diff --git a/.changeset/secret-mask-single-source.md b/.changeset/secret-mask-single-source.md
new file mode 100644
index 0000000000..fdb8072bf0
--- /dev/null
+++ b/.changeset/secret-mask-single-source.md
@@ -0,0 +1,53 @@
+---
+"@objectstack/spec": minor
+"@objectstack/objectql": patch
+"@objectstack/service-settings": patch
+---
+
+fix(spec): declare the eight-bullet credential read mask once, in spec (#7572)
+
+The string a client sees in place of a credential it may not read back was
+declared **twice**, byte-identical by convention only:
+
+- `SECRET_MASK` in `@objectstack/objectql` — the encrypted-**field** read mask on
+  the generic CRUD path (ADR-0100 §A/§B);
+- `SETTINGS_SECRET_MASK` in `@objectstack/service-settings` — the settings REST
+  read boundary, added by #7522.
+
+Nothing bound them. An edit to either literal would desynchronise the two masked
+reads a console sees, and the break would be invisible from both sides: each
+package asserted against its own copy, so both suites stay green while the two
+surfaces disagree. That matters more than a cosmetic mismatch — the console
+renders "configured vs not configured" from this value and echoes it back
+unchanged on save, and both write paths read that echo as "unchanged"
+(ADR-0100 §B3). A drifted mask silently turns an unchanged form round-trip into a
+real write of the mask's literal text over a live credential.
+
+**What changed.** The mask is declared once, in `@objectstack/spec` — the
+contract face both sides already depend on — as `SECRET_MASK` in
+`spec/src/data/secret-mask.ts`, alongside the rest of the ADR-0100 surface
+(`data/field.zod.ts`, `data/object.zod.ts`). Both readers now import that one
+declaration:
+
+- `@objectstack/objectql` **re-exports** it, so its public API is byte-for-byte
+  unchanged — `SECRET_MASK` is still exported from the package root and from
+  `core`, with the same name, value and literal type. No consumer changes.
+- `@objectstack/service-settings` aliases it as `SETTINGS_SECRET_MASK`, keeping
+  the name that package publishes and every existing import of it working.
+
+**The framework-agnostic property of the settings service is intact.** #7522
+declined to import the constant because reaching it meant depending on
+`@objectstack/objectql`, the whole data engine — that reasoning was right and
+still holds; no objectql import was added. It never applied to `@objectstack/spec`,
+which is already a dependency of the package and already in its runtime graph
+(`manifest.ts` → `@objectstack/platform-objects/system` → `@objectstack/spec/data`).
+
+**New public API:** `SECRET_MASK` on `@objectstack/spec/data`. Additive — nothing
+was removed or renamed on any package.
+
+The literal keeps its deliberate spelling (eight U+2022 BULLETs written out, not
+an escape or a `.repeat(8)`), so a grep for the mask a client actually received
+still lands on the declaration; a source-level pin holds that, next to a byte pin
+on the value. The far-side literal pins in `plugin-audit` and `driver-memory` are
+deliberately left restating the mask — a pin whose job is to catch the constant
+changing must not import the constant.
diff --git a/packages/objectql/src/secret-fields.test.ts b/packages/objectql/src/secret-fields.test.ts
index aad8ec0f5e..6de46a044b 100644
--- a/packages/objectql/src/secret-fields.test.ts
+++ b/packages/objectql/src/secret-fields.test.ts
@@ -13,6 +13,7 @@
 import { describe, it, expect, beforeEach } from 'vitest';
 import { ObjectQL } from './engine.js';
 import { SECRET_MASK, isSecretRef } from './secret-fields.js';
+import { SECRET_MASK as SPEC_SECRET_MASK } from '@objectstack/spec/data';
 import type { ICryptoProvider, CryptoHandle, CryptoContext } from '@objectstack/spec/contracts';
 
 // ---- minimal stub driver (equality-only WHERE) ----------------------------
@@ -146,6 +147,27 @@ async function buildEngine(withCrypto: boolean) {
   return { engine, stores, crypto, driver };
 }
 
+/**
+ * [#7572] This package no longer DECLARES the read mask — it re-exports the one
+ * `@objectstack/spec` declares, so the encrypted-field path and the settings
+ * REST path cannot serve two different masks.
+ *
+ * The pin restates the literal on purpose. Every assertion below compares an
+ * engine read against the imported `SECRET_MASK`, which stays green whatever
+ * that constant says; only a restated copy can catch the mask's bytes changing
+ * under this package, and only the identity check can catch the re-export being
+ * quietly replaced by a fresh local literal — the exact shape #7572 removed.
