diff --git a/src/support/cloud-manager.js b/src/support/cloud-manager.js
new file mode 100644
index 000000000..93947f999
--- /dev/null
+++ b/src/support/cloud-manager.js
@@ -0,0 +1,137 @@
+/*
+ * Copyright 2026 Adobe. All rights reserved.
+ * This file is licensed to you under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License. You may obtain a copy
+ * of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under
+ * the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
+ * OF ANY KIND, either express or implied. See the License for the specific language
+ * governing permissions and limitations under the License.
+ */
+import { InvokeCommand, LambdaClient } from '@aws-sdk/client-lambda';
+
+/**
+ * Client for the Cloud Manager (CM) connector Lambda.
+ *
+ * api-service cannot reach Cloud Manager's private API directly from its own
+ * network; a dedicated connector service reaches it (SITES-47815) and this
+ * client synchronously invokes that connector Lambda.
+ *
+ * It is invoked from the post-ack onboarding path only (queueDeliveryConfigWriter),
+ * never before the Slack 3s ack — the connector retries a lossy network path
+ * and can take a few seconds.
+ *
+ * All methods degrade gracefully (never throw to the caller) so onboarding is
+ * never blocked by CM: when the connector isn't configured/deployed/authorized,
+ * they return `{ verified: false, degraded: true }` and log a warning.
+ *
+ * @class
+ */
+export class CloudManagerClient {
+  /**
+   * @param {object} opts
+   * @param {string} [opts.region] - AWS region (from context.runtime.region).
+   * @param {string} [opts.functionName] - CM connector Lambda name
+   *   (env.CM_CONNECTOR_FUNCTION_NAME).
+   * @param {object} [opts.log] - logger.
+   */
+  constructor({ region, functionName, log } = {}) {
+    this.functionName = functionName;
+    this.log = log;
+    this.client = functionName ? new LambdaClient(region ? { region } : {}) : null;
+  }
+
+  /** @returns {boolean} whether the connector is configured and can be invoked. */
+  get enabled() {
+    return Boolean(this.functionName && this.client);
+  }
+
+  /**
+   * Invoke the connector with an action payload and return its parsed JSON result.
+   * @param {object} payload - e.g. { action: 'get_program', programId }.
+   * @returns {Promise<object>} the connector's response body.
+   * @throws if the connector is not configured or the invocation errors.
+   */
+  async invokeAction(payload) {
+    if (!this.enabled) {
+      throw new Error('CloudManager connector is not configured (CM_CONNECTOR_FUNCTION_NAME)');
+    }
+    const res = await this.client.send(new InvokeCommand({
+      FunctionName: this.functionName,
+      InvocationType: 'RequestResponse',
+      Payload: Buffer.from(JSON.stringify(payload)),
+    }));
+    const text = res.Payload ? Buffer.from(res.Payload).toString('utf8') : '';
+    if (res.FunctionError) {
+      throw new Error(`CloudManager connector error (${res.FunctionError}): ${text.slice(0, 300)}`);
+    }
+    try {
+      return text ? JSON.parse(text) : {};
+    } catch {
+      throw new Error(`CloudManager connector returned non-JSON: ${text.slice(0, 300)}`);
+    }
+  }
+
+  /**
+   * GET /api/program/{programId}.
+   * @param {string} programId
+   * @returns {Promise<object>} connector response { ok, statusCode, data }.
+   */
+  async getProgram(programId) {
+    return this.invokeAction({ action: 'get_program', programId });
+  }
+
+  /**
+   * GET /api/program/{programId}/environments.
+   * @param {string} programId
+   * @returns {Promise<object>} connector response { ok, statusCode, data }.
+   */
+  async listEnvironments(programId) {
+    return this.invokeAction({ action: 'list_environments', programId });
+  }
+
+  /**
+   * Best-effort verification that a (host-regex-derived) programId actually
+   * exists in Cloud Manager. Never throws — degrades so onboarding continues.
