@@ -354,18 +354,35 @@ describe('aiTestActionHandler — live-call hint carries the cloud boundary (#11
     });
   }
 
-  // Contrast control, so the assertions above cannot be satisfied by blanket-
-  // rewording every hint in this file: the embedder hint names
-  // `@objectstack/embedder-openai`, which IS built in this repo (8 path hits
-  // under `git ls-tree -r --name-only HEAD | grep -cF /embedder-openai/`, against
-  // 0 for `/service-ai/`), so that instruction is followable as written and stays
-  // a plain mount line. Asserted here, deliberately not edited — commit 99ccbb9c8 fences
-  // this site out by name.
-  it('leaves the embedder hint a plain mount line — its package IS built here', async () => {
-    const r = await runTestEmbedder({ embedder_provider: 'openai', embedder_api_key: 'sk-test' });
+  // The embedder hint used to stand here as this block's contrast control — a
+  // plain "Mount @objectstack/embedder-openai + a knowledge adapter to exercise
+  // live calls", kept because that package IS built in this repo. Followable,
+  // but measured false for the button it answered (#24769): no package in this
+  // repo registers `ai/test_embedder`, so mounting it never made "Test
+  // embedder" live. Its replacement is pinned with the embedder handler below;
+  // the three branches above are still exercised one by one, so a blanket
+  // rewording cannot stand in for them.
+});
+
+/**
+ * #24769 — "Test embedder" is now answered (the handler is in the plugin's
+ * default map), and what it answers is a form check: no embedding request is
+ * sent and no package in this repo replaces it with a live probe. A green
+ * answer must say so, and must not name a package whose mounting would make the
+ * check live.
+ */
+describe('aiTestEmbedderActionHandler — a form check says it is one (#24769)', () => {
+  it('states that no embedding request was sent, and promises no live call', async () => {
+    const r = await runTestEmbedder({
+      embedder_provider: 'openai',
+      embedder_api_key: 'sk-test',
+      embedder_model: 'text-embedding-3-small',
+    });
     expect(r.ok).toBe(true);
-    expect(String(r.message)).toContain(
-      'Mount @objectstack/embedder-openai + a knowledge adapter to exercise live calls',
-    );
+    expect(r.severity).toBe('info');
+    const message = String(r.message);
+    expect(message).toContain('text-embedding-3-small');
+    expect(message).toMatch(/no embedding request was sent/);
+    expect(message).not.toMatch(/to exercise live calls/);
   });
 });
@@ -427,12 +427,18 @@ export const aiTestActionHandler: SettingsActionHandler = async ({ values, paylo
 };
 
 /**
- * Built-in fallback handler for `ai/test_embedder`. Real implementation
- * with a live `embed()` round-trip lives in `@objectstack/service-ai` or
- * `@objectstack/service-knowledge` and overrides this stub at runtime.
+ * Handler for `ai/test_embedder` ("Test embedder"), registered by
+ * `SettingsServicePlugin`'s default `actionHandlers` map (#24769).
  *
- * This fallback validates form completeness only — no network call —
- * so the button is useful even when no embedder plugin is mounted.
+ * It checks form completeness only — a provider is chosen, an API key is
+ * present (Ollama excepted), a Base URL is present for `custom` / `azure` —
+ * and sends NO embedding request. Nothing in this repository replaces it with
+ * a live probe: neither `@objectstack/embedder-openai` nor
+ * `@objectstack/service-knowledge` registers `ai/test_embedder` (a plugin that
+ * did would call `SettingsService.registerAction`, which replaces this
+ * handler). So its success message says what was checked and that no request
+ * was sent, and names no package whose mounting would make this check live —
+ * none does.
  */
 export const aiTestEmbedderActionHandler: SettingsActionHandler = async ({ values, payload }) => {
   const overrides = extractOverrides(payload);
@@ -469,8 +475,8 @@ export const aiTestEmbedderActionHandler: SettingsActionHandler = async ({ value
     ok: true,
     severity: 'info',
     message:
-      `${provider} embedder configured (model=${model}). ` +
-      'Mount @objectstack/embedder-openai + a knowledge adapter to exercise live calls.',
+      `${provider} embedder settings are complete (model=${model}). ` +
+      'This checks the form only — no embedding request was sent.',
   };
 };
 
