diff --git a/assistant/src/__tests__/attachment-content-route.test.ts b/assistant/src/__tests__/attachment-content-route.test.ts
index 57168a19116..48d65211559 100644
--- a/assistant/src/__tests__/attachment-content-route.test.ts
+++ b/assistant/src/__tests__/attachment-content-route.test.ts
@@ -136,7 +136,7 @@ describe('handleGetAttachmentContent — file-backed', () => {
     expect(Buffer.from(body).toString()).toBe('fghij');
   });
 
-  test('returns 416 for unsatisfiable range', () => {
+  test('returns 416 when start is beyond file size', () => {
     const filePath = join(testDir, 'test-416.mp4');
     const content = Buffer.from('short');
     writeFileSync(filePath, content);
@@ -156,6 +156,32 @@ describe('handleGetAttachmentContent — file-backed', () => {
     expect(res.status).toBe(416);
   });
 
+  test('clamps oversized end to fileSize-1 per RFC 7233', async () => {
+    const filePath = join(testDir, 'test-clamp.mp4');
+    const content = Buffer.from('0123456789');
+    writeFileSync(filePath, content);
+
+    const attachment = createFileBackedAttachment({
+      filename: 'test-clamp.mp4',
+      mimeType: 'video/mp4',
+      sizeBytes: content.length,
+      filePath,
+    });
+
+    // Request bytes=5-999 on a 10-byte file; end should be clamped to 9
+    const req = new Request('http://localhost/v1/attachments/' + attachment.id + '/content', {
+      headers: { Range: 'bytes=5-999' },
+    });
+    const res = handleGetAttachmentContent(attachment.id, req);
+
+    expect(res.status).toBe(206);
+    expect(res.headers.get('Content-Range')).toBe(`bytes 5-9/${content.length}`);
+    expect(res.headers.get('Content-Length')).toBe('5');
+
+    const body = await res.arrayBuffer();
+    expect(Buffer.from(body).toString()).toBe('56789');
+  });
+
   test('returns 404 when file is missing from disk', () => {
     const attachment = createFileBackedAttachment({
       filename: 'missing.mp4',
diff --git a/assistant/src/memory/db.ts b/assistant/src/memory/db.ts
index e54e2c4352b..7803d5b3950 100644
--- a/assistant/src/memory/db.ts
+++ b/assistant/src/memory/db.ts
@@ -1672,12 +1672,18 @@ function migrateRemoveAssistantIdColumns(database: ReturnType<typeof drizzle<typ
           data_base64 TEXT NOT NULL,
           content_hash TEXT,
           thumbnail_base64 TEXT,
-          created_at INTEGER NOT NULL
+          created_at INTEGER NOT NULL,
+          storage_kind TEXT DEFAULT 'inline_base64',
+          file_path TEXT,
+          sha256 TEXT,
+          expires_at INTEGER
         )
       `);
       raw.exec(/*sql*/ `
-        INSERT INTO attachments_new (id, original_filename, mime_type, size_bytes, kind, data_base64, content_hash, thumbnail_base64, created_at)
-        SELECT id, original_filename, mime_type, size_bytes, kind, data_base64, content_hash, thumbnail_base64, created_at FROM attachments
+        INSERT INTO attachments_new (id, original_filename, mime_type, size_bytes, kind, data_base64, content_hash, thumbnail_base64, created_at, storage_kind, file_path, sha256, expires_at)
+        SELECT id, original_filename, mime_type, size_bytes, kind, data_base64, content_hash, thumbnail_base64, created_at,
+          COALESCE(storage_kind, 'inline_base64'), file_path, sha256, expires_at
+        FROM attachments
       `);
       raw.exec(/*sql*/ `DROP TABLE attachments`);
       raw.exec(/*sql*/ `ALTER TABLE attachments_new RENAME TO attachments`);
diff --git a/assistant/src/runtime/routes/attachment-routes.ts b/assistant/src/runtime/routes/attachment-routes.ts
index 88c90723fbe..4b65805cf0a 100644
--- a/assistant/src/runtime/routes/attachment-routes.ts
+++ b/assistant/src/runtime/routes/attachment-routes.ts
@@ -206,9 +206,9 @@ function handleFileContent(
   }
 
   const start = parseInt(rangeMatch[1], 10);
-  const end = rangeMatch[2] ? parseInt(rangeMatch[2], 10) : fileSize - 1;
+  const end = rangeMatch[2] ? Math.min(parseInt(rangeMatch[2], 10), fileSize - 1) : fileSize - 1;
 
-  if (start >= fileSize || end >= fileSize || start > end) {
+  if (start >= fileSize || start > end) {
     return new Response('Range not satisfiable', {
       status: 416,
       headers: { 'Content-Range': `bytes */${fileSize}` },