Glad to have you! This guide will go over all of the features you can use to expand Reactive Alchemy to fit it more seamlessly into your modpack.

Config Options

There are three config files; two in the config folder, and one in each world's serverconfigs. For reference, these are the options each contain:

Common Config

#Options:
[config]
	#The crucible performs a stage of its calculations once every X game ticks. Lower numbers are more responsive, but laggier. [Default: 5]
	#Range: 1 ~ 900
	crucibleTickDelay = 5
 (If the crucible is causing server tick lag, this is the first thing you can change.)
 
	#The crucible affect entities with an area of this radius. [Default: 12]
	#Range: 2 ~ 64
	crucibleRange = 12
 (This is the range for reaction effects, and some other things.)

	#The crucible checks an area this many blocks in radius up to a few times a second. Do not set this too high. [Default: 6]
	#Range: 2 ~ 64
	areaMemoryRange = 6
 (This is the range for the area memory system. The time of each area memory update increases in an n-cubed fashion with this value.)

	#Certain effects might teleport entities if they are not in this blacklist. [Default: "minecraft:ender_dragon", "minecraft:wither"]
	doNotTeleport = ["minecraft:ender_dragon", "minecraft:wither"]
 (Add any LivingEntity entities that you need to never be teleportable.)
 
 	#Whether acid should dissolve entity blocks. This would delete the contents of said blocks. [Default: false]
	acidMeltBlockEntities = false
 (Self explanatory.)

	#Blocks with a base break time beyond this cannot be displaced or made to fall. For finer control, use the relevant block tags. [Default: 35.0]
	#Range: 0.0 ~ 10000.0
	maxMoveBlockBreakTime = 35.0
(This controls how tough blocks can be before they are not able to be displaced or made to fall by Motion Salts. For reference, an Iron Block passes the default threshold, but Deepslate does not. Higher values are more permissive. Blocks with negative hardness (e.g. Bedrock) are always unmovable by this system, and an additional deny list exists in the block tags.)
 
 	#The maximum number of blocks that can be displaced at once by a certain effect. [Default: 128]
	#Range: 4 ~ 4096
	maxDisplaceCount = 128
(How many blocks can be displaced when a structure of adjacent Framed Motion Salt Block is electrified. Note that this many blocks will be operated on in one tick by the initial displacement, which might cause a lag spike if you set it too high.)

	#The maximum distance that a block like Copper can convey a displacement pulse [Default: 8]
	#Range: 1 ~ 4096
	copperDisplaceConductRange = 8
(If a displacement-conductive block is placed next to a Framed Motion Salt Block, the displacement effect scans up to this many blocks in a direction to find another Framed Motion Salt Block to chain with.)

	#Whether to register the /reactive command on startup. [Default: true]
	registerCommand = true
(If true, when the server launches, you will have access to the /reactive command. Only people with at least level 2 permissions may use the command. It allows operators to generate Warp Bottles to any position, list and reload the world's reactions, and manually edit the Power content of a Crucible. Could be useful when working with custom Powers.)

	#This enables the GUI for Litmus Paper. Disabling it restores the original chat-based reporting. [Default: true]
	litmusScreen = true
(Since 9.14.0, Litmus Paper shows a GUI with its readout instead of just printing the lines into the chat. If you dislike this change, it can be reverted here.)

	#Staff Balance:
(Various settings that determine how powerful the Staves of Power are. Hopefully self explanatory.)
	[config.staff_balance]
		#Range:
		[config.staff_balance.range]
			#The range to which the Blazing Staff of Power's fireballs are accurate. [Default: 24]
			#Range: 4 ~ 1024
			blazeStaffRange = 24
			#The range of the Radiant Staff of Power. [Default: 64]
			#Range: 4 ~ 1024
			lightStaffRange = 64
			#The range of the Arcane Staff of Power. [Default: 6]
			#Range: 4 ~ 1024
			mindStaffRange = 6
			#The range of the Spectral Staff of Power. [Default: 16]
			#Range: 4 ~ 1024
			soulStaffRange = 16
			#The size of the area of effect for the Living Staff of Power. [Default: 5]
			#Range: 4 ~ 1024
			vitalStaffRange = 5
			#The range of the Warping Staff of Power. [Default: 12]
			#Range: 4 ~ 1024
			warpStaffRange = 12

