@@ -0,0 +1,13 @@
+---
+'@objectstack/core': patch
+'@objectstack/plugin-auth': patch
+---
+
+fix(core, plugin-auth): a failed organization probe says `readFailed` too, and an auth mail no longer reads a failed settings read as "no default currency" (#27733, #27710)
+
+Clause-②: no — `resolveLocalizationContext`'s result keeps its shape; the existing `readFailed?: true` member gains one more trigger. Nothing new is exported from a package entry.
+Metadata-protocol: none
+
+- **Before.** For a caller that names no organization where no wall stands, `resolveLocalizationContext` first asks `sys_organization` which organization's rows it may read. A store fault on that probe answered the built-ins with no `readFailed`, so messaging graded a mail whose `{{ amount | currency }}` hole then had no default as permanent (`TEMPLATE_INVALID`) and dead-lettered it. And the auth mails (verification, password reset, invitations, magic link, notices) read every failed settings read as "the organization has no default currency": such a mail failed with `TEMPLATE_INVALID` and its "set localization.currency" remedy during a transient fault.
+- **Now.** A probe that throws `AuthzStoreUnavailableError` answers `readFailed: true`, the same as a failed `sys_setting` read, so messaging retries the delivery. That answer is cached in neither memo, since no value was read: the next request asks again. A posture that cannot be read is not a store fault and still answers no `readFailed`. The auth mail's currency read rejects on `readFailed`; when the render then refuses for want of a default, the mail is rendered once more without sending with the no-currency code `XXX`: if that renders, the mail fails with an error that names the failed read and carries no `TEMPLATE_*` code, so sending it again once the read succeeds works; if it still refuses, that refusal stands.
+- **Unchanged.** A read that succeeds and finds no default keeps today's refusal and remedy, on both paths. A template with no no-argument `currency` hole is sent during a read fault. The failure memo for a failed `sys_setting` read is unchanged.
@@ -38,7 +38,7 @@
  * `tryFind`'s `catch` — read that before changing anything on this path.
  */
 
-import { AuthzStoreUnavailableError } from './authz-store-unavailable.js';
+import { AuthzStoreUnavailableError, isAuthzStoreUnavailableError } from './authz-store-unavailable.js';
 // [commit 6a180e42d, ruled 2026-08-30] `isMissingTableError` is the one "was this READ
 // failure just an unprovisioned table?" predicate. It was `@objectstack/metadata`'s
 // until this resolver needed it; metadata depends on core, so the ruling relocated
@@ -2216,14 +2216,17 @@ type LocalizationResult = {
   locale: string;
   currency?: string;
   /**
-   * Present only when the direct `sys_setting` read THREW (a backend fault),
-   * on a fresh read and on a memoized one alike: every value above is then the
-   * built-in default, not a stored answer. Absent, a missing `currency` means
-   * the read succeeded and the organization has no default, which is permanent
-   * until someone sets one; present, it means nothing was learned, and a caller
-   * that would refuse work for want of a default retries instead. A
-   * settings-service refusal never sets it (#11877), and it does not lengthen
-   * the failure memo. (#27257)
+   * Present only when the direct `sys_setting` read could not be answered
+   * because the store failed: the read itself THREW (a backend fault), on a
+   * fresh read and on a memoized one alike (#27257), or the `sys_organization`
+   * probe that decides whose rows it may read threw
+   * `AuthzStoreUnavailableError`, so it never ran (#27733). Every value above
+   * is then the built-in default, not a stored answer. Absent, a missing
+   * `currency` means the read succeeded and the organization has no default,
+   * which is permanent until someone sets one; present, it means nothing was
+   * learned, and a caller that would refuse work for want of a default retries
+   * instead. A settings-service refusal never sets it (#11877), and it does
+   * not lengthen the failure memo; a probe fault writes no memo at all.
    */
   readFailed?: true;
 };
@@ -2647,7 +2650,9 @@ function putLocalizationEntry(ql: object, key: string, entry: LocalizationCacheE
  * every request (#10221). A settings-service refusal is not a backend fault
  * and never populates that memo (#11877). Such an answer carries
  * `readFailed: true`, fresh and memoized alike, so a caller can tell "the read
- * failed" from "the read found no default" (#27257).
+ * failed" from "the read found no default" (#27257). So does an answer whose
+ * `sys_organization` probe failed and so read no row (#27733); that one is
+ * cached in neither memo, since it holds no value to keep.
  *
  * A SUCCESSFUL read is cached too, since #11966 (leg C of #11633) — but only
  * when the engine carries the write-epoch and middleware seams, and only until
@@ -2684,12 +2689,20 @@ export async function resolveLocalizationContext(input: ResolveLocalizationInput
     }
   }
 
