Atlas / MCP servers / jasonjgardner / Blockbench

BlockbenchBLOCK

Name: Blockbench
Author: jasonjgardner

mcp/jasonjgardner/blockbench

MCP server by jasonjgardner · blockbench · blockbench plugin · mcp server · Audited 2026-10-03

⚑ Report / re-scan Source ↗

Adds MCP server to Blockbench

Verdict

BLOCK

Grade

Trust score

62 /100

Exposed tools

49 36r · 12w · 1d

Transport

stdio · streamable-http

License

GPL-3.0

Stars

476

Overview

From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.

Demo Reel

https://github.com/user-attachments/assets/c67d0dd8-ee50-40ba-b308-a84a21772901

All scenes, models, and textures created through Blockbench MCP plugin using agent skills. (Rendered in Blender)

[](https://skills.sh/jasonjgardner/blockbench-mcp-project)

Plugin Installation

Open the desktop version of Blockbench, go to File > Plugins and click the "Load Plugin from URL" and paste in this URL:

[https://jasonjgardner.github.io/blockbench-mcp-plugin/mcp.js](https://jasonjgardner.github.io/blockbench-mcp-plugin/mcp.js)

Model Context Protocol Servers

This repository contains two MCP server options.

Headless `.bbmodel` (stdio)

A separate stdio MCP server edits, validates, converts and renders .bbmodel files directly, without Blockbench running. Each agent can start its own process, so several can work in parallel while you keep using the editor. Run it straight from GitHub:

npx -y github:jasonjgardner/blockbench-mcp-plugin --root ./models

See headless/README.md for client configuration, the tool list and limits.

Blockbench Desktop Plugin (HTTP)

Configure the MCP server under Blockbench settings: Settings > General > MCP Server Port and MCP Server Endpoint.

The following installation settings examples use the default values of :3000/bb-mcp

Installation

The examples below configure the desktop plugin over HTTP and the headless server over stdio. You can use either server or both. HTTP requires Blockbench running with the plugin installed; stdio requires Node.js with npm and starts its own server process.

For headless examp

Read from source at commit 8b99cc7a4565OBSERVED · 2026-10-03

Connect

Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control.

claude-code

claude mcp add blockbench-mcp -- npx -y [email protected]

claude-desktop

{
  "mcpServers": {
    "blockbench-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "[email protected]"
      ]
    }
  }
}

Exposed tools (49)

36 read · 12 write · 1 destructive. Blast radius: 1 tool can delete or overwrite — an agent that can be talked into calling a tool can be talked into calling this one.

