Claude Bridge for s&box, NOW! With Codex

(Revamped for NATIVE MCP) · MAJOR TOOLSET UPDATE

Build s&box games by talking to Claude, Codex, or any AI.

273 native tools · 28 toolsets, served by s&box's built-in editor MCP server. An AI working inside your editor: writing scripts, creating GameObjects, wiring components, building whole systems, physics, networking, UI, lighting, characters, terrain, vehicles, cutscenes. You describe it; the AI builds it, screenshots it, sees the image, and fixes it.

But the tools aren't the real story, the bridge ships a 🧠 brain. The plugins bundle sbox-cookbook: a code-grounded knowledge base mined from 51 real, shipped, open-source s&box games. The AI reaches for proven, shipped patterns, real inventories, economies, save systems, netcode, whole genre playbooks, instead of guessing.

📖 Docs & changelog: sboxskins.gg/claudebridge · setup · changelog · troubleshooting · FAQ
📬 Feedback: [email protected] or GitHub Issues

🆕 NOW with Codex

The s&box Codex Bridge is a first-party distribution of the whole experience for OpenAI Codex: same 273 tools, same cookbook brain, same screenshot-verify workflow, generated from the Claude plugin by the same scripts, so the two can never drift.

codex plugin marketplace add LouSputthole/Sbox-Claude --ref codex-v2.2.0
codex plugin add sbox-codex-bridge@sboxskins

And because the editor hosts the MCP server, any MCP client connects over local HTTP, no Node.js required.

⚡ Start here: the one-command plugin

/plugin marketplace add LouSputthole/Sbox-Claude
/plugin install sbox-claude          (then restart Claude Code)

That single install gives you:

🧠 The brain: sbox-cookbook, the #1 reason to use this
🤖 A specialist game-dev agent: knows the workflow, the gotchas, when to reach for the cookbook
📸 The screenshot workflow skill: build → screenshot → verify → fix, so the AI is never building blind
🔌 Both MCP servers registered: the native editor endpoint + the optional lifeline, zero version drift
👋 Onboarding: first connect checks the bridge, detects your libraries, suggests a first move

You still install the s&box addon from this page (see Install below).

🧠 The brain: build like a shipped game, not a guess

The hardest part of building with an AI isn't typing C#, it's knowing the right pattern. Where does the money live so a client can't forge it? How do you sign a save file? Get those wrong and it compiles, then desyncs, dupes currency, or corrupts saves.

sbox-cookbook answers exactly those questions: 11 engine references, 18 system how-tos, 20 genre playbooks, all citing real source from 51 shipped games. Ask "how do I build a tycoon / an inventory / a save system?" and it loads the grounded recipe.

🎮 Genre playbooks: tycoon/idle, deathmatch, platformer, survival/horror, card-battler, gacha, social-hub, sandbox, vehicles, roleplay, more, each with the system stack, a build order, and how real games did it
⚙️ Game systems: inventory, economy, shops, saves, progression, loot tables, leaderboards, crafting, dialogue, round flow, waves, anti-cheat
🔩 Engine fundamentals: networking & authority, player controllers, Razor UI, physics & traces, lifecycle, world-gen, performance

It also carries the cross-cutting laws that bite every system: authority gating, host-authoritative money/health/score, request → apply → confirm RPCs, sanitize-and-clamp-on-load saves. The kind of thing you only learn by shipping.

💬 How it works

You: "Make a player controller with WASD, mouse look, double-jump, and a flashlight."
Claude: writes the script, wires the input, sets up the spotlight, then aims a camera, sees the PNG right in the tool result, and checks its own work.

You: "Build me an inventory with a hotbar."
Claude: opens the cookbook's inventory recipe, builds it host-authoritative like real games do, then runs networking_lint to confirm it actually replicates.

You: "Does my game actually work with two players?"
Claude: runs start_multiplayer_test: a REAL second game client boots, joins a private lobby, and plays in your session. (New in v2.2.0.)

✅ Great at: game systems through conversation. controllers, NPCs, networking, UI, prefabs, vehicles, cutscenes, whole genre loops, clean, working s&box C#.

🟡 Serviceable at: map building. It sees its own screenshots now, so it's not blind, but final visual polish still wants your eyes.

