@@ -0,0 +1,82 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * [#25467 cut 28] The code-datasource predicates, from
+ * `ObjectStackProtocolImplementation`, moved out of `protocol.ts` whole: the
+ * two answers to "is this datasource name defined in code?" (#21899, #21944).
+ *
+ *  - `isDeclaredCodeDatasource` — does an installed package declare it, or
+ *    does the host register it from code? The `/meta` door's artifact-backed
+ *    verdict and the stored-row lock read it.
+ *  - `isHostCodeDatasource` — the host's code-datasource set alone, the
+ *    first half of that answer and exactly what the datasource-admin boot
+ *    restore reads.
+ *
+ * A MOVE, not a redesign. Each function below is the body of the
+ * `ObjectStackProtocolImplementation` method of the same name as it stood,
+ * re-indented one level and otherwise unedited.
+ *
+ * ## How the moved bodies reach the class
+ *
+ * The shape #23050 set for `rest-server.ts` (its `data-action-routes.ts`
+ * header carries the full reasoning), as `protocol-batch-data.ts` applies it.
+ * The class keeps each method — the published `dist/*.d.ts` lists its name,
+ * docblock and declared signature — and its body is one literal of exactly
+ * the {@link CodeDatasourcePredicatesHost} members it reads, plus a `.call`.
+ * The `engine` and `getServicesRegistry` fields are handed over as getters,
+ * so each read finds them as they stand at call time;
+ * `isDeclaredCodeDatasource`'s call to `isHostCodeDatasource` is handed over
+ * as a closure, so it still reaches the class method. Every caller keeps
+ * calling the class methods.
+ *
+ * What the bodies read from elsewhere, they import from where `protocol.ts`
+ * imports it. Nothing re-exports this module, so the published surface does
+ * not move.
+ */
+
+import { PLURAL_TO_SINGULAR } from '@objectstack/spec/shared';
+import type { ObjectStackProtocolImplementation } from './protocol.js';
+
+/**
+ * The `ObjectStackProtocolImplementation` members the functions below read —
+ * every one of them, and no other; each function's `this` is the `Pick` of
+ * the members it reads. Each is typed AS the class member (an indexed access
+ * on the class), so a change to a member's signature on the class is a change
+ * here too, and naming a member the class does not have is a compile error.
+ */
+export interface CodeDatasourcePredicatesHost {
+    readonly engine: ObjectStackProtocolImplementation['engine'];
+    readonly getServicesRegistry: ObjectStackProtocolImplementation['getServicesRegistry'];
+    readonly isHostCodeDatasource: ObjectStackProtocolImplementation['isHostCodeDatasource'];
+}
+
+/** The body of `ObjectStackProtocolImplementation#isDeclaredCodeDatasource`; the method's docblock there is its contract. */
+export function isDeclaredCodeDatasource(
+    this: Pick<CodeDatasourcePredicatesHost, 'engine' | 'isHostCodeDatasource'>,
+    type: string,
+    name: string,
+): boolean {
+    if ((PLURAL_TO_SINGULAR[type] ?? type) !== 'datasource') return false;
+    if (this.isHostCodeDatasource(type, name)) return true;
+    const registry = (this.engine as any)?.registry;
+    if (typeof registry?.getAllPackages !== 'function') return false;
+    for (const record of registry.getAllPackages() as unknown[]) {
+        const declared = (record as { manifest?: { datasources?: unknown } } | null | undefined)
+            ?.manifest?.datasources;
+        if (Array.isArray(declared) && declared.some((ds) => (ds as { name?: unknown } | null)?.name === name)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+/** The body of `ObjectStackProtocolImplementation#isHostCodeDatasource`; the method's docblock there is its contract. */
+export function isHostCodeDatasource(
+    this: Pick<CodeDatasourcePredicatesHost, 'getServicesRegistry'>,
+    type: string,
+    name: string,
+): boolean {
+    if ((PLURAL_TO_SINGULAR[type] ?? type) !== 'datasource') return false;
+    const hostCode = this.getServicesRegistry?.().get('code-datasource-names') as { has?: unknown } | undefined;
+    return typeof hostCode?.has === 'function' && (hostCode as { has(n: string): boolean }).has(name);
+}
@@ -419,6 +419,8 @@ import { emitMetaItemPublished, notifyMutationListenersLocal, publishMetadataMut
 import { hierarchyResolverMounted, orgWallEnforced, rlsMembershipResolverKeys, tenancyPostureInForce } from './protocol-authoring-posture-probes.js';
 // [#25467 cut 27] The automation service's flow reads: the stored-flow canonicalizer and the engine's registrations.
 import { flowRegistrationsOf, resolveFlowCanonicalizer, resolveFlowRegistrationReader } from './protocol-automation-flow-reads.js';
+// [#25467 cut 28] The code-datasource predicates: declared by an installed package, or registered by the host.
+import { isDeclaredCodeDatasource, isHostCodeDatasource } from './protocol-code-datasource-predicates.js';
 
 /**
  * Canonical Zod schema per metadata type lives in
@@ -15673,18 +15675,13 @@ export class ObjectStackProtocolImplementation implements
      *    datasource stays creatable, editable and removable through this door.
      */
     private isDeclaredCodeDatasource(type: string, name: string): boolean {
-        if ((PLURAL_TO_SINGULAR[type] ?? type) !== 'datasource') return false;
-        if (this.isHostCodeDatasource(type, name)) return true;
-        const registry = (this.engine as any)?.registry;
-        if (typeof registry?.getAllPackages !== 'function') return false;
-        for (const record of registry.getAllPackages() as unknown[]) {
-            const declared = (record as { manifest?: { datasources?: unknown } } | null | undefined)
-                ?.manifest?.datasources;
-            if (Array.isArray(declared) && declared.some((ds) => (ds as { name?: unknown } | null)?.name === name)) {
-                return true;
-            }
-        }
-        return false;
+        // [#25467 cut 28] The body moved to `protocol-code-datasource-predicates.ts` (see `CodeDatasourcePredicatesHost`).
+        const readEngine = () => this.engine;
+        const host: ThisParameterType<typeof isDeclaredCodeDatasource> = {
+            get engine() { return readEngine(); },
+            isHostCodeDatasource: (...a) => this.isHostCodeDatasource(...a),
+        };
+        return isDeclaredCodeDatasource.call(host, type, name);
     }
 
     /**
@@ -15695,9 +15692,12 @@ export class ObjectStackProtocolImplementation implements
      * those rows to that warning).
      */
     private isHostCodeDatasource(type: string, name: string): boolean {
-        if ((PLURAL_TO_SINGULAR[type] ?? type) !== 'datasource') return false;
-        const hostCode = this.getServicesRegistry?.().get('code-datasource-names') as { has?: unknown } | undefined;
-        return typeof hostCode?.has === 'function' && (hostCode as { has(n: string): boolean }).has(name);
+        // [#25467 cut 28] The body moved to `protocol-code-datasource-predicates.ts` (see `CodeDatasourcePredicatesHost`).
+        const readGetServicesRegistry = () => this.getServicesRegistry;
+        const host: ThisParameterType<typeof isHostCodeDatasource> = {
+            get getServicesRegistry() { return readGetServicesRegistry(); },
+        };
+        return isHostCodeDatasource.call(host, type, name);
     }
 
     /**