-  const { value: read, backendFailed } = await resolveLocalizationContextUncached(input);
+  const { value: read, backendFailed, probeFailed } = await resolveLocalizationContextUncached(input);
   // [#27257] The kind travels ON the answer, and the memo stores that same
   // answer, so a hit inside the failure TTL still says the read failed.
-  const value: LocalizationResult = backendFailed ? { ...read, readFailed: true } : read;
+  const value: LocalizationResult = backendFailed || probeFailed ? { ...read, readFailed: true } : read;
   if (!cacheable) return value;
 
+  if (probeFailed) {
+    // [#27733] No read ran, so there is no value to memoise: the next request
+    // asks again. Only the entry this answer superseded is dropped (no LIVE
+    // one was found above), so no earlier answer outlives it either.
+    localizationCache.get(ql)?.delete(cacheKey);
+    return value;
+  }
+
   if (backendFailed) {
     putLocalizationEntry(ql, cacheKey, {
       value,
@@ -2734,32 +2747,41 @@ export async function resolveLocalizationContext(input: ResolveLocalizationInput
  *    ({@link resolveGuestOrganization}) under that same posture.
  *
  * A failed derivation reads nothing (`unowned`): no organization's row is read
- * on a guess, and the built-in defaults answer. This fallback is reached only
+ * on a guess, and the built-in defaults answer. When it failed because the
+ * store did (`AuthzStoreUnavailableError` from the `sys_organization` probe),
+ * `probeFailed` says so, and the answer carries `readFailed` (#27733); any
+ * other throw (an unreadable posture) is not transient and says nothing more.
+ * This fallback is reached only
  * when the settings service is absent or has just failed, so it takes no
  * inputs that service would supply.
  *
  * ⛔ Kept by design, not drift: the requested posture where the service reads
  * the one in force, and a failed derivation degraded where the service
  * propagates it — both make this fallback the stricter reader.
  */
-async function localizationFallbackReach(ql: any, organizationId: string | undefined): Promise<OrganizationReach> {
+async function localizationFallbackReach(
+  ql: any,
+  organizationId: string | undefined,
+): Promise<{ reach: OrganizationReach; probeFailed: boolean }> {
   try {
-    return await resolveOrganizationReach({
+    const reach = await resolveOrganizationReach({
       callerOrganizationId: organizationId,
       wallStands: () => postureEnforcesWall(resolveTenancyPosture()),
       deriveOrganization: () => resolveGuestOrganization(ql, resolveTenancyPosture()),
     });
-  } catch {
-    // The organization could not be derived (`AuthzStoreUnavailableError`):
-    // no organization's row is read on a guess. Not the direct read's own
-    // backend fault, so it does not populate the failure memo (#10221).
-    return UNOWNED_ORGANIZATION_REACH;
+    return { reach, probeFailed: false };
+  } catch (err) {
+    // The organization could not be derived: no organization's row is read on
+    // a guess. Not the direct read's own backend fault, so it does not
+    // populate the failure memo (#10221); a store fault is still a read that
+    // learned nothing (#27733).
+    return { reach: UNOWNED_ORGANIZATION_REACH, probeFailed: isAuthzStoreUnavailableError(err) };
   }
 }
 