🚀 What's new

v2.2.0: args that just work, multiplayer that tells the truth, and Codex

Rotation & vector args fixed everywhere: comma strings, arrays, and objects all parse on every creation, transform, camera, and placement path. The #1 paper cut of the native era is gone.
Multiplayer test harness is LIVE: real sbox.exe clients in private hidden lobbies, truthful status tracking (dead clients report dead), full cleanup and rollback.
NOW with Codex: first public s&box Codex Bridge (see top).

v2.1.0 "Action!": the +30-tool cinematic wave

🎬 Gameplay recording: capture real play to .movie clips; record_playtest = a scripted test plus replayable footage of the run
🎥 Cutscenes without the dock: bake a shot list to a .movie in milliseconds; a true rolling-buffer killcam
🗣️ NPCs that speak: TTS dialogue with moving mouths driven by the live viseme stream, zero recorded VO
💥 Camera feel: shake / punch / tilt presets over the engine's new built-ins
💰 Economy & meta depth: audited ledgers, idle economies, tamper-evident saves, meta-progression, achievements, Elo, speedrun boards, map voting, utility-AI brains, water volumes, day-night sun

v2.0.0 "Native": the bridge moved into the editor

Runs on s&box's own MCP server (port 7269, on by default), no Node.js on the main path
📸 Inline screenshots: the PNG arrives inside the tool result
🔎 Live tool discovery, permission-free reads (57 read-only tools), real error semantics
⏪ Scene checkpoints: the agent-side undo: snapshot, batch-edit, hate it, roll back
🚗 Vehicles toolset, real prefabs with GUID remap, dry-run batch ops

Earlier: v1.20 "Director's Cut" (+19 tools) · v1.18 (LipSync) · v1.9–1.12 (the cookbook, the lint family, CI gates). Full history: sboxskins.gg/claudebridge/changelog.

🛠️ What it can do (273 native tools · 28 toolsets)

Scene & GameObjects: create, clone, transform, parent; hierarchy + selection; find by name/component/tag; one-call scene & project orientation
Scene checkpoints ⏪, snapshot every root object, roll the whole scene back
Batch ops: set/delete/add/reparent across many objects, each with dryRun: true preview
Scripts: write / edit / hotload C#; one-shot scaffolds for controllers, NPC AI, managers, networked players
Components: add/configure anything; typed properties; models, materials, prefab refs; call methods and editor buttons
Multiplayer testing 🆕, boot real second clients into private lobbies; truthful status; plus the full networking codegen family (sync, RPCs, lobbies, host-migration)
Vehicles 🚗, any rigidbody prop → raycast car with driver seat; arcade / drift / offroad / race presets; physgun-lite
Physics: rigidbodies, colliders, joints, raycasts, overlap queries
Lighting & atmosphere: lights, fog, post, skyboxes, probes, day-night sun, render-target cameras (CCTV/mirrors), one-call mood presets
Characters: spawn, dress, pose Citizens; ragdolls; expressions; animgraph; LipSync, and full TTS dialogue with moving mouths
Cinematics & recording 🎬, record gameplay to .movie and replay it; bake cutscenes from a shot list; killcams; camera shake presets; combat text, combo meters, nametags
Terrain & world-gen: sculpt brushes, hills/trails/caves, forest painting, prop scatter, water volumes
Navigation: bake navmesh, query paths
UI & audio: Razor panels (screen + world), BuildHash auto-fixer; sound events + in-editor preview
Inspection & validation 🔍, see what replicates, lint multiplayer footguns, validate scenes, scan broken references, lint C#/Razor before the compiler, diff saves. The AI verifies instead of hoping.
Prefabs, real ones: full engine serialization, true re-instantiation with GUID remap
Self-verify & diagnostics: inline screenshots (single, framed, or full orbit); camera bookmarks & visual baselines; console; restart_editor; the lifeline reads logs and compile errors even when the editor has crashed
Debug & playtest: debug draw, slow-mo, perf counters; scripted in-frame playtests with pass/fail transcripts
Docs & live API search: live reflection of the real loaded SDK + official docs search. A big reason the generated C# actually compiles.
Publishing: validate, configure, thumbnails, package details

📦 Install

1. The addon (everyone): click Install on this page. s&box drops it into your project's Libraries/ automatically.

2. Connect your AI, pick one:

A, Claude Code plugin (recommended): the one-command install at the top. Registers both servers + the brain + the agent + the workflow.
B, Codex plugin: the two commands in the Codex section above.
C, manual / any MCP client:

claude mcp add --transport http sbox http://127.0.0.1:7269/mcp

Optional but recommended, the lifeline, for editor-down diagnostics (needs Node.js 18+):

claude mcp add sbox-lifeline -- npx -y sbox-mcp-server@2 --lifeline

The native server dies with the editor; the lifeline answers "why did the editor crash" when nothing else can.

