TelegArm

A lightweight, pure-managed C# Telegram client built to run on jailbroken Windows RT 8.1 and Windows 10 ARM32 — hardware the official Telegram apps abandoned. It talks MTProto directly (via WTelegramClient) with no native Telegram dependency, so a single AnyCPU build runs everywhere from a Surface RT to a modern x64 desktop.

Runs on

• Windows RT 8.1 (ARM32) — the original Surface / Surface 2 (requires the RT jailbreak to run desktop apps)
• Windows 10 ARM32
• Windows 8.1 / 10 / 11 (x86 / x64 /ARM64)
• *Windows 7 (not tested yet)

One AnyCPU + Prefer32Bit binary covers all of the above (32-bit process on every arch).

Requirements — .NET Framework 4.7

TelegArm needs .NET Framework 4.7 or later on the device. Without it the app will not start, and Windows' own error message never says why.

• Windows RT 8.1 (Surface / Surface 2) — RT ships with .NET 4.5, so you must install 4.7 first: https://go.microsoft.com/fwlink/?linkid=2088632
• Windows 10 ARM32 — already has it. No action needed.
• Windows 8.1 / 10 / 11 (x86 / x64 / ARM64) — usually already present; install from the link above if TelegArm refuses to start.

The installer checks for 4.7 before installing and stops with an explanation if it is missing, rather than installing something that cannot run — and there is a Check requirements button you can press first. The portable build cannot perform that check (it is itself compiled against 4.7, so it fails before any of its own code runs), so install .NET first if you are using it.

Features

• Phone + 2FA login with silent session resume; QR login; multiple accounts
• Chat list and conversations with live updates, bidirectional paging, and combined search (chats + global messages)
• RTL-aware message bubbles (Persian / Arabic), emoji, and animated stickers (.tgs via rlottie)
• Photos with thumbnails + disk cache and a zoom/pan viewer; inline video / GIF (bundled VLC) with a system-player fallback
• Documents: file cards, open, Save / Save As, with background downloads (pause / resume / manager)
• Send media: attach or drag-and-drop photos, videos, and files — Compress / Send-as-file, caption, per-file progress, correct dimensions + poster thumbnails
• Record and send voice notes (OGG/Opus — pure-managed, ARM32-safe) and round video notes
• Message actions: reply (quoted), forward, copy, multi-select, delete (for me / for everyone), retry
• Pinned messages, folders, reactions, polls, inline keyboards & bots, group/channel admin
• Follow-system / Light / Dark theming that tracks the Windows accent color live (no restart)
• Configurable media auto-download and a managed cache folder; notifications with mute
• Touch panning, momentum scrolling, and the on-screen keyboard handled for tablet use

Building

Requirements: Visual Studio 2017, .NET Framework 4.7, C# 7.3.

1. Clone the repo.
2. Provide your own Telegram API credentials — they are deliberately kept out of source control:
   • Register an application at https://my.telegram.org/apps to get an api_id and api_hash.
   • In TelegArm/Core/, copy ApiCredentials.Local.cs.example → ApiCredentials.Local.cs and fill in your values. This file is gitignored and must never be committed.
   • Without it the project still builds (placeholders in ApiCredentials.cs), but it will not authenticate.
3. Build the solution (Debug or Release, AnyCPU). NuGet restores the package dependencies.

Everything the app needs at runtime — the bundled libVLC (per-arch), rlottie, Noto Emoji, and fonts — is carried in the project and copied next to the executable on build, so no manual codec/DLL setup is required.

Continuing development (docs)

The repo is self-documenting so a new contributor — or a fresh AI session — can pick it up cold:

• CLAUDE.md — the top-level orientation (auto-loaded by Claude Code); start here.
• BUILD.md — exact build / run / installer commands and prerequisites.
• STATE.md — current status and the prioritized open-work list.
• INVARIANTS.md — the hard "don't regress these" rules (toolchain, account-data safety, UI/touch).
• mdfiles/ — the deep docs: HANDOFF.md (full orientation), CURRENT_STATE.md, the dated SESSION_*.md narratives, ARCHITECTURE_AND_LOGIC.md, LESSONS_LEARNED.md, BUGS_AND_FIXES.md, CREATIVE_DECISIONS.md, ROADMAP.md, THEME_UI_HANDOFF.md.
• installer/INSTALLER_HANDOFF.md — how to build the RT-runnable AnyCPU installer.

License

TelegArm is released under the GNU General Public License v3.0 only (GPL-3.0-only) — see LICENSE.

Bundled third-party components (WTelegramClient, MaterialSkin.2, LibVLCSharp / libVLC, Newtonsoft.Json, NAudio, Concentus, SixLabors.ImageSharp, QRCoder, rlottie, and the Roboto / Vazirmatn / Noto Emoji assets) remain under their own licenses — see THIRD-PARTY-NOTICES.txt.

Credits

Built on WTelegramClient by Wizou. Developed with assistance from Claude (Anthropic).