 async function resolveLocalizationContextUncached(
   input: ResolveLocalizationInput,
-): Promise<{ value: LocalizationResult; backendFailed: boolean }> {
+): Promise<{ value: LocalizationResult; backendFailed: boolean; probeFailed: boolean }> {
   const { ql, settings, organizationId, userId } = input;
   // ONLY the direct `sys_setting` read below sets this. The settings-service
   // legs deliberately do not — see the cache doc above (#11877).
@@ -2816,7 +2838,7 @@ async function resolveLocalizationContextUncached(
       const locale = coerceLocale(localeRes?.value);
       const currency = coerceCurrency(currencyRes?.value);
       if (tz || locale || currency) {
-        return { value: { timezone: tz ?? 'UTC', locale: locale ?? 'en-US', currency }, backendFailed: false };
+        return { value: { timezone: tz ?? 'UTC', locale: locale ?? 'en-US', currency }, backendFailed: false, probeFailed: false };
       }
     }
   } catch {
@@ -2826,7 +2848,7 @@ async function resolveLocalizationContextUncached(
   // [ADR-0131 D8] The organization this read may draw on — the reach the
   // settings service itself reads with (#25226): never another organization's
   // row, and a row with no organization only where no organization can exist.
-  const reach = await localizationFallbackReach(ql, organizationId);
+  const { reach, probeFailed } = await localizationFallbackReach(ql, organizationId);
   // One read for all three keys instead of a query per key (`$in` on `key`).
   // Inlined (rather than the shared `tryFind`) so a genuine backend fault —
   // as opposed to a legitimate empty result — is visible to the caller above,
@@ -2866,5 +2888,6 @@ async function resolveLocalizationContextUncached(
       currency: coerceCurrency(valueOf('currency')),
     },
     backendFailed,
+    probeFailed,
   };
 }
@@ -7,6 +7,12 @@
 // `readFailed: true` exactly when the direct `sys_setting` read threw, on the
 // fresh read AND on the hit the failure memo serves inside its TTL, and never
 // otherwise.
+//
+// [#27733] The read can also fail one step earlier: a caller that names no
+// organization, where no wall stands, reads the rows of the organization the
+// `sys_organization` probe derives. A store fault there means no row was read,
+// so the answer carries `readFailed: true` too, and writes no memo of either
+// kind, since it holds no value to keep.
 
 import { describe, it, expect, vi, afterEach } from 'vitest';
 import { resolveLocalizationContext } from './resolve-authz-context.js';
@@ -46,6 +52,7 @@ function makeBrokenQl() {
 
 afterEach(() => {
   vi.useRealTimers();
+  vi.unstubAllEnvs();
 });
 
 describe('resolveLocalizationContext — a failed read says so (#27257)', () => {
@@ -104,3 +111,86 @@ describe('resolveLocalizationContext — a failed read says so (#27257)', () =>
     expect(broken.reads.length + healthy.reads.length).toBe(2);
   });
 });
+
+/**
+ * An engine whose `sys_organization` probe throws while `probeBroken` is set
+ * (an outage, not a missing table), and otherwise holds the one organization
+ * `org_a`. It carries the write-epoch and middleware seams, so a success-cache
+ * entry WOULD be kept if the resolver wrote one.
+ */
+function makeProbeQl(rows: Array<Record<string, unknown>>) {
+  const reads: string[] = [];
+  const state = { probeBroken: true };
+  const ql = {
+    reads,
+    state,
+    writeEpoch: { current: 0, bump: () => 0, subscribe: () => () => {} },
+    registerMiddleware: () => {},
+    async find(object: string, o: any) {
+      reads.push(object);
+      if (object === 'sys_organization') {
+        if (state.probeBroken) throw Object.assign(new Error('connection reset'), { code: 'ECONNRESET' });
+        return [{ id: 'org_a' }].slice(0, o?.limit ?? 1);
+      }
+      const where = o?.where ?? {};
+      const matched = rows.filter((r) =>
+        Object.entries(where).every(([k, v]) => {
+          if (k.startsWith('$')) throw new Error(`fake driver: unsupported operator ${k}`);
+          if (v && typeof v === 'object' && '$in' in (v as any)) return (v as any).$in.includes(r[k]);
+          return r[k] === v;
+        }),
+      );
+      // Hold the caller's bound, after the filter and by presence.
+      return typeof o?.limit === 'number' ? matched.slice(0, o.limit) : matched;
+    },
+  };
+  return ql;
+}
+
+describe('resolveLocalizationContext — a failed organization probe says so too (#27733)', () => {
+  const CNY = { namespace: 'localization', key: 'currency', scope: 'tenant', organization_id: 'org_a', value: 'CNY' };
+
+  it('a store fault on the `sys_organization` probe answers the built-ins WITH `readFailed: true`, reading no row', async () => {
+    vi.stubEnv('OS_TENANCY_POSTURE', 'single');
+    const ql = makeProbeQl([CNY]);
+    const answer = await resolveLocalizationContext({ ql });
+    expect(answer).toEqual({ timezone: 'UTC', locale: 'en-US', currency: undefined, readFailed: true });
+    expect(ql.reads).toEqual(['sys_organization']);
+  });
+
+  it('writes no memo: the next request probes again, and once the store answers it reads the stored default', async () => {
+    vi.stubEnv('OS_TENANCY_POSTURE', 'single');
+    const ql = makeProbeQl([CNY]);
+    expect((await resolveLocalizationContext({ ql })).readFailed).toBe(true);
+    expect((await resolveLocalizationContext({ ql })).readFailed).toBe(true);
+    expect(ql.reads).toEqual(['sys_organization', 'sys_organization']);
+    ql.state.probeBroken = false;
+    const recovered = await resolveLocalizationContext({ ql });
+    expect(recovered.currency).toBe('CNY');
+    expect(recovered).not.toHaveProperty('readFailed');
+  });
+
+  it('a probe that SUCCEEDS and finds no organization is a real "no default": no `readFailed`', async () => {
+    vi.stubEnv('OS_TENANCY_POSTURE', 'single');
+    const ql = makeQl([]);
+    const answer = await resolveLocalizationContext({ ql });
+    expect(answer.currency).toBeUndefined();
+    expect(answer).not.toHaveProperty('readFailed');
+  });
+
+  it('a derivation that fails for a reason other than the store (an unreadable posture) is not a failed read', async () => {
+    vi.stubEnv('OS_TENANCY_POSTURE', 'not-a-posture');
+    const ql = makeProbeQl([CNY]);
+    const answer = await resolveLocalizationContext({ ql });
+    expect(answer.currency).toBeUndefined();
+    expect(answer).not.toHaveProperty('readFailed');
+  });
+
+  it('a caller naming its organization is not probed: a broken probe changes nothing', async () => {
+    const ql = makeProbeQl([CNY]);
+    const answer = await resolveLocalizationContext({ ql, organizationId: 'org_a' });
+    expect(answer.currency).toBe('CNY');
+    expect(answer).not.toHaveProperty('readFailed');
+    expect(ql.reads).toEqual(['sys_setting']);
+  });
+});
@@ -1,7 +1,7 @@
 // Copyright (c) 2025 ObjectStack. Licensed under the Apache-2.0 license.
 
