Teaching descriptive text writing in senior high schools requires students to observe objects in detail, develop imagery, and express their observations in coherent and meaningful written language. However, classroom practices are still dominated by conventional learning media that do not adequately support concrete and contextual visualization, resulting in low-quality descriptive texts produced by students. In addition, the potential of local cultural wisdom as an authentic learning resource has not been optimally utilized. This study aimed to develop descriptive text learning media based on Assemblr Edu integrated with the local cultural wisdom of Central Kalimantan and to examine its feasibility and effectiveness in Indonesian language learning for twelfth-grade students. This study employed a research and development approach using the ADDIE model, which includes analysis, design, development, implementation, and evaluation stages. The research subjects involved Indonesian language teachers and twelfth-grade students at SMA Muhammadiyah 1 Palangka Raya and SMA NU Palangka Raya. Data were collected through observation, interviews, questionnaires, and descriptive writing tests. The results showed that the developed learning media were categorized as highly feasible based on validation by media experts, subject-matter experts, and teaching practitioners. The field trial results indicated that the media were effective in improving students’ descriptive writing skills, as reflected in better text structure, more detailed descriptions, and stronger relevance to local cultural contexts. Therefore, descriptive text learning media based on Assemblr Edu integrated with Central Kalimantan local cultural wisdom are feasible and effective for use in Indonesian language learning at the senior high school level. ABSTRAK Pembelajaran menulis teks deskripsi di SMA menuntut kemampuan siswa dalam mengamati objek secara rinci, mengembangkan imaji, dan menuangkannya ke dalam bahasa tulis yang runtut dan bermakna. Namun, praktik pembelajaran di sekolah masih didominasi penggunaan media konvensional yang kurang mendukung visualisasi objek secara konkret dan kontekstual, sehingga berdampak pada rendahnya kualitas teks deskripsi yang dihasilkan siswa. Selain itu, potensi kearifan budaya lokal sebagai sumber belajar autentik belum dimanfaatkan secara optimal. Penelitian ini bertujuan mengembangkan media pembelajaran teks deskripsi berbasis Assemblr Edu bermuatan kearifan budaya lokal Kalimantan Tengah serta menguji kelayakan dan efektivitas penggunaannya dalam pembelajaran Bahasa Indonesia kelas XII SMA. Penelitian ini menggunakan pendekatan penelitian dan pengembangan (Research and Development) dengan model ADDIE yang meliputi tahap analisis, perancangan, pengembangan, implementasi, dan evaluasi. Subjek penelitian melibatkan guru Bahasa Indonesia dan siswa kelas XII di SMA Muhammadiyah 1 Palangka Raya dan SMA NU Palangka Raya. Teknik pengumpulan data dilakukan melalui observasi, wawancara, angket, dan tes menulis teks deskripsi. Hasil penelitian menunjukkan bahwa media pembelajaran yang dikembangkan dinyatakan sangat layak berdasarkan validasi ahli media, ahli materi, dan praktisi pembelajaran. Hasil uji coba lapangan menunjukkan bahwa media pembelajaran efektif meningkatkan kemampuan menulis teks deskripsi siswa, ditandai dengan peningkatan kualitas struktur, kelengkapan deskripsi, dan keterkaitan isi teks dengan konteks budaya lokal. Dengan demikian, media pembelajaran teks deskripsi berbasis Assemblr Edu bermuatan kearifan budaya lokal Kalimantan Tengah layak dan efektif digunakan sebagai alternatif media pembelajaran Bahasa Indonesia di SMA.