tristanmcpherson-R2API icon


A modding API for Risk of Rain 2

Last updated 2 months ago
Total downloads 803969
Total rating 218 
Dependency string tristanmcpherson-R2API-2.5.14
Dependants 718 other mods depend on this mod

This mod requires the following mods to function

bbepis-BepInExPack-3.0.0 icon

Unified BepInEx all-in-one modding pack - plugin framework, detour library

Preferred version: 3.0.0

R2API – a modding API for Risk of Rain 2

Build Status - DEPRECATED
GitHub Actions Build


In the Release version of RoR2, Hopoo Games made a NetworkModCompatibilityHelper class, which can be given a mod list that is then transformed into a hash that will be checked upon client connection in multiplayer.
If the hash doesnt correspond between the server and the connecting client, the connection is refused.

R2API will add mods to that mod list if they:

  • Use the NetworkCompatibility Attribute, either as an custom assembly attribute, or at the top of their plugin class inheriting from BaseUnityPlugin with the first argument being CompatibilityLevel.EveryoneMustHaveMod.
  • Don't have the NetworkCompatibility Attribute or the ManualNetworkRegistrationAttribute anywhere in their assembly.


R2API is a modding framework for other mods to work in, providing centralized and simplified APIs for Risk of Rain 2. This helps keeping mods compatible with each other.

At it's core, R2API should not change how the game behaves without any other mod installed. The only change is to keep mods out of quickplay and prismatic trials by request of the Hopoo Games team.


The contents of R2API should be extracted into the BepInEx folder, such that the files inside the monomod folder in the zip sit in the monomod folder in BepInEx and the files and folder in plugins in the archive is inside your plugins folder.

A succesful installation should look like this:
(click to enlarge)


A lot of documentation is in the included xmldocs, and further information may be on the dedicated R2API wiki. Do not hestiate to ask in the modding discord too!

Bleeding Edge

Unless you are a mod developer, you won't need this.

Want to get the latest versions of R2API? The latest bleeding edge builds of master are hosted on Azure, and may be downloaded using the Artifacts drop down menu.

Note that such builds may be unstable.


The most recent changelog can always be found on the Github. In this readme, only the most recent minor version will have a changelog.










2.3.7 * Fix issue with Twisted Scavengers loot



Available versions

Please note that the install buttons only work if you have compatible client software installed. Otherwise use the zip download links instead.

Upload date Version number Downloads Download link  
2020-9-1 2.5.14 233639 Install
2020-8-26 2.5.11 43543 Install
2020-8-21 2.5.7 40954 Install
2020-8-17 2.5.6 34307 Install
2020-8-17 2.5.4 4011 Install
2020-8-15 2.5.0 14242 Install
2020-7-6 2.4.29 43015 Install
2020-4-23 2.4.21 57147 Install
2020-4-3 2.4.10 48608 Install
2020-3-16 2.4.2 23099 Install
2020-3-16 2.4.1 532 Install
2020-1-26 2.3.22 42641 Install
2020-1-11 2.3.20 17880 Install
2020-1-9 2.3.17 2621 Install
2020-1-26 2.3.14 231 Install
2019-12-21 2.3.7 36460 Install
2019-12-19 2.3.5 9608 Install
2019-11-14 2.3.0 13594 Install
2019-11-14 2.2.54 429 Install
2019-10-15 2.2.32 15332 Install
2019-9-19 2.1.16 33080 Install
2019-8-12 2.1.15 19505 Install
2019-7-7 2.1.0 23073 Install
2019-5-29 2.0.10 30731 Install
2019-5-24 2.0.8 4171 Install
2019-5-22 2.0.6 2497 Install
2019-5-22 2.0.5 1773 Install