 // [#25083] `isCloudManaged`: the ONE accessor the cloud-managed doors below ask.
-import { Plugin, PluginContext, IHttpServer, isCloudManaged, resolveLocalizationContext, resolveRequestExecutionContext, type RequestAuthService } from '@objectstack/core';
+import { Plugin, PluginContext, IHttpServer, isCloudManaged, resolveRequestExecutionContext, type RequestAuthService } from '@objectstack/core';
 import type { BetterAuthOptions } from 'better-auth';
 import {
   AuthConfig,
@@ -23,7 +23,7 @@ import {
 import { isHumanUserRow, OPEN_POSTURE_VERIFICATION_OFF_WARNING } from './audience-posture.js';
 // [#14157] The dev-admin seed's own precondition — "does a login exist?".
 import { decideDevAdminSeedGate } from './dev-admin-seed-gate.js';
-import { withMailTenantCurrency } from './mail-tenant-currency.js';
+import { localizationMailCurrencyResolver, withMailTenantCurrency } from './mail-tenant-currency.js';
 import {
   // ADR-0048 — the Setup/Studio/Account apps moved to their own packages
   // (@objectstack/{setup,studio,account}); plugin-auth no longer registers them.
@@ -1118,13 +1118,14 @@ export class AuthPlugin implements Plugin {
           // A mail template's no-argument `currency` hole formats in the
           // tenant default: added once here for the six auth mail call sites
           // (see mail-tenant-currency.ts), read the way a request reads it.
-          this.authManager.setEmailService(withMailTenantCurrency(emailSvc, async (organizationId) => {
+          // A failed read is not "no default" (#27710).
+          this.authManager.setEmailService(withMailTenantCurrency(emailSvc, localizationMailCurrencyResolver(() => {
             let settings: unknown;
             try { settings = ctx.getService('settings'); } catch { settings = undefined; }
             let ql: unknown;
             try { ql = ctx.getService<IDataEngine>('data'); } catch { ql = undefined; }
-            return (await resolveLocalizationContext({ ql, settings, organizationId })).currency;
-          }));
+            return { ql, settings };
+          })));
           ctx.logger.info('Auth: email service wired (transactional mail enabled)');
         } else {
           // No email service. The verification / password-reset callbacks now