CarrotJuicer

Hooks the decryption function in libnative.dll of ウマ娘プリティーダービー (Umamusume Pretty Derby), to allow inspecting the packets (and provide some useful information during the game).

For Android, refer to Riru-CarrotJuicer.

Usage

Theoretically this should support "modern" versions of Windows, as long as it is x64. But this is only tested with Windows 10 v21H1.

Please make sure that you have installed the latest Visual C++ 2019 Redistributable, otherwise the game would crash at start up time with no message at all.

Unfortunately for now you have to compile it yourself. See "Build" section below.

1. Set up DLL redirection for umamusume.exe. We are looking for version_orig.dll which you should copy from your System32 folder.
2. Start the game as usual (i.e., with DMM launcher). The captured packets will be saved into CarrotJuicer folder in the game directory.
3. You can investigate the responses with msgpack tools like msgpack2json -di 123456789R.msgpack.

Hakuraku has a UI for investigating the captured packets here.

cjedb.json and master.mdb

Starting from v1.2, CarrotJuicer would print extra info that may help users to make strategic decisions. Some features depend on an optional external data file CarrotJuicer\cjedb.json. If this file is missing, some features will be disabled.

The Releases in this repo would bundle the latest file as of that time, but you may wish to check for updates here from time to time, especially after a new charactor or support card is added.

In addition, CarrotJuicer will attempt to read master.mdb directly from the game's data directory (in %USERPROFILE%\AppData\LocalLow\Cygames\umamusume\master) with a bundled SQLite engine. (Sorry for the bloating file size, but the game itself takes 4GB anyway, so we are as trivial as some rounding error.) If you somehow moved it, please at least make sure a link is available.

cjconfig.json

To tweak CarrotJuicer's features, create a file named CarrotJuicer\cjconfig.json in the same directory. If a config item is missing (or we fail to parse this file), the default value will be used.

Supported options and their default values:

{
	"save_request": true,
	"save_response": true,

	"enable_ansi_colors": true, // Enable features that depend on ANSI colors. Works only on Windows 10 v1511+.

	"enable_notifier": false,
	"notifier_host": "",
	"notifier_connection_timeout_msec": 100,
	"notifier_print_error": true,

	"aoharu_team_sort_with_speed": true, // If false, sort with rank score.
	"aoharu_print_team_average_status_max_turn": 0,

	"climax_print_shop_items": true,
}

aoharu_print_team_average_status_max_turn

This option will cause the average status of team members to be printed, before the requested turn ends. For instance, setting this to 24 would enable this feature throughout the first year.

This might be useful if you would like to precisely control the training levels.

Notifier

If cjconfig.json sets enable_notifier to true, we will attempt to notify a listener whenever a response is received.

notifier_host is required, and it should include scheme, host and optionally, port. For instance, it can be set to http://127.0.0.1:4693. In this case, we will send a POST request to http://127.0.0.1:4693/notify/response, with the raw response msgpack data as body.

This does not support multiple listeners, and if you indeed would like to do this, you will have to write a demultiplexing server yourself.

Note that this HTTP request blocks the game, to avoid potential races with the listener. There is an option notifier_connection_timeout_msec which defaults to 100 ms. If the listener is not running, we will at most wait for 100 ms during connection setup so we don't slow down the game too much. If notifier_print_error is true, an error message will be printed when we fail to notify the listener. Note that non-200 responses from the listener are always printed regardless the value of notifier_print_error.

race_scenario

In packets containing races, there is a base64-encoded field, often named race_scenario. This includes per-frame and per-chara information in the race.

More details can be found in README of Hakuraku. Its web UI is able to parse this field for you.

Requests

Requests (files ending with Q.msgpack) are not actually msgpack. The current observation is:

• The first 4 bytes likely represent a little-endian int. We name it offset, currently always observed to be 0xA6 (166).
• The following 52 bytes [+0x04, +0x38) never change for a single client, even across sessions. We did not test whether this is per-account or per-client.
• The following 114 bytes [+0x38, +0xAA) are different for each request.
• All remaining is a standard msgpack message. This starts at +0xAA which is exactly offset + 4.

To investigate the content, remove the first 170 bytes and use msgpack tools, like tail -c+171 123456789Q.msgpack | msgpack2json -d.

Build

0. Install vcpkg, and make sure to enable VS integration by running vcpkg integrate install.
1. git clone
2. Spin up Visual Studio 2019, and press "Build".

Credits

This module is largely copied from inspired by umamusume-localify.