@@ -0,0 +1,12 @@
+---
+"@objectstack/metadata-protocol": minor
+---
+
+`ObjectStackProtocolImplementation.declinesStoredRow(type, name)` is now public, so a door that serves a stored row out of the layered read can ask the same decision the reads make
+
+Clause-②: yes (widening)
+
+- The method answers `true` for exactly the names whose stored `sys_metadata` row the active reads (`getMetaItem`, the list, and the `effective` layer of `getMetaItemLayered`) do not adopt: a flow name a managed package ships (the answer `isShippedFlowName` gives), and a datasource name the host registers from code (one an installed package declares in `*.datasource.ts`, or the host's `default`). Every other type and name answers `false`.
+- The `GET /meta/:type/:name/published` doors in `@objectstack/rest` and `@objectstack/runtime` now ask this method in place of `isShippedFlowName`. A door asks it, and does not restate either half or the host's code-datasource set.
+- `isShippedFlowName` stays public and unchanged.
+- The only change to the public surface is this one added method. No signature, schema or accept set changes, and no behaviour of this package changes.
@@ -0,0 +1,10 @@
+---
+"@objectstack/rest": patch
+---
+
+`GET /api/v1/meta/datasource/:name/published` serves a code-defined datasource's code definition while a stored row under its name still exists
+
+Clause-②: no
+
+- For a datasource name the host registers from code (one an installed package declares in `*.datasource.ts`, or the host's `default`), the published door now serves the layered read's `effective` layer, which is the code definition. Before this change it served the leftover stored `sys_metadata` row, with that row's label, `origin` and connection settings, while `GET /api/v1/meta/datasource/:name`, the `/meta/datasource` list and `/layers` all served the code definition. The door now asks the protocol's `declinesStoredRow`, the one decision those reads make, in place of `isShippedFlowName`. A shipped flow name is answered as before.
+- Unchanged: a runtime datasource's stored row is still what the door serves, and so is every stored row of every other type. A protocol that does not provide `declinesStoredRow` still gets the stored row. The row itself stays at rest, `/layers` still reports it in `overlay`, and `DELETE /api/v1/meta/datasource/:name` still removes it as the repair.
@@ -0,0 +1,10 @@
+---
+"@objectstack/runtime": patch
+---
+
+The runtime dispatcher's `GET /meta/datasource/:name/published` serves a code-defined datasource's code definition while a stored row under its name still exists
+
+Clause-②: no
+
+- This is the dispatcher twin of the `@objectstack/rest` published door, and it now answers the same way. For a datasource name the host registers from code (one an installed package declares in `*.datasource.ts`, or the host's `default`), the door serves the layered read's `effective` layer, which is the code definition, instead of the leftover stored row. It asks the protocol's `declinesStoredRow` in place of `isShippedFlowName`. A shipped flow name is answered as before.
+- Unchanged: a runtime datasource's stored row, and every stored row of every other type, is served as before. So is every row when the protocol does not provide `declinesStoredRow`.
@@ -0,0 +1,86 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * [#21986] `declinesStoredRow` is PUBLIC on `ObjectStackProtocolImplementation`,
+ * so the published-snapshot doors (`GET /meta/:type/:name/published`, the REST
+ * route and its dispatcher twin) can ask it instead of `isShippedFlowName`.
+ *
+ * What a door relies on, pinned here once: the one predicate answers BOTH name
+ * classes whose stored row the active reads decline, and nothing else.
+ *
+ *  - a FLOW name the loader's set holds (`isShippedFlowName`'s answer);
+ *  - a CODE-DEFINED DATASOURCE name: one an installed package declares, or one
+ *    the host registers from code (`code-datasource-names`, here `default`).
+ *
+ * Every other name answers false: a flow no package ships, a runtime
+ * datasource, the same name under another type, a missing or empty name.
+ *
+ * The calls below go through the class's own declared type, never an `any`
+ * cast, so `tsc --noEmit` over this file (the package's `typecheck` includes
+ * `src/**`) fails if the member stops being public.
+ */
+import { describe, expect, it } from 'vitest';
+import { ObjectStackProtocolImplementation } from './protocol.js';
+
+const FLOW_PACKAGE = 'com.example.pkg';
+const SHIPPED_FLOW = 'pkg_flow';
+const CUSTOMER_FLOW = 'customer_flow';
+const CODE_DS = 'showcase_external';
+const HOST_DS = 'default';
+const RUNTIME_DS = 'rt_datasource_21986';
+
+/**
+ * A partial registry: the loader's entry for {@link SHIPPED_FLOW} carries its
+ * package id (the shape `lookupArtifactItem` reads off a registry with no
+ * `getArtifactItem`), and one installed package declares {@link CODE_DS}. The
+ * services registry carries the host's code-datasource set.