+ */
+describe('objectql SECRET_MASK re-export (#7572)', () => {
+  it('is the spec declaration, not a copy', () => {
+    expect(SECRET_MASK).toBe(SPEC_SECRET_MASK);
+  });
+
+  it('is the eight-bullet mask ADR-0100 pins', () => {
+    expect(SECRET_MASK).toBe('••••••••');
+  });
+});
+
 describe('objectql secret-field channel', () => {
   let ctx: Awaited<ReturnType<typeof buildEngine>>;
   beforeEach(async () => { ctx = await buildEngine(true); });
diff --git a/packages/objectql/src/secret-fields.ts b/packages/objectql/src/secret-fields.ts
index 15f743e254..5cf965a3ab 100644
--- a/packages/objectql/src/secret-fields.ts
+++ b/packages/objectql/src/secret-fields.ts
@@ -38,8 +38,17 @@ export const SECRET_REF_PREFIX = 'secret:';
  * Value returned in place of a secret field on a normal read. Indicates
  * "a secret is set" without leaking the handle id or the plaintext. A field
  * with no stored secret resolves to `null` instead.
+ *
+ * Declared in `@objectstack/spec` and re-exported here (#7572), because the
+ * same mask is the contract on a second surface this package cannot see: the
+ * settings REST read boundary in `@objectstack/service-settings`, which is
+ * deliberately framework-agnostic and does not depend on objectql. Two
+ * byte-identical literals bound by convention were what #7572 removed — the
+ * re-export keeps this package's public API unchanged while leaving exactly one
+ * definition. ⛔ Do not restate the literal here; edit it in
+ * `spec/src/data/secret-mask.ts`, where it is pinned.
  */
-export const SECRET_MASK = '••••••••';
+export { SECRET_MASK } from '@objectstack/spec/data';
 
 /** Wrap a `sys_secret` handle id as the opaque ref persisted on the row. */
 export function makeSecretRef(handleId: string): string {
diff --git a/packages/services/service-settings/src/settings-secret-redaction.test.ts b/packages/services/service-settings/src/settings-secret-redaction.test.ts
new file mode 100644
index 0000000000..6922f86f93
--- /dev/null
+++ b/packages/services/service-settings/src/settings-secret-redaction.test.ts
@@ -0,0 +1,57 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * [#7572] `SETTINGS_SECRET_MASK` is the ADR-0100 credential read mask under this
+ * package's published name — the SAME declaration, not a copy of it.
+ *
+ * #7522 shipped it as a second byte-identical literal, bound to objectql's
+ * `SECRET_MASK` by convention alone. Nothing compared them, and nothing could
+ * have: each package asserted against its own constant, so an edit to either
+ * literal would desynchronise the mask a console sees on the settings REST read
+ * from the mask it sees on an encrypted FIELD read, with both suites still green.
+ *
+ * The hoist into `@objectstack/spec` removed the second declaration. This pin
+ * holds what the hoist alone cannot: that this export still resolves to it. A
+ * re-introduced local literal — the natural next edit for anyone who reads the
+ * framework-agnostic note in the module header and stops there — passes every
+ * behaviour test in `settings-routes.test.ts` (those compare a route response
+ * against this very constant, so they move with it) and fails HERE the moment
+ * its bytes differ.
+ *
+ * The literal is restated below for the same reason the spec-side pin restates
+ * it: a check that imported the constant to describe the constant would be true
+ * by construction. The bytes and the grep-findable spelling are pinned at the
+ * declaration itself, in `spec/src/data/secret-mask.test.ts`.
+ */
+
+import { describe, it, expect } from 'vitest';
+
+import { SECRET_MASK } from '@objectstack/spec/data';
+
+import { SETTINGS_SECRET_MASK, dropEchoedSecretMasks, redactSecretValues } from './settings-secret-redaction.js';
+
+describe('SETTINGS_SECRET_MASK is the shared ADR-0100 mask (#7572)', () => {
+  it('is the spec declaration, not a copy', () => {
+    expect(SETTINGS_SECRET_MASK).toBe(SECRET_MASK);
+  });
+
+  it('is the eight-bullet mask', () => {
+    expect(SETTINGS_SECRET_MASK).toBe('••••••••');
+  });
+
+  it('serves the shared mask on read — a client comparing against the FIELD mask recognises it', () => {
+    const out = redactSecretValues(
+      { smtp_password: { value: 'hunter2', source: 'global', locked: false } },
+      new Set(['smtp_password']),
+    );
+    expect(out.smtp_password.value).toBe(SECRET_MASK);
+  });
+
+  it('reads an echo of the shared mask as "unchanged" — the write half of the same contract', () => {
+    // What a console echoes back is whatever it was SERVED, which is the shared
+    // constant; the drop has to key off that same string or the echo becomes a
+    // real write of eight bullets over a live secret.
