State Machine
by heipiao
State Machine lets players build deterministic finite-state machines out of placed blocks, with states that emit redstone signals.
What it does
A machine is built from blocks that each hold a state, and transitions between states are triggered by item stacks treated as an input alphabet. The current state of a machine can drive a redstone signal, so the output follows the input sequence. The mod runs on client and server, so both sides need it. Files target Fabric for 1.20.1, 1.21.1 and 1.21.8, with 0.0.3+1.21.8 as the latest file, under the GNU Lesser General Public License v3.0 or later.
Key features
Placed state blocks
Blocks placed in the world carry a state, so a machine is laid out as physical construction.
Item stack alphabet
Item stacks are assigned as the input symbols, and each transition fires when its item is presented.
Redstone output
The current state of a machine can emit a redstone signal, letting the machine control other circuits.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
How it compares
Offhand on Top is server-side only, open source under the MIT License and built for 1.21 – 1.21.1, so players can join without it. Igneous Machines is open source under the GNU Lesser General Public License v3.0 only and covers 1.19.2 – 1.20.2 with client and server. Redstone Battery is open source under the MIT License for 26.1.2 only, and runs on client and server.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| State Machine | Fabric | 1.20.1 – 1.21.8 | Client and server | 2026-02-13 |
| Offhand on Top | Fabric | 1.21 – 1.21.1 | Server-side only | 2024-09-08 |
| Igneous Machines | Fabric | 1.19.2 – 1.20.2 | Client and server | 2025-09-11 |
| Redstone Battery | Fabric | 26.1.2 | Client and server | 2026-08-25 |
Questions
Does State Machine need to be installed on the server?
In the catalog
State Machine is one of 8,499 Technology mods on ModsFinder, and one of 4,201 Technology mods for Fabric. 17,695 mods support Minecraft 1.21.8.
More from heipiao
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What the author says
With this mod you can build a deterministic finite-state machine in Minecraft. The set of items (NOT ITEM STACKS) in your game is your alphabet. States are placed blocks. If a state is the current one of some state machine it will emit redstone signal.
Official listing
- Modrinth page
- modrinth.com/mod/state-machine
- Owner
- heipiao
- Published
- 2026-02-12
- Updated on Modrinth
- 2026-02-13
- Facts verified
- 2026-10-15