+   * @param {string} programId
+   * @returns {Promise<{verified: boolean, degraded?: boolean, statusCode?: number,
+   *   program?: object, error?: string}>}
+   */
+  async verifyProgram(programId) {
+    if (!this.enabled) {
+      this.log?.info('[cloud-manager] connector not configured; skipping program verification');
+      return { verified: false, degraded: true };
+    }
+    if (!programId) {
+      return { verified: false, degraded: true };
+    }
+    try {
+      const r = await this.getProgram(programId);
+      if (!r?.ok) {
+        this.log?.warn(`[cloud-manager] program ${programId} not verified (status ${r?.statusCode})`);
+        return { verified: false, statusCode: r?.statusCode, program: r?.data };
+      }
+      return {
+        verified: true, statusCode: r.statusCode, program: r.data,
+      };
+    } catch (e) {
+      this.log?.warn(`[cloud-manager] verifyProgram(${programId}) failed, degrading: ${e.message}`);
+      return { verified: false, degraded: true, error: e.message };
+    }
+  }
+}
+
+/**
+ * Build a CloudManagerClient from a Lambda context (env + runtime + log).
+ * @param {object} context
+ * @returns {CloudManagerClient}
+ */
+export function createCloudManagerClient(context = {}) {
+  const { env = {}, runtime = {}, log } = context;
+  return new CloudManagerClient({
+    region: runtime.region || env.AWS_REGION,
+    functionName: env.CM_CONNECTOR_FUNCTION_NAME,
+    log,
+  });
+}
diff --git a/src/support/utils.js b/src/support/utils.js
index bb7b86dfb..f64d24a15 100644
--- a/src/support/utils.js
+++ b/src/support/utils.js
@@ -40,6 +40,7 @@ import {
   PROMISE_TOKEN_REQUIRED_ERROR_CODE,
 } from '../utils/constants.js';
 import { updateRumConfig } from './rum-config-service.js';
+import { createCloudManagerClient } from './cloud-manager.js';
 // Two signals indicate a previous paid onboarding:
 // 1. ahref-paid-pages import — unique to the paid profile's import set.
 // 2. onboardConfig.lastProfile === 'paid' — set for sites backfilled via script or onboarded
@@ -1507,6 +1508,23 @@ export async function queueDeliveryConfigWriter(
         minutes,
         updateRedirects,
       };
+
+      // SITES-47815: the programId/environmentId above are derived by regex on
+      // the AEM CS hostname (extractDeliveryConfigFromPreviewUrl), never checked
+      // against Cloud Manager. Best-effort verify the program actually exists in
+      // CM via the connector Lambda (the service that can reach CM's private
+      // API). This runs post-ack, so its latency is off the Slack 3s window, and
+      // it degrades gracefully: when the connector is not configured/deployed/
+      // authorized it is a no-op and onboarding proceeds on the regex-derived
+      // values. `programVerified` is additive telemetry for the audit-worker.
+      const cloudManager = createCloudManagerClient(context);
+      const { verified, degraded } = await cloudManager.verifyProgram(String(programId));
+      redirectParams.programVerified = verified;
+      if (!verified && !degraded) {
+        log.warn(
+          `[delivery-config-writer] Cloud Manager did not verify program ${programId} for ${resolvedBaseURL}; proceeding on regex-derived delivery config.`,
+        );
+      }
     } else {
       log.info(
         `[delivery-config-writer] ${skipMessage}; CDN detection only.`,
diff --git a/test/support/cloud-manager.test.js b/test/support/cloud-manager.test.js
new file mode 100644
index 000000000..45e17bf7c
--- /dev/null
+++ b/test/support/cloud-manager.test.js
@@ -0,0 +1,122 @@
+/*
+ * Copyright 2026 Adobe. All rights reserved.
+ * This file is licensed to you under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License. You may obtain a copy
+ * of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under
+ * the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
+ * OF ANY KIND, either express or implied. See the License for the specific language
+ * governing permissions and limitations under the License.