 
@@ -145,20 +145,28 @@ describe('knowledgeTestActionHandler', () => {
     expect(message).not.toMatch(/Mount @objectstack\/knowledge-turso to exercise live calls/);
   });
 
-  // Contrast, so the assertion above cannot be satisfied by blanket-rewording every
-  // hint: ragflow's plugin IS built here, and its hint stays the plain mount line.
-  it('ragflow live-call hint stays a plain mount line (its plugin is built here)', async () => {
-    const r = await knowledgeTestActionHandler({
-      values: {
-        adapter: 'ragflow',
-        ragflow_base_url: 'http://localhost:9380',
-        ragflow_api_key: 'k',
-      },
-    } as any);
-    expect(r.ok).toBe(true);
-    expect(String(r.message)).toContain(
-      'Mount @objectstack/knowledge-ragflow to exercise live calls',
-    );
+  // #24769 — "Test connection" is now answered (the handler is in the plugin's
+  // default map), and what it answers is a form check: no package in this repo
+  // reads this namespace or registers `knowledge/test`, so nothing replaces it
+  // with a live probe. Every green answer on a remote adapter must say no
+  // connection was attempted. Ragflow's hint used to be "Mount
+  // @objectstack/knowledge-ragflow to exercise live calls" — followable (the
+  // plugin IS built here) but false for this button, which mounting it never
+  // made live; no answer may carry that promise.
+  it('every green answer on a remote adapter says no connection was attempted', async () => {
+    const remote: Array<[string, Record<string, unknown>]> = [
+      ['turso, no URL', { adapter: 'turso' }],
+      ['turso, local file', { adapter: 'turso', turso_url: 'file:./knowledge.db' }],
+      ['turso, managed', { adapter: 'turso', turso_url: 'libsql://x.turso.io', turso_auth_token: 't' }],
+      ['ragflow', { adapter: 'ragflow', ragflow_base_url: 'http://localhost:9380', ragflow_api_key: 'k' }],
+    ];
+    for (const [label, values] of remote) {
+      const r = await knowledgeTestActionHandler({ values } as any);
+      expect(r.ok, label).toBe(true);
+      const message = String(r.message);
+      expect(message, label).toMatch(/no connection was attempted/);
+      expect(message, label).not.toMatch(/to exercise live calls/);
+    }
   });
 
   it('rejects ragflow without base URL', async () => {
 
@@ -137,12 +137,24 @@ const manifest = {
 export const knowledgeSettingsManifest = manifest as unknown as SettingsManifest;
 
