diff --git a/test/business-adapter.test.mjs b/test/business-adapter.test.mjs
index 5eb8210..83da9f7 100644
--- a/test/business-adapter.test.mjs
+++ b/test/business-adapter.test.mjs
@@ -1,6 +1,6 @@
 import assert from 'node:assert/strict';
 import { execFile } from 'node:child_process';
-import { mkdtemp, readFile, readdir, rm, stat } from 'node:fs/promises';
+import { mkdir, mkdtemp, readFile, readdir, rm, stat, writeFile } from 'node:fs/promises';
 import http from 'node:http';
 import os from 'node:os';
 import path from 'node:path';
@@ -130,3 +130,104 @@ test('bundled Business adapter atomically replaces a shared session under concur
   assert.equal((await stat(sessionFile)).mode & 0o777, 0o600);
   assert.deepEqual((await readdir(stateDir)).filter((entry) => entry.endsWith('.tmp')), []);
 });
+
+test('bundled Business adapter sends repeated local attachments through the workspace operation', async (t) => {
+  const stateHome = await mkdtemp(path.join(os.tmpdir(), 'mere-business-bundled-attachments-'));
+  t.after(() => rm(stateHome, { recursive: true, force: true }));
+
+  const markdownPath = path.join(stateHome, 'approval-packet.md');
+  const jsonPath = path.join(stateHome, 'receipt.json');
+  await writeFile(markdownPath, '# Approval packet\n', 'utf8');
+  await writeFile(jsonPath, '{"ok":true}\n', 'utf8');
+
+  let received;
+  const server = http.createServer(async (request, response) => {
+    if (request.method !== 'POST' || request.url !== '/api/cli/v2') {
+      response.writeHead(404).end();
+      return;
+    }
+    received = {
+      authorization: request.headers.authorization,
+      body: JSON.parse(await readBody(request)),
+    };
+    response.writeHead(200, { 'content-type': 'application/json' });
+    response.end(JSON.stringify({ ok: true, data: { threadId: 'thread_1', messageId: 'message_1' } }));
+  });
+  await new Promise((resolve) => server.listen(0, '127.0.0.1', resolve));
+  t.after(() => new Promise((resolve) => server.close(resolve)));
+
+  const address = server.address();
+  assert.ok(address && typeof address === 'object');
+  const workspaceUrl = `http://127.0.0.1:${address.port}`;
+  const session = sessionPayload('attachments');
+  session.workspace.host = workspaceUrl;
+  session.workspaces[0].host = workspaceUrl;
+  const stateDir = path.join(stateHome, 'mere-business');
+  await mkdir(stateDir, { recursive: true });
+  await writeFile(
+    path.join(stateDir, 'session.json'),
+    `${JSON.stringify({ ...session, version: 1, baseUrl: workspaceUrl })}\n`,
+    'utf8',
+  );
+
+  const env = {
+    ...process.env,
+    HOME: stateHome,
+    XDG_STATE_HOME: stateHome,
+    MERE_ROOT: path.join(stateHome, 'missing-mere-root'),
+    MERE_CLI_SOURCE: 'bundled',
+  };
+  const result = await execFileAsync(
+    process.execPath,
+    [
+      rootCli,
+      'business',
+      'mail',
+      'send',
+      '--mailbox-id',
+      'mb_1',
+      '--to',
+      'director@example.com',
+      '--subject',
+      'Approval packet',
+      '--body',
+      'Attached.',
+      '--attach',
+      markdownPath,
+      '--attach',
+      jsonPath,
+      '--yes',
+      '--json',
+    ],
+    { cwd: repoRoot, env },
+  );
+
+  assert.equal(result.stderr, '');
+  assert.deepEqual(JSON.parse(result.stdout), { messageId: 'message_1', threadId: 'thread_1' });
+  assert.deepEqual(received, {
+    authorization: 'Bearer fake-access-attachments',
+    body: {
+      op: 'mail.send',
+      input: {
+        mailboxId: 'mb_1',
+        to: ['director@example.com'],
+        cc: [],
+        bcc: [],
+        attachments: [
+          {
+            filename: 'approval-packet.md',
+            mimeType: 'text/markdown; charset=utf-8',
+            contentBase64: Buffer.from('# Approval packet\n').toString('base64'),
+          },
+          {
+            filename: 'receipt.json',
+            mimeType: 'application/json; charset=utf-8',
+            contentBase64: Buffer.from('{"ok":true}\n').toString('base64'),
+          },
+        ],
+        subject: 'Approval packet',
+        bodyText: 'Attached.',
+      },
+    },
+  });
+});