IMC Messages

Inter-Mod-Communication messages are a system provided by Forge/FML which allows communication between mods without requiring any "hard" dependency on an API/code.
Mods can send messages to other mods in InterModEnqueueEvent containing a key and a value (String, int, CompoundNBT ...) and the receiving mod can parse them in InterModProcessEvent.

Thereby they are a lightweight alternative to using another mods API, but far less powerful.
They should be sent during init using InterModComms#send.

Vampirism's Messages

With Vampirism, you can send the following messages to Vampirism for better compatibility between your mod and Vampirism: Find the parsing code here

No-Sundamage Biome

Disable sun damage for a biome of yours.

key: "nosundamage-biome"
payload: registry name of the biome as ResourceLocation

Configuration per dimension id is only available per API as they might not be assigned during init.

Disable Blood Bar

You can request to disable the replacement of the food bar with the blood bar.

key: disable-blood-bar
payload: none