		#Frequency:
		[config.staff_balance.frequency]
			#The Radiant Staff of Power will activate every this many ticks while right click is held. [Default: 7]
			#Range: 2 ~ 60
			lightStaffFrequency = 7
			#The Blazing Staff of Power will activate every this many ticks while right click is held. [Default: 10]
			#Range: 2 ~ 60
			blazeStaffFrequency = 10
			#The Spectral Staff of Power will activate every this many ticks while right click is held. [Default: 14]
			#Range: 2 ~ 60
			soulStaffFrequency = 14
			#The Arcane Staff of Power will activate every this many ticks while right click is held. [Default: 10]
			#Range: 2 ~ 60
			mindStaffFrequency = 10

		#Effect Power:
		[config.staff_balance.power]
			#Blazing Staves of Power shoot fireballs that cause explosions of this size. If 0, uses a blaze-like not explosive fireball instead. [Default: 0]
			#Range: 0 ~ 10
			blazeStaffExplosionSize = 0
			#Undead caught in the Radiant Staff of Power's beam will take this much fire damage each activation. [Default: 7.0]
			#Range: 1.0 ~ 100.0
			lightStaffPowerVsUndead = 7.0
			#Whether the Radiant Staff of Power produces permanent light sources. When false, its lights will gradually vanish. [Default: true]
			lightStaffLightsPermanent = true
			#Each bolt from the Arcane Staff of Power will do this much magic damage. [Default: 2.0]
			#Range: 1.0 ~ 100.0
			mindStaffPower = 2.0
			#The maximum number of bolts that the Arcane Staff of Power can hit a single target with each activation. [Default: 2]
			#Range: 1 ~ 40
			mindStaffMaxHits = 2
			#How many missiles the Arcane Staff of Power shoots each activation. [Default: 4]
			#Range: 1 ~ 20
			mindStaffBaseMissiles = 4
			#How many TOTAL missiles the Arcane Staff of Power shoots each activation while enchanted with Wide Range. Recommended to be higher than the prior key. [Default: 7]
			#Range: 2 ~ 40
			mindStaffEnchantedMissiles = 7
			#Living entities within the Spectral Staff of Power's area of effect will take this much magic damage each activation. [Default: 3.0]
			#Range: 1.0 ~ 100.0
			soulStaffPower = 4.0
			#The Vital Staff of Power gives this level of Health Boost to affected entities. [Default: 3]
			#Range: 1 ~ 5
			vitalStaffHealthBoost = 3
			#The Vital Staff of Power gives this level of Regeneration to affected entities. [Default: 3]
			#Range: 1 ~ 5
			vitalStaffRegeneration = 3
			#Whether the Warping Staff of Power can bind to players. If allowed, this means one can teleport players with no warning from across the map once bound. [Default: false]
			warpStaffAffectsPlayers = false

Server Config

#World Specific Value Options:
[wsv]
	#The seed value used to generate world-specific values. By default, it is set to your world seed on world load. If you change this, some alchemy rules will change!
	#Range: -9223372036854775808 ~ 9223372036854775807
	seed = 42
	#Whether to use the above customized alchemy seed instead of the automatically generated one.
	useCustomSeed = false
(You can set a customized seed for your instance/modpack if you prefer the rules not to change in each new world.)

