https://bitbucket.org/TeamJM/journeymap-api
This plugin-style (soft dependency) API gives modders the interfaces and utilities needed in their development environment to create waypoints, overlays and markers in JourneyMap
Modpack Authors: You don't need this. Don't put this in your modpack.
Minecraft Players: You don't need this. Don't download this in the Curse app.
Mod Developers: You need this. If you want to integrate your mod with JourneyMap, that is.
This API is a "soft dependency." You code to it, but your mod doesn't need to (should not) include this code in your own jars. The actual implementation of the API ships inside JourneyMap. If JourneyMap isn't loaded, then your plugin code will never be activated.
Want to know more?
Source, build configs for Forge Gradle, and example code are here: https://bitbucket.org/TeamJM/journeymap-api