BindAlias

A Minecraft Fabric client mod that allows creating custom aliases and key bindings to automate complex in-game actions with simple key presses. Also enables autonomous AI agent control via an in-game HTTP API — agents can see, reason about, and act in Minecraft independently. Use with the BindAlias MCP tool to let AI play the game.

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Overview

BindAlias enhances your Minecraft gameplay by letting you define custom aliases for sequences of actions and bind them to keys. Whether you need to quickly swap inventory slots, automate elytra flight, or chain multiple actions (like using a bow or placing blocks that not even in your hotbars or second hand), this mod simplifies repetitive tasks through configurable aliases and key bindings.

Features

• Custom Aliases: Create reusable aliases for single or multiple in-game actions (e.g., swap items, use abilities, move).
• Key Bindings: Bind aliases to keys, with support for separate actions on key press and release.
• Built-in Aliases: Predefined aliases for common actions (e.g., swapSlot, wait, use, attack).
• Command System: Intuitive commands to manage aliases and bindings (e.g., /alias, /bind, /unbind).
• Config Persistence: Saves aliases and bindings in a config file, loaded automatically when joining servers.
• Chained Actions: Combine aliases to create complex sequences (e.g., equip elytra → use firework → fly).
• AI Agent Support: Built-in HTTP API (GET /state, GET /screenshot, POST /runAlias, etc.) for AI agent control. Use with the BindAlias MCP tool to let AI agents see, reason about, and act in your Minecraft world.

Installation

1. Ensure you have Fabric Loader installed for your Minecraft version.
2. Download the latest bind-alias-*.*.*.jar from the releases page.
3. Place the JAR file in your Minecraft mods folder.
4. Launch Minecraft with the Fabric loader.

Usage

Core Concepts

• Alias: A custom or built-in action (or sequence of actions) that can be executed.
• Key Binding: A link between a physical key (e.g., mouse5, keyboard.g) and an alias (or two aliases: one for press, one for release).

Built-in Aliases

BindAlias includes prebuilt aliases for common actions. They are divided into aliases with arguments and * aliases without arguments*.

Aliases with Arguments

Note: Slots follow Minecraft's internal numbering:

• 1-9 → Hotbar slots
• 10-36 → Inventory slots (10-19 = first row)
• 37-40 → Equipment slots (37 = feet, 38 = legs, 39 = chest, 40 = head)
• 41 → Offhand slot
• u can cover args with double quotes so that the white space inside will not be referred as split mark.
• RECOMMENDED for nested definitions: When using alias, bind, unbind, say, sendCommand, or localSay builtin aliases inside other alias definitions, use semicolon ; instead of space as the divider between arguments. This allows you to use normal space dividers in the nested definition without conflict. Example: alias +testAlias bind/v;+anotherAlias alias/+yetAnotherAlias;+anotherAlias;+jump alias/+nextAlias;wait/2;+yetAnotherAlias wait/1 bind/x;+testAlias - here semicolons separate the arguments for these builtin aliases, while spaces work normally.

