Loadstring

local Params = {
 RepoURL = "https://raw.githubusercontent.com/luau/SynSaveInstance/main/",
 SSI = "saveinstance",
}
local synsaveinstance = loadstring(game:HttpGet(Params.RepoURL .. Params.SSI .. ".luau", true), Params.SSI)()
local Options = {} -- All Options can be found here https://github.com/luau/UniversalSynSaveInstance/blob/main/saveinstance.lua#L772
synsaveinstance(Options)

Universal Syn Save Instance

Or shortly USSI, a project aimed at resurrecting saveinstance function from Synapse X Source 2019 & Other Executor Source leaks .
Reason: Many Executors fail miserably at providing good user experience when it comes to tinkering with saving instances.

Notes

• Credits are appreciated 💖
• Do NOT claim you wrote this
• Do NOT forget to include the License

💖 Support Us & Our Work:

DISCORD SERVER:

https://discord.com/invite/wx4ThpAsmw / https://discord.gg/wx4ThpAsmw

TO-DOs:

• !!! Custom fallback Decompiler for ModuleScripts using require and then iterating through it, gathering all info about functions using getupvals/getprotos/getconsts, converting all DataTypes using tostring or Descriptors, and then perhaps converting to JSON. (Make use of op-codes from Dex?) !!!

• Check out varios Leaked Executors (Especially their Init / Lua scripts) to expand knowledge on the whole subject of saveinstance

• Look into adding support for Binary Format Output (rbxl/rbxm)

  • Users can already convert to Binary Format by
    1. Open the File
    2. Click on top left "FILE" text and select "Save to File As"
    3. Make Sure rbxl/rbxm format is selected (not XML!)
    4. Click Save
  • .RBXL files are similar to .RBXLX files but are saved in Binary format, which helps reduce the file size.
  • ! Check out Rojo Rbx Dom Binary & Roblox Format Specifications Binary for more documentation about the Binary File Format!
  • ! Also see buffer, bit32 libraries as well as pack/unpack from the string library for more information on how you can implement something like this!
  • ! Rbx-Binary-Format

• Add custom decompiler in case executor doesn't have one but has getscriptbytecode (UMF)

  • https://github.com/TheSeaweedMonster/Lua-Scripts/blob/main/decompile.lua

• Add custom timeout logic for decompiler instead of relying on executor to have one

  • Using threads & coroutines.

• Add continue where needed

• Add Documentation similar to KRNL Docs or Synapse X Docs / Synapse X Docs Old

• Merge SharedStrings and sharedstrings tables

• Add fallback function for appendfile (whether through storing current xml as string or with use of readfile) Removed Appendfile entirely

• Add getproperties as fallback for specialinfo

• Add Redirects to some special (in a bad way 😡) values, more info @ PropertyPatches v1 PropertyPatches v2+PropertyPatches v3, otherwise they will fallback to default when file is opened

  • Not all though, test each & see if it carries over or not (when file is opened)..
  • All current redirects: Here

• Add more Fixes for Errors that can pop up during opening process

• Add Optional tags support

• Add readbinarystring or readbinarystringpropertyvalue/readbspval/getbspval (elysian) as fallback for gethiddenproperty

• Add table.clone instead {} in some cases if possible

• Avoid scanning for default values of properties if those properties won't get serialized anyway (e.g. don't have a Descriptor)

• Add --!native tag just in case

• Find default values of binarystring properties (MaximumADHD might have a clue)

  • LOOK INTO Instance:IsPropertyModified & Instance:ResetPropertyToDefault

• Auto-Detect DataTypes/ValueType Categories of Properties (CFrame, UDim2 so on) Full API Dump Solves this ?

• Bring said DataType serializer into an outside function

• Bypass NotCreatable by hardcoding links/references/indexes to said Classes Should be Solved by IsPropertyModified

  • Example: Terrain class can be indexed by doing workspace.Terrain but is NotCreatable

• Check if table.concat is actually the fastest way as compared to other alternatives (IT'S NOT)

• Do clean-up in inheritor & (API Dumps solve this, illogical) automatically assume the top-most class that owns the property, while also cleaning up said property from classes that inherit from it

  • This will be only be needed if we try to implement our own scanning for hidden properties in which case a lot of duplicates might arise that need to be tracked down to instance they all inherit from & cleaned up respectively

• Fix indexes being mixed up after table.remove shifting

• Hidden properties

  • Scan for them Full API Dump Solves this
  • Scan game & map instances in format {ClassName = {Instance1, Instance2} }, if none found then attempt to create proper Replica for them Full API Dump Solves this
  • This will help with getting many ValueTypes accurately, especially BinaryStrings vs strings
  • Inherit them properly & do the clean-up Full API Dump Solves this
  • Tell whether ValueType is string or BinaryString Full API Dump Solves this

• Support for Model files:

  • rbxmx (xml)
  • rbxm (binary)

• Possibly convert to non-Name tables & use instance references instead (Perhaps make a config Bool Toggle for this, false by default), ex. DecompileIgnore = {game.CoreGui} Add too much complexity for now

