Feature Matrix

v1.5.10 1.20.1 / 1.21.1 Forge Fabric

Everything CNPCExtended offers, compared across platforms at a glance.

30+

Total Features

30+

Shared (Both)

Platform-Only

Platforms

✔ Supported ─ Not yet ✘ N/A

⚙

Core (Server-Side)

Forge + Fabric

Feature	Forge 1.20.1	Fabric 1.21.1
Script Injection (cnpcext global)	✔	✔
Client Bridge API (getClientBridge())	✔	✔
Global Script Preloading	✔	✔
Global NPC Data Preloading	✔	✔
Script Commands (registerCommand())	✔	✔
/cnpcext CLI Commands	✔	✔
ModConfig (common.toml)	✔	✔
ClientConfig (skip menu)
Skip Menu (auto-load world/server)

🌐

HTML GUI (Client)

Forge + Fabric

Feature	Forge 1.20.1	Fabric 1.21.1	Notes
HTML GUI (MCEF Chromium)	✔	✔	Full HTML/CSS/JS rendered in-game
Bridge JS (window.cnpc)	✔	✔	sendEvent, onEvent, close, initData
MC Item Overlays	✔	✔	Real ItemStack rendering on HTML elements
Entity Overlays	✔	✔	Full entity rendering (NPCs, players) via data-mc-entity
Clip Rects (data-mc-clip)	✔	✔	Scissor clipping for scrollable item lists
Client Queries	✔	✔	Video, keybinds, sound, player state, packs
Client Script Engine	✔	✔	JSR-223 JavaScript on client side
Key State Tracking	✔	✔	bridge.isKeyHeld(), isInGui(), isTyping()
Client Key Events	✔	✔	clientKeyPressed, clientKeyReleased, clientKeyHeld

📺

HTML Overlays (HUD)

Forge + Fabric

Render HTML on the HUD layer — skill bars, HP bars, quest trackers. Game stays fully playable.

Feature	Forge 1.20.1	Fabric 1.21.1
openOverlay(name, file, x, y, w, h, data)	✔	✔
updateOverlay(name, data) — auto-dedup	✔	✔
hideOverlay / showOverlay / closeOverlay	✔	✔
Multiple simultaneous overlays (up to 8)	✔	✔
Persistent overlays (survive relog)	✔	✔
Auto-cleanup on disconnect	✔	✔
Item overlays on HUD	✔	✔
Entity overlays on HUD	✔	✔
Fade-in animation	✔	✔
Interactive mode (cursor unlock)	✔	✔

🎨

Vanilla HUD Hiding

Forge + Fabric

Selectively hide vanilla HUD elements. Resets on disconnect.

Element	hideHudElement() Name	Forge 1.20.1	Fabric 1.21.1
Hotbar + item name	hotbar	✔	✔
XP bar + level number	experience	✔	✔
Hearts + food + armor + air	health	✔	✔
Armor icons only	armor	✔	✔
Hunger bar only	food	✔	✔
Crosshair	crosshair	✔	✔
Potion effects	effects	✔	✔
Action bar text	actionbar	✔	✔
Chat display	chat	✔	✔
Sidebar scoreboard	scoreboard	✔	✔
Tab player list	tablist	✔	✔
All at once	all	✔	✔

📁

Asset Loading

Forge + Fabric

Load images, CSS, JS, and fonts from the scripts folder via the cnpc:// custom CEF scheme.

Feature	Forge 1.20.1	Fabric 1.21.1
cnpc:// custom CEF scheme	✔	✔
window.cnpc.assetUrl in bridge JS	✔	✔
Auto-sync scripts path on join	✔	✔
Path traversal protection	✔	✔
Works in HTML GUIs	✔	✔
Works in HTML Overlays	✔	✔

🎬

Cutscene System

Forge + Fabric

Keyframe-based camera cutscenes with visual HTML editor, fade transitions, per-keyframe easing, player protection, and script phase events.