Alias	Description	Example
log	Logs a message to the game console (for debugging).	log/Hello World
slot/slotNumber	Switches to a specific hotbar slot (1-9). Accepts variable names.	slot/3 (switches to hotbar slot 3), slot/mySlot (uses variable)
swapSlot/slot1/slot2	Swaps items between two inventory slots (1-9 hotbar, 10-36 inventory, 37-40 armor, 41 offhand). Works in any container screen; use cN for the Nth slot of the open menu (e.g. crafting table c1 = result, furnace c3 = output) — enables crafting/forging/enchanting. Accepts variable names (plain slots only).	swapSlot/10/39 (swaps inventory slot 10 with chestplate slot), swapSlot/c1/10 (takes crafting result into slot 10)
swapSlot/slot1	Swaps items between the currently held hotbar slot (main hand) and the specified slot1. Accepts variable names.	swapSlot/19 (swaps current hotbar slot with inventory slot 19)
wait/ticks	Pauses execution for a specified number of ticks (20 ticks = 1 second). Accepts variable names.	wait/20 (waits 1 second), wait/myTicks (uses variable)
yaw/degrees	Adjusts player yaw (horizontal rotation) by a relative degree value. Accepts variable names.	yaw/90 (turns 90° right), yaw/myVar (uses variable)
pitch/degrees	Adjusts player pitch (vertical rotation) by a relative degree value. Accepts variable names.	pitch/-30 (looks 30° down), pitch/myVar (uses variable)
setYaw/degrees	Sets player yaw to an absolute degree value (0 = north, 90 = east). Accepts variable names.	setYaw/180 (faces south), setYaw/myVar (uses variable)
setPitch/degrees	Sets player pitch to an absolute degree value (-90 = straight up, 90 = straight down). Accepts variable names.	setPitch/0 (looks straight ahead), setPitch/myVar (uses variable)
alias/args	almost same as command alias, except u need to cover args with double quotes.	alias/"meow say/nya~" (create or replace an alias)
bind/args	almost same as command bind, except u need to cover args with double quotes.	bind/"m meow wait/0 +fly" (create or replace a bind)
unbind/keyName	almost same as command unbind.	unbind/m (unbind binds on a key)
say/string	say a chat message.	say/"How old r u?" (send a chat message that is "how old r u?")
localSay/string	display a chat message on the local client only, without sending to the server. Useful for testing, notifications, and debug output.	localSay/"Debug: slot is /(mySlot)" (local-only message)
sendCommand/command	send a command.	sendCommand/"gamemode creative" (send a command that is "gamemode creative")
var/varName/source	Store a value into a variable. Sources: hotbarSlot, itemsOfSlot0-9, pitch, yaw, or a number.	var/mySlot/hotbarSlot (store hotbar slot), var/angle/pitch (store pitch angle)
applyRecipe/query	Place an unlocked, craftable recipe into the crafting grid of the open recipe menu (inventory / crafting table / furnace), like clicking it in the recipe book. No crafting is performed. Query: result-item id (minecraft:torch / torch) or locale-name substring (iron sword). Errors (no menu open / not unlocked / missing ingredients) go to the local game chat.	applyRecipe/torch
reapply/action	Manually re-assert a held-down boolean alias (attack, use, forward, back, left, right, jump, sneak, sprint, drop, openInventory). Useful at the end of a UserAlias after screen transitions.	reapply/forward (re-presses forward key if held)
openInventory/state	Opens (1) or closes (0) the inventory screen.	openInventory/1 (opens inventory), openInventory/0 (closes inventory)

Numeric aliases support variable references: yaw, pitch, setYaw, setPitch, slot, swapSlot, wait, and setPerspective all accept variable names (e.g., yaw/myVar or slot/mySlot) in place of raw numbers.

Aliases without Arguments

These are shorthand aliases that map to common state=1 (start) and state=0 (stop) actions for simpler usage:

