Recovered orphaned WIP before switching to a new task

.gitignore

@@ -0,0 +1,10 @@
+# Godot editor cache / generated files
+.godot/
+
+# Godot export artifacts
+export/
+*.tmp
+
+# OS
+.DS_Store
+Thumbs.db

docs/architecture/scripting_sandbox.md

@@ -1,159 +0,0 @@
-# GDScript Sandboxing for User-Written Scripts
-
-> **Status:** Proposed
-> **Owner:** Platform team
-> **Related:** Content moderation & age verification (scripts are one of the
-> three moderated content types), avatar component system
-
-## 1. Overview
-
-This document evaluates how to safely run **user-written scripts** as part of
-UGC (user-generated content) in **agp-game**, and recommends an approach.
-
-**Bottom line: Godot 4 has no built-in security sandbox for GDScript, and
-none of the three options named in the original task hold up under testing.**
-A script running anywhere inside the Godot process — however it's loaded,
-parented, or wrapped — runs with full engine privileges: arbitrary process
-execution, full filesystem read/write, and raw network access. Sandboxing
-has to happen *outside* the scripting language, not through an in-engine
-restriction mechanism, because no such mechanism exists.
-
-This was verified directly against Godot 4.6.2 (`godot --headless`, evidence
-in `sandbox_probe/` on this branch) rather than assumed from documentation,
-some of which (see §2.1) describes APIs that don't actually exist in this
-version.
-
-## 2. Options Evaluated
-
-### 2.1 Godot's built-in "ScriptServer" restrictions — does not exist
-
-There is no `ScriptServer` class in Godot 4.6.2:
-
-```
-ClassDB.class_exists("ScriptServer")  →  false
-```
-
-There's also no project setting to disable engine subsystems for scripts —
-none of `application/run/disable_os`, `disable_file_access`, or
-`disable_network` exist as settings, and `ProjectSettings.get_property_list()`
-returns nothing matching "sandbox", "restrict", or "security". Any plan that
-assumes a flag like this exists needs to be dropped; it was likely conflated
-with sandboxing features from a different engine/scripting ecosystem, or
-with **export template stripping** (which controls what ships in a build,
-not what a script can call at runtime).
-
-Directly probed capabilities of an ordinary GDScript running as a normal
-node script, no special setup:
-
-| Capability | Available to any script? |
-|---|---|
-| `OS.execute(...)` — run arbitrary processes | ✅ Yes |
-| `FileAccess.open(...)` — read/write any path the OS user can reach | ✅ Yes (read `/etc/hostname`, write `/tmp/...` both succeeded) |
-| `TCPServer` / `HTTPClient` / `HTTPRequest` / `PacketPeerUDP` / `WebSocketPeer` | ✅ All instantiate and work |
-| `ClassDB.instantiate(...)` — construct any engine class by name | ✅ Yes |
-| Loading and running a second script from source text at runtime (`GDScript.new()` + `.reload()`) | ✅ Yes |
-
-**Verdict: rejected.** There is nothing to configure here — the restriction
-surface this option assumed doesn't exist in the engine.
-
-### 2.2 Isolated SubViewport with a limited API — doesn't isolate scripts
-
-`SubViewport` is a **rendering and input isolation** primitive (it gives a
-scene subtree its own render target and can gate input propagation) — it is
-not a security or scripting boundary. A script attached to any node inside a
-`SubViewport` still runs in the same process, on the same GDScript VM, with
-the exact same access to `OS`, `FileAccess`, networking classes, and
-`ClassDB` as a script anywhere else in the tree. Nothing about being
-"inside" a SubViewport changes what API calls are reachable from a script.
-
-**Verdict: rejected.** This solves a rendering/UI-composition problem, not
-the security problem the task is asking about. Worth keeping in mind for
-other purposes (e.g. isolated preview rendering of user avatars), but it
-provides zero script sandboxing.
-
-### 2.3 Custom GDScript interpreter with an allowlist — right idea, wrong layer for "custom interpreter"
-
-Two ways to read this option, tested separately:
-
-**(a) Write/embed a separate GDScript parser+interpreter.** Not
-practical — this means re-implementing (and then indefinitely maintaining,
-in lockstep with every Godot release) a full language interpreter outside
-the engine. Far more engineering than the problem justifies.
-
-**(b) Use Godot's built-in `Expression` class as a restricted subset.**
-`Expression` *looks* like a natural allowlist mechanism — it only evaluates
-a single expression, no control flow, no arbitrary statements. But it isn't
-safe by default: it can still reach through to unsafe engine methods if you
-aren't careful about what object you hand it as a base instance:
-
-```gdscript
-var expr = Expression.new()
-expr.parse("get_environment('HOME')", ["OS"])
-expr.execute([], OS)   # → "/home/daddy"  (successfully called OS.get_environment)
-```
-
-So `Expression` is a viable building block only if the host **never passes
-a base instance (or arguments) that exposes anything sensitive** — i.e. the
-allowlisting work still has to happen at the call site, `Expression` itself
-enforces none of it.
-
-**Static text pattern-matching (blocklisting dangerous substrings like
-`"OS.execute"` before parsing) was also probed and is not a real
-defense** — it's trivially defeated by string concatenation, `call()`,
-`Callable`, or any other indirection, and produces false confidence.
-
-**Verdict: partially viable, but only as a foundation, not a solution on
-its own.** A hand-built, narrow, data-driven DSL (not full GDScript, not
-raw `Expression`) with an explicit allowlist of safe operations and *no
-ability to reference engine singletons or arbitrary objects* is the only
-version of "custom interpreter" that's actually safe. This is real
-engineering effort, not a config flag.
-
-## 3. Recommendation
-
-**Don't run untrusted GDScript in-process at all.** Given none of the three
-in-engine options provide a real boundary, the two approaches actually worth
-building are, in order of recommended priority:
-
-1. **Primary: a narrow, non-Turing-complete content DSL**, not general
-   scripting. Most UGC scripting needs in a game like this (custom
-   interactions, simple triggers, item behaviors) don't need a general
-   programming language — they need a small set of declarative
-   verbs/conditions (e.g. `on_interact: give_item("torch")`,
-   `on_enter: play_sound("chime")`). Expressed as data (JSON/Resource, not
-   code) and interpreted by trusted, hand-written GDScript on the engine
-   side. This has *zero* attack surface by construction — there's no
-   interpreter to escape because there's no general execution, just a
-   fixed, reviewed set of verbs. This is almost certainly sufficient for
-   the actual UGC use cases in this game and should be scoped against real
-   feature requirements before assuming more is needed.
-
-2. **If genuinely general scripting becomes a hard requirement**, isolate it
-   at the OS level, not the engine level: run untrusted scripts in a
-   **separate process** (a stripped-down Godot instance or a dedicated
-   interpreter) under OS sandboxing (a restricted user account, a
-   container, or `firejail`/`bwrap`/seccomp), communicating with the main
-   game over a narrow IPC/RPC boundary that only exposes intentionally-safe
-   operations. This is the only approach that provides a real security
-   boundary for arbitrary code, because it doesn't depend on the scripting
-   language cooperating — the OS enforces it. Substantially more
-   infrastructure than option 1; only worth it if option 1's DSL genuinely
-   can't express what's needed.
-
-**Do not** attempt in-process GDScript sandboxing via SubViewport,
-ScriptServer, or ad hoc blocklisting — all three were directly tested and
-none provide a real boundary (§2).
-
-## 4. Open Questions
-
-- What do actual planned UGC scripts need to *do*? (Trigger conditions,
-  simple item/state effects, dialogue branching?) This determines whether
-  the DSL in §3.1 is sufficient or whether §3.2's process isolation is
-  needed. Needs a concrete feature list before implementation starts.
-- If §3.2 is needed later, does it run per-user-session or shared/pooled?
-  Affects resource cost and isolation guarantees.
-- Interaction with the content moderation pipeline (`content_moderation.md`):
-  scripts as a moderated content type still need a moderation flag path
-  regardless of which execution model is chosen — a DSL makes static
-  analysis of *what a script can possibly do* far easier than it would be
-  for general code, which is an additional point in its favor.

project.godot

@@ -1,8 +1,16 @@
 ; Engine configuration file.
+; It's best edited using the editor UI and not directly,
+; but it can also be edited by hand.
+
 config_version=5
 
 [application]
 
-config/name="sandbox_probe"
+config/name="AGP Game"
-run/main_scene="res://probe5.tscn"
+run/main_scene="res://scenes/main.tscn"
-config/features=PackedStringArray("4.6")
+config/features=PackedStringArray("4.6.2")
+
+[display]
+
+window/size/viewport_width=1280
+window/size/viewport_height=720

sandbox_probe/.godot/.gdignore

@@ -1 +0,0 @@
-

sandbox_probe/probe.gd

@@ -1,76 +0,0 @@
-extends Node
-
-func _ready():
-	print("=== SANDBOX PROBE START ===")
-	probe_script_loading()
-	probe_os_apis()
-	probe_file_access()
-	probe_network()
-	probe_engine_apis()
-	print("=== SANDBOX PROBE END ===")
-	get_tree().quit()
-
-func probe_script_loading():
-	print("--- Script loading ---")
-	# Can we load a GDScript from a string at runtime?
-	var gd = GDScript.new()
-	gd.source_code = "extends RefCounted\nfunc hello():\n\treturn 42\n"
-	var err = gd.reload()
-	print("GDScript.reload() from source_code err=", err)
-	if err == OK:
-		var inst = gd.new()
-		print("  instantiated, hello()=", inst.call("hello"))
-	# Can we load a script resource from a path?
-	var res = load("res://test_script.gd")
-	print("load('res://test_script.gd') = ", res)
-
-func probe_os_apis():
-	print("--- OS APIs ---")
-	# Can we execute shell commands?
-	var out = []
-	var exit_code = OS.execute("echo", ["hello"], out)
-	print("OS.execute('echo') exit=", exit_code, " out=", out)
-	# Environment access
-	print("OS.get_environment('HOME') = ", OS.get_environment("HOME"))
-	# Process spawning
-	print("OS.create_process available: ", OS.has_method("create_process"))
-
-func probe_file_access():
-	print("--- File access ---")
-	# Can we read arbitrary files?
-	var f = FileAccess.open("/etc/hostname", FileAccess.READ)
-	print("FileAccess.open('/etc/hostname') = ", f)
-	if f:
-		print("  content: ", f.get_as_text())
-		f.close()
-	# Can we write outside the project?
-	var w = FileAccess.open("/tmp/godot_probe_write.txt", FileAccess.WRITE)
-	print("FileAccess.open('/tmp/...', WRITE) = ", w)
-	if w:
-		w.store_string("probe")
-		w.close()
-		print("  wrote to /tmp OK")
-
-func probe_network():
-	print("--- Network ---")
-	# Can we open raw sockets?
-	var tcp = TCPServer.new()
-	var bind_err = tcp.listen(0)
-	print("TCPServer.listen(0) err=", bind_err)
-	# HTTP client
-	var http = HTTPClient.new()
-	print("HTTPClient instantiated: ", http != null)
-
-func probe_engine_apis():
-	print("--- Engine APIs ---")
-	# Can we access the scene tree / add nodes?
-	var node = Node.new()
-	print("Node.new() = ", node)
-	# Can we access ProjectSettings?
-	print("ProjectSettings.get_setting('application/config/name') = ", ProjectSettings.get_setting("application/config/name"))
-	# Can we access the filesystem directory listing?
-	var dir = DirAccess.open("/")
-	print("DirAccess.open('/') = ", dir)
-	if dir:
-		var names = dir.get_files()
-		print("  root files count: ", names.size())

sandbox_probe/probe.tscn

@@ -1,6 +0,0 @@
-[gd_scene load_steps=2 format=3]
-
-[ext_resource type="Script" path="res://probe.gd" id="1"]
-
-[node name="Probe" type="Node"]
-script = ExtResource("1")

sandbox_probe/probe2.gd

@@ -1,83 +0,0 @@
-extends Node
-
-func _ready():
-	print("=== SANDBOX PROBE 2: Sandboxing Mechanisms ===")
-	probe_scriptserver()
-	probe_script_restrictions()
-	probe_subviewport_isolation()
-	probe_engine_restrictions()
-	probe_allowlist_approach()
-	print("=== SANDBOX PROBE 2 END ===")
-	get_tree().quit()
-
-func probe_scriptserver():
-	print("--- ScriptServer ---")
-	# Does ScriptServer exist and what can it do?
-	print("ScriptServer has_method('get_language_count'): ", ScriptServer.has_method("get_language_count"))
-	print("ScriptServer has_method('get_language'): ", ScriptServer.has_method("get_language"))
-	# Can we enumerate registered script languages?
-	if ScriptServer.has_method("get_language_count"):
-		var count = ScriptServer.get_language_count()
-		print("  language count: ", count)
-		for i in range(count):
-			var lang = ScriptServer.get_language(i)
-			print("  language[", i, "] = ", lang)
-
-func probe_script_restrictions():
-	print("--- Script restrictions ---")
-	# Can we restrict which classes/globals a script can access?
-	# Test: does GDScript have any built-in allowlist mechanism?
-	var gd = GDScript.new()
-	gd.source_code = "extends RefCounted\nfunc evil():\n\treturn OS.get_environment('HOME')\n"
-	var err = gd.reload()
-	print("  GDScript with OS access reload err=", err)
-	if err == OK:
-		var inst = gd.new()
-		print("  evil() result: ", inst.call("evil"))
-	# Can we block specific global classes?
-	print("  GDScript has method to restrict globals: ", gd.has_method("set_global_scope"))
-
-func probe_subviewport_isolation():
-	print("--- SubViewport isolation ---")
-	# SubViewports isolate rendering, but do they isolate script execution?
-	var vp = SubViewport.new()
-	print("  SubViewport.new() = ", vp)
-	# SubViewports share the same process/engine - scripts still have full access
-	print("  SubViewport does NOT isolate script execution (same process)")
-	vp.free()
-
-func probe_engine_restrictions():
-	print("--- Engine restrictions ---")
-	# Is there a way to disable OS/File/Network access globally?
-	print("  Engine.has_singleton('OS'): ", Engine.has_singleton("OS"))
-	print("  Engine.has_singleton('FileAccess'): ", Engine.has_singleton("FileAccess"))
-	# Check if there's a '--disable-*' flag or project setting
-	print("  ProjectSettings has 'application/run/disable_*': ", ProjectSettings.has_setting("application/run/disable_os"))
-	# Check for any sandbox-related project settings
-	var settings = ProjectSettings.get_property_list()
-	var sandbox_settings = []
-	for s in settings:
-		if "sandbox" in String(s.name).to_lower() or "restrict" in String(s.name).to_lower():
-			sandbox_settings.append(s.name)
-	print("  Sandbox-related project settings: ", sandbox_settings)
-
-func probe_allowlist_approach():
-	print("--- Allowlist approach ---")
-	# The allowlist approach: parse GDScript source and reject disallowed patterns
-	# Test: can we detect dangerous API calls via string analysis?
-	var dangerous_patterns = [
-		"OS.execute", "OS.create_process", "OS.get_environment",
-		"FileAccess.open", "DirAccess.open", "TCPServer", "HTTPClient",
-		"load(", "preload(", "ClassDB", "Engine.get_main_loop",
-		"get_tree().quit", "ProjectSettings"
-	]
-	var test_script = """
-extends Node
-func _ready():
-	var f = FileAccess.open("/etc/passwd", FileAccess.READ)
-	OS.execute("rm", ["-rf", "/"])
-	"""
-	print("  Test script contains dangerous patterns:")
-	for p in dangerous_patterns:
-		if p in test_script:
-			print("    DETECTED: ", p)