+ */
+function makeProtocol(): ObjectStackProtocolImplementation {
+    const loaderEntry = { name: SHIPPED_FLOW, label: 'Loader', _packageId: FLOW_PACKAGE };
+    const engine = {
+        registry: {
+            getItem: (type: string, name: string) =>
+                (type === 'flow' || type === 'flows') && name === SHIPPED_FLOW ? loaderEntry : undefined,
+            getAllPackages: () => [{
+                manifest: { id: 'com.example.showcase', datasources: [{ name: CODE_DS, driver: 'sqlite', config: {} }] },
+            }],
+        },
+    };
+    const services = new Map<string, unknown>([['code-datasource-names', new Set([HOST_DS])]]);
+    return new ObjectStackProtocolImplementation(engine as never, () => services);
+}
+
+describe('[#21986] the published predicate: declinesStoredRow answers both name classes, and only those', () => {
+    it('a shipped flow name, in either type spelling — what isShippedFlowName answers', () => {
+        const protocol = makeProtocol();
+        for (const type of ['flow', 'flows']) {
+            expect(protocol.isShippedFlowName(type, SHIPPED_FLOW), type).toBe(true);
+            expect(protocol.declinesStoredRow(type, SHIPPED_FLOW), type).toBe(true);
+        }
+    });
+
+    it('a code-defined datasource name: one a package declares, and one the host registers from code', () => {
+        const protocol = makeProtocol();
+        for (const type of ['datasource', 'datasources']) {
+            expect(protocol.declinesStoredRow(type, CODE_DS), type).toBe(true);
+            expect(protocol.declinesStoredRow(type, HOST_DS), type).toBe(true);
+            // Not a flow answer: the datasource half is its own.
+            expect(protocol.isShippedFlowName(type, CODE_DS), type).toBe(false);
+        }
+    });
+
+    it('control: every other name keeps its stored row', () => {
+        const protocol = makeProtocol();
+        expect(protocol.declinesStoredRow('flow', CUSTOMER_FLOW)).toBe(false);
+        expect(protocol.declinesStoredRow('datasource', RUNTIME_DS)).toBe(false);
+        // The same names under another type.
+        expect(protocol.declinesStoredRow('object', CODE_DS)).toBe(false);
+        expect(protocol.declinesStoredRow('object', HOST_DS)).toBe(false);
+        expect(protocol.declinesStoredRow('view', SHIPPED_FLOW)).toBe(false);
+        // A name that is not one.
+        for (const name of [undefined, null, '', 42]) {
+            expect(protocol.declinesStoredRow('datasource', name), String(name)).toBe(false);
+            expect(protocol.declinesStoredRow('flow', name), String(name)).toBe(false);
+        }
+    });
+});
@@ -16746,10 +16746,9 @@ export class ObjectStackProtocolImplementation implements
      *
      * [#21922] The layered read asks this predicate through
      * {@link declinesStoredRow}, which also declines the stored row of a
-     * code-defined datasource name. The published doors ask this predicate
-     * alone, so for such a name they still serve the stored row: the active
-     * overlay row, as the route's spec describes it. That door is not moved
-     * here.
+     * code-defined datasource name. [#21986] The published doors ask
+     * {@link declinesStoredRow} in its place, so for such a name they serve
+     * the code definition too.
      */
     isShippedFlowName(type: string, name: unknown): boolean {
         if ((PLURAL_TO_SINGULAR[type] ?? type) !== 'flow') return false;
@@ -16806,8 +16805,18 @@ export class ObjectStackProtocolImplementation implements
      * (`storedRowServed`, the fact {@link servedLockState}'s `deletable`
      * reads), the `_lock` gate's overlay layer ({@link overlayLockLayerAt},
      * read whether or not the row is adopted), and the DELETE's own row probe.
+     *
+     * [#21986] PUBLIC so a door that serves a stored row out of the layered
+     * read can ASK it, never re-derive it: `GET /meta/:type/:name/published`
+     * (the REST route and its dispatcher twin) reads {@link getMetaItemLayered}
+     * and, when a stored row is present and this predicate holds for the
+     * answer's `type` and `name`, serves the `effective` layer (the loader's
+     * body, or the code definition) instead of the row. Every other stored row
+     * is served as before. A door asks this method alone: ⛔ no door restates
+     * either half, or the host's code-datasource set. A write door does not
+     * ask it; the writes keep their own refusals.