+    const patch = dropEchoedSecretMasks({ smtp_password: SECRET_MASK }, new Set(['smtp_password']));
+    expect(patch).toEqual({});
+  });
+});
diff --git a/packages/services/service-settings/src/settings-secret-redaction.ts b/packages/services/service-settings/src/settings-secret-redaction.ts
index 262ba08bf7..115ea2cdfe 100644
--- a/packages/services/service-settings/src/settings-secret-redaction.ts
+++ b/packages/services/service-settings/src/settings-secret-redaction.ts
@@ -20,9 +20,10 @@
  * it is still an exposure, and the REST response is the one surface that should
  * never carry the cleartext.
  *
- * The mask shape is NOT invented here — it mirrors the encrypted-**field**
- * convention ADR-0100 pins for `secret` / `password` columns on the generic CRUD
- * path (`SECRET_MASK` in `@objectstack/objectql`, exercised by the
+ * The mask shape is NOT invented here — it IS the encrypted-**field** convention
+ * ADR-0100 pins for `secret` / `password` columns on the generic CRUD path
+ * (`SECRET_MASK`, declared in `@objectstack/spec` and re-exported by
+ * `@objectstack/objectql`, exercised by the
  * `records-forms.encrypted-field-behavior` checklist item):
  *
  *  - **read**: a set value becomes the mask; an unset one stays `null`, so the
@@ -33,17 +34,21 @@
  *    key is DROPPED from the patch, so a form round-trip that echoes the mask
  *    does not overwrite the stored secret with the mask's literal text.
  *
- * The constant is redeclared rather than imported because this service is
- * deliberately framework-agnostic (see the `settings-service.ts` header): it
- * defines its own minimal `SettingsEngine` instead of importing `IDataEngine`,
- * and does not depend on `@objectstack/objectql` at all. Taking a runtime
- * dependency on the whole data engine to reach one string would undo that. The
- * long-term fix is to hoist the mask into a package both sides already depend on
- * (`@objectstack/spec`) and have objectql re-export it — recorded on #7522 as
- * follow-up rather than done here, since it is a cross-package move on a
- * security card.
+ * The mask itself is now IMPORTED, not redeclared (#7572). #7522 shipped a
+ * second byte-identical literal here and said why: this service is deliberately
+ * framework-agnostic (see the `settings-service.ts` header) — it defines its own
+ * minimal `SettingsEngine` instead of importing `IDataEngine`, and does not
+ * depend on `@objectstack/objectql` at all, so taking a runtime dependency on
+ * the whole data engine to reach one string was not worth it. That reasoning
+ * held against depending on **objectql**, and it still does. It does not apply
+ * to `@objectstack/spec`, which is where the mask now lives: spec is already a
+ * dependency of this package, and already in its runtime graph (`manifest.ts`
+ * → `@objectstack/platform-objects/system` → `@objectstack/spec/data`). The
+ * framework-agnostic property is untouched — no objectql import was added here
+ * or anywhere in this package.
  */
 
+import { SECRET_MASK } from '@objectstack/spec/data';
 import type { ResolvedSettingValue } from '@objectstack/spec/system';
 
 /**
@@ -51,12 +56,14 @@ import type { ResolvedSettingValue } from '@objectstack/spec/system';
  * is set" without leaking its cleartext; an unset secret resolves to `null`
  * instead, so set-vs-unset stays observable.
  *
- * Byte-identical to `SECRET_MASK` in `@objectstack/objectql` (ADR-0100) — eight
- * U+2022 BULLET characters — so one client-side comparison recognises a masked
- * read from either surface. Spelled as the literal, not an escape, so a grep for
- * the mask finds both declarations.
+ * The ADR-0100 credential read mask under the name this package publishes — the
+ * SAME declaration objectql re-exports as `SECRET_MASK`, not a copy of it
+ * (#7572), so one client-side comparison recognises a masked read from either
+ * surface and no edit can leave the two disagreeing. The literal, its eight
+ * U+2022 BULLET characters and its grep-findable spelling are pinned at the
+ * declaration in `@objectstack/spec` (`data/secret-mask.ts`).