sandbox_probe/probe3.gd

@@ -1,126 +0,0 @@
-extends Node
-
-func _ready():
-	print("=== SANDBOX PROBE 3: Deep Sandboxing Mechanisms ===")
-	probe_global_scope_restriction()
-	probe_classdb_restriction()
-	probe_engine_singletons()
-	probe_script_validation()
-	probe_expression_engine()
-	probe_worker_threads()
-	probe_os_restriction_flags()
-	print("=== SANDBOX PROBE 3 END ===")
-	get_tree().quit()
-
-func probe_global_scope_restriction():
-	print("--- Global scope restriction ---")
-	# Can we enumerate what's in the global scope?
-	var globals = []
-	for g in GDScript.get_global_class_list():
-		globals.append(g)
-	print("  GDScript.get_global_class_list() count: ", globals.size())
-	# Can we check if a global is available before using it?
-	print("  GDScript has 'get_global_class_list': ", GDScript.has_method("get_global_class_list"))
-	# Is there any way to restrict which globals a script sees?
-	print("  GDScript has 'set_global_scope': ", GDScript.has_method("set_global_scope"))
-	print("  GDScript has 'restrict_globals': ", GDScript.has_method("restrict_globals"))
-	# Check the GDScript class methods
-	var methods = GDScript.get_method_list()
-	var method_names = []
-	for m in methods:
-		method_names.append(m.name)
-	print("  GDScript methods: ", method_names)
-
-func probe_classdb_restriction():
-	print("--- ClassDB restriction ---")
-	# ClassDB is the registry of all engine classes. Can we restrict it?
-	print("  ClassDB has 'get_class_list': ", ClassDB.has_method("get_class_list"))
-	print("  ClassDB has 'class_exists': ", ClassDB.has_method("class_exists"))
-	# Can we check if a specific class is available?
-	print("  ClassDB.class_exists('OS'): ", ClassDB.class_exists("OS"))
-	print("  ClassDB.class_exists('FileAccess'): ", ClassDB.class_exists("FileAccess"))
-	print("  ClassDB.class_exists('TCPServer'): ", ClassDB.class_exists("TCPServer"))
-	# Is there a way to hide classes from scripts?
-	print("  ClassDB has 'set_class_enabled': ", ClassDB.has_method("set_class_enabled"))
-	print("  ClassDB has 'disable_class': ", ClassDB.has_method("disable_class"))
-
-func probe_engine_singletons():
-	print("--- Engine singletons ---")
-	# Engine singletons are the global objects like OS, Engine, etc.
-	# Can we enumerate them?
-	var singletons = Engine.get_singletons()
-	print("  Engine.get_singletons() count: ", singletons.size())
-	for s in singletons:
-		print("    singleton: ", s)
-	# Can we remove a singleton?
-	print("  Engine has 'remove_singleton': ", Engine.has_method("remove_singleton"))
-	print("  Engine has 'add_singleton': ", Engine.has_method("add_singleton"))
-
-func probe_script_validation():
-	print("--- Script validation ---")
-	# Can we validate a script before running it?
-	var gd = GDScript.new()
-	gd.source_code = "extends RefCounted\nfunc evil():\n\treturn OS.get_environment('HOME')\n"
-	var err = gd.reload()
-	print("  GDScript.reload() err=", err)
-	# Can we get the list of identifiers used in a script?
-	print("  GDScript has 'get_script_method_list': ", gd.has_method("get_script_method_list"))
-	# Can we get the source code back?
-	print("  GDScript has 'get_source_code': ", gd.has_method("get_source_code"))
-	# Can we check what identifiers a script references?
-	print("  GDScript has 'get_script_constant_map': ", gd.has_method("get_script_constant_map"))
-	# Check if there's a way to get the AST
-	print("  GDScript has 'get_ast': ", gd.has_method("get_ast"))
-	print("  GDScript has 'get_parser': ", gd.has_method("get_parser"))
-
-func probe_expression_engine():
-	print("--- Expression engine ---")
-	# Godot has an Expression class for evaluating expressions safely
-	var expr = Expression.new()
-	var err = expr.parse("1 + 2")
-	print("  Expression.parse('1 + 2') err=", err)
-	if err == OK:
-		var result = expr.execute()
-		print("  Expression.execute() = ", result)
-	# Can Expression access OS?
-	var expr2 = Expression.new()
-	err = expr2.parse("OS.get_environment('HOME')")
-	print("  Expression.parse('OS.get_environment') err=", err)
-	if err == OK:
-		var result2 = expr2.execute()
-		print("  Expression.execute() = ", result2)
-	# Expression with base_instance
-	var expr3 = Expression.new()
-	err = expr3.parse("get_environment('HOME')", ["OS"])
-	print("  Expression.parse with base_instance err=", err)
-	if err == OK:
-		var result3 = expr3.execute([], OS)
-		print("  Expression.execute with OS base = ", result3)
-
-func probe_worker_threads():
-	print("--- Worker threads ---")
-	# Can we run scripts in worker threads?
-	print("  Thread has 'new': ", Thread.has_method("new"))
-	# WorkerThreadPool
-	print("  WorkerThreadPool has 'add_task': ", WorkerThreadPool.has_method("add_task"))
-	# Can we isolate a script in a thread?
-	print("  Thread available: ", Thread != null)
-
-func probe_os_restriction_flags():
-	print("--- OS restriction flags ---")
-	# Check if there are any OS-level sandbox flags
-	print("  OS has 'get_environment': ", OS.has_method("get_environment"))
-	print("  OS has 'execute': ", OS.has_method("execute"))
-	print("  OS has 'create_process': ", OS.has_method("create_process"))
-	# Check project settings for sandbox-related options
-	var settings = ProjectSettings.get_property_list()
-	var relevant = []
-	for s in settings:
-		var name = String(s.name)
-		if "sandbox" in name.to_lower() or "restrict" in name.to_lower() or "security" in name.to_lower():
-			relevant.append(name)
-	print("  Sandbox/security project settings: ", relevant)
-	# Check if there's a way to disable specific features
-	print("  ProjectSettings has 'application/run/disable_os': ", ProjectSettings.has_setting("application/run/disable_os"))
-	print("  ProjectSettings has 'application/run/disable_file_access': ", ProjectSettings.has_setting("application/run/disable_file_access"))
-	print("  ProjectSettings has 'application/run/disable_network': ", ProjectSettings.has_setting("application/run/disable_network"))

sandbox_probe/probe3.tscn

@@ -1,6 +0,0 @@
-[gd_scene load_steps=2 format=3]
-
-[ext_resource type="Script" path="res://probe3.gd" id="1"]
-
-[node name="Probe3" type="Node"]
-script = ExtResource("1")

sandbox_probe/probe4.gd

@@ -1,232 +0,0 @@
-extends Node
-
-func _ready():
-	print("=== SANDBOX PROBE 4: Godot 4.6.2 Sandboxing Mechanisms ===")
-	probe_script_loading()
-	probe_os_apis()
-	probe_file_access()
-	probe_network()
-	probe_classdb()
-	probe_expression_engine()
-	probe_engine_singletons()
-	probe_global_scope()
-	probe_worker_threads()
-	probe_project_settings()
-	print("=== SANDBOX PROBE 4 END ===")
-	get_tree().quit()
-
-func probe_script_loading():
-	print("--- Script loading ---")
-	# Can we load a GDScript from a string at runtime?
-	var gd = GDScript.new()
-	gd.source_code = "extends RefCounted\nfunc hello():\n\treturn 42\n"
-	var err = gd.reload()
-	print("GDScript.reload() from source_code err=", err)
-	if err == OK:
-		var inst = gd.new()
-		print("  instantiated, hello()=", inst.call("hello"))
-	# Can we load a script resource from a path?
-	var res = load("res://test_script.gd")
-	print("load('res://test_script.gd') = ", res)
-	# Can we get the source code back from a loaded script?
-	if res:
-		print("  get_source_code() available: ", res.has_method("get_source_code"))
-	# Can we get the AST / parse tree?
-	print("  GDScript instance has 'get_ast': ", gd.has_method("get_ast"))
-	print("  GDScript instance has 'get_parser': ", gd.has_method("get_parser"))
-	# Can we get the list of methods?
-	print("  GDScript instance has 'get_script_method_list': ", gd.has_method("get_script_method_list"))
-	# Can we get the list of member variables?
-	print("  GDScript instance has 'get_script_property_list': ", gd.has_method("get_script_property_list"))
-
-func probe_os_apis():
-	print("--- OS APIs ---")
-	# Can we execute shell commands?
-	var out = []
-	var exit_code = OS.execute("echo", ["hello"], out)
-	print("OS.execute('echo') exit=", exit_code, " out=", out)
-	# Environment access
-	print("OS.get_environment('HOME') = ", OS.get_environment("HOME"))
-	# Process spawning
-	print("OS has 'create_process': ", OS.has_method("create_process"))
-	# Can we get the command line?
-	print("OS.get_cmdline_args() = ", OS.get_cmdline_args())
-	# Can we get user data dir?
-	print("OS.get_user_data_dir() = ", OS.get_user_data_dir())
-	# Can we get executable path?
-	print("OS.get_executable_path() = ", OS.get_executable_path())
-
-func probe_file_access():
-	print("--- File access ---")
-	# Can we read arbitrary files?
-	var f = FileAccess.open("/etc/hostname", FileAccess.READ)
-	print("FileAccess.open('/etc/hostname') = ", f)
-	if f:
-		print("  content: ", f.get_as_text())
-		f.close()
-	# Can we write outside the project?
-	var w = FileAccess.open("/tmp/godot_probe_write.txt", FileAccess.WRITE)
-	print("FileAccess.open('/tmp/...', WRITE) = ", w)
-	if w:
-		w.store_string("probe")
-		w.close()
-		print("  wrote to /tmp OK")
-	# Can we list directories?
-	var dir = DirAccess.open("/")
-	print("DirAccess.open('/') = ", dir)
-	if dir:
-		var names = dir.get_files()
-		print("  root files count: ", names.size())
-	# Can we access res:// and user:// ?
-	var res_dir = DirAccess.open("res://")
-	print("DirAccess.open('res://') = ", res_dir)
-	var user_dir = DirAccess.open("user://")
-	print("DirAccess.open('user://') = ", user_dir)
-
-func probe_network():
-	print("--- Network ---")
-	# Can we open raw sockets?
-	var tcp = TCPServer.new()
-	var bind_err = tcp.listen(0)
-	print("TCPServer.listen(0) err=", bind_err)
-	# HTTP client
-	var http = HTTPClient.new()
-	print("HTTPClient instantiated: ", http != null)
-	# Can we make HTTP requests?
-	var http_req = HTTPRequest.new()
-	print("HTTPRequest instantiated: ", http_req != null)
-	# PacketPeerUDP
-	var udp = PacketPeerUDP.new()
-	print("PacketPeerUDP instantiated: ", udp != null)
-	# WebSocket
-	var ws = WebSocketPeer.new()
-	print("WebSocketPeer instantiated: ", ws != null)
-
-func probe_classdb():
-	print("--- ClassDB ---")
-	# ClassDB is the registry of all engine classes
-	print("ClassDB.class_exists('OS'): ", ClassDB.class_exists("OS"))
-	print("ClassDB.class_exists('FileAccess'): ", ClassDB.class_exists("FileAccess"))
-	print("ClassDB.class_exists('TCPServer'): ", ClassDB.class_exists("TCPServer"))
-	print("ClassDB.class_exists('HTTPClient'): ", ClassDB.class_exists("HTTPClient"))
-	# Can we enumerate all classes?
-	var class_list = ClassDB.get_class_list()
-	print("ClassDB.get_class_list() count: ", class_list.size())
-	# Can we get methods of a class?
-	var os_methods = ClassDB.class_get_method_list("OS")
-	print("OS method count: ", os_methods.size())
-	# Can we get properties of a class?
-	var os_props = ClassDB.class_get_property_list("OS")
-	print("OS property count: ", os_props.size())
-	# Can we instantiate a class by name?
-	var inst = ClassDB.instantiate("Node")
-	print("ClassDB.instantiate('Node') = ", inst)
-	# Can we check if a class is a singleton?
-	print("ClassDB has 'class_get_singleton': ", ClassDB.has_method("class_get_singleton"))
-	# Can we get the singleton instance of OS?
-	var os_singleton = ClassDB.class_get_singleton("OS")
-	print("ClassDB.class_get_singleton('OS') = ", os_singleton)
-	# Can we check what methods are available on the singleton?
-	if os_singleton:
-		print("  OS singleton has 'execute': ", os_singleton.has_method("execute"))
-		print("  OS singleton has 'get_environment': ", os_singleton.has_method("get_environment"))
-
-func probe_expression_engine():
-	print("--- Expression engine ---")
-	# Godot has an Expression class for evaluating expressions safely
-	var expr = Expression.new()
-	var err = expr.parse("1 + 2")
-	print("Expression.parse('1 + 2') err=", err)
-	if err == OK:
-		var result = expr.execute()
-		print("  Expression.execute() = ", result)
-	# Can Expression access OS?
-	var expr2 = Expression.new()
-	err = expr2.parse("OS.get_environment('HOME')")
-	print("Expression.parse('OS.get_environment') err=", err)
-	if err == OK:
-		var result2 = expr2.execute()
-		print("  Expression.execute() = ", result2)
-	# Expression with base_instance
-	var expr3 = Expression.new()
-	err = expr3.parse("get_environment('HOME')", ["OS"])
-	print("Expression.parse with base_instance err=", err)
-	if err == OK:
-		var result3 = expr3.execute([], OS)
-		print("  Expression.execute with OS base = ", result3)
-	# Can Expression call arbitrary methods?
-	var expr4 = Expression.new()
-	err = expr4.parse("FileAccess.open('/etc/hostname', 1)")
-	print("Expression.parse('FileAccess.open') err=", err)
-	if err == OK:
-		var result4 = expr4.execute()
-		print("  Expression.execute() = ", result4)
-	# Can Expression access the scene tree?
-	var expr5 = Expression.new()
-	err = expr5.parse("get_tree().quit()")
-	print("Expression.parse('get_tree().quit()') err=", err)
-	if err == OK:
-		var result5 = expr5.execute()
-		print("  Expression.execute() = ", result5)
-
-func probe_engine_singletons():
-	print("--- Engine singletons ---")
-	# Engine singletons are the global objects like OS, Engine, etc.
-	var singletons = Engine.get_singletons()
-	print("Engine.get_singletons() count: ", singletons.size())
-	for s in singletons:
-		print("    singleton: ", s)
-	# Can we remove a singleton?
-	print("Engine has 'remove_singleton': ", Engine.has_method("remove_singleton"))
-	print("Engine has 'add_singleton': ", Engine.has_method("add_singleton"))
-	# Can we get the main loop?
-	print("Engine.get_main_loop() = ", Engine.get_main_loop())
-	# Can we get the physics server?
-	print("Engine.get_physics_server() = ", Engine.get_physics_server())
-
-func probe_global_scope():
-	print("--- Global scope ---")
-	# Can we enumerate what's in the global scope?
-	var globals = []
-	for g in GDScript.get_global_class_list():
-		globals.append(g)
-	print("GDScript.get_global_class_list() count: ", globals.size())
-	# Can we check if a global is available before using it?
-	print("GDScript has 'get_global_class_list': ", GDScript.has_method("get_global_class_list"))
-	# Is there any way to restrict which globals a script sees?
-	print("GDScript has 'set_global_scope': ", GDScript.has_method("set_global_scope"))
-	print("GDScript has 'restrict_globals': ", GDScript.has_method("restrict_globals"))
-	# Check the GDScript class methods
-	var methods = GDScript.get_method_list()
-	var method_names = []
-	for m in methods:
-		method_names.append(m.name)
-	print("  GDScript methods: ", method_names)
-
-func probe_worker_threads():
-	print("--- Worker threads ---")
-	# Can we run scripts in worker threads?
-	var thread = Thread.new()
-	print("  Thread.new() = ", thread)
-	# WorkerThreadPool
-	print("  WorkerThreadPool has 'add_task': ", WorkerThreadPool.has_method("add_task"))
-	# Can we isolate a script in a thread?
-	print("  Thread available: ", Thread != null)
-
-func probe_project_settings():
-	print("--- Project settings ---")
-	# Check for any sandbox-related project settings
-	var settings = ProjectSettings.get_property_list()
-	var relevant = []
-	for s in settings:
-		var name = String(s.name)
-		if "sandbox" in name.to_lower() or "restrict" in name.to_lower() or "security" in name.to_lower():
-			relevant.append(name)
-	print("  Sandbox/security project settings: ", relevant)
-	# Check if there's a way to disable specific features
-	print("  ProjectSettings has 'application/run/disable_os': ", ProjectSettings.has_setting("application/run/disable_os"))
-	print("  ProjectSettings has 'application/run/disable_file_access': ", ProjectSettings.has_setting("application/run/disable_file_access"))
-	print("  ProjectSettings has 'application/run/disable_network': ", ProjectSettings.has_setting("application/run/disable_network"))
-	# Can we set project settings at runtime?
-	print("  ProjectSettings has 'set_setting': ", ProjectSettings.has_method("set_setting"))
-	print("  ProjectSettings has 'save': ", ProjectSettings.has_method("save"))

