synty_sync

Sync your Synty Store library to a local folder. Detects new packs, version bumps, and skips files you already have.

Windows only. Tested on Windows 11 with PowerShell. May work on macOS/Linux but has not yet been verified.

WHY

Built this mostly for myself, I'm a bit of a digital hoarder and wanted a way to keep my full Synty library on disk and in sync without manually clicking through dozens of packs every time something updates.

THIS IS A TOOL FOR DOWNLOADING LEGALLY ACQUIRED SYNTY PACKS FROM THE OFFICIAL SYNTY WEBSITE (https://syntystore.com). SYNTY'S TERMS OF SERVICE APPLY TO THE ASSETS; THE SCRIPT DOES NOT CHANGE ANYTHING ABOUT LICENSING OR ATTRIBUTION.

HOW

Quick start

git clone https://github.com/rustamismagilov/synty_sync.git
cd synty_sync
pip install -r requirements.txt
python synty_sync.py --path "path/to/folder" --dry-run

The first run with --dry-run shows you exactly what will be downloaded and where, without touching the filesystem. Drop --dry-run to actually download.

Cookies setup

The script authenticates by reading cookies your browser already has after you log into syntystore.com. There is no automated login.

1. Log into https://syntystore.com in your browser.
2. Install Get cookies.txt LOCALLY for Firefox or Chrome.
3. While on syntystore.com, click the extension and export cookies as cookies.txt.
4. Save it next to synty_sync.py (or pass --cookies "path/to/cookies.txt").

When cookies expire, the script reports "Could not detect customer id" or "Authentication failed". Repeat the process to refresh.

CLI flags

Flag	Description
--path "path/to/folder"	Required. Local folder where pack subfolders live.
--cookies "path/to/cookies.txt"	Path to cookies.txt (Netscape format). Defaults to cookies.txt next to the script.
--dry-run	Print the plan and exit. No files written.
--force	Re-download every file, ignoring local versions.
--pack "substring"	Only sync packs whose title contains this substring. Repeatable.
--no-icons	Skip ICON .png / .jpg files.
--formats unity,unreal,godot,source	Comma-separated engine variants to include. Omit to include all.
--latest-only	Per pack, keep only the newest version of each engine family.
--prune-old	Keep only the newest version of each build. Older copies go to the Recycle Bin. Combine with --dry-run to preview.
--workers N	Concurrent downloads. Default 4.

Common workflows

# Preview
python synty_sync.py --path "path/to/folder" --dry-run

# Preview if there is something new to download/upgrade in packs with "Sci-Fi" in the title
python synty_sync.py --path "path/to/folder" --pack "Sci-Fi" --dry-run

# Preview if there is something new to download/upgrade for the latest Unity packs without icons
python synty_sync.py --path "path/to/folder" --formats unity --latest-only --no-icons --dry-run

# Preview packs with "Battle Royale" in the title using 1 worker
python synty_sync.py --path "path/to/folder" --pack "Battle Royale" --workers 1 --dry-run

# Sync everything to a specified folder
python synty_sync.py --path "path/to/folder"

# Sync everything to a specified folder with 8 workers (faster, but can hit download limits)
python synty_sync.py --path "path/to/folder" --workers 8

# Sync everything with a custom cookies file path (can be in a different folder/disk)
python synty_sync.py --path "path/to/folder" --cookies "C:/secrets/cookies.txt"

# Sync only the specified pack to a specified folder (e.g. POLYGON - City pack)
python synty_sync.py --path "path/to/folder" --pack "POLYGON - City"

# Sync packs whose title contains "POLYGON" OR "SIMPLE"
python synty_sync.py --path "path/to/folder" --pack "POLYGON" --pack "SIMPLE"

# Sync only latest Unity packs to a specified folder
python synty_sync.py --path "path/to/folder" --formats unity --latest-only

# Sync only source files without icons to a specified folder
python synty_sync.py --path "path/to/folder" --formats source --no-icons

# Sync only Unity and Unreal files without icons to a specified folder
python synty_sync.py --path "path/to/folder" --formats unity,unreal --no-icons

# Sync only latest Unity packs without icons to a specified folder
python synty_sync.py --path "path/to/folder" --formats unity --latest-only --no-icons

# Force re-download EVERY file (useful if something seems corrupted)
python synty_sync.py --path "path/to/folder" --force

# Re-download EVERY file from only "POLYGON - City pack" to a specified folder
python synty_sync.py --path "path/to/folder" --pack "POLYGON - City" --force

