Your s&box editor is now an AI-agent workspace. 273 native tools let Claude, or any AI, write the C#, build the scene, wire the components, screenshot its own work, and fix what's wrong. You describe what you want; it builds it and checks it.
Addon installed from the s&box Asset Library? Connect any MCP client in one command. The editor hosts the server, so there's no Node.js to set up:
claude mcp add --transport http sbox http://127.0.0.1:7269/mcpWant the full experience: cookbook brain, specialist agent, and the screenshot workflow? The Claude Code plugin wires both servers for you: /plugin marketplace add LouSputthole/Sbox-Claude → /plugin install sbox-claude.
v2 moved the bridge off the file-IPC transport and onto s&box's built-in editor MCP server(in the editor since July 2026, on by default). No more 50 ms file polling and no Node.js on the main path. Read-only tools carry a permission hint so clients run them without prompts, and failures are real thrown errors instead of { error } payloads buried in a success. Here's what that unlocks:
Runs on s&box's built-in editor MCP server: streamable HTTP on loopback port 7269, on by default. No file polling, no Node.js on the main path; hotload re-registers tools live.
search_tools finds the right tool across 28 described toolsets, list_toolsets / describe_toolset browse them, and call_tools batches several into one round trip. No 200-tool flat list to scroll.
take_screenshot, screenshot_from, and screenshot_orbit return the PNG inside the tool result. Claude sees what it built immediately, no file path to read back.
checkpoint_scene snapshots every root object before a risky batch; restore_checkpoint rolls the whole scene back. Checkpoint, batch-edit 40 props, hate it, roll back: the agent-side undo.
create_prefab writes full engine serialization; instantiate_prefab rebuilds the entire tree with GUID remap, so repeat instantiations never collide.
batch_set_property, batch_delete, and batch_add_component retint or restructure many objects in one call, each with dryRun: true to preview before anything is applied.
create_vehicle_controller turns any rigidbody prop into a raycast car with a built-in driver seat; tune_vehicle applies arcade / drift / offroad / race handling presets.
playtest runs a scripted loop in play mode and asserts the result in-frame (walk, jump, catch the airborne frame) so a gameplay loop is verifiable, not just a static scene.
v2 also adds scene-health scans (find_broken_references) and one-call orientation (describe_project / describe_scene), plus a lifeline for dead editors: an optional slim diagnostics server that keeps answering logs and compile errors when the editor crashes and takes the native server with it. Tool names are unchanged from v1.x. Upgrading is one command plus updating the addon. The bridge has kept growing since, now at v2.2.0: 286 tools / 278 handlers, 273 served natively across 28 toolsets, plus the 7-tool lifeline. Details in the changelog.
The bridge isn't Claude-only anymore. The s&box Codex Bridge plugin ships from the same repo for OpenAI Codex users: the same 286 tools, native editor MCP, lifeline diagnostics, API brain, and the cookbook and workflow skills.
codex plugin marketplace add LouSputthole/Sbox-Claude --ref codex-v2.2.0
codex plugin add sbox-codex-bridge@sboxskinsThe tools aren't the real story. The companion plugin bundles sbox-cookbook: a code-grounded knowledge base of how to actually build games in s&box, mined from real, shipped, open-source s&box games plus the modern engine source. So the AI reaches for proven, shipped patterns: real inventories, economies, save systems, shops, gacha, progression, multiplayer netcode, whole genre playbooks, instead of guessing.
Ask for a system by name(“build me a host-authoritative shop”) and it routes to the grounded recipe for that problem.
273 native tools across 28 toolsets. Here are the big areas.
Create, clone, transform, parent, and find objects; full hierarchy + editor selection; scripts, scenes, and prefabs.
Add/remove any component; one-call scaffolds for health, inventory, save systems, economies, shops, leaderboards, and more.
Rigidbodies, colliders, joints, raycasts, and volume-overlap queries.
Lights, fog, post-FX, skyboxes, reflection probes, and one-call mood presets (Horror Night, Foggy Dawn…).
Spawn, dress, and pose Citizens; equip props; drive the AnimationGraph and play named animations.
Heightmap sculpt brushes, hills, trails, cave paths, forest scatter & density painting.
Network spawn, sync, RPCs, then lint for multiplayer footguns and inspect exactly what replicates.
Generate behavior state machines (patrol → chase → search) with sight cones, hearing, patrol routes, and spawners.
Run scripted gameplay loops with in-frame assertions; draw debug shapes; pause / slow-mo / fast-forward the running game; read live performance counters.
Reflects the real loaded SDK and searches the official s&box docs, so the generated C# actually compiles.
You: “Make a player controller with WASD, mouse look, double-jump, and a flashlight.”
Claude: writes the script, adds the component, wires the input, sets up the spotlight, then aims a camera, screenshots it, and checks its own work.
You: “Build me an inventory system with a hotbar.”
Claude: opens the cookbook's inventory recipe, builds it the way real games do (host-authoritative, networked, drag-and-drop), then runs networking_lint to confirm it replicates.
Self-verifying.For anything visual, Claude aims a camera, screenshots its work, and the PNG arrives inline in the tool result. It sees the image immediately and fixes what's wrong before showing you. For multiplayer it lints networking and inspects what replicates. And it reads its own logs and compile errors (even when the editor has crashed, via the lifeline) so it closes the build-and-check loop instead of hoping.