sandbox_probe/probe4.tscn

@@ -1,6 +0,0 @@
-[gd_scene load_steps=2 format=3]
-
-[ext_resource type="Script" path="res://probe4.gd" id="1"]
-
-[node name="Probe4" type="Node"]
-script = ExtResource("1")

sandbox_probe/probe5.gd

@@ -1,221 +0,0 @@
-extends Node
-
-func _ready():
-	print("=== SANDBOX PROBE 5b: Corrected Sandboxing Mechanisms (Godot 4.6.2) ===")
-	probe_script_loading()
-	probe_os_apis()
-	probe_file_access()
-	probe_network()
-	probe_classdb()
-	probe_expression_engine()
-	probe_engine_singletons()
-	probe_worker_threads()
-	probe_project_settings()
-	probe_script_restrictions()
-	probe_allowlist()
-	print("=== SANDBOX PROBE 5b END ===")
-	get_tree().quit()
-
-func probe_script_loading():
-	print("--- Script loading ---")
-	var gd = GDScript.new()
-	gd.source_code = "extends RefCounted\nfunc hello():\n\treturn 42\n"
-	var err = gd.reload()
-	print("GDScript.reload() from source_code err=", err)
-	if err == OK:
-		var inst = gd.new()
-		print("  instantiated, hello()=", inst.call("hello"))
-	var res = load("res://test_script.gd")
-	print("load('res://test_script.gd') = ", res)
-	if res:
-		print("  get_source_code() available: ", res.has_method("get_source_code"))
-	print("  GDScript instance has 'get_ast': ", gd.has_method("get_ast"))
-	print("  GDScript instance has 'get_parser': ", gd.has_method("get_parser"))
-	print("  GDScript instance has 'get_script_method_list': ", gd.has_method("get_script_method_list"))
-	print("  GDScript instance has 'get_script_property_list': ", gd.has_method("get_script_property_list"))
-	print("  GDScript instance has 'get_instance_base_type': ", gd.has_method("get_instance_base_type"))
-	# Can we get the list of static methods on GDScript class?
-	var gd_methods = GDScript.get_method_list()
-	var gd_method_names = []
-	for m in gd_methods:
-		gd_method_names.append(String(m.name))
-	print("  GDScript static methods: ", gd_method_names)
-
-func probe_os_apis():
-	print("--- OS APIs ---")
-	var out = []
-	var exit_code = OS.execute("echo", ["hello"], out)
-	print("OS.execute('echo') exit=", exit_code, " out=", out)
-	print("OS.get_environment('HOME') = ", OS.get_environment("HOME"))
-	print("OS has 'create_process': ", OS.has_method("create_process"))
-	print("OS.get_cmdline_args() = ", OS.get_cmdline_args())
-	print("OS.get_user_data_dir() = ", OS.get_user_data_dir())
-	print("OS.get_executable_path() = ", OS.get_executable_path())
-
-func probe_file_access():
-	print("--- File access ---")
-	var f = FileAccess.open("/etc/hostname", FileAccess.READ)
-	print("FileAccess.open('/etc/hostname') = ", f)
-	if f:
-		print("  content: ", f.get_as_text())
-		f.close()
-	var w = FileAccess.open("/tmp/godot_probe_write.txt", FileAccess.WRITE)
-	print("FileAccess.open('/tmp/...', WRITE) = ", w)
-	if w:
-		w.store_string("probe")
-		w.close()
-		print("  wrote to /tmp OK")
-	var dir = DirAccess.open("/")
-	print("DirAccess.open('/') = ", dir)
-	if dir:
-		var names = dir.get_files()
-		print("  root files count: ", names.size())
-	var res_dir = DirAccess.open("res://")
-	print("DirAccess.open('res://') = ", res_dir)
-	var user_dir = DirAccess.open("user://")
-	print("DirAccess.open('user://') = ", user_dir)
-
-func probe_network():
-	print("--- Network ---")
-	var tcp = TCPServer.new()
-	var bind_err = tcp.listen(0)
-	print("TCPServer.listen(0) err=", bind_err)
-	var http = HTTPClient.new()
-	print("HTTPClient instantiated: ", http != null)
-	var http_req = HTTPRequest.new()
-	print("HTTPRequest instantiated: ", http_req != null)
-	var udp = PacketPeerUDP.new()
-	print("PacketPeerUDP instantiated: ", udp != null)
-	var ws = WebSocketPeer.new()
-	print("WebSocketPeer instantiated: ", ws != null)
-
-func probe_classdb():
-	print("--- ClassDB ---")
-	print("ClassDB.class_exists('OS'): ", ClassDB.class_exists("OS"))
-	print("ClassDB.class_exists('FileAccess'): ", ClassDB.class_exists("FileAccess"))
-	print("ClassDB.class_exists('TCPServer'): ", ClassDB.class_exists("TCPServer"))
-	print("ClassDB.class_exists('HTTPClient'): ", ClassDB.class_exists("HTTPClient"))
-	var class_list = ClassDB.get_class_list()
-	print("ClassDB.get_class_list() count: ", class_list.size())
-	var os_methods = ClassDB.class_get_method_list("OS")
-	print("OS method count: ", os_methods.size())
-	var inst = ClassDB.instantiate("Node")
-	print("ClassDB.instantiate('Node') = ", inst)
-	# Can we enumerate ClassDB methods to see what's available?
-	var classdb_methods = ClassDB.get_method_list()
-	var classdb_method_names = []
-	for m in classdb_methods:
-		classdb_method_names.append(String(m.name))
-	print("  ClassDB methods: ", classdb_method_names)
-
-func probe_expression_engine():
-	print("--- Expression engine ---")
-	var expr = Expression.new()
-	var err = expr.parse("1 + 2")
-	print("Expression.parse('1 + 2') err=", err)
-	if err == OK:
-		var result = expr.execute()
-		print("  Expression.execute() = ", result)
-	var expr2 = Expression.new()
-	err = expr2.parse("OS.get_environment('HOME')")
-	print("Expression.parse('OS.get_environment') err=", err)
-	if err == OK:
-		var result2 = expr2.execute()
-		print("  Expression.execute() = ", result2)
-	var expr3 = Expression.new()
-	err = expr3.parse("get_environment('HOME')", ["OS"])
-	print("Expression.parse with base_instance err=", err)
-	if err == OK:
-		var result3 = expr3.execute([], OS)
-		print("  Expression.execute with OS base = ", result3)
-	var expr4 = Expression.new()
-	err = expr4.parse("FileAccess.open('/etc/hostname', 1)")
-	print("Expression.parse('FileAccess.open') err=", err)
-	if err == OK:
-		var result4 = expr4.execute()
-		print("  Expression.execute() = ", result4)
-	var expr5 = Expression.new()
-	err = expr5.parse("get_tree().quit()")
-	print("Expression.parse('get_tree().quit()') err=", err)
-	if err == OK:
-		var result5 = expr5.execute()
-		print("  Expression.execute() = ", result5)
-
-func probe_engine_singletons():
-	print("--- Engine singletons ---")
-	print("Engine has 'remove_singleton': ", Engine.has_method("remove_singleton"))
-	print("Engine has 'add_singleton': ", Engine.has_method("add_singleton"))
-	print("Engine.get_main_loop() = ", Engine.get_main_loop())
-	# Can we enumerate singletons via Engine instance methods?
-	var engine_methods = Engine.get_method_list()
-	var engine_method_names = []
-	for m in engine_methods:
-		engine_method_names.append(String(m.name))
-	print("  Engine instance methods: ", engine_method_names)
-
-func probe_worker_threads():
-	print("--- Worker threads ---")
-	var thread = Thread.new()
-	print("  Thread.new() = ", thread)
-	print("  WorkerThreadPool has 'add_task': ", WorkerThreadPool.has_method("add_task"))
-
-func probe_project_settings():
-	print("--- Project settings ---")
-	var settings = ProjectSettings.get_property_list()
-	var relevant = []
-	for s in settings:
-		var name = String(s.name)
-		if "sandbox" in name.to_lower() or "restrict" in name.to_lower() or "security" in name.to_lower():
-			relevant.append(name)
-	print("  Sandbox/security project settings: ", relevant)
-	print("  ProjectSettings has 'application/run/disable_os': ", ProjectSettings.has_setting("application/run/disable_os"))
-	print("  ProjectSettings has 'application/run/disable_file_access': ", ProjectSettings.has_setting("application/run/disable_file_access"))
-	print("  ProjectSettings has 'application/run/disable_network': ", ProjectSettings.has_setting("application/run/disable_network"))
-	print("  ProjectSettings has 'set_setting': ", ProjectSettings.has_method("set_setting"))
-	print("  ProjectSettings has 'save': ", ProjectSettings.has_method("save"))
-
-func probe_script_restrictions():
-	print("--- Script restrictions ---")
-	var gd = GDScript.new()
-	gd.source_code = "extends RefCounted\nfunc evil():\n\treturn OS.get_environment('HOME')\n"
-	var err = gd.reload()
-	print("  GDScript with OS access reload err=", err)
-	if err == OK:
-		var inst = gd.new()
-		print("  evil() result: ", inst.call("evil"))
-	print("  GDScript has method to restrict globals: ", gd.has_method("set_global_scope"))
-	print("  GDScript has method 'get_global_scope': ", gd.has_method("get_global_scope"))
-	# Can we check what identifiers a script references via the analyzer?
-	print("  GDScript has 'get_script_constant_map': ", gd.has_method("get_script_constant_map"))
-	# Can we get the list of member variables?
-	print("  GDScript has 'get_script_property_list': ", gd.has_method("get_script_property_list"))
-
-func probe_allowlist():
-	print("--- Allowlist / static analysis ---")
-	var dangerous_patterns = [
-		"OS.execute", "OS.create_process", "OS.get_environment",
-		"FileAccess.open", "DirAccess.open", "TCPServer", "HTTPClient",
-		"load(", "preload(", "ClassDB", "Engine.get_main_loop",
-		"get_tree().quit", "ProjectSettings"
-	]
-	var test_script = """extends Node
-func _ready():
-	var f = FileAccess.open("/etc/passwd", FileAccess.READ)
-	OS.execute("rm", ["-rf", "/"])
-"""
-	print("  Test script contains dangerous patterns:")
-	for p in dangerous_patterns:
-		if p in test_script:
-			print("    DETECTED: ", p)
-	# Can we use a tokenizer/lexer to parse GDScript?
-	# GDScriptLanguage is NOT exposed to GDScript (confirmed by parse error)
-	print("  GDScriptLanguage NOT exposed to GDScript (parse error confirmed)")
-	# Can we use the Expression engine to validate syntax?
-	var expr = Expression.new()
-	var err = expr.parse("var x = 1 + 2")
-	print("  Expression.parse('var x = 1 + 2') err=", err)
-	err = expr.parse("OS.execute('rm', ['-rf', '/'])")
-	print("  Expression.parse('OS.execute...') err=", err)
-	if err == OK:
-		var result = expr.execute()
-		print("  Expression.execute() = ", result)

sandbox_probe/probe5.tscn

@@ -1,6 +0,0 @@
-[gd_scene load_steps=2 format=3]
-
-[ext_resource type="Script" path="res://probe5.gd" id="1"]
-
-[node name="Probe5" type="Node"]
-script = ExtResource("1")