      */
-    private declinesStoredRow(type: string, name: unknown): boolean {
+    declinesStoredRow(type: string, name: unknown): boolean {
         if (this.isShippedFlowName(type, name)) return true;
         return typeof name === 'string' && name !== '' && this.isDeclaredCodeDatasource(type, name);
     }
 
@@ -586,11 +586,14 @@ describe('[#21002] the published door follows the layered read for a shipped flo
     it('control: a protocol that brings no such predicate keeps today\'s answer, the stored row', async () => {
         const { engine, metadata, protocol } = shippedHarness();
         await storeActiveRow(engine, 'flow', SHIPPED, flowBody(SHIPPED, 'STORED'));
-        // The same protocol with the predicate hidden from the door only; its
-        // own methods keep calling it on the real instance.
+        // The same protocol with the predicate the door asks hidden from the
+        // door only; its own methods keep calling it on the real instance.
+        // [#21986] That predicate is `declinesStoredRow`. `isShippedFlowName`
+        // stays visible, so this also pins that the door does not fall back
+        // to it: a protocol without the one predicate gets the stored row.
         const withoutPredicate = new Proxy(protocol, {
             get(target, key) {
-                if (key === 'isShippedFlowName') return undefined;
+                if (key === 'declinesStoredRow') return undefined;
                 const value = Reflect.get(target, key);
                 return typeof value === 'function' ? value.bind(target) : value;
             },
@@ -602,3 +605,107 @@ describe('[#21002] the published door follows the layered read for a shipped flo
         expect(res.body).toMatchObject({ name: SHIPPED, label: 'STORED' });
     }, 60_000);
 });
+
+/**
+ * [#21986] The other name class whose stored row the layered read declines: a
+ * CODE-DEFINED DATASOURCE name (here one an installed package declares). The
+ * by-name read, the list and the layered read's effective layer serve the code
+ * definition, the MetadataService's registration, and the stored row is
+ * residue, still reported in `overlay`. This door asks the protocol's one
+ * predicate for both name classes, `declinesStoredRow`, with the answer's own
+ * `type` / `name`, so it serves that effective layer too. A runtime
+ * datasource's stored row is still served.
+ *
+ * The cold-boot reading over the real showcase composition is recorded on the
+ * PR; the predicate's two halves are pinned in `metadata-protocol`.
+ */
+describe('[#21986] the published door serves a code-defined datasource\'s code definition over a stored row', () => {
+    const CODE_DS = 'showcase_external';
+    const RUNTIME_DS = 'rt_datasource_21986';
+    const CODE_LABEL = 'External Analytics (SQLite)';
+    const SHADOW_LABEL = 'Shadow 21986';
+    const dsBody = (name: string, label: string, origin: 'code' | 'runtime', filename: string) => ({
+        name, label, driver: 'sqlite', config: { filename }, origin,
+    });
+
+    /**
+     * The file's engine double, with an installed package that declares
+     * {@link CODE_DS}, and the MetadataService holding the code definition the
+     * runtime registers at boot (and a copy of the runtime datasource under a
+     * label its row does not carry, so the control can tell which layer answered).
+     */
+    async function datasourceHarness() {
+        const { engine, rows } = makeStubEngine();
+        engine.registry = {
+            registerItem: () => {},
+            registerObject: () => {},
+            getPackage: () => undefined,
+            getItem: () => undefined,
+            getAllPackages: () => [{
+                manifest: {
+                    id: 'com.example.showcase',
+                    datasources: [{ name: CODE_DS, label: CODE_LABEL, driver: 'sqlite', config: { filename: 'x.db' } }],
+                },
+            }],
+        };
+        const metadata = new MetadataManager({});
+        await metadata.register('datasource', CODE_DS, dsBody(CODE_DS, CODE_LABEL, 'code', `${CODE_DS}.db`));
+        await metadata.register('datasource', RUNTIME_DS, dsBody(RUNTIME_DS, 'Runtime (MetadataService copy)', 'runtime', 'rt.db'));
+        const protocol = makeProtocol(engine, metadata);
+        return { engine, rows, metadata, protocol };
+    }
+
+    async function storeActiveRow(engine: any, name: string, body: unknown) {
+        await engine.insert('sys_metadata', {
+            type: 'datasource', name, organization_id: null, package_id: null, state: 'active',
+            metadata: JSON.stringify(body), checksum: 'sha256:stored', version: 1,
+        });
+    }
+
+    /**
+     * {@link setup}, read by a caller the `/meta` doors admit to a datasource
+     * read: `datasource` reads require `manage_platform_settings`, the
+     * capability the datasource admin door requires.
