Developer Data Storage

Where each kind of data belongs. (Oxide equivalent: “Data Storage” + “Data Files” + “Configuring Plugins”.)

Decision table

Data	Lua API	C# API	File	Notes
User settings	greg.config.*	GregModSettingsService / GregConfigService	config.json / MelonPreferences	Survives updates; shown in Settings Hub
Runtime state	greg.save.*	GregModSave, GregSaveEngine	save.json / sidecars	Write-through; save_now() forces flush
Bulk files	greg.io.*	—	<modId>/data/…	Sandboxed; JSON helpers included
Structured data	greg.json.*	Newtonsoft.Json	—	parse / stringify (Lua)
World/grid state	—	GregSaveEngine (LiteDB), GregModPack	gregSave_<guid>.greg.db, pack DTOs	Gated writes; array bridges for Il2Cpp

Lua APIs (exact)

-- config (config.json) and save (save.json): same shape
greg.config.get(key) / greg.config.get_or(key, default)
greg.config.set(key, value)            -- write-through
greg.config.delete(key)                -- -> bool
greg.config.has(key)                   -- -> bool
greg.config.keys()                     -- -> table
greg.save.save_now()                   -- -> bool (force flush)

-- files, sandboxed to <modId>/data/
greg.io.read_file(path)                -- alias: read_text
greg.io.write_file(path, content)      -- alias: write_text
greg.io.append_file(path, content)
greg.io.delete_file(path)
greg.io.file_exists(path)              -- -> bool
greg.io.list_files(pattern?)           -- -> table
greg.io.read_json(path)                -- -> table or nil
greg.io.write_json(path, table)        -- -> bool
greg.io.data_dir                       -- read-only string

-- json
greg.json.parse(text)                  -- -> table/string/number/boolean or nil
greg.json.stringify(value)             -- -> string ("" on failure)

-- modules
require("name")                        -- <modDir>/<name>.lua, cached
require("@shared/name")                -- shared folder

Sandbox: CoreModules.Preset_SoftSandbox; ResolveSafe rejects traversal (.., /, \); search patterns are sanitized; migrated legacy data/data nesting is handled automatically. Anything outside <modId>/data/ is rejected by design.

C# APIs

• GregConfigService.LoadConfig<T> / SaveConfig<T> — typed JSON, directories auto-created.
• GregPersistenceService.Set<T> / Get<T> / Has / Delete — %AppData%/gregCore/Saves/<key>.json, traversal-guarded names.
• GregModSave.Create / Fill / Read / ReadAll / Upsert / Remove — vanilla-list items keyed by modFolderName (ItemSave DTO with position/rotation/float+int arrays).
• GregModPack builder + reader — ShopItem / StaticItem / DllRef / Snapshot DTOs with Il2Cpp array bridges (To/FromFloat/Int/BoolArray).
• GregSaveEngine (LiteDB) — Initialize / SaveAll (gated) / LoadAll / SaveGridState / LoadGridState / GetCollection<T>; IsGregSave validates the header. Only grid/wall state belongs here.
• GregSaveGuard.RegisterSidecar / RegisterVanillaModuleMap — hook your world edits into backup → write → sanitize → load (see Core Save Engine).

Rules

1. Never write vanilla save structures directly — go through sidecars/DTOs.
2. Never reuse shop/item IDs or GUIDs (ranges: 100, 1000/2000/3000, 9001+ — see Developer Shop Items).
3. Keep settings (user edits) separate from state (game writes).
4. Validate on load: one bad entry must never abort the whole load (per-entry null-guards, like GregNetworkIdHealing).