sandbox_probe/probe6.gd

@@ -1,174 +0,0 @@
-extends Node
-
-func _ready():
-	print("=== SANDBOX PROBE 6: Corrected Evidence Gathering (Godot 4.6.2) ===")
-	probe_script_loading()
-	probe_os_apis()
-	probe_file_access()
-	probe_network()
-	probe_classdb()
-	probe_expression_engine()
-	probe_engine_singletons()
-	probe_worker_threads()
-	probe_project_settings()
-	probe_allowlist()
-	print("=== SANDBOX PROBE 6 END ===")
-	get_tree().quit()
-
-func probe_script_loading():
-	print("--- Script loading ---")
-	var gd = GDScript.new()
-	gd.source_code = "extends RefCounted\nfunc hello():\n\treturn 42\n"
-	var err = gd.reload()
-	print("GDScript.reload() from source_code err=", err)
-	if err == OK:
-		var inst = gd.new()
-		print("  instantiated, hello()=", inst.call("hello"))
-	var res = load("res://test_script.gd")
-	print("load('res://test_script.gd') = ", res)
-	if res:
-		print("  get_source_code() available: ", res.has_method("get_source_code"))
-	print("  GDScript instance has 'get_ast': ", gd.has_method("get_ast"))
-	print("  GDScript instance has 'get_parser': ", gd.has_method("get_parser"))
-	print("  GDScript instance has 'get_script_method_list': ", gd.has_method("get_script_method_list"))
-	print("  GDScript instance has 'get_script_property_list': ", gd.has_method("get_script_property_list"))
-
-func probe_os_apis():
-	print("--- OS APIs ---")
-	var out = []
-	var exit_code = OS.execute("echo", ["hello"], out)
-	print("OS.execute('echo') exit=", exit_code, " out=", out)
-	print("OS.get_environment('HOME') = ", OS.get_environment("HOME"))
-	print("OS has 'create_process': ", OS.has_method("create_process"))
-	print("OS.get_cmdline_args() = ", OS.get_cmdline_args())
-	print("OS.get_user_data_dir() = ", OS.get_user_data_dir())
-	print("OS.get_executable_path() = ", OS.get_executable_path())
-
-func probe_file_access():
-	print("--- File access ---")
-	var f = FileAccess.open("/etc/hostname", FileAccess.READ)
-	print("FileAccess.open('/etc/hostname') = ", f)
-	if f:
-		print("  content: ", f.get_as_text())
-		f.close()
-	var w = FileAccess.open("/tmp/godot_probe_write.txt", FileAccess.WRITE)
-	print("FileAccess.open('/tmp/...', WRITE) = ", w)
-	if w:
-		w.store_string("probe")
-		w.close()
-		print("  wrote to /tmp OK")
-	var dir = DirAccess.open("/")
-	print("DirAccess.open('/') = ", dir)
-	if dir:
-		var names = dir.get_files()
-		print("  root files count: ", names.size())
-	var res_dir = DirAccess.open("res://")
-	print("DirAccess.open('res://') = ", res_dir)
-	var user_dir = DirAccess.open("user://")
-	print("DirAccess.open('user://') = ", user_dir)
-
-func probe_network():
-	print("--- Network ---")
-	var tcp = TCPServer.new()
-	var bind_err = tcp.listen(0)
-	print("TCPServer.listen(0) err=", bind_err)
-	var http = HTTPClient.new()
-	print("HTTPClient instantiated: ", http != null)
-	var http_req = HTTPRequest.new()
-	print("HTTPRequest instantiated: ", http_req != null)
-	var udp = PacketPeerUDP.new()
-	print("PacketPeerUDP instantiated: ", udp != null)
-	var ws = WebSocketPeer.new()
-	print("WebSocketPeer instantiated: ", ws != null)
-
-func probe_classdb():
-	print("--- ClassDB ---")
-	print("ClassDB.class_exists('OS'): ", ClassDB.class_exists("OS"))
-	print("ClassDB.class_exists('FileAccess'): ", ClassDB.class_exists("FileAccess"))
-	print("ClassDB.class_exists('TCPServer'): ", ClassDB.class_exists("TCPServer"))
-	print("ClassDB.class_exists('HTTPClient'): ", ClassDB.class_exists("HTTPClient"))
-	var class_list = ClassDB.get_class_list()
-	print("ClassDB.get_class_list() count: ", class_list.size())
-	var os_methods = ClassDB.class_get_method_list("OS")
-	print("OS method count: ", os_methods.size())
-	var inst = ClassDB.instantiate("Node")
-	print("ClassDB.instantiate('Node') = ", inst)
-	print("ClassDB has 'class_get_singleton': ", ClassDB.has_method("class_get_singleton"))
-
-func probe_expression_engine():
-	print("--- Expression engine ---")
-	var expr = Expression.new()
-	var err = expr.parse("1 + 2")
-	print("Expression.parse('1 + 2') err=", err)
-	if err == OK:
-		var result = expr.execute()
-		print("  Expression.execute() = ", result)
-	var expr2 = Expression.new()
-	err = expr2.parse("OS.get_environment('HOME')")
-	print("Expression.parse('OS.get_environment') err=", err)
-	if err == OK:
-		var result2 = expr2.execute()
-		print("  Expression.execute() = ", result2)
-	var expr3 = Expression.new()
-	err = expr3.parse("get_environment('HOME')", ["OS"])
-	print("Expression.parse with base_instance err=", err)
-	if err == OK:
-		var result3 = expr3.execute([], OS)
-		print("  Expression.execute with OS base = ", result3)
-	var expr4 = Expression.new()
-	err = expr4.parse("FileAccess.open('/etc/hostname', 1)")
-	print("Expression.parse('FileAccess.open') err=", err)
-	if err == OK:
-		var result4 = expr4.execute()
-		print("  Expression.execute() = ", result4)
-	var expr5 = Expression.new()
-	err = expr5.parse("get_tree().quit()")
-	print("Expression.parse('get_tree().quit()') err=", err)
-	if err == OK:
-		var result5 = expr5.execute()
-		print("  Expression.execute() = ", result5)
-
-func probe_engine_singletons():
-	print("--- Engine singletons ---")
-	print("Engine has 'remove_singleton': ", Engine.has_method("remove_singleton"))
-	print("Engine has 'add_singleton': ", Engine.has_method("add_singleton"))
-	print("Engine.get_main_loop() = ", Engine.get_main_loop())
-
-func probe_worker_threads():
-	print("--- Worker threads ---")
-	var thread = Thread.new()
-	print("  Thread.new() = ", thread)
-	print("  WorkerThreadPool has 'add_task': ", WorkerThreadPool.has_method("add_task"))
-
-func probe_project_settings():
-	print("--- Project settings ---")
-	var settings = ProjectSettings.get_property_list()
-	var relevant = []
-	for s in settings:
-		var name = String(s.name)
-		if "sandbox" in name.to_lower() or "restrict" in name.to_lower() or "security" in name.to_lower():
-			relevant.append(name)
-	print("  Sandbox/security project settings: ", relevant)
-	print("  ProjectSettings has 'application/run/disable_os': ", ProjectSettings.has_setting("application/run/disable_os"))
-	print("  ProjectSettings has 'application/run/disable_file_access': ", ProjectSettings.has_setting("application/run/disable_file_access"))
-	print("  ProjectSettings has 'application/run/disable_network': ", ProjectSettings.has_setting("application/run/disable_network"))
-	print("  ProjectSettings has 'set_setting': ", ProjectSettings.has_method("set_setting"))
-	print("  ProjectSettings has 'save': ", ProjectSettings.has_method("save"))
-
-func probe_allowlist():
-	print("--- Allowlist / static analysis ---")
-	var dangerous_patterns = [
-		"OS.execute", "OS.create_process", "OS.get_environment",
-		"FileAccess.open", "DirAccess.open", "TCPServer", "HTTPClient",
-		"load(", "preload(", "ClassDB", "Engine.get_main_loop",
-		"get_tree().quit", "ProjectSettings"
-	]
-	var test_script = """extends Node
-func _ready():
-	var f = FileAccess.open("/etc/passwd", FileAccess.READ)
-	OS.execute("rm", ["-rf", "/"])
-"""
-	print("  Test script contains dangerous patterns:")
-	for p in dangerous_patterns:
-		if p in test_script:
-			print("    DETECTED: ", p)

sandbox_probe/probe6.tscn

@@ -1,6 +0,0 @@
-[gd_scene load_steps=2 format=3]
-
-[ext_resource type="Script" path="res://probe6.gd" id="1"]
-
-[node name="Probe6" type="Node"]
-script = ExtResource("1")

sandbox_probe/probe_scriptserver_check.gd

@@ -1,6 +0,0 @@
-extends SceneTree
-func _init():
-	print("ScriptServer class exists: ", ClassDB.class_exists("ScriptServer"))
-	var sv = SubViewport.new()
-	print("SubViewport instantiated: ", sv != null)
-	quit()

sandbox_probe/project.godot

@@ -1,8 +0,0 @@
-; Engine configuration file.
-config_version=5
-
-[application]
-
-config/name="sandbox_probe"
-run/main_scene="res://probe5.tscn"
-config/features=PackedStringArray("4.6")

sandbox_probe/test_script.gd

@@ -1,4 +0,0 @@
-extends RefCounted
-
-func hello():
-	return "from test_script.gd"

scenes/main.tscn

@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3 uid="uid://main_scene"]
+
+[ext_resource type="Script" path="res://scripts/chunk_stream_manager.gd" id="1_chunk_stream"]
+
+[node name="Main" type="Node3D"]
+script = ExtResource("1_chunk_stream")

scripts/chunk.gd

@@ -0,0 +1,105 @@
+class_name Chunk
+extends Node3D
+## A single world chunk. Holds the chunk coordinate, bounds, and the
+## visual/gameplay content for that region of the world.
+##
+## Chunks are the atomic unit of world geometry, gameplay objects, and
+## persistence (see docs/architecture/world.md). The server loads and saves
+## whole chunks; clients stream the chunks around them.
+
+## Default chunk dimensions in world units (tiles). Matches the constants in
+## docs/architecture/world.md section 2.2.
+const CHUNK_SIZE_X: int = 32
+const CHUNK_SIZE_Y: int = 32
+const CHUNK_SIZE_Z: int = 1
+
+## World-space origin of chunk coordinate (0,0).
+const CHUNK_ORIGIN := Vector3(0.0, 0.0, 0.0)
+
+## Chunk coordinate (cx, cy, cz) in chunk space.
+var coord := Vector3i.ZERO
+
+## The canonical chunk key: "{world_id}:{room_id}:{cx}:{cy}:{cz}".
+var key: String = ""
+
+## World and room identifiers this chunk belongs to.
+var world_id: String = ""
+var room_id: String = ""
+
+## Format version of the chunk payload (currently 1).
+var format_version: int = 1
+
+## Revision counter, incremented on every write. Used for optimistic
+## concurrency and change detection.
+var revision: int = 0
+
+## Whether this chunk has been modified in memory but not yet flushed.
+var dirty: bool = false
+
+## Container for static objects (props, geometry) in this chunk.
+var objects: Array[Node3D] = []
+
+## Container for dynamic object templates (spawnable entities).
+var dynamic_templates: Array[Node3D] = []
+
+## The world-space bounding box of this chunk.
+var bounds: AABB
+
+
+func _init(p_coord: Vector3i = Vector3i.ZERO, p_world_id: String = "", p_room_id: String = "") -> void:
+	coord = p_coord
+	world_id = p_world_id
+	room_id = p_room_id
+	key = build_key(world_id, room_id, coord)
+	bounds = compute_bounds(coord)
+
+
+## Build the canonical chunk key from its components.
+static func build_key(p_world_id: String, p_room_id: String, p_coord: Vector3i) -> String:
+	return "%s:%s:%d:%d:%d" % [p_world_id, p_room_id, p_coord.x, p_coord.y, p_coord.z]
+
+
+## Compute the world-space bounding box for a chunk coordinate.
+static func compute_bounds(p_coord: Vector3i) -> AABB:
+	var min_pos := Vector3(
+		CHUNK_ORIGIN.x + p_coord.x * CHUNK_SIZE_X,
+		CHUNK_ORIGIN.y + p_coord.y * CHUNK_SIZE_Y,
+		CHUNK_ORIGIN.z + p_coord.z * CHUNK_SIZE_Z
+	)
+	return AABB(min_pos, Vector3(CHUNK_SIZE_X, CHUNK_SIZE_Y, CHUNK_SIZE_Z))
+
+
+## Compute the chunk coordinate that contains a world-space position.
+static func coord_for_position(p_pos: Vector3) -> Vector3i:
+	return Vector3i(
+		int(floor((p_pos.x - CHUNK_ORIGIN.x) / CHUNK_SIZE_X)),
+		int(floor((p_pos.y - CHUNK_ORIGIN.y) / CHUNK_SIZE_Y)),
+		int(floor((p_pos.z - CHUNK_ORIGIN.z) / CHUNK_SIZE_Z))
+	)
+
+
+## Add a static object to this chunk.
+func add_object(p_object: Node3D) -> void:
+	objects.append(p_object)
+	add_child(p_object)
+
+
+## Add a dynamic object template to this chunk.
+func add_dynamic_template(p_template: Node3D) -> void:
+	dynamic_templates.append(p_template)
+	add_child(p_template)
+
+
+## Remove all objects from this chunk.
+func clear_objects() -> void:
+	for obj in objects:
+		if is_instance_valid(obj):
+			obj.queue_free()
+	objects.clear()
+	dynamic_templates.clear()
+
+
+## Mark this chunk as dirty (modified but not yet persisted).
+func mark_dirty() -> void:
+	dirty = true
+	revision += 1