 /**
- * Built-in fallback handler for `knowledge/test`. The real probe with
- * a live `healthCheck()` round-trip lives in `@objectstack/service-knowledge`
- * and overrides this stub at runtime (mirrors the AI / storage patterns).
+ * The sentence every answer on a remote adapter carries, so a green "Test
+ * connection" is never read as a connection that succeeded.
+ */
+const FORM_CHECK_ONLY = 'This checks the form only — no connection was attempted.';
+
+/**
+ * Handler for `knowledge/test` ("Test connection"), registered by
+ * `SettingsServicePlugin`'s default `actionHandlers` map (#24769).
  *
- * This fallback only validates form completeness so the button is
- * usable when no knowledge adapter plugin is mounted.
+ * It checks form completeness only — a Turso auth token beside a managed
+ * `libsql://` URL, a RAGFlow Base URL and API key — and opens NO connection.
+ * Nothing in this repository replaces it with a live probe:
+ * `@objectstack/service-knowledge`, `@objectstack/knowledge-memory` and
+ * `@objectstack/knowledge-ragflow` neither read this namespace nor register
+ * `knowledge/test` (a plugin that did would call
+ * `SettingsService.registerAction`, which replaces this handler). So every
+ * answer on a remote adapter says no connection was attempted, and none names
+ * a package whose mounting would make this check live — none does.
  */
 export const knowledgeTestActionHandler: SettingsActionHandler = async ({ values, payload }) => {
   const overrides = extractOverrides(payload);
@@ -163,7 +175,9 @@ export const knowledgeTestActionHandler: SettingsActionHandler = async ({ values
       return {
         ok: true,
         severity: 'info',
-        message: 'No URL configured — adapter will reuse the tenant\'s primary libSQL connection at runtime.',
+        message:
+          'No URL configured — adapter will reuse the tenant\'s primary libSQL connection at runtime. ' +
+          FORM_CHECK_ONLY,
       };
     }
     const u = String(url);
@@ -178,7 +192,7 @@ export const knowledgeTestActionHandler: SettingsActionHandler = async ({ values
       ok: true,
       severity: 'info',
       message:
-        `Turso adapter configured (${u}). Live calls need @objectstack/knowledge-turso, ` +
+        `Turso adapter configured (${u}). ${FORM_CHECK_ONLY} Live calls need @objectstack/knowledge-turso, ` +
         'which this platform does not ship: it is built in the ObjectStack Cloud monorepo ' +
         'and published on its own version track, so check that it offers a release ' +
         'compatible with your platform version before mounting it.',
@@ -195,7 +209,7 @@ export const knowledgeTestActionHandler: SettingsActionHandler = async ({ values
     return {
       ok: true,
       severity: 'info',
-      message: `RAGFlow adapter configured (${merged.ragflow_base_url}). Mount @objectstack/knowledge-ragflow to exercise live calls.`,
+      message: `RAGFlow adapter configured (${merged.ragflow_base_url}). ${FORM_CHECK_ONLY}`,
     };
   }
 
 
@@ -46,6 +46,8 @@ import {
   smsTestActionHandler,
   storageTestActionHandler,
   aiTestActionHandler,
+  aiTestEmbedderActionHandler,
+  knowledgeTestActionHandler,
 } from './manifests/index.js';
 import { settingsBuiltinTranslations } from './translations/index.js';
 
@@ -79,8 +81,12 @@ export interface SettingsServicePluginOptions {
   env?: Record<string, string | undefined>;
   /**
    * Action handlers to register at boot, keyed by namespace and action
-   * id. The bundled `mail.test` handler is registered automatically
-   * unless this object is provided.
+   * id. When omitted, the bundled handler of every `action_button` the
+   * builtin manifests declare is registered (`mail.test`, `sms.test`,
+   * `storage.test`, `ai.test`, `ai.test_embedder`, `knowledge.test`;
+   * `reset` is served by the service for every namespace). Providing this
+   * object replaces that whole default map. A plugin may still replace any
+   * one handler later with `SettingsService.registerAction`.
    */
   actionHandlers?: Record<string, Record<string, import('./settings-service.types.js').SettingsActionHandler>>;
 }
@@ -121,11 +127,16 @@ export class SettingsServicePlugin implements Plugin {
     this.opts = {
       ...opts,
       manifests: opts.manifests ?? builtinSettingsManifests,
+      // One entry per `action_button` a builtin manifest declares against the
+      // settings action route — a declared button with no entry here answers
+      // "No handler registered" (#24769). `settings-default-action-handlers.pin.test.ts`
+      // enumerates the manifests and holds this map to them.
       actionHandlers: opts.actionHandlers ?? {
         mail: { test: mailTestActionHandler },
         sms: { test: smsTestActionHandler },
         storage: { test: storageTestActionHandler },
-        ai: { test: aiTestActionHandler },
+        ai: { test: aiTestActionHandler, test_embedder: aiTestEmbedderActionHandler },
+        knowledge: { test: knowledgeTestActionHandler },
       },
     };
   }