tristanmcpherson-R2API icon


A modding API for Risk of Rain 2

Last updated 2 months ago
Total downloads 691921
Total rating 203 
Dependency string tristanmcpherson-R2API-2.5.14
Dependants 557 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 128521 Install
2020-8-26 2.5.11 43157 Install
2020-8-21 2.5.7 40869 Install
2020-8-17 2.5.6 34199 Install
2020-8-17 2.5.4 3972 Install
2020-8-15 2.5.0 14155 Install
2020-7-6 2.4.29 42956 Install
2020-4-23 2.4.21 57053 Install
2020-4-3 2.4.10 48551 Install
2020-3-16 2.4.2 23034 Install
2020-3-16 2.4.1 501 Install
2020-1-26 2.3.22 42563 Install
2020-1-11 2.3.20 17821 Install
2020-1-9 2.3.17 2576 Install
2020-1-26 2.3.14 178 Install
2019-12-21 2.3.7 36403 Install
2019-12-19 2.3.5 9552 Install
2019-11-14 2.3.0 13561 Install
2019-11-14 2.2.54 382 Install
2019-10-15 2.2.32 15305 Install
2019-9-19 2.1.16 33037 Install
2019-8-12 2.1.15 19456 Install
2019-7-7 2.1.0 23020 Install
2019-5-29 2.0.10 30662 Install
2019-5-24 2.0.8 4138 Install
2019-5-22 2.0.6 2455 Install
2019-5-22 2.0.5 1709 Install