Tool	Risk	Description
`Demo`	read	Runs the demo.
`Turntable`	read	Reference model
`add_locator`	write	Adds a locator: a named point on a bone where particle effects (and sounds) spawn and which they follow as the bone animates. Exported as a Bedrock bone locator. Requires a format with locators (Bedrock Entity, GeckoLib, Generic Model). One undo step.
`bbmodel_convert_legacy`	read	Writes a copy of a .bbmodel in the 4.10 layout that Blockbench 4.x can open (a 5.0 file opens there as an empty scene). Mirrors Blockbench
`bbmodel_create`	write	Creates a new, empty .bbmodel file (format 5.0). Build it up with bbmodel_edit. Refuses to replace an existing file unless overwrite is true.
`bbmodel_export_bedrock_geometry`	read	Compiles a .bbmodel to Minecraft Bedrock geometry (.geo.json) using the same conventions as Blockbench
`bbmodel_export_java_block`	read	Compiles a .bbmodel to a Minecraft Java Edition block/item model .json the way Blockbench
`bbmodel_export_modded_entity`	read	Compiles a .bbmodel to a Java entity model class with the same templates and code generation as Blockbench
`bbmodel_find_elements`	read	Finds elements in a .bbmodel file by name, type, containing group or texture. Returns world-space bounds for each match.
`bbmodel_get_node`	read	Returns the saved data of one group or element (by UUID or exact name), its parent, and its world-space bounds. Group results list their children.
`bbmodel_import_java_block`	write	Converts a Minecraft Java Edition block/item model .json into a new java_block .bbmodel, porting Blockbench
`bbmodel_info`	read	Summarizes a .bbmodel file: format, version, resolution, node counts, world-space bounds and the current revision. Start here before editing.
`bbmodel_list_animations`	read	Lists animation clips with length, loop mode and, per animated bone, how many keyframes each channel has.
`bbmodel_list_textures`	read	Lists the textures of a .bbmodel file with their index, size, and whether the image is embedded. Image data is not returned.
`bbmodel_outline`	write	Returns the group/element tree of a .bbmodel file. Set transforms to include origins, rotations and cube from/to.
`bbmodel_particle_pack`	read	Delivers the particle effects a .bbmodel
`bbmodel_render`	read	Renders a .bbmodel file to a PNG with bb-render (headless three.js WebGPU), without Blockbench. Returns the image and its path. Optionally poses the model at a time in an animation clip. Views are relative to the model
`bbmodel_sample_pose`	read	Evaluates an animation at a time and returns each animated bone
`bbmodel_web_url`	read	Makes a link that opens a .bbmodel (or a Bedrock/Java .json model) in the Blockbench web app, with the file carried in the URL
`blockbench_code_eval_safety`	read	Critical safety guide for agents using code evaluation/execution tools with Blockbench v5.0+. Contains breaking changes, quick reference, common mistakes, and safe code patterns for native module usage.
`blockbench_native_apis`	read	Essential information about Blockbench v5.0 native API security model and requireNativeModule() usage. Use this when working with Node.js modules, file system access, or native APIs in Blockbench plugins.
`create_brush_preset`	write	Creates a custom brush preset with specified settings. Omitted settings are stored as unset so loading the preset keeps the current value.
`create_offscreen_view`	write	Creates a private offscreen viewport that renders the current project without moving the user
`create_particle_effect`	write	Creates a Bedrock particle effect (the Snowstorm format Blockbench, Minecraft Bedrock and GeckoLib use) from a preset plus design knobs, or from raw JSON. Writes <pack_root>/particles/<name>.json (and an optional custom texture to textures/particle/), validates it, and loads it into Blockbench
`create_project`	write	Creates a project with the given name and format, and returns a resource link to its live .bbmodel file.
`delete_offscreen_view`	destructive	Disposes an offscreen view and releases its WebGL context. The user
`export_model`	read	Compiles the current project through a codec whose native export action is available. Returns JSON metadata and a live .bbmodel resource link; result_format=
`export_particle_pack`	read	Delivers particle effects to a Bedrock resource pack: writes particles/<name>.json and copies custom textures to textures/particle/, then returns the particle_effects map to paste into the client entity so animation keyframe names resolve. Defaults to every effect the project
`foreign_schema`	read	Uses a foreign schema.
`geckolib_list_easings`	read	Lists every easing name GeckoLib accepts on keyframes, which of them read easingArgs, and each argument
`get_average_fps`	read	Measures the average frames per second of Blockbench
`get_capabilities`	read	Discover Blockbench/plugin versions, desktop or web environment, active project summary, and registered model formats. Returns detailed boolean format features (null means unknown; includes molang and java_cube_shade_direction_override) plus the format
`get_project_info`	read
`hytale_animation_workflow`	read	Guide for creating animations for Hytale models. Covers 60 FPS timing, quaternion rotations, visibility keyframes, loop modes, and common animation patterns.
`hytale_attachments`	read	Guide for creating and managing attachments in Hytale models. Covers attachment collections, piece bones, modular equipment, and best practices.
`hytale_model_creation`	read	Comprehensive guide for creating Hytale character and prop models. Covers format selection, node limits, shading modes, stretch, quads, and best practices.
`list_export_formats`	read	Lists registered export codecs, file extensions, compile/export support, and availability under the native export action
`list_modes`	read	Lists Blockbench editor tabs/modes with IDs, names, native availability, and the current mode. Includes plugin-added modes. Use before set_mode to discover whether Edit, Paint, Animate, or Display is available for the current project. Camera angles are controlled separately by set_camera_angle.
`list_particle_effects`	read	Lists particle effects loaded in Blockbench with their file, summary, texture status and validation warnings, every particle keyframe that uses them, keyframes that have no preview file or point at missing locators, and the client-entity particle_effects map a Bedrock pack needs.
`list_particle_presets`	read	Lists particle effect presets (smoke, fire, sparks, magic, glow, snow, drip, ...), built-in sprites and textures, materials and facing modes. Every preset uses a texture that ships with Minecraft and Blockbench, so it previews and runs with no image file. Read this before create_particle_effect.
`list_views`	read	Lists render targets: the user
`manage_particle_keyframes`	read	Adds, removes or lists particle keyframes on an animation
`model_creation_strategy`	read	A strategy for creating a new 3D model in Blockbench.
`no_description`	read
`no_execute`	write	Fine.
`resize_offscreen_view`	read	Changes the pixel size of an offscreen view. The user
`set_mode`	write	Switches Blockbench
`trigger_action`	write	Triggers an available Blockbench Action and respects its condition. The native action owns Undo; only a newly opened dialog may be auto-confirmed.
`update_particle_effect`	write	Changes an existing particle effect file with design knobs (only the components each knob owns are rewritten) or replaces it with raw JSON, validates it, saves it and refreshes the preview. Also loads an effect file from disk that Blockbench has not seen yet. Blockbench desktop only.