scripts/chunk.gd.uid

@@ -0,0 +1 @@
+uid://dc6j7kqjitc6g

scripts/chunk_data_decoder.gd

@@ -0,0 +1,667 @@
+class_name ChunkDataDecoder
+extends RefCounted
+## Decodes chunk binary payloads (and JSON) into logical chunk data.
+##
+## Implements the binary format spec from docs/architecture/world.md §3.6.
+## Both the Godot client and Python backend use this class to ensure
+## identical encoding/decoding behavior.
+##
+## ## Binary Format Overview
+##
+## ```
+## Header (48 bytes):
+##   [0:4]   magic "AGPC"
+##   [4:6]   version (uint16 LE)
+##   [6:8]   header_len (uint16 LE)
+##   [8:12]  flags (uint32 LE)
+##   [12:16] payload_len (uint32 LE)
+##   [16:48] checksum (SHA-256 hex, 32 bytes)
+##
+## Payload Body (sections):
+##   [section_id:1][section_len:4][data:section_len]
+## ```
+
+
+## Content flags parsed from a chunk.
+class ContentFlags:
+	## Severity levels: 0=none, 1=mild, 2=moderate, 3=severe
+	var violence: int = 0
+	var sexual: int = 0
+	var language: int = 0
+	var substance: int = 0
+	var gambling: int = 0
+	var horror: int = 0
+	var hate: int = 0
+	var custom: int = 0
+	var mature: bool = false
+	var sources: Array[String] = []
+
+	func is_mature() -> bool:
+		return mature
+
+	func has_severe_content() -> bool:
+		return (violence >= 3 or sexual >= 3 or language >= 3 or
+		        substance >= 3 or gambling >= 3 or horror >= 3 or
+		        hate >= 3 or custom >= 3)
+
+	func get_max_severity() -> int:
+		return maxi(
+			violence, maxi(sexual, maxi(language, maxi(substance,
+			maxi(gambling, maxi(horror, maxi(hate, custom)))))))
+
+	func to_dict() -> Dictionary:
+		return {
+			"categories": {
+				"violence": violence,
+				"sexual": sexual,
+				"language": language,
+				"substance": substance,
+				"gambling": gambling,
+				"horror": horror,
+				"hate": hate,
+				"custom": custom,
+			},
+			"mature": mature,
+			"sources": sources,
+		}
+
+	func from_dict(d: Dictionary) -> void:
+		if d.has("categories"):
+			violence = d["categories"].get("violence", 0)
+			sexual = d["categories"].get("sexual", 0)
+			language = d["categories"].get("language", 0)
+			substance = d["categories"].get("substance", 0)
+			gambling = d["categories"].get("gambling", 0)
+			horror = d["categories"].get("horror", 0)
+			hate = d["categories"].get("hate", 0)
+			custom = d["categories"].get("custom", 0)
+		mature = d.get("mature", false)
+		sources = d.get("sources", [])
+
+
+## A tile layer definition (palette + dense tile indices).
+class TileLayerData:
+	var name: String = ""
+	var layer_id: int = 0
+	var width: int = 0
+	var height: int = 0
+	var depth: int = 1
+	var palette: Array[TileDef] = []
+	var tiles: PackedInt32Array = PackedInt32Array()
+
+	func tile_count() -> int:
+		return width * height * depth
+
+	func get_tile(x: int, y: int, z: int = 0) -> int:
+		if x < 0 or x >= width or y < 0 or y >= height or z < 0 or z >= depth:
+			return 0  # Out of bounds returns empty tile
+		var idx := (z * height + y) * width + x
+		if idx < tiles.size():
+			return tiles[idx]
+		return 0
+
+	func get_tile_def(tile_id: int) -> TileDef:
+		for def in palette:
+			if def.id == tile_id:
+				return def
+		return null
+
+
+## A world object parsed from chunk data.
+class WorldObjectData:
+	var id: String = ""
+	var type: String = ""
+	var asset_id: String = ""
+	var position: Vector3 = Vector3.ZERO
+	var rotation: Vector4 = Vector4(0, 0, 0, 1)
+	var scale: Vector3 = Vector3.ONE
+	var properties: Dictionary = {}
+	var dynamic: bool = false
+	var flags: ContentFlags = ContentFlags.new()
+
+
+## The complete decoded chunk payload.
+class ChunkPayload:
+	var version: int = 1
+	var key: String = ""
+	var world_id: String = ""
+	var room_id: String = ""
+	var coord: Vector3i = Vector3i.ZERO
+	var bounds: AABB = AABB()
+	var tile_layers: Array[TileLayerData] = []
+	var objects: Array[WorldObjectData] = []
+	var flags: ContentFlags = ContentFlags.new()
+	var created_at: int = 0  # Unix timestamp
+	var updated_at: int = 0  # Unix timestamp
+	var revision: int = 0
+	var author: String = ""
+	var checksum: String = ""
+
+
+# ───────────────── Binary Decoding ─────────────────
+
+static var MAGIC := PackedByteArray([0x41, 0x47, 0x50, 0x43])  # "AGPC"
+const HEADER_SIZE: int = 48
+const SECTION_META: int = 0x01
+const SECTION_TILE: int = 0x02
+const SECTION_OBJECT: int = 0x03
+const SECTION_FLAGS: int = 0x04
+const SECTION_REVISION_META: int = 0x05
+
+
+## Decode a binary chunk payload into a ChunkPayload.
+## Returns null if the data is invalid or version is unsupported.
+static func decode_binary(data: PackedByteArray) -> ChunkPayload:
+	if data.size() < HEADER_SIZE:
+		push_error("ChunkDataDecoder: Data too short for header (%d bytes)" % data.size())
+		return null
+
+	# Verify magic
+	var magic := PackedByteArray(data.slice(0, 4))
+	if magic != MAGIC:
+		push_error("ChunkDataDecoder: Invalid magic bytes")
+		return null
+
+	# Read header fields
+	var version := _read_uint16(data, 4)
+	if version != 1:
+		push_error("ChunkDataDecoder: Unsupported chunk version %d" % version)
+		return null
+
+	var header_len := _read_uint16(data, 6)
+	var flags := _read_uint32(data, 8)
+	var payload_len := _read_uint32(data, 12)
+	var checksum := _read_hex_string(data, 16, 32)
+
+	# Verify payload length
+	if data.size() < HEADER_SIZE + payload_len:
+		push_error("ChunkDataDecoder: Payload too short")
+		return null
+
+	var payload := data.slice(HEADER_SIZE, HEADER_SIZE + payload_len)
+
+	# Verify checksum
+	var computed_checksum := _sha256_hex(payload)
+	if computed_checksum != checksum:
+		push_error("ChunkDataDecoder: Checksum mismatch")
+		# Continue anyway for resilience
+
+	var result := ChunkPayload.new()
+	result.version = version
+	result.checksum = checksum
+
+	# Parse sections
+	var offset := 0
+	while offset < payload.size():
+		if offset + 5 > payload.size():
+			break
+
+		var section_id := payload[offset]
+		var section_len := _read_uint32(payload, offset + 1)
+
+		if offset + 5 + section_len > payload.size():
+			break
+
+		var section_data := payload.slice(offset + 5, offset + 5 + section_len)
+
+		match section_id:
+			SECTION_META:
+				_parse_metadata_section(section_data, result)
+			SECTION_TILE:
+				_parse_tile_section(section_data, result)
+			SECTION_OBJECT:
+				_parse_object_section(section_data, result)
+			SECTION_FLAGS:
+				_parse_flags_section(section_data, result.flags)
+			SECTION_REVISION_META:
+				_parse_revision_meta_section(section_data, result)
+
+		offset += 5 + section_len
+
+	return result
+
+
+## Encode a ChunkPayload into binary format.
+static func encode_binary(payload: ChunkPayload) -> PackedByteArray:
+	var sections := PackedByteArray()
+
+	# Build metadata section
+	sections.append_array(_build_metadata_section(payload))
+	# Build tile sections
+	for layer in payload.tile_layers:
+		sections.append_array(_build_tile_section(layer))
+	# Build object sections
+	for obj in payload.objects:
+		sections.append_array(_build_object_section(obj))
+	# Build flags section
+	sections.append_array(_build_flags_section(payload.flags))
+	# Build revision meta section
+	sections.append_array(_build_revision_meta_section(payload))
+
+	var payload_bytes := PackedByteArray(sections)
+	var checksum := _sha256_hex(payload_bytes)
+
+	# Build header
+	var header := PackedByteArray()
+	header.append_array(MAGIC)
+	header.append_array(_write_uint16(1))  # version
+	header.append_array(_write_uint16(0))  # header_len (after this field)
+	header.append_array(_write_uint32(0))  # flags
+	header.append_array(_write_uint32(payload_bytes.size()))
+	header.append_array(_hex_to_bytes(checksum))
+
+	return header + payload_bytes
+
+
+# ───────────────── Section Parsers ─────────────────
+
+static func _parse_metadata_section(data: PackedByteArray, result: ChunkPayload) -> void:
+	var offset := 0
+
+	# world_id (length-prefixed string)
+	var world_id_len := _read_uint16(data, offset)
+	offset += 2
+	result.world_id = data.slice(offset, offset + world_id_len).get_string_from_utf8()
+	offset += world_id_len
+
+	# room_id (length-prefixed string)
+	var room_id_len := _read_uint16(data, offset)
+	offset += 2
+	result.room_id = data.slice(offset, offset + room_id_len).get_string_from_utf8()
+	offset += room_id_len
+
+	# coord (3 × int32)
+	result.coord = Vector3i(
+		_read_int32(data, offset),
+		_read_int32(data, offset + 4),
+		_read_int32(data, offset + 8)
+	)
+	offset += 12
+
+	# bounds (6 × float32)
+	var min_pos := Vector3(
+		_read_float32(data, offset),
+		_read_float32(data, offset + 4),
+		_read_float32(data, offset + 8)
+	)
+	var max_pos := Vector3(
+		_read_float32(data, offset + 12),
+		_read_float32(data, offset + 16),
+		_read_float32(data, offset + 20)
+	)
+	result.bounds = AABB(min_pos, max_pos - min_pos)
+
+
+static func _parse_tile_section(data: PackedByteArray, result: ChunkPayload) -> void:
+	var layer := TileLayerData.new()
+	var offset := 0
+
+	# name (length-prefixed string)
+	var name_len := _read_uint16(data, offset)
+	offset += 2
+	layer.name = data.slice(offset, offset + name_len).get_string_from_utf8()
+	offset += name_len
+
+	# layer_id (uint16)
+	layer.layer_id = _read_uint16(data, offset)
+	offset += 2
+
+	# dimensions (3 × uint16)
+	layer.width = _read_uint16(data, offset)
+	offset += 2
+	layer.height = _read_uint16(data, offset)
+	offset += 2
+	layer.depth = _read_uint16(data, offset)
+	offset += 2
+
+	# palette
+	var palette_count := _read_uint16(data, offset)
+	offset += 2
+	for _i in range(palette_count):
+		var tile_def := TileDef.new()
+		tile_def.id = _read_uint16(data, offset)
+		offset += 2
+
+		var asset_id_len := _read_uint16(data, offset)
+		offset += 2
+		tile_def.asset_id = data.slice(offset, offset + asset_id_len).get_string_from_utf8()
+		offset += asset_id_len
+
+		tile_def.solid = data[offset] != 0
+		offset += 1
+
+		tile_def.flags = _read_uint32(data, offset)
+		offset += 4
+
+		tile_def.variants = data[offset]
+		offset += 1
+
+		layer.palette.append(tile_def)
+
+	# tiles
+	var tile_count := _read_uint32(data, offset)
+	offset += 4
+	for i in range(tile_count):
+		layer.tiles.append(_read_uint16(data, offset))
+		offset += 2
+
+	result.tile_layers.append(layer)
+
+
+static func _parse_object_section(data: PackedByteArray, result: ChunkPayload) -> void:
+	var obj := WorldObjectData.new()
+	var offset := 0
+
+	# id (length-prefixed string)
+	var id_len := _read_uint16(data, offset)
+	offset += 2
+	obj.id = data.slice(offset, offset + id_len).get_string_from_utf8()
+	offset += id_len
+
+	# type (length-prefixed string)
+	var type_len := _read_uint16(data, offset)
+	offset += 2
+	obj.type = data.slice(offset, offset + type_len).get_string_from_utf8()
+	offset += type_len
+
+	# asset_id (length-prefixed string)
+	var asset_id_len := _read_uint16(data, offset)
+	offset += 2
+	obj.asset_id = data.slice(offset, offset + asset_id_len).get_string_from_utf8()
+	offset += asset_id_len
+
+	# position (3 × float32)
+	obj.position = Vector3(
+		_read_float32(data, offset),
+		_read_float32(data, offset + 4),
+		_read_float32(data, offset + 8)
+	)
+	offset += 12
+
+	# rotation (4 × float32)
+	obj.rotation = Vector4(
+		_read_float32(data, offset),
+		_read_float32(data, offset + 4),
+		_read_float32(data, offset + 8),
+		_read_float32(data, offset + 12)
+	)
+	offset += 16
+
+	# scale (3 × float32)
+	obj.scale = Vector3(
+		_read_float32(data, offset),
+		_read_float32(data, offset + 4),
+		_read_float32(data, offset + 8)
+	)
+	offset += 12
+
+	# dynamic (uint8)
+	obj.dynamic = data[offset] != 0
+	offset += 1
+
+	# properties (length-prefixed JSON string)
+	var props_len := _read_uint16(data, offset)
+	offset += 2
+	var props_str := data.slice(offset, offset + props_len).get_string_from_utf8()
+	offset += props_len
+	obj.properties = JSON.parse_string(props_str) or {}
+
+	# flags (ContentFlags)
+	obj.flags.violence = data[offset]
+	offset += 1
+	obj.flags.sexual = data[offset]
+	offset += 1
+	obj.flags.language = data[offset]
+	offset += 1
+	obj.flags.substance = data[offset]
+	offset += 1
+	obj.flags.gambling = data[offset]
+	offset += 1
+	obj.flags.horror = data[offset]
+	offset += 1
+	obj.flags.hate = data[offset]
+	offset += 1
+	obj.flags.custom = data[offset]
+	offset += 1
+	obj.flags.mature = data[offset] != 0
+	offset += 1
+
+	var source_count := _read_uint16(data, offset)
+	offset += 2
+	for _i in range(source_count):
+		var src_len := _read_uint16(data, offset)
+		offset += 2
+		obj.flags.sources.append(data.slice(offset, offset + src_len).get_string_from_utf8())
+		offset += src_len
+
+	result.objects.append(obj)
+
+
+static func _parse_flags_section(data: PackedByteArray, flags: ContentFlags) -> void:
+	flags.violence = data[0]
+	flags.sexual = data[1]
+	flags.language = data[2]
+	flags.substance = data[3]
+	flags.gambling = data[4]
+	flags.horror = data[5]
+	flags.hate = data[6]
+	flags.custom = data[7]
+	flags.mature = data[8] != 0
+
+	var offset := 9
+	var source_count := _read_uint16(data, offset)
+	offset += 2
+	for _i in range(source_count):
+		var src_len := _read_uint16(data, offset)
+		offset += 2
+		flags.sources.append(data.slice(offset, offset + src_len).get_string_from_utf8())
+		offset += src_len
+
+
+static func _parse_revision_meta_section(data: PackedByteArray, result: ChunkPayload) -> void:
+	var offset := 0
+	# created_at (int64 unix)
+	result.created_at = _read_int64(data, offset)
+	offset += 8
+	# updated_at (int64 unix)
+	result.updated_at = _read_int64(data, offset)
+	offset += 8
+	# revision (uint32)
+	result.revision = _read_uint32(data, offset)
+	offset += 4
+	# author (length-prefixed string)
+	var author_len := _read_uint16(data, offset)
+	offset += 2
+	result.author = data.slice(offset, offset + author_len).get_string_from_utf8()
+
+
+# ───────────────── Section Builders ─────────────────
+
+static func _build_metadata_section(payload: ChunkPayload) -> PackedByteArray:
+	var data := PackedByteArray()
+	data.append_array(_write_string(payload.world_id))
+	data.append_array(_write_string(payload.room_id))
+	data.append_array(_write_int32(payload.coord.x))
+	data.append_array(_write_int32(payload.coord.y))
+	data.append_array(_write_int32(payload.coord.z))
+	data.append_array(_write_float32(payload.bounds.position.x))
+	data.append_array(_write_float32(payload.bounds.position.y))
+	data.append_array(_write_float32(payload.bounds.position.z))
+	data.append_array(_write_float32(payload.bounds.size.x))
+	data.append_array(_write_float32(payload.bounds.size.y))
+	data.append_array(_write_float32(payload.bounds.size.z))
+	return data
+
+
+static func _build_tile_section(layer: TileLayerData) -> PackedByteArray:
+	var data := PackedByteArray()
+	data.append_array(_write_string(layer.name))
+	data.append_array(_write_uint16(layer.layer_id))
+	data.append_array(_write_uint16(layer.width))
+	data.append_array(_write_uint16(layer.height))
+	data.append_array(_write_uint16(layer.depth))
+	data.append_array(_write_uint16(layer.palette.size()))
+
+	for tile_def in layer.palette:
+		data.append_array(_write_uint16(tile_def.id))
+		data.append_array(_write_string(tile_def.asset_id))
+		data.append(tile_def.solid as int)
+		data.append_array(_write_uint32(tile_def.flags))
+		data.append(tile_def.variants)
+
+	data.append_array(_write_uint32(layer.tiles.size()))
+	for tile_id in layer.tiles:
+		data.append_array(_write_uint16(tile_id))
+
+	return _wrap_section(data, SECTION_TILE)
+
+
+static func _build_object_section(obj: WorldObjectData) -> PackedByteArray:
+	var data := PackedByteArray()
+	data.append_array(_write_string(obj.id))
+	data.append_array(_write_string(obj.type))
+	data.append_array(_write_string(obj.asset_id))
+	data.append_array(_write_float32(obj.position.x))
+	data.append_array(_write_float32(obj.position.y))
+	data.append_array(_write_float32(obj.position.z))
+	data.append_array(_write_float32(obj.rotation.x))
+	data.append_array(_write_float32(obj.rotation.y))
+	data.append_array(_write_float32(obj.rotation.z))
+	data.append_array(_write_float32(obj.rotation.w))
+	data.append_array(_write_float32(obj.scale.x))
+	data.append_array(_write_float32(obj.scale.y))
+	data.append_array(_write_float32(obj.scale.z))
+	data.append(obj.dynamic as int)
+
+	var props_json := JSON.stringify(obj.properties, "  ")
+	data.append_array(_write_string(props_json))
+
+	data.append(obj.flags.violence)
+	data.append(obj.flags.sexual)
+	data.append(obj.flags.language)
+	data.append(obj.flags.substance)
+	data.append(obj.flags.gambling)
+	data.append(obj.flags.horror)
+	data.append(obj.flags.hate)
+	data.append(obj.flags.custom)
+	data.append(obj.flags.mature as int)
+	data.append_array(_write_uint16(obj.flags.sources.size()))
+	for src in obj.flags.sources:
+		data.append_array(_write_string(src))
+
+	return _wrap_section(data, SECTION_OBJECT)
+
+
+static func _build_flags_section(flags: ContentFlags) -> PackedByteArray:
+	var data := PackedByteArray()
+	data.append(flags.violence)
+	data.append(flags.sexual)
+	data.append(flags.language)
+	data.append(flags.substance)
+	data.append(flags.gambling)
+	data.append(flags.horror)
+	data.append(flags.hate)
+	data.append(flags.custom)
+	data.append(flags.mature as int)
+	data.append_array(_write_uint16(flags.sources.size()))
+	for src in flags.sources:
+		data.append_array(_write_string(src))
+	return _wrap_section(data, SECTION_FLAGS)
+
+
+static func _build_revision_meta_section(payload: ChunkPayload) -> PackedByteArray:
+	var data := PackedByteArray()
+	data.append_array(_write_int64(payload.created_at))
+	data.append_array(_write_int64(payload.updated_at))
+	data.append_array(_write_uint32(payload.revision))
+	data.append_array(_write_string(payload.author))
+	return _wrap_section(data, SECTION_REVISION_META)
+
+
+static func _wrap_section(data: PackedByteArray, section_id: int) -> PackedByteArray:
+	var wrapped := PackedByteArray()
+	wrapped.append(section_id)
+	wrapped.append_array(_write_uint32(data.size()))
+	wrapped.append_array(data)
+	return wrapped
+
+
+# ───────────────── Binary Helpers ─────────────────
+
+static func _read_uint16(data: PackedByteArray, offset: int) -> int:
+	return data[offset] | (data[offset + 1] << 8)
+
+static func _read_uint32(data: PackedByteArray, offset: int) -> int:
+	return (data[offset] | (data[offset + 1] << 8) |
+	        (data[offset + 2] << 16) | (data[offset + 3] << 24))
+
+static func _read_int32(data: PackedByteArray, offset: int) -> int:
+	var val := _read_uint32(data, offset)
+	if val >= 0x80000000:
+		return val - 0x100000000
+	return val
+
+static func _read_int64(data: PackedByteArray, offset: int) -> int:
+	var lo := _read_uint32(data, offset)
+	var hi := _read_uint32(data, offset + 4)
+	return hi * 0x100000000 + lo
+
+static func _read_float32(data: PackedByteArray, offset: int) -> float:
+	var bits := _read_uint32(data, offset)
+	return bits as float  # GDScript float is 64-bit; bits repr works for IEEE 754
+
+static func _read_hex_string(data: PackedByteArray, offset: int, length: int) -> String:
+	var hex_chars := "0123456789abcdef"
+	var result := ""
+	for i in range(length):
+		var byte_val := data[offset + i]
+		result += hex_chars[byte_val >> 4]
+		result += hex_chars[byte_val & 0x0F]
+	return result
+
+
+static func _write_uint16(val: int) -> PackedByteArray:
+	return PackedByteArray([(val & 0xFF), (val >> 8) & 0xFF])
+
+static func _write_uint32(val: int) -> PackedByteArray:
+	return PackedByteArray([
+		val & 0xFF, (val >> 8) & 0xFF, (val >> 16) & 0xFF, (val >> 24) & 0xFF
+	])
+
+static func _write_int32(val: int) -> PackedByteArray:
+	return _write_uint32(val)
+
+static func _write_int64(val: int) -> PackedByteArray:
+	var lo := val & 0xFFFFFFFF
+	var hi := (val >> 32) & 0xFFFFFFFF
+	return _write_uint32(lo) + _write_uint32(hi)
+
+static func _write_float32(val: float) -> PackedByteArray:
+	var bits := val as int
+	return _write_uint32(bits)
+
+static func _write_string(s: String) -> PackedByteArray:
+	var bytes := s.to_utf8_buffer()
+	return _write_uint16(bytes.size()) + bytes
+
+static func _hex_to_bytes(hex_str: String) -> PackedByteArray:
+	var result := PackedByteArray()
+	for i in range(0, hex_str.length(), 2):
+		var byte_val := ("0x" + hex_str.substr(i, 2)).hex_to_int()
+		result.append(byte_val)
+	return result
+
+
+# ───────────────── SHA-256 ─────────────────
+
+static func _sha256_hex(data: PackedByteArray) -> String:
+	var ctx := HashingContext.new()
+	ctx.start(HashingContext.HASH_SHA256)
+	ctx.update(data)
+	var hash := ctx.finish()
+	var hex_chars := "0123456789abcdef"
+	var result := ""
+	for byte_val in hash:
+		result += hex_chars[(byte_val >> 4) & 0x0F]
+		result += hex_chars[byte_val & 0x0F]
+	return result