Alias	Equivalent To	Description
+attack	builtinAttack/1	Starts attacking (holds left-click).
-attack	builtinAttack/0	Stops attacking (releases left-click).
+use	builtinUse/1	Starts using held item (holds right-click).
-use	builtinUse/0	Stops using held item (releases right-click).
+forward	builtinForward/1	Starts moving forward.
-forward	builtinForward/0	Stops moving forward.
+back	builtinBack/1	Starts moving backward.
-back	builtinBack/0	Stops moving backward.
+left	builtinLeft/1	Starts moving left.
-left	builtinLeft/0	Stops moving left.
+right	builtinRight/1	Starts moving right.
-right	builtinRight/0	Stops moving right.
+jump	builtinJump/1	Starts jumping (holds jump key).
-jump	builtinJump/0	Stops jumping (releases jump key).
+sneak	builtinSneak/1	Starts sneaking (holds sneak key).
-sneak	builtinSneak/0	Stops sneaking (releases sneak key).
+sprint	builtinSprint/1	Starts sprinting (holds sprint key).
-sprint	builtinSprint/0	Stops sprinting (releases sprint key).
+drop	builtinDrop/1	Presses the drop key. Holding continuously drops items in both the 3D game and container/inventory screens (vanilla-compatible, with initial repeat-delay). Drops full stack when combined with keyboard control key.
-drop	builtinDrop/0	Releases the drop key.
+openInventory	builtinOpenInventory/1	Opens the inventory screen.
-openInventory	builtinOpenInventory/0	Closes the inventory screen (if open).
pickItem	—	Triggers vanilla pick-block on the targeted block/entity.
swapHand	_	Swaps items between main hand and offhand.
+silent	builtinSilent/1	Enables silent mode (suppresses command feedback messages).
-silent	builtinSilent/0	Disables silent mode (re-enables command feedback messages).
+lockKey/<target>	builtinLock/<target>/1	Locks a game key or custom alias. Use gameKey:attack, gameKey:forward, etc. for vanilla keys, or an alias name for custom aliases.
-lockKey/<target>	builtinLock/<target>/0	Unlocks a previously locked game key or custom alias.
cyclePerspective	—	Cycles through camera perspectives (FPS → TPS → TPS2).
FPS	builtinSetPerspective/0	Switches to first-person view.
TPS	builtinSetPerspective/1	Switches to third-person back view.
TPS2	builtinSetPerspective/2	Switches to third-person front view.
reloadCFG	—	Reloads the config file (applies changes without restarting).
unloadCFGAliases	—	Removes all aliases that were loaded from the config file.
unloadCFGBinds	—	Removes all keybindings that were loaded from the config file.
unloadCFGVars	—	Removes all variables that were loaded from the config file.
unloadCFGAll	—	Removes all aliases, keybindings, and variables loaded from config.

Variables

Variables let you capture and reuse in-game values (hotbar slot, pitch/yaw angles, item counts, etc.).

Sources for var/varName/source:

Source	Description	Example
hotbarSlot	Current hotbar slot (1-9)	var/mySlot/hotbarSlot
itemsOfSlotN	Item count in slot N (0=offhand, 1-9=hotbar)	var/count/itemsOfSlot2
pitch	Player's current pitch angle (float)	var/myPitch/pitch
yaw	Player's current yaw angle (float)	var/myYaw/yaw
42 or 3.14	A literal number (int or float)	var/backup/42

Variables can then be used as arguments in any numeric alias (e.g., yaw/myVar, slot/mySlot, wait/myTicks).

Variable-related commands:

Command	Purpose	Example
/var <name> <source>	Create or update a variable.	/var mySlot hotbarSlot
/unloadCFGVars	Remove all config-loaded variables.	/unloadCFGVars

AI Agent / MCP HTTP Server

BindAlias includes a built-in HTTP server that enables AI agents (such as Claude, ChatGPT, or custom automation scripts) to observe and control your Minecraft client. This is the companion mod for the BindAlias MCP tool.

Hosting guide: See src/MCP_HOSTING_GUIDE.md for step-by-step instructions on setting up a game for agents, connecting the MCP bridge, and managing long-running agent sessions.

The server listens on http://localhost:25575 (falls back to the next free port, up to +9, when occupied — the chosen port is logged) and provides:

Endpoint	Method	Description
/state	GET	Full game-state snapshot + drained message channels (envelope)
/screenshot	GET	In-memory PNG screenshot (base64) + envelope (no chat spam, no file I/O)
/runAlias	POST	Execute alias chains remotely (e.g., swapSlot/1/2)
/defineAlias	POST	Define new aliases via API (feedback arrives in the chat channel)
/readCFG	GET	Read the current config file contents (raw text, no envelope)
/writeCFG	POST	Write to the config file (modify binds, aliases, variables)
/listRecipes	GET	List recipes unlocked in the recipe book (diff or per-query answers)

Every game-interacting endpoint answers with the same envelope: {"tick":N, "state":{...}, "chat":[...], "mod":[...], "sound":[...], "recipe":[...]} — state is a full snapshot for /state and a changed-members-only diff for everything else (omitted when nothing changed); chat (game chat), mod (mod log), sound (subtitled sounds with compass direction + distance) and recipe (newly unlocked recipes) are message channels drained exactly once per message and omitted when empty. All state info is also visible on the vanilla HUD or the open screen.