#Balance Options:
[balance]
	#The scale that the Reduction reaction sets nearby creatures to. [Default: 0.6]
	#Range: 0.05 ~ 0.95
	shrinkSmallSize = 0.6
	#The scale that the Enlargement reaction sets nearby creatures to. [Default: 1.5]
	#Range: 1.05 ~ 10.0
	growLargeSize = 1.5
	#The step height that the Reduction reaction sets nearby creatures to. Normal is 0.6. [Default: 0.45]
	#Range: 0.01 ~ 0.6
	shrinkSmallStep = 0.45
	#The step height that the Enlargement reaction sets nearby creatures to. Normal is 0.6. [Default: 1.0]
	#Range: 0.6 ~ 5.0
	growLargeStep = 1.05
	#The number of ticks between Vortex Stone activations. Values 8 or below allow for infinite upward flight. [Default: 9]
	#Range: 0 ~ 64
	vortexStoneCooldown = 9
(As each entry says, this controls the balancing of a few things in the mod.)

    	#A list of reaction aliases to disable. To see the reaction aliases, use /reactive reaction list [Default: []]
	disabledReactions = []
(Enter a list of reaction aliases (in quotes) here to prevent them from being added to the world when reactions are loaded. This happens each world load, or if you run /reactive reaction reload)

Client Config

#Client Side Options:
[config]
	#Whether to show the sources of each Power in JEI. Disable this for a greater challenge.
	showPowerSources = true
(This shows the players every item that is a power source. Originally, I did not intend this to be the way the mod was played, but I've been convinced that it's better to tell players things like this. If you want a challenge, turn this off!)
	
	#Whether to render all Powers using vanilla Water's icon. Use if a rendering mod makes the custom water textures break or not animate.
	doNotChangeWaterTexture = false
(This is a Sodium compat feature. If you're using Sodium's Animate Only Visible Textures setting, rendering of custom water textures will break, so you can either turn that off or use this setting.)

	#Whether to allow Litmus Paper to use multicolored text. Disable if the colored text is hard to read.
	colorizeLitmusOutput = true
(As of version 8, Litmus Paper will attempt to color the lines of its measurements to match the powers they're discussing. This setting disables that system, in case it causes eyestrain or readability issues.)

	#Whether to show Powers as JEI ingredients.
	listPowersAsIngredients = true
(Powers are JEI ingredients, so they show up in JEI by default. If you'd rather hide them, you can.)

        #Whether gateways should change their renderer to attempt to be compatible with Iris/Oculus if it is detected. Disable if rendering of gateways looks bad or you want them to be invisible with shaders on.
	irisCompat = true

If you're interested in using the experimental Iris shader compatibility feature, I'd recommend checking the guide at Iris Shader Compatibility. Your mileage may vary!

Adding Power Sources

Any item can be added as a power source by adding it to one of these following tags:

reactive:body_sources
reactive:caustic_sources
reactive:curse_sources
reactive:light_sources
reactive:mind_sources
reactive:soul_sources
reactive:verdant_sources
reactive:vital_sources
reactive:warp_sources
reactive:omen_sources (Game version 1.21.1+ only)
reactive:flow_sources (Game version 1.21.1+ only)

Note that blaze sources cannot be added. To specify that an item is "high potency", i.e. that it should return substantially more power than normal, assign it to the tag reactive:high_potency. Please take care not to replace my tag definition unless you want to overwrite my assignments of items to powers.

If you have disabled the feature to allow players to see power sources in JEI, please be careful to choose only logical sources and/or hint at them in your pack documentation.

Adding Recipes

Specifying Powers

Whenever you need to write a Power into one of the following recipes (in the 'reagent' sections), you may use any of the following values:

reactive:body
reactive:blaze
reactive:caustic
reactive:curse
reactive:light
reactive:mind
reactive:soul
reactive:verdant
reactive:vital
reactive:warp
reactive:esoteric_x
reactive:esoteric_y
reactive:esoteric_z
reactive:omen (Game version 1.21.1+ only)
reactive:flow (Game version 1.21.1+ only)
reactive:astral

Specifying Reactants

Reactants are the input ingredients for these recipes. They can be specified as an item or tag, like so:

"reactant": {
    "item": "namespace:input_item"
 }

"reactant": {
    "tag": "namespace:tag"
}

Note that you don't need to use the '#' character when specifying a tag.