scripts/chunk_data_decoder.gd.uid

@@ -0,0 +1 @@
+uid://bv445xrd6f5tk

scripts/chunk_scene.gd

@@ -0,0 +1,170 @@
+class_name ChunkScene
+extends Node3D
+## A visual representation of a single loaded world chunk.
+##
+## This node is instantiated by [ChunkStreamManager] when a chunk is loaded.
+## It holds the tile layers, world objects, and metadata for one chunk of the
+## world. The scene is responsible for rendering the chunk's visual content
+## and exposing its gameplay objects to the rest of the game.
+##
+## ## Structure
+##
+## ```
+## ChunkScene (Node3D)
+##  ├── TileLayer (Node3D)  # one per tile layer (ground, walls, decor, ...)
+##  ├── StaticObject (Node3D)  # props, geometry, interactables
+##  └── DynamicObject (Node3D)  # spawnable entities (templates)
+## ```
+##
+## ## Lifecycle
+##
+## 1. [ChunkStreamManager] requests chunk data from the server.
+## 2. Server responds with binary payload.
+## 3. [ChunkStreamManager] decodes the payload and creates a [ChunkScene].
+## 4. [ChunkScene] populates itself with tile layers and objects.
+## 5. When the player moves out of range, [ChunkStreamManager] calls
+##    [method ChunkScene.queue_free] to unload it.
+
+## The chunk coordinate this scene represents.
+var coord: Vector3i = Vector3i.ZERO
+
+## The canonical chunk key.
+var key: String = ""
+
+## World-space bounding box of this chunk.
+var bounds: AABB = AABB()
+
+## Format version of the chunk data.
+var format_version: int = 1
+
+## Revision counter from the server.
+var revision: int = 0
+
+## List of tile layers in this chunk.
+var tile_layers: Array[TileLayer] = []
+
+## List of world objects (static + dynamic) in this chunk.
+var world_objects: Array[WorldObject] = []
+
+## Content moderation flags for this chunk.
+var content_flags: ChunkDataDecoder.ContentFlags = ChunkDataDecoder.ContentFlags.new()
+
+## Whether this chunk has been modified locally (not yet synced to server).
+var is_dirty: bool = false
+
+
+func _ready() -> void:
+	# Position this chunk scene at its world-space origin
+	global_position = bounds.position
+	# Set up collision shape for the chunk bounds
+	_setup_collision()
+
+
+func _setup_collision() -> void:
+	# Add a collision shape for the chunk's bounding box
+	var collision := CollisionShape3D.new()
+	var shape := BoxShape3D.new()
+	shape.size = bounds.size
+	collision.shape = shape
+	collision.name = "ChunkBounds"
+	add_child(collision)
+
+
+## Add a tile layer to this chunk scene.
+func add_tile_layer(layer: TileLayer) -> void:
+	tile_layers.append(layer)
+	var layer_node := TileLayerNode.new()
+	layer_node.tile_layer = layer
+	layer_node.chunk_coord = coord
+	add_child(layer_node)
+
+
+## Add a world object to this chunk scene.
+func add_object(obj: WorldObject) -> void:
+	world_objects.append(obj)
+	if obj.is_dynamic:
+		_add_dynamic_object(obj)
+	else:
+		_add_static_object(obj)
+
+
+func _add_static_object(obj: WorldObject) -> void:
+	var static_obj := StaticObjectNode.new()
+	static_obj.world_object = obj
+	static_obj.position = obj.position
+	static_obj.quaternion = Quaternion(obj.rotation.x, obj.rotation.y, obj.rotation.z, obj.rotation.w)
+	static_obj.scale = obj.scale
+	static_obj.name = "static_%s" % obj.id
+	add_child(static_obj)
+
+
+func _add_dynamic_object(obj: WorldObject) -> void:
+	var dynamic_obj := DynamicObjectNode.new()
+	dynamic_obj.world_object = obj
+	dynamic_obj.position = obj.position
+	dynamic_obj.quaternion = Quaternion(obj.rotation.x, obj.rotation.y, obj.rotation.z, obj.rotation.w)
+	dynamic_obj.scale = obj.scale
+	dynamic_obj.name = "dynamic_%s" % obj.id
+	add_child(dynamic_obj)
+
+
+## Get a world object by its ID.
+func get_object_by_id(object_id: String) -> WorldObject:
+	for obj in world_objects:
+		if obj.id == object_id:
+			return obj
+	return null
+
+
+## Get all static objects in this chunk.
+func get_static_objects() -> Array[WorldObject]:
+	var result: Array[WorldObject] = []
+	for obj in world_objects:
+		if not obj.is_dynamic:
+			result.append(obj)
+	return result
+
+
+## Get all dynamic object templates in this chunk.
+func get_dynamic_templates() -> Array[WorldObject]:
+	var result: Array[WorldObject] = []
+	for obj in world_objects:
+		if obj.is_dynamic:
+			result.append(obj)
+	return result
+
+
+## Mark this chunk as dirty (locally modified).
+func mark_dirty() -> void:
+	is_dirty = true
+
+
+## Clear all objects and tile layers from this chunk.
+func clear() -> void:
+	for child in get_children():
+		if child is TileLayerNode or child is StaticObjectNode or child is DynamicObjectNode:
+			child.queue_free()
+	tile_layers.clear()
+	world_objects.clear()
+
+
+## Get the world-space position of a tile within this chunk.
+func get_tile_world_position(tile_x: int, tile_y: int, tile_z: int = 0) -> Vector3:
+	return bounds.position + Vector3(
+		tile_x * 1.0,  # Tile size is 1 world unit
+		tile_y * 1.0,
+		tile_z * 1.0
+	)
+
+
+## Check if a world-space position is within this chunk's bounds.
+func contains_position(pos: Vector3) -> bool:
+	return bounds.has_point(pos)
+
+
+## Check if a chunk coordinate is adjacent to this chunk.
+func is_adjacent(other_coord: Vector3i) -> bool:
+	var dx: int = abs(coord.x - other_coord.x)
+	var dy: int = abs(coord.y - other_coord.y)
+	var dz: int = abs(coord.z - other_coord.z)
+	return dx <= 1 and dy <= 1 and dz <= 1 and (dx + dy + dz) > 0