  • This will allow for more flexibility of saveinstancing

• Remove Useless tables & functions of specialinfo Repurposed

• Implement Luau Syntax (important for performance!):

  • Compound Operators
  • Avoid using next, ipairs & pairs
  • [BENCHMARK] Interpolated strings instead of concat
  • [BENCHMARK] next, and numerical loops on both lua & luau to decide which and where to use
  • Type-checking (😩🙀)
  • local maxValue = if a > b then a else b expressions
  • print(Bob has {count} apple(s)!) expressions
  • Floor division

• Speed things up as much as possible

  • Requires benchmarks
  • Requires looking at other scripts of ours that are aimed at speed & performance

• Support for NotScriptable Properties

  • Requires gethiddenproperty support

• Support for as many KRNL-like saveinstance Options & UNC:

  • Change mode to invalid mode like "custom" if you only want to save ExtraInstances
  • Decompile (! This takes priority over OPTIONS.noscripts if set !)
  • DecompileIgnore
  • DecompileTimeout (! This takes priority over OPTIONS.timeout if set !)
  • ExtraInstances
  • FilePath
  • IgnoreDefaultProps
  • IsolateStarterPlayer
  • NilInstances
  • Object (for .rbxmx files)
  • RemovePlayerCharacters
  • SavePlayers
  • ShowStatus
    • Add Drawing Library support for ShowStatus
  • [-] IsolatePlayerGui Use IsolateLocalPlayer instead
  • Callback
  • Clipboard/CopyToClipboard
  • Binary (rbxl/rbxm)

• Support for as many Executors as possible (🤢🤮)

• Use getspecialinfo fallback function carefully as it's hardcoded Useless because there's no way to tell if the Property Values of those instances are default or not

  • LOOK INTO Instance:IsPropertyModified & Instance:ResetPropertyToDefault

• Isolators must clear

• Store all functions outside that are used during saveinstancing for sake of performance

• Remove buffersize, savebuffer & so on for sake of performance by concatenating strings to total string then writing it to file (no extra steps like table.concat) table.concat proved faster in the case of huge amount of concatenations

  • Test table.concat vs string ..= with a full buffer (this benchmark differs per usecase)

• Make sure BinaryStrings are compared to Defaults properly (aka in same format)

• Add Option to restart saveinstance from the point that it crashed on

• Check out DataType Exceptions

• Add README Similar to current Synapse

• Ignore all properties of instances that aren't Local or Module Scripts except Name if mode is set to "scripts"

• Maybe modes should do more than just affecting the list of instances to save, like changing IgnoreDefaultProperties to false if mode is "full" for example

• Add Support for SharedStrings

  • Fun fact: SharedStrings can also be used for ValueTypes that aren't SharedString, this behavior is not documented anywhere but makes sense (Could create issues though, due to potential ValueType mix-up). By replacing <BinaryString name="Tags">Base64EncodedValue</BinaryString> with <SharedString name="Tags">UniqueIdentifierForSharedString</SharedString> & putting <SharedString md5="UniqueIdentifierForSharedString">Base64EncodedValue</SharedString> into SharedStrings container you can achieve this amazing behaviour. This should be only enabled using an optional setting
    Only known to work with (probably because both are base64 encoded):
  • BinaryString

• Add Lua & Luau versions instead of merged (WARNING: LUAU WILL ALWAYS BE MORE UPDATED THAN LUA VERSION - IDC & CBA SIMPLY, lua version exists just for sake of old & bad executors, ask devs of your executors to support luau as its latest & greatest)

• Add Support for multiple Instances to be saved as a model

• Do something about devs renaming Services therefore bypassing Ignore lists (CoreGui/CorePackages are not affected)

  • LOOK INTO Instance:IsPropertyModified & Instance:ResetPropertyToDefault

• Fix Player's Characters not being visible (must Refresh MeshId)

  • "https://assetdelivery.roblox.com/v1/asset/?id=" Could cause issues too (needs testing)
  • Perhaps add a possible FIX script to README

• Be able to exclude / blacklist any mentions of certain string in other strings

  • Example: You wish to blacklist your player's name from appearing in any property value
  • Default options like IsolateSomething might also use / influence this

• Force disable ParticleEmitters in case something like IgnorePropertiesOfNotScriptsOnScriptsMode is enabled (they stack in one place and create huge lag)

• Be able to specify which special properties you want saved (to avoid saving all)

Acknowledgments

This document is based largely on the efforts of @Anaminus & @Dekkonot, authors of the Roblox Format Specifications. Additional resources include:

• Syngp Synapse X Source code 2019 for base saveinstance code (extended by @mblouka & @Acrillis)
• Rojo Rbx Dom Xml for being a fallback documentation in case something wasn't clear in the Roblox Format Specifications
• Roblox File Format for a list of redirects of old/deprecated xml properties that still use the old tag values
• Roblox Client Tracker for an extended & close to full JSON Api Dump (with hidden properties & default values)

*** View source code of this file for more credits