diff --git a/src/commands/api.ts b/src/commands/api.ts
index 73bf940..5d6d183 100644
--- a/src/commands/api.ts
+++ b/src/commands/api.ts
@@ -150,6 +150,7 @@ export const handleCat: Command = {
     example: '/cat',
     argsRequired: false
   },
+  slashGenerator: true,
   generator: async () => {
     try {
       // Fetch a cat and process it (this sounds funny to me idk why)
diff --git a/src/commands/games.ts b/src/commands/games.ts
index c794a69..83c467a 100644
--- a/src/commands/games.ts
+++ b/src/commands/games.ts
@@ -1,3 +1,4 @@
+import { CommandOptionType } from 'slash-create'
 import { Command } from '../imports/types.js'
 import { evaluate } from 'mathjs'
 
@@ -29,7 +30,17 @@ export const handleChoose: Command = {
     description: 'Choose between multiple options.',
     fullDescription: 'Choose between multiple options.',
     example: '/choose cake|ice cream|pasta',
-    usage: '/choose <option 1>|(option 2)|(option 3)...'
+    usage: '/choose <option 1>|(option 2)|(option 3)...',
+    slashOptions: [{
+      name: 'choices',
+      description: 'The choices to choose from. Each option should be separated like: item1|item2',
+      required: true,
+      type: CommandOptionType.STRING
+    }]
+  },
+  slashGenerator: context => {
+    const choices = context.options.choices.split('|')
+    return `I choose: ${choices[Math.floor(Math.random() * choices.length)]}`
   },
   generator: (message, args) => {
     // Is it used correctly?
@@ -46,8 +57,15 @@ export const handleReverse: Command = {
     description: 'Reverse a sentence.',
     fullDescription: 'Reverse a sentence.',
     example: '/reverse hello',
-    usage: '/reverse <text>'
+    usage: '/reverse <text>',
+    slashOptions: [{
+      name: 'text',
+      description: 'The text to reverse.',
+      required: true,
+      type: CommandOptionType.STRING
+    }]
   },
+  slashGenerator: context => context.options.text.split('').reverse().join(''),
   generator: (message, args) => args.join(' ').split('').reverse().join('')
 }
 