Feature	Forge 1.20.1	Fabric 1.21.1
startCutscene(player, name, options)	✔	✔
stopCutscene / pauseCutscene / resumeCutscene	✔	✔
isInCutscene(player)	✔	✔
moveCamera(player, json) — ad-hoc keyframes	✔	✔
cutscene(e) phase event handler	✔	✔
Visual editor GUI (HTML)	✔	✔
Per-keyframe easing (11 curves)	✔	✔
Keep position on end	✔	✔
Fade transitions	✔	✔
Cinematic black bars	✔	✔
FOV lock + hand hidden	✔	✔
Mouse look blocked	✔	✔
Player protection (freeze + invulnerable)	✔	✔
Disconnect/reconnect failsafe	✔	✔
Catmull-Rom camera interpolation	✔	✔
Sub-tick camera smoothing (60fps+)	✔	✔
/cnpcext cutscene play <name> <player>	✔	✔

📡

API Method Reference

cnpcext — Server Script Global

Method	Forge 1.20.1	Fabric 1.21.1
getClientBridge(mcPlayer)	✔	✔
openHtmlGui(e, file, w, h, json)	✔	✔
registerCommand(name, json)	✔	✔
openOverlay(e, name, file, x, y, w, h, json)	✔	✔
updateOverlay(e, name, json)	✔	✔
hideOverlay / showOverlay	✔	✔
closeOverlay / hasOverlay	✔	✔
hideHudElement(e, element)	✔	✔
showHudElement(e, element)	✔	✔
startCutscene(player, name, optionsJson)	✔	✔
stopCutscene(player)	✔	✔
pauseCutscene / resumeCutscene	✔	✔
isInCutscene(player)	✔	✔
moveCamera(player, keyframesJson)	✔	✔
entityId(entity)	✔	✔
entityNbt(entity)	✔	✔

IClientBridge — via getClientBridge()

Method	Forge 1.20.1	Fabric 1.21.1
openHtmlGui(file, w, h, json)	✔	✔
closeHtmlGui()	✔	✔
sendToBrowser(event, json)	✔	✔
queryVideoSettings(cb)	✔	✔
queryKeybinds(cb)	✔	✔
querySoundSettings(cb)	✔	✔
queryPlayerState(cb)	✔	✔
queryResourcePacks(cb)	✔	✔
openOverlay(name, file, x, y, w, h, json)	✔	✔
updateOverlay(name, json)	✔	✔
hideOverlay / showOverlay / closeOverlay	✔	✔
hasOverlay(name)	✔	✔
hideHudElement(element)	✔	✔
showHudElement(element)	✔	✔
isKeyHeld(keyCode)	✔	✔
getKeyHoldDuration(keyCode)	✔	✔
isInGui()	✔	✔
isTyping()	✔	✔
getOpenScreen()	✔	✔

window.cnpc — Browser-Side JS

Property / Method	HTML GUI	HTML Overlay
initData	✔	✔
assetUrl	✔	✔
onEvent(name, cb)	✔	✔
sendEvent(name, data)	✔	✔
close()	✔	✔
setOverlayItems(items)	✔	✔
setClipRect(rect)	✔	✔

📦

Network Packets

ActionType	Forge 1.20.1	Fabric 1.21.1
OPEN_HTML_GUI	✔	✔
CLOSE_HTML_GUI	✔	✔
SEND_TO_BROWSER	✔	✔
RUN_CLIENT_SCRIPT	✔	✔
SEND_TO_CLIENT	✔	✔
OPEN_OVERLAY	✔	✔
UPDATE_OVERLAY	✔	✔
CLOSE_OVERLAY	✔	✔
HIDE_OVERLAY	✔	✔
SHOW_OVERLAY	✔	✔
SET_OVERLAY_INTERACTIVE	✔	✔
CLOSE_ALL_OVERLAYS	✔	✔
HIDE_HUD_ELEMENT	✔	✔
SHOW_HUD_ELEMENT	✔	✔
SYNC_SCRIPTS_PATH	✔	✔
PacketCutsceneStart (S→C)	✔	✔
PacketCutsceneStop (S→C)	✔	✔

⚠

Known Issues & Fixes

v1.5

Discovered via user testing. Fixed on both platforms.

Issue	Status	Details
Blurry overlay text	FIXED	Overlay browser was sized at width × guiScale instead of native window pixel ratio. Text rendered at half resolution then stretched.
Black flash on HTML load	FIXED	CEF needs a few frames to paint after creation. Added fade-in animation (skip 8 frames + fade over 10 frames).
Cursor detaches from game	FIXED	CEF's default cursorChangeListener calls glfwSetInputMode(GLFW_CURSOR_NORMAL) during HTML load. Fix: no-op cursor listener on overlay browsers.
Overlay breaks on window resize	FIXED	Item/entity overlay positions misaligned after resizing MC window. Fix: auto-resize browser each frame via checkResize().