Trust audit

BLOCKgrade D · trust 62/100 Do not install this without reading the findings. The audit found something that could harm you or your machine.

Layer	What it checks	Result
L0	Provenance & inventory	PASS
L1	Static analysis of the code	FAIL
L2	Instruction surface (what it tells the agent)	FAIL
L3	Class-specific surface	WARN
L4	Behavioural (sandbox)	SKIPPED

What the source does

Filesystem: declared (2 observation(s))
Network: declared (2 observation(s))
Shell: declared (2 observation(s))
Dependencies: not all pinned
Secrets in source: none-found

Findings (25)

HIGHCode injection · code.eval_exec · CWE-78, CWE-94, CWE-95

server/tools/ui.ts:218

result = await eval(code.trim());

Why it matters. evaluates text as code

Fix. remove; use a parser or a dispatch table

HIGHPrompt injection · prompt.credential_read · CWE-94, CWE-1427

.agents/skills/bun-development/SKILL.md:240

// Access environment variables

Why it matters. asks the agent to read credentials

MEDIUMInsecure crypto · crypto.weak_random · CWE-327, CWE-338

headless/mesh/draft.ts:26

return Array.from({ length }, () => KEY_CHARS[Math.floor(Math.random() * KEY_CHARS.length)] ?? "a").join("");

MEDIUMObfuscation / stealth · obf.zero_width · CWE-506, CWE-94

server/tools/texture/texture-set-import.ts:32

const LEADING_BYTE_ORDER_MARK = /^/;

MEDIUMSupply chain · prompt.pipe_to_shell · CWE-829, CWE-1357

.agents/skills/bun-development/SKILL.md:28

curl -fsSL https://bun.sh/install | bash

MEDIUMSupply chain · prompt.pipe_to_shell · CWE-829, CWE-1357

.agents/skills/bun-development/SKILL.md:586

curl -fsSL https://bun.sh/install | bash

MEDIUMFilesystem / path · mcp.destructive_tools · CWE-22, CWE-59

delete_offscreen_view

Why it matters. 1 tool(s) can delete or overwrite

Fix. prefer a read-only mode or scoped tokens; the page states the blast radius

LOWInventory / provenance · inv.binary · CWE-1104

lib/ai-disclosure.test.ts

ai-disclosure.test.ts

Why it matters. a compiled or binary member cannot be reviewed from source

Fix. ship source, or explain the binary in the README

LOWInventory / provenance · inv.hidden_file · CWE-1104

.coderabbit.yaml

.coderabbit.yaml

Why it matters. hidden member outside the usual dotfiles

Fix. review its purpose

LOWFilesystem / path · fs.traversal · CWE-22, CWE-59

benchmarks/harness.test.ts:394

'{"action":"read_context","path":"../../.env"}',

LOWFilesystem / path · fs.traversal · CWE-22, CWE-59

headless/render/input.test.ts:35

texture("embedded", { source: embedded, path: secret, relative_path: "../../secret.png" }),

LOWFilesystem / path · fs.traversal · CWE-22, CWE-59

headless/server.test.ts:141

const outside = await session.call("bbmodel_info", { file: "../../etc/model.bbmodel" });

LOWFilesystem / path · fs.traversal · CWE-22, CWE-59

headless/server.test.ts:311

const outside = await session.call("blockbench_launch", { file: "../../elsewhere/model.bbmodel" });

LOWFilesystem / path · fs.traversal · CWE-22, CWE-59

lib/particles/particles.test.ts:257

["../../outside/pwn", "/abs/tex", "C:/tex", "textures\\particle\\x", "textures//x"].forEach((texture) => {

LOWNetwork egress · net.metadata_ip · CWE-200, CWE-319

server/net-security.test.ts:127

"127.0.0.1", "0.0.0.0", "10.1.2.3", "100.64.0.1", "169.254.169.254", "172.16.0.1", "172.31.255.255",

Why it matters. cloud metadata endpoint: the classic SSRF credential grab

LOWNetwork egress · net.metadata_ip · CWE-200, CWE-319

server/tools/import.test.ts:148

"http://169.254.169.254/latest/meta-data",

Why it matters. cloud metadata endpoint: the classic SSRF credential grab