  */
-export const SETTINGS_SECRET_MASK = '••••••••';
+export const SETTINGS_SECRET_MASK = SECRET_MASK;
 
 /** Mask one resolved value: the effective value AND every cascade entry. */
 function maskResolved(resolved: ResolvedSettingValue): ResolvedSettingValue {
diff --git a/packages/spec/api-surface/data.json b/packages/spec/api-surface/data.json
index 7c34172f05..5db2c195e1 100644
--- a/packages/spec/api-surface/data.json
+++ b/packages/spec/api-surface/data.json
@@ -484,6 +484,7 @@
     "SEARCH_AUTO_EXCLUDED_FIELDS (const)",
     "SEARCH_AUTO_EXCLUDED_TYPES (const)",
     "SEARCH_VIRTUAL_TYPES (const)",
+    "SECRET_MASK (const)",
     "SINGLE_OPTION_TYPES (const)",
     "SQLDialect (type)",
     "SQLDialectSchema (const)",
diff --git a/packages/spec/export-origins/data.json b/packages/spec/export-origins/data.json
index 601ca826fa..96501936ad 100644
--- a/packages/spec/export-origins/data.json
+++ b/packages/spec/export-origins/data.json
@@ -484,6 +484,7 @@
     "SEARCH_AUTO_EXCLUDED_FIELDS": "src/data/search-fields.ts#SEARCH_AUTO_EXCLUDED_FIELDS (const)",
     "SEARCH_AUTO_EXCLUDED_TYPES": "src/data/search-fields.ts#SEARCH_AUTO_EXCLUDED_TYPES (const)",
     "SEARCH_VIRTUAL_TYPES": "src/data/search-fields.ts#SEARCH_VIRTUAL_TYPES (const)",
+    "SECRET_MASK": "src/data/secret-mask.ts#SECRET_MASK (const)",
     "SINGLE_OPTION_TYPES": "src/data/field-value.zod.ts#SINGLE_OPTION_TYPES (const)",
     "SQLDialect": "src/data/driver-sql.zod.ts#SQLDialect (type)",
     "SQLDialectSchema": "src/data/driver-sql.zod.ts#SQLDialectSchema (const)",
diff --git a/packages/spec/src/data/index.ts b/packages/spec/src/data/index.ts
index d3ad441c31..c9f6ff3975 100644
--- a/packages/spec/src/data/index.ts
+++ b/packages/spec/src/data/index.ts
@@ -54,6 +54,12 @@ export * from './object.zod';
 // `enable.apiMethods` whitelist into its effective operation set (#3391).
 export * from './api-derivation';
 export * from './field.zod';
+// The credential read mask (ADR-0100) — the ONE string a masked read serves, in
+// place of the two byte-identical literals objectql and service-settings each
+// declared until #7572. Both now import this one, so the mask a console sees on
+// the encrypted-FIELD path cannot desynchronise from the mask it sees on the
+// settings REST path.
+export * from './secret-mask';
 // The unknown-authoring-key lint's CORE — comparator, finding shape, curated
 // guidance tables (#3786). Kept frontend-safe: the stack WALKER that imports
 // every schema lives in kernel/metadata-authoring-lint.ts, so this subpath's
diff --git a/packages/spec/src/data/secret-mask.test.ts b/packages/spec/src/data/secret-mask.test.ts
new file mode 100644
index 0000000000..d755c87252
--- /dev/null
+++ b/packages/spec/src/data/secret-mask.test.ts
@@ -0,0 +1,55 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * [#7572] The credential read mask's two load-bearing properties, pinned where
+ * the mask is now declared: its BYTES and its SPELLING.
+ *
+ * Hoisting the constant into `spec` removed the drift *between* the two former
+ * copies — objectql's `SECRET_MASK` and service-settings' `SETTINGS_SECRET_MASK`
+ * are the same declaration now, so they cannot desynchronise. What a single
+ * declaration does NOT remove is an edit to that declaration, and this mask has
+ * a wider blast radius than its one line suggests: a console renders
+ * "configured vs not configured" from it, echoes it back unchanged on save, and
+ * both write paths read that echo as "unchanged" (ADR-0100 §B3). Change the
+ * bytes and every already-rendered form's echo stops being recognised — it
+ * becomes a genuine write of eight bullets over a live credential.
+ *
+ * So this file keeps its OWN copy of the literal and compares. That restatement
+ * is the point: a pin that imported the constant to check the constant would be
+ * green by construction. The far-side pins in plugin-audit and driver-memory
+ * restate it for the same reason and are deliberately left alone (#7572).
+ *
+ * The spelling half is not decoration either. #7572 records it as a property to
+ * preserve: the mask is written as the literal — not `'•'.repeat(8)`, not
+ * an escape — so that someone who greps for the eight bullets a client actually
+ * received lands on the declaration. Nothing but a source read can hold that,
+ * since every spelling produces the identical value.
