Batch-convert many tdata folders

If you have a directory full of tdata folders (one per Telegram account, say from a backup tool), you can convert them in parallel via the Python API.

import asyncio
from pathlib import Path
from opentele.api import API, CreateNewSession
from opentele.td import TDesktop


async def convert_one(tdata: Path, sessions_dir: Path) -> tuple[Path, bool, str]:
    session_path = sessions_dir / f"{tdata.parent.name}.session"
    if session_path.exists():
        return session_path, False, "already exists"
    try:
        td = TDesktop(str(tdata))
        if not td.isLoaded():
            return session_path, False, "tdata failed to load"
        client = await td.ToTelethon(
            session=str(session_path),
            flag=CreateNewSession,
            api=API.TelegramDesktop.Generate(),
        )
        # Disconnect cleanly so .session file is flushed.
        res = client.disconnect()
        if asyncio.iscoroutine(res):
            await res
        return session_path, True, "ok"
    except Exception as exc:
        return session_path, False, repr(exc)


async def main(root: Path, sessions_dir: Path, *, concurrency: int = 4):
    sessions_dir.mkdir(parents=True, exist_ok=True)
    tdatas = sorted(p for p in root.rglob("tdata") if p.is_dir())
    print(f"found {len(tdatas)} tdata folders")

    sem = asyncio.Semaphore(concurrency)

    async def guarded(tdata: Path):
        async with sem:
            return await convert_one(tdata, sessions_dir)

    results = await asyncio.gather(*(guarded(t) for t in tdatas))
    for session_path, ok, reason in results:
        flag = "OK" if ok else "SKIP"
        print(f"  {flag:4s} {session_path.name:40s} {reason}")


if __name__ == "__main__":
    asyncio.run(main(
        root=Path("/path/to/backup-root"),
        sessions_dir=Path("./out-sessions"),
        concurrency=4,
    ))

Tips

• Concurrency = 2-4 is usually enough. Each conversion talks to Telegram's auth API; pushing higher gets you rate-limited.
• Each new session counts as a new device in Telegram's "active sessions" list. If you only need to read messages and want to keep the device list clean, use UseCurrentSession instead of CreateNewSession (but then the original Telegram Desktop will be logged out).
• For thousands of tdata folders, persist progress to a JSON file so you can resume after failures — the example above is the minimal version.

Read-only inspection

If you only need to know what accounts are in each tdata (UserId, DC, etc.) without going to the network, use the CLI. The shell loop below is sequential (use xargs -0 -P4 if you want real parallelism):

find /backup-root -name tdata -type d -print0 | while IFS= read -r -d '' t; do
    opentele-ng info "$t" --json
done | jq -s '[.[] | .accounts[]]'

This never touches the Telegram API and is safe to run on any number of tdata folders.