+     */
+    function setupAsPlatformAdmin(protocol: unknown, metadata: unknown) {
+        const rest = setup(protocol, metadata);
+        (rest as any).resolveExecCtx = async () => ({ userId: 'u_platform', systemPermissions: ['manage_platform_settings'] });
+        return rest;
+    }
+
+    it('a stored row under a code-defined datasource name: the door answers the code definition, the layered effective layer', async () => {
+        const { engine, rows, metadata, protocol } = await datasourceHarness();
+        await storeActiveRow(engine, CODE_DS, dsBody(CODE_DS, SHADOW_LABEL, 'runtime', 'shadow-external.db'));
+        expect(rows.size).toBe(1);
+
+        // The decision this door follows: a stored layer IS present, and the
+        // layered read put the code definition over it.
+        const layered: any = await protocol.getMetaItemLayered({ type: 'datasource', name: CODE_DS });
+        expect(layered.overlay).toMatchObject({ origin: 'runtime', label: SHADOW_LABEL });
+        expect(layered.effective).toMatchObject({ origin: 'code', label: CODE_LABEL });
+
+        const rest = setupAsPlatformAdmin(protocol, metadata);
+        for (const type of ['datasource', 'datasources']) {
+            const res = await callPublished(rest, { type, name: CODE_DS });
+
+            expect(res.statusCode, type).toBe(200);
+            expect(res.body, type).toMatchObject({ name: CODE_DS, origin: 'code', label: CODE_LABEL });
+            expect(JSON.stringify(res.body), type).not.toContain('shadow-external.db');
+            expect(res.body, type).toEqual(layered.effective);
+        }
+        // The row stays at rest: the door read past it, nothing removed it.
+        expect(rows.size).toBe(1);
+    }, 60_000);
+
+    it('control: a runtime datasource\'s stored row is still what the door serves', async () => {
+        const { engine, metadata, protocol } = await datasourceHarness();
+        await storeActiveRow(engine, RUNTIME_DS, dsBody(RUNTIME_DS, 'Runtime (stored row)', 'runtime', 'rt.db'));
+
+        const layered: any = await protocol.getMetaItemLayered({ type: 'datasource', name: RUNTIME_DS });
+        const res = await callPublished(setupAsPlatformAdmin(protocol, metadata), { type: 'datasource', name: RUNTIME_DS });
+
+        expect(res.statusCode).toBe(200);
+        expect(res.body).toMatchObject({ name: RUNTIME_DS, label: 'Runtime (stored row)' });
+        expect(res.body).toEqual(layered.overlay);
+    }, 60_000);
+});
@@ -8621,24 +8621,30 @@ export class RestServer {
                                         : {}),
                                 });
                                 if (layered?.overlay !== undefined && layered?.overlay !== null) {
-                                    // [#21002, ADR-0126 §2] When the layered
-                                    // read put the LOADER's body over this stored
-                                    // row — a shipped flow name, decided by the
-                                    // protocol's `isShippedFlowName` — this door
-                                    // serves that effective layer, not the row:
-                                    // `flow` is Regime C, "never an overlay read
-                                    // path". The predicate is ASKED of its owner
-                                    // with the answer's own `type` / `name`,
-                                    // never re-derived here, so this door and
+                                    // [#21002, #21986, ADR-0126 §2, ADR-0062 D4]
+                                    // When the layered read put a code layer
+                                    // over this stored row, this door serves
+                                    // that effective layer, not the row. The
+                                    // protocol decides it with one predicate,
+                                    // `declinesStoredRow`, for both name
+                                    // classes: a shipped flow name (the
+                                    // loader's body; `flow` is Regime C,
+                                    // "never an overlay read path") and a
+                                    // code-defined datasource name (the code
+                                    // definition; "code wins on collision").
+                                    // The predicate is ASKED of its owner with
+                                    // the answer's own `type` / `name`, never
+                                    // re-derived here, so this door, the
+                                    // by-name read, the list and
                                     // `getMetaItemLayered` read one rule. Every
                                     // other stored row is served exactly as
                                     // before — an `object` too, whose effective
                                     // layer differs from its row by folding, not
                                     // by this decision — and so is every row of a
                                     // protocol that brings no such predicate.
-                                    const shippedFlow: { isShippedFlowName?(type: string, name: unknown): boolean } = publishedProtocol;
-                                    publishedOverlay = typeof shippedFlow.isShippedFlowName === 'function'
-                                        && shippedFlow.isShippedFlowName(layered.type, layered.name)
+                                    const decliner: { declinesStoredRow?(type: string, name: unknown): boolean } = publishedProtocol;
+                                    publishedOverlay = typeof decliner.declinesStoredRow === 'function'
+                                        && decliner.declinesStoredRow(layered.type, layered.name)
                                         ? layered.effective
                                         : layered.overlay;
                                 }