropped_stale` metric; store generation with the entry for multi-instance\n  - Surfaced by: Architecture — A2 (D4 → A)\n  - Files: `auth/AuthCache.ts`, `auth/AuthCache.test.ts`\n  - Verify: concurrency test both orderings (invalidate during in-flight mint → absent; mint then invalidate → removed); metric asserted\n- [ ] **T3 (P1, human: ~1.5 days / CC: ~25 min)** — auth/broker — Restructure `validateAndDispatch()` into `validateToken → loadClaims → decideAccess → dispatch` with typed `AuthError` hierarchy and one fail-closed top-level handler\n  - Surfaced by: Code quality — C1 / Architecture — A3 (D5 → A)\n  - Files: `auth/AuthBroker.ts`, `auth/errors.ts` (new), `auth/AuthBroker.test.ts`\n  - Verify: per-step tests incl. error branch; every `AuthError` class → deny + reason, never dispatch; unknown error → deny `internal`\n- [ ] **T4 (P1, human: ~1 day / CC: ~20 min)** — tests/auth — Record `legacyAuthFlow.characterization.test.ts` against the existing `legacyAuthFlow()` BEFORE any rewrite, over the full fixture matrix; then run the matrix against `AuthBroker` with intended-delta assertions for D4/D5\n  - Surfaced by: Test review — T1 CRITICAL (D6 → A)\n  - Files: `tests/auth/legacyAuthFlow.characterization.test.ts` (new), fixtures\n  - Verify: suite green against legacy first; identical outcomes against `AuthBroker` except the two asserted deltas\n- [ ] **T5 (P1, human: ~1 day / CC: ~20 min)** — tests/e2e — Add 4 E2E flows: login → request → dispatch; logout → denied; suspension → in-flight and next denied; revocation → denied\n  - Surfaced by: Test review — T1 (D6 → A)\n  - Files: `tests/e2e/auth-flows.e2e.ts` (new)\n  - Verify: all 4 pass with flag on and with flag off\n- [ ] **T6 (P1, human: ~half day / CC: ~10 min)** — auth/composition — Put the broker flow behind `auth.brokerFlow` feature flag; legacy path remains until TODO D9\n  - Surfaced by: Test review — T1 (D6 → A, reversibility)\n  - Files: `auth/composition.ts`, flag config\n  - Verify: flip flag in E2E; both paths serve requests\n- [ ] **T7 (P2, human: ~1 h / CC: n/a, author input)** — auth/token-store — Author writes `TokenStore`'s responsibility into the plan (distinct from `AuthCache`; no second copy of adapter entries; no duplicated key rules), then implement with tests\n  - Surfaced by: Scope Challenge — S1 (D2 → A accepted condition) / Architecture — A4\n  - Files: plan section \"Accepted amendments → Scope\", `auth/TokenStore.ts`, `auth/TokenStore.test.ts`\n  - Verify: plan section filled; tests cover the stated responsibility\n- [ ] **T8 (P2, human: ~2 h / CC: ~5 min)** — auth/policy — `RequestPolicy` constructed with no dependencies; allow/deny table test over claims × tenant context\n  - Surfaced by: Code quality — C3 / Test review — T5\n  - Files: `auth/RequestPolicy.ts`, `auth/RequestPolicy.test.ts`\n  - Verify: table test green; `AuthBroker` tests use the real policy\n- [ ] **T9 (P3, human: ~1 h / CC: ~5 min)** — auth/* — Add inline ASCII diagrams to `AuthBroker.ts`, `AuthCache.ts`, `composition.ts`, characterization test; update any existing diagrams in the 12 touched files\n  - Surfaced by: Architecture — A5 / Code quality — C4, C5\n  - Files: as listed\n  - Verify: diagrams match code in the same commit\n\n_No new tasks from Performance (all deferred to TODOs D7, D8)._\n\n### TODOS (not persisted to TODOS.md — plan mode; TODOS.md does not exist)\n\n## Auth\n\n### Cache IDP discovery metadata and JWKS per issuer, then re-evaluate parallelization\n**What:** Add per-issuer caches for OIDC discovery (hours TTL) and JWKS (minutes-hours TTL, refresh on unknown `kid`, no unbounded refetch loop); then measure remaining IDP calls per validation and parallelize only genuinely independent ones.\n**Why:** 5 sequential IDP round trips per cache-miss validation is the dominant auth latency; caching removes most of them and reduces IDP load, unlike Promise.all which increases burst load 5x.\n**Context:** Deferred from the Multi-tenant Auth Refactor by D1 to keep it behavior-neutral. Verify first which of the 5 calls are metadata vs per-token. Layer 1 practice per SSOJet / OneUptime references in the eng review. Start in the `validateToken` step of `AuthBroker` once the D5 pipeline lands.