+ */
+/* eslint-env mocha */
+import { expect } from 'chai';
+import sinon from 'sinon';
+import { CloudManagerClient, createCloudManagerClient } from '../../src/support/cloud-manager.js';
+
+const payload = (obj) => ({ Payload: Buffer.from(JSON.stringify(obj)) });
+const log = { info: () => {}, warn: () => {}, error: () => {} };
+
+describe('CloudManagerClient', () => {
+  let sandbox;
+  beforeEach(() => {
+    sandbox = sinon.createSandbox();
+  });
+  afterEach(() => {
+    sandbox.restore();
+  });
+
+  describe('enabled', () => {
+    it('is false without a function name', () => {
+      expect(new CloudManagerClient({ log }).enabled).to.equal(false);
+    });
+    it('is true with a function name', () => {
+      expect(new CloudManagerClient({ functionName: 'fn', log }).enabled).to.equal(true);
+    });
+  });
+
+  describe('invokeAction', () => {
+    it('sends an InvokeCommand and parses the JSON payload', async () => {
+      const c = new CloudManagerClient({ functionName: 'fn', log });
+      const send = sandbox.stub(c.client, 'send').resolves(payload({ ok: true, statusCode: 200 }));
+      const res = await c.invokeAction({ action: 'get_program', programId: 'p1' });
+      expect(res).to.deep.equal({ ok: true, statusCode: 200 });
+      const sent = send.firstCall.args[0].input;
+      expect(sent.FunctionName).to.equal('fn');
+      expect(sent.InvocationType).to.equal('RequestResponse');
+      expect(JSON.parse(Buffer.from(sent.Payload).toString())).to.deep.equal({ action: 'get_program', programId: 'p1' });
+    });
+
+    it('throws when not configured', async () => {
+      const c = new CloudManagerClient({ log });
+      await expect(c.invokeAction({ action: 'x' })).to.be.rejectedWith(/not configured/);
+    });
+
+    it('throws on a Lambda FunctionError', async () => {
+      const c = new CloudManagerClient({ functionName: 'fn', log });
+      sandbox.stub(c.client, 'send').resolves({ FunctionError: 'Unhandled', Payload: Buffer.from('{"errorMessage":"boom"}') });
+      await expect(c.invokeAction({ action: 'x' })).to.be.rejectedWith(/connector error \(Unhandled\)/);
+    });
+
+    it('throws on a non-JSON payload', async () => {
+      const c = new CloudManagerClient({ functionName: 'fn', log });
+      sandbox.stub(c.client, 'send').resolves({ Payload: Buffer.from('not json') });
+      await expect(c.invokeAction({ action: 'x' })).to.be.rejectedWith(/non-JSON/);
+    });
+  });
+
+  describe('verifyProgram (graceful degradation)', () => {
+    it('degrades (no throw) when the connector is not configured', async () => {
+      const res = await new CloudManagerClient({ log }).verifyProgram('p1');
+      expect(res).to.deep.equal({ verified: false, degraded: true });
+    });
+
+    it('degrades when no programId is supplied', async () => {
+      const c = new CloudManagerClient({ functionName: 'fn', log });
+      const send = sandbox.stub(c.client, 'send');
+      const res = await c.verifyProgram(undefined);
+      expect(res.degraded).to.equal(true);
+      expect(send.called).to.equal(false);
+    });
+
+    it('returns verified:true when CM confirms the program', async () => {
+      const c = new CloudManagerClient({ functionName: 'fn', log });
+      sandbox.stub(c.client, 'send').resolves(payload({ ok: true, statusCode: 200, data: { id: 'p1' } }));
+      const res = await c.verifyProgram('p1');
+      expect(res.verified).to.equal(true);
+      expect(res.program).to.deep.equal({ id: 'p1' });
+    });
+
+    it('returns verified:false (not degraded) when CM responds not-ok', async () => {
+      const c = new CloudManagerClient({ functionName: 'fn', log });
+      sandbox.stub(c.client, 'send').resolves(payload({ ok: false, statusCode: 404 }));
+      const res = await c.verifyProgram('p1');
+      expect(res).to.include({ verified: false, statusCode: 404 });
+      expect(res.degraded).to.equal(undefined);
+    });
+
+    it('degrades when the invocation throws (e.g. AccessDenied before IAM grant)', async () => {
+      const c = new CloudManagerClient({ functionName: 'fn', log });
+      sandbox.stub(c.client, 'send').rejects(new Error('AccessDeniedException'));
+      const res = await c.verifyProgram('p1');
+      expect(res).to.include({ verified: false, degraded: true });
+      expect(res.error).to.match(/AccessDenied/);
+    });
+  });
+
+  describe('createCloudManagerClient', () => {
+    it('reads function name from env and region from runtime', () => {
+      const c = createCloudManagerClient({
+        env: { CM_CONNECTOR_FUNCTION_NAME: 'spacecat-services--cm-connector' },
+        runtime: { region: 'us-east-1' },
+        log,
+      });
+      expect(c.enabled).to.equal(true);
+      expect(c.functionName).to.equal('spacecat-services--cm-connector');
+    });
+
+    it('is disabled when the env var is absent', () => {
+      expect(createCloudManagerClient({ env: {}, log }).enabled).to.equal(false);
+    });
+  });
+});