@@ -58,8 +76,15 @@ export const handle8ball: Command = {
     fullDescription: 'Random answers to random questions.',
     usage: '/8ball <question>',
     example: '/8ball Will I flunk my exam?',
-    invalidUsageMessage: 'Please ask the 8ball a question.'
+    invalidUsageMessage: 'Please ask the 8ball a question.',
+    slashOptions: [{
+      name: 'question',
+      description: 'The question you wish to ask the 8ball.',
+      required: true,
+      type: CommandOptionType.STRING
+    }]
   },
+  slashGenerator: true,
   generator: () => {
     // Possible responses, taken from Diary Of A Wimpy Kid: Hard Luck.
     const responses = [
@@ -81,7 +106,23 @@ export const handleZalgo: Command = {
     description: 'The zalgo demon\'s writing.',
     fullDescription: 'The zalgo demon\'s handwriting.',
     usage: '/zalgo <text>',
-    example: '/zalgo sup'
+    example: '/zalgo sup',
+    slashOptions: [{
+      name: 'text',
+      description: 'The text to convert into the zalgo demon\'s handwriting.',
+      required: true,
+      type: CommandOptionType.STRING
+    }]
+  },
+  slashGenerator: context => {
+    let newMessage = ''
+    context.options.text.split('').forEach((element: string) => {
+      newMessage += element
+      for (let i = 0; i < Math.floor(Math.random() * 5) + 1; i++) {
+        newMessage += characters[Math.floor(Math.random() * characters.length)]
+      }
+    })
+    return newMessage.length >= 2000 ? context.options.text : newMessage
   },
   generator: (message, args) => {
     const textToZalgo = args.join(' ').split('')
@@ -103,7 +144,20 @@ export const handleDezalgo: Command = {
     description: 'The zalgo demon\'s writing.',
     fullDescription: 'Read the zalgo demon\'s writing.',
     usage: '/dezalgo <text>',
-    example: '/dezalgo ḥ̛̓e̖l̽͞҉lͦͅoͥ'
+    example: '/dezalgo ḥ̛̓e̖l̽͞҉lͦͅoͥ',
+    slashOptions: [{
+      name: 'text',
+      description: 'The zalgo demon\'s handwriting to be converted to regular text.',
+      required: true,
+      type: CommandOptionType.STRING
+    }]
+  },
+  slashGenerator: context => {
+    let newMessage = ''
+    context.options.text.split('').forEach((element: string) => {
+      if (!characters.includes(element)) newMessage += element
+    })
+    return newMessage
   },
   generator: (message, args) => {
     let newMessage = ''
@@ -121,7 +175,30 @@ export const handleRepeat: Command = {
     description: 'Repeat a string.',
     fullDescription: 'Repeat a string.',
     usage: '/repeat <number of times> <string to repeat>',
-    example: '/repeat 10 a'
+    example: '/repeat 10 a',
+    slashOptions: [{
+      name: 'number',
+      description: 'The number of times to repeat the text.',
+      required: true,
+      type: CommandOptionType.INTEGER
+    }, {
+      name: 'text',
+      description: 'The text to repeat as many times as you want.',
+      required: true,
+      type: CommandOptionType.STRING
+    }]
+  },
+  slashGenerator: context => {
+    const number = context.options.number
+    const text = context.options.text as string
+    if (number * text.length >= 2001) {
+      return { content: 'To prevent spam, your excessive message has not been repeated.', error: true }
+    } else if (text === '_' || text === '*' || text === '~') {
+      return { content: 'This is known to lag users and is disabled.', error: true }
+    }
+    let generatedMessage = ''
+    for (let x = 0; x < number; x++) { generatedMessage += text }
+    return generatedMessage
   },
   generator: (message, args) => {
     // All arguments.
@@ -147,7 +224,29 @@ export const handleRandom: Command = {
     fullDescription: 'Returns a random number, by default between 0 and 10.',
     usage: '/random (starting number) (ending number)',
     example: '/random 1 69',
-    argsRequired: false
+    argsRequired: false,
+    slashOptions: [{
+      name: 'start',
+      description: 'The number which the random number should be higher than or equal to.',
+      required: false,
+      type: CommandOptionType.INTEGER
+    }, {
+      name: 'end',
+      description: 'The number which the random number should be lower than.',
+      required: false,
+      type: CommandOptionType.INTEGER
+    }]
+  },
+  slashGenerator: context => {
+    if (typeof context.options.start === 'number' && typeof context.options.end === 'number') {
+      const number1 = context.options.start
+      const number2 = context.options.end
+      return `The number.. is.. ${Math.floor(Math.random() * (number2 - number1)) + number1}`
+    } else if (typeof context.options.end === 'number') {
+      return `The number.. is.. ${Math.floor(Math.random() * context.options.end)}`
+    } else if (typeof context.options.start === 'number') {
+      return { content: 'You must provide an end number if providing a start number.', error: true }
+    } else return `The number.. is.. ${Math.floor(Math.random() * 10)}`
   },
   generator: (message, args) => {
     // If argument length is 1 and the argument is a number..
@@ -175,7 +274,21 @@ export const handleCalculate: Command = {
 More info here: https://mathjs.org/docs/expressions/syntax.html`,
     usage: '/calculate <expression>',
     example: '/calculate 2 + 2',
-    invalidUsageMessage: 'Specify an expression >_<'
+    invalidUsageMessage: 'Specify an expression >_<',
+    slashOptions: [{
+      name: 'expression',
+      description: 'The math expression to be evaluated.',
+      required: true,
+      type: CommandOptionType.STRING
+    }]
+  },
+  slashGenerator: context => {
+    try {
+      const expr = context.options.expression
+      return `${evaluate(expr.split(',').join('.').split('÷').join('/').toLowerCase())}`
+    } catch (e) {
+      return { content: 'Invalid expression >_<', error: true }
+    }
   },
   generator: (message, args) => {
     try {
@@ -192,8 +305,17 @@ export const handleDistort: Command = {
     description: 'Pretty distorted text.',
     fullDescription: 'Pretty distorted text.',
     usage: '/distort <text>',
-    example: '/distort lol'
+    example: '/distort lol',
+    slashOptions: [{
+      name: 'text',
+      description: 'The text to be distorted.',
+      required: true,
+      type: CommandOptionType.STRING
+    }]
   },
+  slashGenerator: context => context.options.text.split(' ').map((i: string) => (
+    i.split('').join('*') + (i.length % 2 === 0 ? '*' : '')
+  )).join(' '),
   generator: (message, args) => args.map(i => (
     i.split('').join('*') + (i.length % 2 === 0 ? '*' : '')
   )).join(' ')
diff --git a/src/commands/tools.ts b/src/commands/tools.ts
index ad60520..6ffaa2d 100644
--- a/src/commands/tools.ts
+++ b/src/commands/tools.ts
@@ -50,6 +50,7 @@ export const handleUptime: Command = {
     example: '/uptime',
     argsRequired: false
   },
+  slashGenerator: true,
   generator: () => {
     const d = moment.duration(Math.floor(process.uptime() * 1000))
     const days = Math.floor(d.asDays())
diff --git a/src/imports/types.ts b/src/imports/types.ts
index 4e24468..348de59 100644
--- a/src/imports/types.ts
+++ b/src/imports/types.ts
@@ -3,6 +3,7 @@ import { AdvancedMessageContent, Client, Message } from 'eris'
 import CommandParser from '../client.js'
 import { Db } from 'mongodb'
 import { TriviaSession } from '../commands/trivia.js'
+import { ApplicationCommandOption, CommandContext } from 'slash-create'
 
