Instructions to use CaptchaKraken/CaptchaKraken-Lora-v1.2 with libraries, inference providers, notebooks, and local apps. Follow these links to get started.
- Libraries
- PEFT
How to use CaptchaKraken/CaptchaKraken-Lora-v1.2 with PEFT:
from peft import PeftModel from transformers import AutoModelForCausalLM base_model = AutoModelForCausalLM.from_pretrained("Qwen/Qwen3.5-9B") model = PeftModel.from_pretrained(base_model, "CaptchaKraken/CaptchaKraken-Lora-v1.2") - Notebooks
- Google Colab
- Kaggle
CaptchaKraken-Lora-v1.2
LoRA adapter for Qwen/Qwen3.5-9B, trained on CaptchaKraken's synthetic puzzle
generators. First CaptchaKraken model with animated ("video") challenge
support, and the first trained against prompt generation 2.
Training run 20260812-005302. Verdict: ready-to-deploy — passed all three
gates uncapped.
Requires captchakraken >= 2.5.0
This adapter answers generation-2 prompts. Every previously published CaptchaKraken model is generation 1, and sending this model a generation-1 prompt does not error — it silently degrades on every puzzle.
Client releases before 2.5.0 hardcode generation-1 prompt text and have no way
to know otherwise, so do not point an older client at these weights. From
2.5.0 the client ships a model registry that maps this repo to generation 2 and
serves the matching templates automatically; prompts.json here carries the
exact text the weights were trained on, for anyone building their own client.
pip install "captchakraken>=2.5.0" # or: npm install captchakraken@^2.5.0
Usage
Serve the adapter on top of the base model and disable thinking, or the
reasoning parser routes the answer into reasoning and leaves content empty:
chat_template_kwargs = {"enable_thinking": false}
Coordinates are on a normalized 0–1000 scale (top-left (0,0), bottom-right
(1000,1000)). Send the template matching the detected puzzle type as the text
part of the user turn, image first. Animated puzzles are sent as one multi-image
prompt of keyframes; the answer names the keyframe it acted on. See
prompts.json → selection_rule.
Pixel budget matters as much as the prompt: this adapter was trained with
MIN_PIXELS=200704 (448²) and MAX_PIXELS=518400 (720²). Qwen clamps each
image's area into that band, so serving it under a different one shows the model
a puzzle at a scale it never learned to read.
Training
| Base | Qwen/Qwen3.5-9B |
| Method | LoRA, r=64, alpha=128, dropout 0.05 |
| Targets | language model + visual tower (merger excluded) |
| Epochs | 3 |
| LR | 1e-4 |
| Batch / grad accum | 1 / 8 |
| Max pixels | 518,400 |
| Train entries | 58,500 (1,548 val) |
| Data | synthetic generator output only |
Real captured puzzles are deliberately excluded from training and kept for evaluation — that separation is what reveals when a generator stops matching the real puzzle.
Evaluation
All three gates run against this adapter, prompt-pinned to generation 2.
| Tier | What it measures | Result |
|---|---|---|
| 1 | Hermetic pytest + prompt parity | pass |
| 2 | Graded solve rate vs. real, held-out static captchas | pass — overall 0.6155 (baseline 0.5535, tolerance 0) |
| 3 | Driving live HTML fixtures to completion, both ports | pass |
Tier 2 is a graded score over real captures the model never trained on, not a pass/fail solve rate; treat it as a regression signal, not a marketing number.
License
CaptchaKraken Source-Available License v1.1 — see LICENSE.
You may use this commercially inside a product that delivers value beyond captcha solving itself: scrapers, data pipelines, your own browser automation, QA and accessibility tooling. Running it alongside a stealth or antidetect browser to automate your own work is explicitly permitted (§2(c)).
You may not, without a separate commercial agreement:
- sell, resell, or offer for a fee any captcha-solving service or API whose primary value is solving captchas (§3(a));
- distribute thin wrappers whose primary purpose is captcha solving (§3(b));
- proxy or relay this model's outputs through a paid or public API as a captcha-solving service (§3(c));
- ship it as a built-in captcha feature of a stealth / antidetect browser, profile manager, or automation platform you distribute to third parties (§3(d)) — note this restricts shipping it to others, not using it.
In short: you may build with this, but you may not sell the solve.
Commercial licensing: https://captchakraken.com
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