Renewable resources, farmed by frogs. Prime slimes with iron, copper, diamonds, or whatever resource you want, feed them to your frogs, and harvest the Froglights they drop. Slime Milkers keep the loop running unattended.
That is the whole loop. Everything below makes it bigger, faster, or hands-off.
Stop running around priming wild slimes. Build a Slime Milker:
No power, no pipes required, and hoppers feed and drain it. Toss catalysts into a placed Slime Milk source to push it further: more spawns before it runs dry, faster spawning, more slimes per spawn, or one that never runs dry at all. And every variant's milk is its own liquid, so fluid pipes and tanks can pump it, carry it, and place it back as the same slime - a fully automated milk line if you want one.
Every Froglight melts back down. Build a Froglight Crucible and park it over a heat source - a torch works on day one, lava and fire melt faster:
Your frogs are not interchangeable. Each one has stats that decide how much it eats, how much it drops, and how far it reaches, and you improve them by breeding. Pair two frogs on a treat and the offspring blends its parents and can climb a notch higher, so you ladder a line toward the cap and merge two specialists into one well-rounded producer. A breed never comes out worse than its parents, and a pack that just wants the plain loop can switch breeding off.
Build the Terrarium, a sealed multiblock habitat, and the loop runs on its own. Pipe Slime Milk into the controller, ceiling sprinklers rain slimes into the cavity, frogs raised inside eat them, and the Froglights collect in an output hatch for piping out. Bred stats carry through. It is the hands-off endgame for a resource farm, and a frog perch (a sweetslimed lily pad) pins a single frog over a collection point if you would rather keep things simple.
There is a tier past the everyday loop. Splash a potion onto a slime before a frog eats it and the Froglight keeps that effect, ready to place as a glowing aura, hold for yourself, or wear. Breed predator frogs that hunt real mobs for their real drops, cross them into Apex Frogs, and install those on boss altars - the Wither, the Ender Dragon, the Warden, and the Elder Guardian each get a buildable arena that summons and harvests them for raw boss drops and bottled experience, no fight required. The Froglight Cleaver is a sword that drops a slime's Froglight on the kill; the Ender Dragon's altar pays a Princess's Kiss that turns a frog into a tradeable villager. And any frog drops Frog Legs, a renewable meat for a world short on animals.
New to the mod? Craft the in-game guide book (a book plus a slime ball) for an illustrated walkthrough of the whole thing, with build diagrams for the Terrarium and each altar. It needs Patchouli installed, and modpack authors can extend it with their own pages.
Data-driven and extensible: adding a new resource is a single JSON file, no code and no recompile. JEI Information pages auto-extend to teach the new entry. Cross-mod resources for Mekanism, Create, Applied Energistics 2, AllTheOres, Mystical Agriculture, Powah, Industrial Foregoing, Refined Storage, and more come included, each gated behind a soft mod-loaded check that silently skips when the source mod is absent, so the same jar is safe in any pack. A deep set of config switches lets a pack ship exactly the parts it wants, down to individual resources or whole systems.
Full authoring guide: docs on GitHub.
They are all optional. The mod works fine without them; you just lose the contextual UI and the in-game guide.
Productive Frogs is mature and stable. New resources, cross-mod support, and polish land as they are ready - there are no fixed version gates, and updates keep both new and existing worlds working. Have a request? The issue tracker is open.
Not planned: a Fabric port. Productive Frogs is NeoForge-only by design and will stay that way.
