# Yu-Gi-Oh! Online 3: reconstructing early server exchanges and YPK extraction

> ygo3-research reconstructs early Yu-Gi-Oh! Online 3 server exchanges and provides a YPK archive extractor. Its experimental Python server responds to observed authentication, profile, player-list and selection requests and documents packet encryption, length masking and nested data encoding. The client currently stops after player selection.

- Type: Case study
- Targets: Game · Protocol
- Category: Independent reconstruction cases
- Relationship: Independent reconstruction project
- Sources reviewed: 2026-11-06
- Added to the catalog: 2026-11-08
- Original resource: <https://github.com/iteratequickly/ygo3-research>
- Primary source: <https://github.com/iteratequickly/ygo3-research/blob/25afbbb7726e84315ed00b793aac29040a7aaca6/README.md>
- Catalog page: <https://awesomerea.org/resources/ygo3-research-case/>
- Record JSON: <https://awesomerea.org/resources/ygo3-research-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/ygo3-research-case/index.md)

## Requirements & limits

- **Prerequisites:** Windows, Python 3.12 and PyCryptodome for the local server; the YPK extractor uses the Python standard library.
- **Prerequisites:** The original game client and local configuration are needed for server experiments.
- **Limits:** Development is paused; offline play and duel functionality are incomplete.
- **License:** MIT License.

## Primary sources

1. <https://github.com/iteratequickly/ygo3-research/blob/25afbbb7726e84315ed00b793aac29040a7aaca6/README.md>

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## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.