+ */
+
+import fs from 'node:fs';
+import path from 'node:path';
+import url from 'node:url';
+
+import { describe, it, expect } from 'vitest';
+
+import { SECRET_MASK } from './secret-mask';
+
+const HERE = path.dirname(url.fileURLToPath(import.meta.url));
+const SOURCE = path.resolve(HERE, 'secret-mask.ts');
+
+describe('SECRET_MASK — the credential read mask (ADR-0100 / #7572)', () => {
+  it('is exactly eight U+2022 BULLET characters', () => {
+    // Restated on purpose — see the module header.
+    expect(SECRET_MASK).toBe('••••••••');
+    expect([...SECRET_MASK]).toHaveLength(8);
+    expect(new Set([...SECRET_MASK].map((c) => c.codePointAt(0)))).toEqual(new Set([0x2022]));
+    // No surrogate pairs, so the UTF-16 length matches the code-point count —
+    // the property every `value.length === 8` reader downstream relies on.
+    expect(SECRET_MASK).toHaveLength(8);
+  });
+
+  it('is spelled as the literal in source, so a grep for the mask finds it', () => {
+    const source = fs.readFileSync(SOURCE, 'utf8');
+    expect(source).toContain("export const SECRET_MASK = '••••••••';");
+  });
+});
diff --git a/packages/spec/src/data/secret-mask.ts b/packages/spec/src/data/secret-mask.ts
new file mode 100644
index 0000000000..af0c58bf1e
--- /dev/null
+++ b/packages/spec/src/data/secret-mask.ts
@@ -0,0 +1,61 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * The credential read mask (ADR-0100) — the one string a client sees in place
+ * of a value it is not allowed to read back.
+ *
+ * # Why this lives in `spec` and not next to either reader
+ *
+ * "A masked read looks like THIS" is a **client-facing contract**, and it is
+ * consumed by two independent surfaces that never call each other:
+ *
+ *   - the encrypted-**field** read path in `@objectstack/objectql` — `secret`
+ *     and generic `password` columns masked on `find`/`findOne`/`$expand`
+ *     (ADR-0100 §A/§B), re-exported from that package as `SECRET_MASK` for
+ *     hosts and privileged consumers;
+ *   - the settings **REST boundary** in `@objectstack/service-settings`, whose
+ *     `SETTINGS_SECRET_MASK` is this same constant under the name that package
+ *     publishes (#7522).
+ *
+ * Until #7572 each of those declared its own byte-identical literal, bound by
+ * nothing but convention. That duplication is invisible while it holds and
+ * silent when it breaks: an edit to either literal desynchronises the two
+ * masked-read faces a console sees, and *both* packages' suites stay green,
+ * because each asserts against its own copy. The console cannot be shown two
+ * different masks — it renders "configured vs not configured" from this value
+ * and echoes it back unchanged on save (the echoed-mask write guard, ADR-0100
+ * §B3), so a drifted mask silently turns "unchanged" into "overwrite".
+ *
+ * `spec` is the contract face both sides already depend on, so the mask is
+ * declared here **once** and imported. Neither reader takes a new dependency to
+ * reach it: objectql is built on spec, and service-settings — which is
+ * deliberately framework-agnostic and does NOT depend on objectql — already
+ * loads `@objectstack/spec/data` at runtime through
+ * `@objectstack/platform-objects`' object declarations.
+ *
+ * # The literal is spelled out on purpose
+ *
+ * Eight U+2022 BULLET characters, written as the literal rather than as a
+ * `•` escape or a `.repeat(8)`, so that a plain grep for the mask a client
+ * actually received finds this declaration. Pinned by `secret-mask.test.ts` in
+ * both directions — the bytes AND the spelling — because "spelled so it can be
+ * found" is a property no type can carry.
+ */
+
+/**
+ * Value served in place of a credential on a masked read: `secret` and generic
+ * `password` fields on the engine's generic read path (ADR-0100), and secret-
+ * backed settings on the settings REST read path (#7522).
+ *
+ * Says "a value is set" without leaking the plaintext or the storage handle. An
+ * UNSET credential reads back `null` instead, never this mask — the masking is
+ * presence-preserving on both surfaces, which is what lets a console render
+ * "configured" vs "not configured" at all.
+ *
+ * Writing this exact string back is treated as "unchanged" and dropped by both
+ * write paths, so a form round-trip that echoes what it read cannot overwrite
+ * the stored credential with the mask's literal text. Accepted cost, recorded in
+ * ADR-0100 §B3: eight bullets cannot itself be stored as a credential value
+ * through an echoing client.
+ */
+export const SECRET_MASK = '••••••••';