CipherDropX is a lightweight Python library that dynamically extracts and executes transformation routines from YouTube’s base.js player file.
Unlike many tools, it:
- 🧠 Parses without JS runtime – no Node.js or browser needed
- ⚙️ Works offline – just use cached
base.jsand decode anywhere - 📦 Minimal dependencies – pure regex & logic
Perfect for CLI tools, embedded devices, or headless batch jobs.
pip install cipherdropx(Python 3.9 or newer is recommended)
* Whenever you already have a copy of base.js (downloaded once, shipped with your own binaries, etc.) and need to transform many signatures without re‑downloading the player file each time. * When you want to keep network, JavaScript and heavy AST libraries out of your build.
- Create a
CipherDropXinstance with the raw base.js text. - Extract the algorithm once via
.get_algorithm()– you can cache or serialise it. - Feed the algorithm back with
.update()(or skip and keep the internal one). - Run
.run(sig)to obtain the transformed signature. - The result is stored in
.signature.
importrequestsfromcipherdropximportCipherDropX# 1️⃣ Pull the latest player file (≈100 kB)url="https://www.youtube.com/s/player/9fe2e06e/player_ias.vflset/ja_JP/base.js"res=requests.get(url)
res.raise_for_status() # ensure HTTP 200# 2️⃣ Build the decipher helper from raw JScdx=CipherDropX(res.text) # ↖️ parses method table & CHALL stubalgo=cdx.get_algorithm() # ↖️ returns Algorithm object (can be cached)cdx.update(algo) # ↖️ loads the algorithm into the instance# 3️⃣ Apply it to any signature stringsig="1A2B3C4D5E6F7G8H9I0JKLMNOPQRSTUVWX"cdx.run(sig) # ↖️ executes splice / swap / reverse stepsprint("Original :", sig)
print("Deciphered:", cdx.signature) # transformed outputfrompathlibimportPathfromcipherdropximportCipherDropX# 1️⃣ Load player file that was stored previouslybasejs_text=Path("./assets/base_20250616.js").read_text(encoding="utf‑8")
# 2️⃣ Initialise helper (parsing happens once)cdx=CipherDropX(basejs_text)
# ▶️ If you saved the algorithm earlier you could do:# cached_algo = json.loads(Path("algo.json").read_text())# cdx.update(cached_algo)# otherwise just generate it again:algorithm=cdx.get_algorithm()
cdx.update(algorithm)
# 3️⃣ Transform signaturesig="ABCDEF1234567890"cdx.run(sig)
print(cdx.signature)Algorithmis just a list of(action, argument)tuples – safe tojson.dumpand reuse later.- You can keep one base.js offline and only refresh it if YouTube ships a new player revision.
Apache‑2.0 – see the LICENSE file for details.
CipherDropX is provided solely for educational and integration purposes. You are responsible for complying with the terms of service of the platform you interact with.