Example agent usage:

# Check what the player sees
curl http://localhost:25575/state

# Execute an alias chain
curl -X POST http://localhost:25575/runAlias -d "swapSlot/1/2/wait/2/+attack"

# Take a screenshot
curl http://localhost:25575/screenshot -o screen.png

Example Config

/var offHand 41
/alias jumpOnce +jump wait/0 -jump
## 36->elytra; 27->firework
/alias +fly swapSlot/36/39 jumpOnce wait/0 jumpOnce swapSlot/27/41 +use -use TPS
/alias -fly swapSlot/36/39 swapSlot/27/41 wait/2 FPS
/alias +fastUse_Var swapSlot/varFastUse/offHand +use
/alias -fastUse_Var -use swapSlot/varFastUse/offHand
/alias +fastAttack_Var swapSlot/varFastAttack wait/1 +attack
/alias -fastAttack_Var -attack swapSlot/varFastAttack

# alias fly_on +silent bind/"mouse5 fly_off" -silent +fly
# alias fly_off +silent bind/"mouse5 fly_on" -silent -fly

/bind w +forward
/bind a +left
/bind s +back
/bind d +right
/bind space +jump
/bind left.shift +sneak
/bind left.control +sprint
/bind mouse1 +attack
/bind mouse2 +use
/bind mouse5 +fly
## water; powder_snow; food; ender_pearl; bow;... 3 fast use slots
/bind mouse4 var/varFastUse/19 +fastUse_Var
/bind b var/varFastUse/20 +fastUse_Var
/bind v var/varFastUse/28 +fastUse_Var
## fortune_pickaxe 1 fast mine slot
/bind n var/varFastAttack/29 +fastAttack_Var

Configuration

• Config File: At config/bind-alias.cfg. Automatically created if there is not one.
• Auto-Load: Aliases and bindings in the config file are loaded automatically when the mod loads.
• Manual Edit: You can directly edit the config file to add/modify aliases/bindings (use the same syntax as in-game commands). See the Example Config section above for a complete real-world config.

Commands Reference

Command	Purpose	Example
/alias <name> <definition>	Create a custom alias.	/alias myAlias +jump wait/1 -jump
/bind <key> <definition>	Bind a key to a sequence of aliases by definition of this command or an existing alias.For each definition split by divide mark(things inside double quotes would still be a same block) starts with + or -, it will create an opposite alias. For the 1st eg, it also bind -forward and +back to release of keyboard key g	/bind g +forward wait/10 -back OR /bind n +drop
/bindByAliasName <key> <alias>	Bind a key to an existing alias.	/bindByAliasName mouse5 +fly
/unbind <key>	Remove a key binding.	/unbind mouse5
/reloadCFG	Reload config from file.	/reloadCFG
/var <name> <source>	Create/update a variable. Sources: hotbarSlot, itemsOfSlot0-9, pitch, yaw, or a number.	/var mySlot hotbarSlot, /var angle pitch
/unloadCFGAliases	Remove all aliases loaded from config.	/unloadCFGAliases
/unloadCFGBinds	Remove all keybindings loaded from config.	/unloadCFGBinds
/unloadCFGVars	Remove all variables loaded from config.	/unloadCFGVars
/unloadCFGAll	Remove all aliases, binds, and variables loaded from config.	/unloadCFGAll

Notes

• Compatibility: Works with most Fabric mods; may conflict with mods that modify key handling or inventory mechanics.
• Minecraft Version: Requires Minecraft 1.21+ (Yarn mappings) or 26.x (Mojang mappings). Check the release page for version-specific builds (filenames include the MC version).
• Variables: Supports integer and floating-point values. Numeric aliases (yaw, pitch, setYaw, setPitch, slot, swapSlot, wait, setPerspective) accept variable names in place of raw numbers.
• Safety: Avoid excessive automation on servers with anti-cheat systems (some actions may be flagged).
• MCP Server: The built-in HTTP API listens on port 25575 by default (falls back to the next free port when occupied). Pair with the BindAlias MCP tool for AI agent integration.

Contributing

Contributions are welcome! Feel free to open issues for bugs/feature requests or submit pull requests with improvements.

License

This mod is licensed under the Creative Commons Zero v1.0 Universal.