Upgrade detection

For each remote file the script identifies a slot based on (base_name, engine_variant). For example:

• POLYGON_BattleRoyale_Unity_2022_3 is one slot
• POLYGON_BattleRoyale_Unity_2021_3 is a different slot
• POLYGON_BattleRoyale_Unreal_5_4 is yet another

Within each slot, the local pack folder is scanned for files of the same slot. Three actions can result:

• first-download: no file in this slot exists locally; download it.
• new-version: a same-slot file exists locally with a different version; download the new one. The old file is kept by default. Pass --prune-old to delete it after the new file lands.
• skip: same version (or a newer one) is already on disk. Nothing happens.

With --prune-old, the script also cleans up older versions sitting in your pack folders. For each slot, only the newest file stays on disk. Everything older is sent to the OS trash (Recycle Bin on Windows, Trash on macOS / Linux). Nothing is permanently deleted — you can restore from the trash if you change your mind. The output adds a PRUNE LIST showing exactly which files will be removed, plus a prune row in the summary with the total count and size. Always run with --dry-run first to preview.

Want to keep an old version forever? Rename it to include _ARCHIVED, _BACKUP, or _KEEP anywhere in the name (any case) — those files are skipped on every future prune.

--latest-only collapses multiple engine-version slots into one group keyed by engine family (Unity / Unreal / Godot / Source). The newest (engine_version, pack_version) wins. So an asset with Unreal 4.25, 5.0, and 5.4 builds will plan only the 5.4 build under --latest-only.

--no-icons excludes ICON files. --formats excludes engine variants you don't want, but never affects icons, so use both flags together if needed.

Recognized filename patterns

Synty's file naming is inconsistent across packs, but this tool handles every variant. Examples:

Example	Notes
POLYGON_BattleRoyale_Unity_2022_3_v1_9_0.unitypackage	Named engine + pack version
POLYGON_Halloween_Masks_2022_3_v1_2_0.unitypackage	Bare engine version (no Unity_ prefix)
SIMPLE_Space_Unreal_4.15_v1_0_0.zip	Engine version with a . separator
POLYGON_BattleRoyale_Source_Files_v4.zip	Source files with version
SIMPLE_Cars_SourceFiles.zip	Source files without version
INTERFACE_Apocalypse_HUD_Source_Sprites_v3.zip	Any Source_* variant, not just Source_Files
SidekickCharacterTool_0_4_0_UE53.zip	UE family, no _v… version suffix
POLYGON_Fantasy_Characters_ICON.jpg	Icon, any common image extension (.png / .jpg / .jpeg / .webp)

Output

After parsing, you will be able to see a table of every planned file with columns Status / Pack / New file / Destination, and a summary table showing per-action count and total size, e.g.:

SUMMARY:
╭──────────────────────┬─────────────╮
│ Action               │ Count       │
├──────────────────────┼─────────────┤
│ first-download       │ 43 (2.3GB)  │
├──────────────────────┼─────────────┤
│ new-version          │ 1 (0.1GB)   │
├──────────────────────┼─────────────┤
│ skip                 │ 357 (25GB)  │
├──────────────────────┼─────────────┤
│ TOTAL TO DOWNLOAD:   │ 44 (2.4GB)  │
╰──────────────────────┴─────────────╯

In --dry-run the script stops after parsing the library. In normal mode it prompts if you actually want to download files (after previewing summary and all files):

[•] Download 44 files (2.4GB)? [Y/n]:

Press Y or Enter to start the download, anything else to abort. After download finishes:

• If all files are OK, you will see: [✓] Done.
• If some files failed, you will see an interactive prompt [•] N download(s) failed. Retry? [Y/n]:. Press Y or Enter to re-run only the failed items, press anything else to cancel. It will loop until everything is downloaded or you interrupt (with Ctrl+C).

A manifest.json is written into --path recording every successful download (sha256, size, version, action).

Known issues

• HTTP 503 mid-download: Synty's CDN occasionally rate-limits. First, just wait a few minutes and let the limit reset. Then use the retry prompt at the end of the run, or rerun with --workers 2 to reduce concurrency.
• [WinError 32] on rename: Windows antivirus briefly locks the freshly downloaded .part file. The retry prompt at the end of the run almost always clears it.
• Could not detect customer id: cookies.txt is missing required entries or expired. Repeat the Cookies setup step.