 export interface DB {
   gunfight: {
@@ -33,6 +34,8 @@ export interface Context { tempDB: DB, db: Db, commandParser: CommandParser, cli
 export type CommandResponse = string | AdvancedMessageContent & { error?: boolean }
 export type IveBotCommandGeneratorFunction = (msg: Message, args: string[], ctx: Context) =>
 void | Promise<void> | CommandResponse | Promise<CommandResponse>
+export type IveBotSlashGeneratorFunction = (context: CommandContext, ctx: Context) =>
+void | Promise<void> | CommandResponse | Promise<CommandResponse>
 export type IveBotCommandGenerator = IveBotCommandGeneratorFunction|string|AdvancedMessageContent
 export interface Command {
   opts: CommandOptions
@@ -40,6 +43,7 @@ export interface Command {
   name: string
   generator: IveBotCommandGenerator
   postGenerator?: (message: Message, args: string[], sent?: Message, ctx?: Context) => void
+  slashGenerator?: true | IveBotSlashGeneratorFunction
 }
 export interface CommandOptions {
   argsRequired?: boolean
@@ -58,7 +62,8 @@ export interface CommandOptions {
     userIDs?: string[]
     roleNames?: string[]
     custom?: (message: Message) => boolean
-    permissions?: {}
+    permissions?: { [permission: string]: boolean }
     roleIDs?: string[]
   }
+  slashOptions?: ApplicationCommandOption[]
 }
diff --git a/src/index.ts b/src/index.ts
index 3fcdbba..7d0ed76 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,7 +1,7 @@
 import 'json5/lib/require.js'
 // Tokens and stuff.
-import { AdvancedMessageContent, Client, MessageWebhookContent } from 'eris'
-import { SlashCommand, SlashCreator, GatewayServer } from 'slash-create'
+import { Client, MessageWebhookContent } from 'eris'
+import { SlashCommand, SlashCreator, GatewayServer, CommandContext } from 'slash-create'
 // Get MongoDB.
 import { MongoClient } from 'mongodb'
 // Import fs.
@@ -10,7 +10,7 @@ import { inspect } from 'util'
 import http from 'http'
 import { createCipheriv, createDecipheriv, createHash, randomBytes } from 'crypto'
 // Import types.
-import { DB, Command } from './imports/types.js'
+import { DB, Command, IveBotSlashGeneratorFunction } from './imports/types.js'
 // Import the bot.
 import CommandParser from './client.js'
 import { guildMemberAdd, guildMemberRemove, guildDelete, guildBanAdd } from './events.js'
@@ -52,14 +52,38 @@ creator.withServer(new GatewayServer(
 const commandToSlashCommand = (command: Command): SlashCommand => {
   class IveBotSlashCommand extends SlashCommand {
     constructor (creator: SlashCreator) {
-      super(creator, { name: command.name, description: command.opts.description, options: [] })
+      const reqs = command.opts.requirements
+      const defaultPermission = !(reqs && (reqs.userIDs || reqs.custom))
+      const requiredPermissions = []
+      if (reqs && reqs.permissions) {
+        // TODO: Does not support falsy permissions. Do we convert this to straightforward [] type?
+        for (const permission in reqs.permissions) {
+          if (reqs.permissions[permission]) {
+            const translatedName = permission.toLowerCase().split('_').map((value, index) => (
+              index === 0 ? value : value.substr(0, 1).toUpperCase() + value.substr(1)
+            ))
+            requiredPermissions.push(translatedName.join(''))
+          }
+        }
+      }
+      super(creator, {
+        name: command.name,
+        description: command.opts.description.replace(/</g, '').replace(/>/g, ''),
+        defaultPermission,
+        requiredPermissions,
+        options: command.opts.slashOptions || []
+      })
     }
 