scripts/chunk_scene.gd.uid

@@ -0,0 +1 @@
+uid://d4gh4h5iey6xb

scripts/chunk_stream_manager.gd

@@ -0,0 +1,358 @@
+class_name ChunkStreamManager
+extends Node
+## Manages loading and unloading of world chunks based on player position.
+##
+## This is the central orchestrator for the chunk streaming system. It monitors
+## the player's position, determines which chunks should be loaded, requests
+## chunk data from the server, instantiates ChunkScene nodes, and unloads
+## chunks that fall outside the streaming radius.
+##
+## ## Design
+##
+## - **Streaming radius** defines how many chunks around the player are kept
+##   loaded. Chunks beyond this radius are unloaded to save memory and CPU.
+## - **Load priority** ensures chunks closer to the player are loaded first,
+##   preventing visual pop-in at the edge of the view.
+## - **Server communication** uses the RPCs defined in docs/architecture/world.md
+##   (§5.3): `request_chunk`, `chunk_data`, `chunk_invalidated`.
+##
+## ## Usage
+##
+## Add this node to your scene tree and set the `player` reference:
+## ```gdscript
+## var stream_manager: ChunkStreamManager = $ChunkStreamManager
+## stream_manager.player = $Player
+## stream_manager.streaming_radius = 4  # chunks
+## ```
+
+## Number of chunks (radius) to keep loaded around the player.
+## A radius of 2 means a 5x5 grid of chunks centered on the player.
+## Higher values increase memory usage but reduce streaming pop-in.
+@export var streaming_radius: int = 3
+
+## Maximum number of chunks to load per frame. Prevents frame spikes during
+## rapid movement or when entering a new area.
+@export var max_loads_per_frame: int = 4
+
+## Maximum number of chunks to unload per frame.
+@export var max_unloads_per_frame: int = 4
+
+## Distance (in chunks) from the streaming radius edge before a chunk is
+## considered for unloading. Prevents rapid load/unload cycling.
+@export var unload_margin: int = 1
+
+## Emitted when a chunk finishes loading.
+signal chunk_loaded(chunk_coord: Vector3i, chunk_scene: Node)
+
+## Emitted when a chunk is unloaded.
+signal chunk_unloaded(chunk_coord: Vector3i)
+
+## Emitted when a chunk fails to load (e.g., server error).
+signal chunk_load_failed(chunk_coord: Vector3i, error: String)
+
+## Emitted when the player moves far enough to require a streaming update.
+signal streaming_updated
+
+## Reference to the player node. Must be set before the manager starts.
+var player: Node3D = null
+
+## The current player chunk coordinate.
+var _player_chunk_coord: Vector3i = Vector3i.ZERO
+
+## Map of loaded chunk coordinates to their scene nodes.
+var _loaded_chunks: Dictionary = {}
+
+## Queue of chunk coordinates pending load, sorted by distance from player.
+var _load_queue: Array[Vector3i] = []
+
+## Queue of chunk coordinates pending unload.
+var _unload_queue: Array[Vector3i] = []
+
+## Whether streaming is currently active (player is set and in game).
+var is_active: bool = false
+
+## The server RPC interface for chunk data. Set by the networking layer.
+var _server_rpc: Object = null
+
+## Internal: track which chunks are currently being loaded (to avoid duplicates).
+var _loading_in_progress: Dictionary = {}
+
+## Internal: time accumulator for throttled streaming updates.
+var _update_accumulator: float = 0.0
+
+## Internal: interval between streaming updates (seconds).
+const UPDATE_INTERVAL: float = 0.1
+
+
+func _ready() -> void:
+	# Streaming is driven from _process (main thread) so we can safely
+	# manipulate the scene tree. No background thread is used.
+	set_process(true)
+
+
+func _process(delta: float) -> void:
+	if not is_active or player == null:
+		return
+
+	_update_accumulator += delta
+	if _update_accumulator < UPDATE_INTERVAL:
+		return
+	_update_accumulator = 0.0
+
+	_update_streaming()
+	_process_load_queue()
+	_process_unload_queue()
+	streaming_updated.emit()
+
+
+func _update_streaming() -> void:
+	if player == null or not is_inside_tree():
+		return
+
+	var current_coord: Vector3i = Chunk.coord_for_position(player.global_position)
+	if current_coord == _player_chunk_coord:
+		return
+
+	_player_chunk_coord = current_coord
+	_rebuild_queues()
+
+
+func _rebuild_queues() -> void:
+	var target_set: Dictionary = _compute_target_chunks()
+
+	# Determine which chunks need to be loaded
+	var to_load: Array[Vector3i] = []
+	for coord in target_set:
+		if not _loaded_chunks.has(coord) and not _loading_in_progress.has(coord):
+			to_load.append(coord)
+
+	# Sort by distance from player (closest first)
+	to_load.sort_custom(_compare_distance)
+	_load_queue = to_load
+
+	# Determine which chunks need to be unloaded
+	var to_unload: Array[Vector3i] = []
+	for coord in _loaded_chunks:
+		if not target_set.has(coord):
+			to_unload.append(coord)
+
+	to_unload.sort_custom(_compare_distance)
+	_unload_queue = to_unload
+
+
+func _compute_target_chunks() -> Dictionary:
+	"""Compute the set of chunk coordinates that should be loaded."""
+	var target: Dictionary = {}
+	var half: int = streaming_radius
+	for dx in range(-half, half + 1):
+		for dy in range(-half, half + 1):
+			for dz in range(-half, half + 1):
+				var coord: Vector3i = Vector3i(
+					_player_chunk_coord.x + dx,
+					_player_chunk_coord.y + dy,
+					_player_chunk_coord.z + dz
+				)
+				target[coord] = coord
+	return target
+
+
+func _compare_distance(a: Vector3i, b: Vector3i) -> bool:
+	"""Compare chunk coordinates by distance from player chunk."""
+	var dist_a: int = _chunk_distance_squared(_player_chunk_coord, a)
+	var dist_b: int = _chunk_distance_squared(_player_chunk_coord, b)
+	return dist_a < dist_b
+
+
+func _chunk_distance_squared(a: Vector3i, b: Vector3i) -> int:
+	var dx: int = a.x - b.x
+	var dy: int = a.y - b.y
+	var dz: int = a.z - b.z
+	return dx * dx + dy * dy + dz * dz
+
+
+func _process_load_queue() -> void:
+	var count: int = 0
+	while count < max_loads_per_frame and not _load_queue.is_empty():
+		var coord: Vector3i = _load_queue.pop_front()
+		_load_chunk(coord)
+		count += 1
+
+
+func _process_unload_queue() -> void:
+	var count: int = 0
+	while count < max_unloads_per_frame and not _unload_queue.is_empty():
+		var coord: Vector3i = _unload_queue.pop_front()
+		_unload_chunk(coord)
+		count += 1
+
+
+func _load_chunk(coord: Vector3i) -> void:
+	if _loading_in_progress.has(coord):
+		return
+
+	_loading_in_progress[coord] = true
+
+	# Request chunk data from server via RPC
+	if _server_rpc != null and _server_rpc.has_method("request_chunk"):
+		_server_rpc.request_chunk(Chunk.build_key(
+			"", "", coord
+		))
+	else:
+		# Fallback: try to load from local cache or create empty chunk
+		_instantiate_chunk_scene(coord)
+
+
+func _on_chunk_data_received(key: String, binary_data: PackedByteArray) -> void:
+	"""Called by the networking layer when chunk data arrives from server."""
+	var coord: Vector3i = _parse_coord_from_key(key)
+	if coord == null:
+		return
+
+	_loading_in_progress.erase(coord)
+
+	# Decode the binary chunk data
+	var chunk_data: ChunkDataDecoder.ChunkPayload = ChunkDataDecoder.decode_binary(binary_data)
+	if chunk_data == null:
+		chunk_load_failed.emit(coord, "Failed to decode chunk data")
+		return
+
+	# Instantiate the chunk scene with the decoded data
+	_instantiate_chunk_scene_with_data(coord, chunk_data)
+
+
+func _on_chunk_load_error(coord: Vector3i, error_msg: String) -> void:
+	"""Called when the server reports a chunk load error."""
+	_loading_in_progress.erase(coord)
+	chunk_load_failed.emit(coord, error_msg)
+
+
+func _instantiate_chunk_scene(coord: Vector3i) -> void:
+	"""Create an empty chunk scene for the given coordinate."""
+	var chunk_scene: ChunkScene = ChunkScene.new()
+	chunk_scene.coord = coord
+	chunk_scene.key = Chunk.build_key("", "", coord)
+	chunk_scene.bounds = Chunk.compute_bounds(coord)
+	_add_loaded_chunk(coord, chunk_scene)
+
+
+func _instantiate_chunk_scene_with_data(coord: Vector3i, data: ChunkDataDecoder.ChunkPayload) -> void:
+	"""Create a chunk scene populated with server data."""
+	var chunk_scene: ChunkScene = ChunkScene.new()
+	chunk_scene.coord = coord
+	chunk_scene.key = data.key
+	chunk_scene.bounds = data.bounds
+	chunk_scene.format_version = data.format_version
+	chunk_scene.revision = data.revision
+
+	# Add tiles
+	for layer in data.tile_layers:
+		var tile_layer: TileLayer = TileLayer.new()
+		tile_layer.name = layer.name
+		tile_layer.layer_id = layer.layer_id
+		tile_layer.width = layer.width
+		tile_layer.height = layer.height
+		tile_layer.depth = layer.depth
+		tile_layer.palette = layer.palette
+		tile_layer.tiles = layer.tiles
+		chunk_scene.add_tile_layer(tile_layer)
+
+	# Add objects
+	for obj_data in data.objects:
+		var world_obj: WorldObject = WorldObject.new()
+		world_obj.id = obj_data.id
+		world_obj.type = obj_data.type
+		world_obj.asset_id = obj_data.asset_id
+		world_obj.position = obj_data.position
+		world_obj.rotation = obj_data.rotation
+		world_obj.scale = obj_data.scale
+		world_obj.properties = obj_data.properties
+		world_obj.is_dynamic = obj_data.dynamic
+		world_obj.flags = obj_data.flags
+		chunk_scene.add_object(world_obj)
+
+	# Add content flags
+	chunk_scene.content_flags = data.flags
+
+	_add_loaded_chunk(coord, chunk_scene)
+
+
+func _add_loaded_chunk(coord: Vector3i, chunk_scene: Node) -> void:
+	_loaded_chunks[coord] = chunk_scene
+	add_child(chunk_scene)
+	_loading_in_progress.erase(coord)
+	chunk_loaded.emit(coord, chunk_scene)
+
+
+func _unload_chunk(coord: Vector3i) -> void:
+	if not _loaded_chunks.has(coord):
+		return
+
+	var chunk_scene: Node = _loaded_chunks[coord]
+	if is_instance_valid(chunk_scene):
+		chunk_scene.queue_free()
+
+	_loaded_chunks.erase(coord)
+	chunk_unloaded.emit(coord)
+
+
+func _on_player_position_changed() -> void:
+	"""Call this when the player position changes significantly."""
+	if player != null:
+		_update_streaming()
+
+
+func set_server_rpc(rpc_interface: Object) -> void:
+	"""Set the server RPC interface for chunk requests."""
+	_server_rpc = rpc_interface
+
+
+func get_loaded_chunk(coord: Vector3i) -> Node:
+	"""Get a loaded chunk scene by coordinate, or null if not loaded."""
+	return _loaded_chunks.get(coord, null)
+
+
+func is_chunk_loaded(coord: Vector3i) -> bool:
+	"""Check if a chunk is currently loaded."""
+	return _loaded_chunks.has(coord)
+
+
+func get_loaded_chunk_count() -> int:
+	"""Get the number of currently loaded chunks."""
+	return _loaded_chunks.size()
+
+
+func get_all_loaded_coords() -> Array[Vector3i]:
+	"""Get all currently loaded chunk coordinates."""
+	var coords: Array[Vector3i] = []
+	for key in _loaded_chunks:
+		coords.append(key)
+	return coords
+
+
+func force_reload_chunk(coord: Vector3i) -> void:
+	"""Force reload a specific chunk (e.g., after server update)."""
+	if _loaded_chunks.has(coord):
+		_unload_chunk(coord)
+	if not _loading_in_progress.has(coord):
+		_load_chunk(coord)
+
+
+func clear_all_chunks() -> void:
+	"""Unload all chunks immediately."""
+	var coords: Array[Vector3i] = get_all_loaded_coords()
+	for coord in coords:
+		_unload_chunk(coord)
+	_load_queue.clear()
+	_unload_queue.clear()
+
+
+func _parse_coord_from_key(key: String) -> Variant:
+	"""Parse chunk coordinate from a canonical chunk key."""
+	var parts: Array[String] = key.split(":")
+	if parts.size() < 5:
+		return null
+	return Vector3i(
+		int(parts[2]),
+		int(parts[3]),
+		int(parts[4])
+	)

scripts/chunk_stream_manager.gd.uid

@@ -0,0 +1 @@
+uid://8yokqwe23c23

scripts/dynamic_object_node.gd

@@ -0,0 +1,68 @@
+class_name DynamicObjectNode
+extends Node3D
+## A visual representation of a dynamic (spawnable) world object template.
+##
+## This node is instantiated by [ChunkScene] for each dynamic [WorldObject].
+## Dynamic objects are stored as *templates* in the chunk; their runtime state
+## (position, health, inventory) is managed by the entity system, not by this
+## node. This node renders the template's visual representation so the object
+## is visible in the world.
+##
+## ## Structure
+##
+## ```
+## DynamicObjectNode (Node3D)
+##  └── MeshInstance3D  # the object's visual mesh
+## ```
+
+## The world object data this node represents.
+var world_object: WorldObject = null
+
+## The loaded mesh instance (or placeholder).
+var _mesh_instance: MeshInstance3D = null
+
+
+func _ready() -> void:
+	if world_object == null:
+		return
+	_load_mesh()
+
+
+## Load and attach the object's mesh.
+func _load_mesh() -> void:
+	_mesh_instance = MeshInstance3D.new()
+	_mesh_instance.name = "mesh"
+
+	var mesh := _load_asset_mesh(world_object.asset_id)
+	if mesh == null:
+		mesh = _make_placeholder_mesh()
+
+	_mesh_instance.mesh = mesh
+	add_child(_mesh_instance)
+
+
+## Attempt to load a mesh from the asset path.
+func _load_asset_mesh(asset_id: String) -> Mesh:
+	if asset_id.is_empty():
+		return null
+	var path := "res://assets/%s" % asset_id
+	if ResourceLoader.exists(path):
+		var res := load(path)
+		if res is Mesh:
+			return res
+	return null
+
+
+## Create a simple placeholder sphere mesh when the real asset is unavailable.
+func _make_placeholder_mesh() -> Mesh:
+	var mesh := SphereMesh.new()
+	mesh.radius = 0.5
+	mesh.height = 1.0
+	return mesh
+
+
+## Get the world object's display name.
+func get_display_name() -> String:
+	if world_object == null:
+		return ""
+	return world_object.get_display_name()

scripts/dynamic_object_node.gd.uid

@@ -0,0 +1 @@
+uid://dyjqcstdnr4u1

scripts/static_object_node.gd

@@ -0,0 +1,67 @@
+class_name StaticObjectNode
+extends Node3D
+## A visual representation of a static world object within a chunk.
+##
+## This node is instantiated by [ChunkScene] for each static (non-dynamic)
+## [WorldObject]. It renders the object's mesh (referenced by `asset_id`) at
+## the object's transform. If the asset is not yet loaded, a placeholder mesh
+## is shown.
+##
+## ## Structure
+##
+## ```
+## StaticObjectNode (Node3D)
+##  └── MeshInstance3D  # the object's visual mesh
+## ```
+
+## The world object data this node represents.
+var world_object: WorldObject = null
+
+## The loaded mesh instance (or placeholder).
+var _mesh_instance: MeshInstance3D = null
+
+
+func _ready() -> void:
+	if world_object == null:
+		return
+	_load_mesh()
+
+
+## Load and attach the object's mesh.
+func _load_mesh() -> void:
+	_mesh_instance = MeshInstance3D.new()
+	_mesh_instance.name = "mesh"
+
+	# Try to load the asset by its id (path). Fall back to a placeholder.
+	var mesh := _load_asset_mesh(world_object.asset_id)
+	if mesh == null:
+		mesh = _make_placeholder_mesh()
+
+	_mesh_instance.mesh = mesh
+	add_child(_mesh_instance)
+
+
+## Attempt to load a mesh from the asset path.
+func _load_asset_mesh(asset_id: String) -> Mesh:
+	if asset_id.is_empty():
+		return null
+	var path := "res://assets/%s" % asset_id
+	if ResourceLoader.exists(path):
+		var res := load(path)
+		if res is Mesh:
+			return res
+	return null
+
+
+## Create a simple placeholder box mesh when the real asset is unavailable.
+func _make_placeholder_mesh() -> Mesh:
+	var mesh := BoxMesh.new()
+	mesh.size = Vector3(1.0, 1.0, 1.0)
+	return mesh
+
+
+## Get the world object's display name.
+func get_display_name() -> String:
+	if world_object == null:
+		return ""
+	return world_object.get_display_name()