Specifying Products

Products are the output items for these recipes. They are specified in standard item stack notation, like so:

Game version 1.21.1+ only

"product": {
    "id": "namespace:output_item"
}

Game version 1.20.1 only

"product": {
    "item": "namespace:output_item"
}

Note that you can add a count or components to this output.

Dissolve Recipes

{
  "type": "reactive:dissolve",
  "reactant": {
    "item": "namespace:input_item"
  },
  "product": {
    "id": "namespace:output_item"
  },
  "needs_electricity": false
}

These recipes do not require that an item is a power source; they simply happen when any quantity of the reactant is added to the Crucible.

"needs_electricity" causes the recipe to require that electrical charge is present in the Crucible for the recipe to work. If it is omitted, false will be assumed by default.

Note that if "needs_electricity" is true and an item is a power source, non-electrified Crucibles will still break down the item! It would simply not return any byproduct.

Transmutation Recipes

{
  "type": "reactive:transmutation",
  "reactant": {
    "item": "namespace:input_item"
  },
  "product": {
    "id": "namespace:output_item"
  },
  "reagents": ["reactive:power1", "reactive:power2", ...],
  "min": 1300,
  "cost": 1000,
  "needs_electricity": false
}

These recipes are like Dissolve recipes, but they have a Power requirement.

"min" refers to the minumum total power balance that must be present for the transmutation to occur.

"cost" refers to the amount of power used (split between the reagents) by each operation.

"needs_electricity", as above, makes the recipe require that the Crucible is electrified.

Precipitation Recipes

Though the mod doesn't describe them in JEI, there are also Precipitation Recipes, which cause items to be generated without a catalyst item. Their format is:

{
  "type": "reactive:precipitation",
  "product": {
    "id": "namespace:output_item"
  },
  "reagents": ["reactive:power1", "reactive:power2", ...],
  "min": 750,
  "cost": 250,
  "reagent_count": 2,
  "needs_electricity": false
}

"min" and "cost" are the same as for transmutation.

"reagent_count" is the number of reagents from the list that are chosen. Which ones are required can therefore be made world-specific. If this value is equal or higher than the number of reagents given, all will be required. Note that adding too many of these recipes would be bad for performance and might make some reactions hard or impossible to cause.

"needs_electricity" is as above.

All recipes support item stack definitions with "count" greater than 1.

Block Tags

The reactive:acid_immune block tag decides which blocks are immune to being dissolved by blocks of acid.

The reactive:can_be_generated block tag decides which blocks are created spontaneously by Unformed Matter. The reaction to create this is hard to start, but can be made maintained with renewable resources.

The reactive:do_not_displace block tag is a deny list for blocks that don't behave when displaced. This includes multi-part blocks like doors and piston heads, since displacement can cut them in half. Blocks above the configured hardness are already immune.

The reactive:do_not_make_fall block tag is a deny list for blocks that do not fall when adjacent to a Motion Salt Block. Blocks above the configured hardness are already immune.

The reactive:displacement_conductive block tag defines which blocks are allowed to act as a bridge between Framed Motion Salt Blocks during displacement. These blocks are immune to displacement as a side effect.

Json Things Integration

This mod has integration with Json Things as of version 9.18, allowing you to add new kinds of Power and new Power Bottles through thingpacks. See Custom Powers with Json Things.

KubeJS Integration

This mod has integration with KubeJS as of version 9, allowing you to add new kinds of Power and new Reactions through KubeJS scripting.

For documentation of these features, please see Custom Content with KubeJS.

I think that's everything! If you have questions or suggestions you can contact me at hyperlynx on Discord, or use the Issues section here.