-    async run (): Promise<string | MessageWebhookContent | void> {
-      let response: string | AdvancedMessageContent | void
+    async run (ctx: CommandContext): Promise<string | MessageWebhookContent | void> {
       if (typeof command.generator !== 'function') return command.generator
-      else response = await Promise.resolve(command.generator(undefined, [], { client, db, tempDB, commandParser }))
-      return typeof response === 'object' ? { ...response, embeds: [response.embed] } : response
+      const func: IveBotSlashGeneratorFunction = command.slashGenerator === true
+        ? command.generator as any
+        : command.slashGenerator
+      const response = await Promise.resolve(func(ctx, { client, db, tempDB, commandParser }))
+      return typeof response === 'object' && response.embed
+        ? { ...response, embeds: [response.embed] }
+        : response
     }
   }
   return new IveBotSlashCommand(creator)
@@ -79,7 +103,7 @@ console.log('Bot connected successfully to MongoDB.')
 const db = mongoClient.db('ivebot')
 const bubbleWrap = <F extends (...args: any[]) => any>(func: F) =>
   (...args: Parameters<F>) => { func(...args).catch(console.error) }
-  // When a server loses a member, it will callback.
+// When a server loses a member, it will callback.
 client.on('guildMemberAdd', bubbleWrap(guildMemberAdd(client, db, tempDB)))
 client.on('guildMemberRemove', bubbleWrap(guildMemberRemove(client, db)))
 client.on('guildBanAdd', bubbleWrap(guildBanAdd(client, db)))
@@ -107,13 +131,16 @@ for (const commandFile of commandFiles) {
       if (commandName === 'TriviaSession') return
       const command = commands[commandName]
       commandParser.registerCommand(command)
-      if (typeof command.generator !== 'function') creator.registerCommand(commandToSlashCommand(command))
-      else if (command.name === 'uptime') creator.registerCommand(commandToSlashCommand(command))
-      else if (command.name === 'cat') creator.registerCommand(commandToSlashCommand(command))
+      // TODO: Custom and user ID requirements not handled yet.
+      const reqs = command.opts.requirements
+      const hasCustomReqs = (reqs && (reqs.custom || reqs.userIDs))
+      if (!hasCustomReqs && (typeof command.generator !== 'function' || command.slashGenerator)) {
+        creator.registerCommand(commandToSlashCommand(command))
+      }
     })
   }
 }
-creator.syncCommands({ deleteCommands: true })
+creator.syncCommands()
 
 // Register setInterval to fulfill delayed tasks.
 setInterval(() => {
diff --git a/yarn.lock b/yarn.lock
index f28e234..65ce6c6 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2478,9 +2478,9 @@ path-key@^3.1.0:
   integrity sha512-ojmeN0qd+y0jszEtoY48r0Peq5dwMEkIlCOu6Q5f41lfkswXuKtYrhgoTpLnyIcHm24Uhqx+5Tqm2InSwLhE6Q==
 
 path-parse@^1.0.6:
-  version "1.0.6"
-  resolved "https://registry.yarnpkg.com/path-parse/-/path-parse-1.0.6.tgz#d62dbb5679405d72c4737ec58600e9ddcf06d24c"
-  integrity sha512-GSmOT2EbHrINBf9SR7CDELwlJ8AENk3Qn7OikK4nFYAu3Ote2+JYNVvkpAEQm3/TLNEJFD/xZJjzyxg3KBWOzw==
+  version "1.0.7"
+  resolved "https://registry.yarnpkg.com/path-parse/-/path-parse-1.0.7.tgz#fbc114b60ca42b30d9daf5858e4bd68bbedb6735"
+  integrity sha512-LDJzPVEEEPR+y48z93A0Ed0yXb8pAByGWo/k5YYdYgpY2/2EsOsksJrq7lOHxryrVOn1ejG6oAp8ahvOIQD8sw==
 
 path-type@^3.0.0:
   version "3.0.0"