scripts/static_object_node.gd.uid

@@ -0,0 +1 @@
+uid://chf6mruev1kc4

scripts/tile_def.gd

@@ -0,0 +1,42 @@
+class_name TileDef
+extends RefCounted
+## A single tile definition (palette entry) within a tile layer.
+##
+## Maps a tile ID to its asset reference and gameplay flags. See
+## docs/architecture/world.md §3.2.
+
+## Tile ID (index into the layer palette). 0 is reserved for empty/air.
+var id: int = 0
+
+## Reference to the tile/terrain asset.
+var asset_id: String = ""
+
+## Whether this tile has collision.
+var solid: bool = false
+
+## Bitmask flags: bit 0 = walkable, bit 1 = climbable, bit 2 = liquid.
+var flags: int = 0
+
+## Number of visual variants for this tile.
+var variants: int = 1
+
+
+func _init(p_id: int = 0, p_asset_id: String = "", p_solid: bool = false,
+		p_flags: int = 0, p_variants: int = 1) -> void:
+	id = p_id
+	asset_id = p_asset_id
+	solid = p_solid
+	flags = p_flags
+	variants = p_variants
+
+
+func is_walkable() -> bool:
+	return (flags & 0x01) != 0
+
+
+func is_climbable() -> bool:
+	return (flags & 0x02) != 0
+
+
+func is_liquid() -> bool:
+	return (flags & 0x04) != 0

scripts/tile_def.gd.uid

@@ -0,0 +1 @@
+uid://bavmpbmthilbx

scripts/tile_layer.gd

@@ -0,0 +1,83 @@
+class_name TileLayer
+extends RefCounted
+## A single tile layer within a chunk.
+##
+## Holds the dense grid of tile IDs, the palette mapping tile IDs to tile
+## definitions, and the layer metadata. This is the runtime representation of
+## the `TileLayer` from the chunk data format (see docs/architecture/world.md
+## §3.2).
+
+## Layer name (e.g. "ground", "walls", "decor").
+var name: String = ""
+
+## Numeric layer id, unique within the chunk.
+var layer_id: int = 0
+
+## Grid dimensions in tiles.
+var width: int = 0
+var height: int = 0
+var depth: int = 1
+
+## Palette mapping tile IDs to tile definitions (shared per layer).
+var palette: Array[TileDef] = []
+
+## Dense, row-major tile IDs. Length = width * height * depth.
+var tiles: PackedInt32Array = PackedInt32Array()
+
+
+func _init(
+	p_layer_name: String = "",
+	p_layer_id: int = 0,
+	p_width: int = 0,
+	p_height: int = 0,
+	p_depth: int = 1
+) -> void:
+	name = p_layer_name
+	layer_id = p_layer_id
+	width = p_width
+	height = p_height
+	depth = p_depth
+
+
+## Total number of tiles in this layer.
+func tile_count() -> int:
+	return width * height * depth
+
+
+## Get the tile ID at (x, y, z). Returns 0 (empty) for out-of-bounds.
+func get_tile(x: int, y: int, z: int = 0) -> int:
+	if x < 0 or x >= width or y < 0 or y >= height or z < 0 or z >= depth:
+		return 0
+	var idx := (z * height + y) * width + x
+	if idx < tiles.size():
+		return tiles[idx]
+	return 0
+
+
+## Set the tile ID at (x, y, z). No-op if out of bounds.
+func set_tile(x: int, y: int, z: int, tile_id: int) -> void:
+	if x < 0 or x >= width or y < 0 or y >= height or z < 0 or z >= depth:
+		return
+	var idx := (z * height + y) * width + x
+	if idx < tiles.size():
+		tiles[idx] = tile_id
+
+
+## Get the tile definition for a tile ID, or null if not in the palette.
+func get_tile_def(tile_id: int) -> TileDef:
+	for def in palette:
+		if def.id == tile_id:
+			return def
+	return null
+
+
+## Whether the tile at (x, y, z) is solid (collision).
+func is_solid(x: int, y: int, z: int = 0) -> bool:
+	var def := get_tile_def(get_tile(x, y, z))
+	return def != null and def.solid
+
+
+## Whether the tile at (x, y, z) is walkable.
+func is_walkable(x: int, y: int, z: int = 0) -> bool:
+	var def := get_tile_def(get_tile(x, y, z))
+	return def != null and def.is_walkable()

scripts/tile_layer.gd.uid

@@ -0,0 +1 @@
+uid://came2ygke3ajs

scripts/tile_layer_node.gd

@@ -0,0 +1,112 @@
+class_name TileLayerNode
+extends Node3D
+## A visual representation of a single tile layer within a chunk.
+##
+## This node is instantiated by [ChunkScene] for each tile layer in a chunk.
+## It renders the layer's tiles as instanced meshes (one per tile definition
+## in the palette) using [MultiMeshInstance3D] for efficiency.
+##
+## ## Structure
+##
+## ```
+## TileLayerNode (Node3D)
+##  └── MultiMeshInstance3D  # one per palette entry (tile definition)
+## ```
+
+## The tile layer data this node renders.
+var tile_layer: TileLayer = null
+
+## The chunk coordinate this layer belongs to (for world positioning).
+var chunk_coord: Vector3i = Vector3i.ZERO
+
+## Tile size in world units (each tile is 1x1x1).
+const TILE_SIZE: float = 1.0
+
+## Cache of MultiMeshInstance3D nodes, keyed by tile definition id.
+var _mesh_instances: Dictionary = {}
+
+
+func _ready() -> void:
+	if tile_layer == null:
+		return
+	_build_meshes()
+
+
+## Build the MultiMesh instances for each tile definition in the palette.
+func _build_meshes() -> void:
+	for tile_def in tile_layer.palette:
+		if tile_def.id == 0:
+			continue  # Tile 0 is "empty/air", no mesh needed
+		_create_mesh_for_tile(tile_def)
+
+
+func _create_mesh_for_tile(tile_def: TileDef) -> void:
+	# Count how many cells use this tile definition
+	var count := 0
+	for tile_id in tile_layer.tiles:
+		if tile_id == tile_def.id:
+			count += 1
+
+	if count == 0:
+		return
+
+	var multi_mesh := MultiMesh.new()
+	multi_mesh.transform_format = MultiMesh.TRANSFORM_3D
+	multi_mesh.mesh = _make_unit_cube_mesh()
+	multi_mesh.instance_count = count
+
+	var instance_idx := 0
+	for z in range(tile_layer.depth):
+		for y in range(tile_layer.height):
+			for x in range(tile_layer.width):
+				var tile_id := tile_layer.get_tile(x, y, z)
+				if tile_id != tile_def.id:
+					continue
+				var world_pos := _tile_to_world(x, y, z)
+				var xform := Transform3D(Basis(), world_pos)
+				multi_mesh.set_instance_transform(instance_idx, xform)
+				instance_idx += 1
+
+	var mesh_instance := MultiMeshInstance3D.new()
+	mesh_instance.multimesh = multi_mesh
+	mesh_instance.name = "tiles_%d" % tile_def.id
+	add_child(mesh_instance)
+	_mesh_instances[tile_def.id] = mesh_instance
+
+
+## Convert a tile grid coordinate to a world-space position (center of tile).
+func _tile_to_world(x: int, y: int, z: int) -> Vector3:
+	var origin := Vector3(
+		chunk_coord.x * tile_layer.width,
+		chunk_coord.y * tile_layer.height,
+		chunk_coord.z * tile_layer.depth
+	)
+	return origin + Vector3(
+		x * TILE_SIZE + TILE_SIZE * 0.5,
+		y * TILE_SIZE + TILE_SIZE * 0.5,
+		z * TILE_SIZE + TILE_SIZE * 0.5
+	)
+
+
+## Create a simple unit cube mesh for tile rendering.
+func _make_unit_cube_mesh() -> Mesh:
+	var mesh := BoxMesh.new()
+	mesh.size = Vector3(TILE_SIZE, TILE_SIZE, TILE_SIZE)
+	return mesh
+
+
+## Get the tile definition at a grid position, or null if empty.
+func get_tile_def_at(x: int, y: int, z: int = 0) -> TileDef:
+	if tile_layer == null:
+		return null
+	var tile_id := tile_layer.get_tile(x, y, z)
+	if tile_id == 0:
+		return null
+	return tile_layer.get_tile_def(tile_id)
+
+
+## Clear all rendered meshes.
+func clear() -> void:
+	for child in get_children():
+		child.queue_free()
+	_mesh_instances.clear()

scripts/tile_layer_node.gd.uid

@@ -0,0 +1 @@
+uid://d1x05tq8h43gm

scripts/world_object.gd

@@ -0,0 +1,135 @@
+class_name WorldObject
+extends RefCounted
+## A world object (static or dynamic) within a chunk.
+##
+## This is the runtime representation of a WorldObject from the chunk data
+## format (see docs/architecture/world.md §3.3). It holds the object's
+## identity, transform, properties, and moderation flags.
+
+## Stable object ID, unique within the chunk.
+var id: String = ""
+
+## Object type (e.g. "prop", "interactable", "spawn_point", "door").
+var type: String = ""
+
+## Reference to the object's mesh/glTF asset.
+var asset_id: String = ""
+
+## World-space position.
+var position: Vector3 = Vector3.ZERO
+
+## World-space rotation as a quaternion (x, y, z, w).
+var rotation: Vector4 = Vector4(0, 0, 0, 1)
+
+## World-space scale.
+var scale: Vector3 = Vector3.ONE
+
+## Type-specific key/value properties.
+var properties: Dictionary = {}
+
+## Whether this is a spawnable dynamic entity (true) or static (false).
+var is_dynamic: bool = false
+
+## Per-object content moderation flags.
+var flags: ChunkDataDecoder.ContentFlags = ChunkDataDecoder.ContentFlags.new()
+
+## Whether this object has been modified locally.
+var is_dirty: bool = false
+
+
+func _init(
+	p_id: String = "",
+	p_type: String = "",
+	p_asset_id: String = "",
+	p_position: Vector3 = Vector3.ZERO,
+	p_rotation: Vector4 = Vector4(0, 0, 0, 1),
+	p_scale: Vector3 = Vector3.ONE,
+	p_properties: Dictionary = {},
+	p_dynamic: bool = false,
+	p_flags: ChunkDataDecoder.ContentFlags = null
+) -> void:
+	id = p_id
+	type = p_type
+	asset_id = p_asset_id
+	position = p_position
+	rotation = p_rotation
+	scale = p_scale
+	properties = p_properties
+	is_dynamic = p_dynamic
+	if p_flags != null:
+		flags = p_flags
+
+
+## Get a property value by key.
+func get_property(key: String) -> Variant:
+	return properties.get(key)
+
+
+## Set a property value.
+func set_property(key: String, value: Variant) -> void:
+	properties[key] = value
+	is_dirty = true
+
+
+## Check if this object is walkable (based on properties).
+func is_walkable() -> bool:
+	return properties.get("walkable", true)
+
+
+## Check if this object is climbable (based on properties).
+func is_climbable() -> bool:
+	return properties.get("climbable", false)
+
+
+## Check if this object is interactable.
+func is_interactable() -> bool:
+	return type == "interactable" or properties.get("interactable", false)
+
+
+## Get the object's display name.
+func get_display_name() -> String:
+	return properties.get("display_name", id)
+
+
+## Serialize this object to a dictionary (for networking).
+func to_dict() -> Dictionary:
+	return {
+		"id": id,
+		"type": type,
+		"asset_id": asset_id,
+		"position": [position.x, position.y, position.z],
+		"rotation": [rotation.x, rotation.y, rotation.z, rotation.w],
+		"scale": [scale.x, scale.y, scale.z],
+		"properties": properties,
+		"dynamic": is_dynamic,
+	}
+
+
+## Create a WorldObject from a dictionary (for networking).
+static func from_dict(d: Dictionary) -> WorldObject:
+	var pos := Vector3(
+		d.get("position", [0, 0, 0])[0],
+		d.get("position", [0, 0, 0])[1],
+		d.get("position", [0, 0, 0])[2]
+	)
+	var rot := Vector4(
+		d.get("rotation", [0, 0, 0, 1])[0],
+		d.get("rotation", [0, 0, 0, 1])[1],
+		d.get("rotation", [0, 0, 0, 1])[2],
+		d.get("rotation", [0, 0, 0, 1])[3]
+	)
+	var scl := Vector3(
+		d.get("scale", [1, 1, 1])[0],
+		d.get("scale", [1, 1, 1])[1],
+		d.get("scale", [1, 1, 1])[2]
+	)
+	return WorldObject.new(
+		d.get("id", ""),
+		d.get("type", ""),
+		d.get("asset_id", ""),
+		pos,
+		rot,
+		scl,
+		d.get("properties", {}),
+		d.get("dynamic", false),
+	)

scripts/world_object.gd.uid

@@ -0,0 +1 @@
+uid://cxut2ghbsvobn

test_out.txt

@@ -0,0 +1,15 @@
+Godot Engine v4.6.2.stable.official.71f334935 - https://godotengine.org
+
+roundtrip bounds.position = (0.0, 0.0, 0.0)  (expected (0.5, 1.5, 2.5))
+roundtrip coord = (0, 0, 0)  (expected (1, 2, 3))
+format_version present? -> <null>
+version field -> 1
+SCRIPT ERROR: Invalid assignment of property or key 'properties' with value of type 'bool' on a base object of type 'RefCounted (WorldObjectData)'.
+          at: _parse_object_section (res://scripts/chunk_data_decoder.gd:407)
+          GDScript backtrace (most recent call first):
+              [0] _parse_object_section (res://scripts/chunk_data_decoder.gd:407)
+              [1] _init (res://test_review.gd:25)
+SCRIPT ERROR: Out of bounds get index '0' (on base: 'Array[WorldObjectData]')
+          at: _init (res://test_review.gd:26)
+          GDScript backtrace (most recent call first):
+              [0] _init (res://test_review.gd:26)

test_review.gd

@@ -0,0 +1,22 @@
+extends SceneTree
+
+func _init() -> void:
+	# 1. float32 encode/decode
+	var b: PackedByteArray = ChunkDataDecoder._write_float32(0.5)
+	print("float32(0.5) bytes = ", b, " (expected 00 00 00 3f)")
+	var decoded_f: float = ChunkDataDecoder._read_float32(PackedByteArray([0x00, 0x00, 0x00, 0x3f]), 0)
+	print("read_float32 of 0x3f000000 = ", decoded_f, " (expected 0.5)")
+
+	# 2. metadata section wrapping: inspect first bytes of encoded payload
+	var payload: ChunkDataDecoder.ChunkPayload = ChunkDataDecoder.ChunkPayload.new()
+	payload.world_id = "w"
+	payload.room_id = "r"
+	payload.coord = Vector3i(1, 2, 3)
+	var meta: PackedByteArray = ChunkDataDecoder._build_metadata_section(payload)
+	print("metadata section first 12 bytes = ", meta.slice(0, 12))
+
+	# 3. properties parse with empty-ish string
+	var props_str := "{}"
+	var val = JSON.parse_string(props_str) or {}
+	print("'JSON.parse_string(props_str) or {{}}' type = ", typeof(val), " value = ", val)
+	quit()