\n**Effort:** M  **Priority:** P2  **Depends on:** this refactor landing (D5 pipeline).\n\n### Remove `auth.brokerFlow` flag and delete legacyAuthFlow() after bake\n**What:** After the broker flow has been at 100% with no flag flips for an agreed bake window, delete `legacyAuthFlow()`, the `auth.brokerFlow` flag, and the legacy half of the characterization harness (keep the matrix against `AuthBroker`).\n**Why:** A permanent flag doubles the maintenance surface of the auth path and keeps dead code the security team still has to audit.\n**Context:** Created by D6. Trigger: flag at 100% for the bake window with zero `auth_cache.put_dropped_stale` anomalies and zero rollbacks.\n**Effort:** S  **Priority:** P2  **Depends on:** this refactor shipped and baked at 100%.\n\n### Bound the AuthCache entry count\n**What:** Verify whether the existing cache adapter bounds entry count; if not, add a max-entries / LRU policy with an evictions-by-size metric.\n**Why:** Expiry-only eviction is unbounded under many tenants × issuers × audiences × policy versions; a policy-version bump orphans every old entry until expiry.\n**Context:** Raised at confidence 5/10 because the adapter source was unavailable. Start by reading the adapter's eviction code and tests (PLAN.md:16-22). If bounded already, close with a note.\n**Effort:** S  **Priority:** P3  **Depends on:** None.\n\n### Unresolved decisions that may bite you later\nNone. All nine decisions (D1–D9) answered. One accepted condition awaits author input and is not a decision: `TokenStore` responsibility (D2 → A condition; task T7).\n\n### Suppressed findings (appendix)\n- `[P3] (confidence: 4/10) PLAN.md:16-17` — policy version in the cache key orphans all entries on a version bump until expiry (memory spike, cache-miss storm). Unverified; adapter behavior on version bump unknown.\n- `[P2] (confidence: 4/10)` — whether the 5 IDP calls are actually independent (plan asserts it). Moot for this refactor after D1; revisit under TODO D7.\n\n### Completion summary\n- Step 0: Scope Challenge — scope reduced per recommendation (D1: parallelization deferred); structure reduction rejected (D2)\n- Architecture Review: 7 issues found\n- Code Quality Review: 5 issues found\n- Test Review: diagram produced, 33 gaps identified\n- Performance Review: 4 issues found (1 suppressed to appendix)\n- NOT in scope: written\n- What already exists: written\n- TODOS.md updates: 3 items proposed to user (3 accepted; not persisted to TODOS.md in plan mode)\n- Failure modes: 0 critical gaps flagged\n- Unresolved decisions: 0 in this review\n- Outside voice: provider codex, disabled (`codex_reviews=disabled`; opt-out, no native replacement)\n- Parallelization: 5 lanes, 3 parallel (+1 blocked on author input) / 1 sequential\n- Lake Score: 4/5 (D2, D3, D4, D5 selected 10/10; D6 selected 9/10; D1, D7–D9 differ in kind)\n\n## GSTACK REVIEW REPORT\n\n| Review | Trigger | Why | Runs | Status | Findings |\n|--------|---------|-----|------|--------|----------|\n| CEO Review | `/plan-ceo-review` | Scope & strategy | 0 | — | — |\n| Outside Review | codex via `/plan-eng-review` | Independent 2nd opinion | 1 | DISABLED (host claude, provider codex, phase plan-review) | skipped |\n| Eng Review | `/plan-eng-review` | Architecture & tests (required) | 1 | CLEAR (PLAN) | 49 issues (7 arch + 5 quality + 4 perf + 33 test gaps), 0 critical gaps |\n| Design Review | `/plan-design-review` | UI/UX gaps | 0 | — | — |\n| DX Review | `/plan-devex-review` | Developer experience gaps | 0 | — | — |\n\n- **OUTSIDE COVERAGE:** codex, plan-review, disabled (`codex_reviews=disabled`), no findings; no completed external review exists.\n- **VERDICT:** ENG CLEARED — ready to implement (all 9 decisions answered, 0 critical gaps; D6 regression contract must be built before any rewrite; T7 TokenStore responsibility is author input, not a blocker to starting lanes A–C).\n\nNO UNRESOLVED DECISIONS\n",
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