3. Verify: with s&box open, ask your AI to run search_tools or "describe the project". Then try:

"Create a cube at 0, 0, 100." · "Make me a drivable car." · "Build me a host-authoritative currency system." (watch it reach for the cookbook) · "Test my game with a second player." (watch a real client boot and join)

🔒 Under the hood

Loopback-only, 100% local: the server binds 127.0.0.1:7269; nothing leaves your machine
273 tools are [McpTool] methods the engine auto-discovers; hotload = live re-registration
Play-mode-safe & path-safe: scene edits refused during play; file ops confined to your project
Full picture: 286 total tools / 278 handlers: 273 native + 7 lifeline + 6 served by native built-ins

🧰 Full tool list

273 native tools · 28 toolsets · 57 read-only. Agents browse these live with list_toolsets / search_tools.

bridge_asset (7): copy_asset_with_dependencies, get_asset_info, inspect_model_geometry, install_asset, list_asset_library, recompile_asset, search_assets

bridge_audio (5): add_tts_voice, assign_sound, create_sound_event, list_sounds, play_sound_preview

bridge_batch (4): batch_add_component, batch_delete, batch_reparent, batch_set_property

bridge_character (12): add_lipsync, add_ragdoll, dress_citizen, equip_model, list_animations, play_animation, pose_citizen, set_animgraph_param, set_bodygroup, set_expression, set_look_at, spawn_citizen

bridge_component (10): add_component_to_new_object, add_component_with_properties, get_all_properties, get_property, invoke_button, invoke_method, list_available_components, set_component_reference, set_property, list_component_buttons

bridge_debug (11): console_run, debug_clear, debug_draw_box, debug_draw_line, debug_draw_ray, debug_draw_sphere, frame_camera, get_bridge_status, get_profiler_stats, restart_editor, set_time_scale

bridge_discovery (5): describe_type, find_in_project, get_method_signature, list_libraries, search_types

bridge_gameobject (27): align_objects, create_gameobject, delete_gameobject, distribute_objects, duplicate_gameobject, find_objects, focus_object, get_bounds, get_scene_hierarchy, get_selected_objects, get_tags, grid_duplicate, group_objects, measure_distance, plan_placements, commit_placement_plan, discard_placement_plan, randomize_transforms, rename_gameobject, replace_model, scatter_props, select_object, set_enabled, set_parent, set_tags, set_tint, set_transform, snap_to_ground

bridge_material (4): assign_material, assign_model, create_material, set_material_property

bridge_moviemaker (10): add_movie_player, author_movie_clip, create_killcam, gameplay_recording_status, list_movies, play_movie, record_gameplay_clip, record_playtest, stop_gameplay_recording, stop_movie

bridge_navigation (2): bake_navmesh, get_navmesh_path

bridge_networking (17): add_host_migration_recovery, add_network_helper, add_rpc_method, add_sync_property, add_targeted_rpc, configure_network, create_host_rpc_action, create_lobby_manager, create_local_player_resolver, create_network_events, create_networked_player, get_network_status, multiplayer_test_status, network_spawn, set_ownership, start_multiplayer_test, stop_multiplayer_test

bridge_npc (7): assign_patrol_route, create_npc_brain, create_npc_schedule_brain, create_npc_spawner, create_utility_ai, place_patrol_route, simulate_npc_perception

bridge_physics (5): add_collider, add_joint, add_physics, physics_overlap, raycast

bridge_playmode (5): get_runtime_property, is_playing, set_runtime_property, start_play, stop_play

bridge_playtest (6): drive_player, drive_player_status, playtest, playtest_abort, playtest_status, simulate_input

bridge_prefab (5): create_prefab, get_prefab_info, instantiate_prefab, list_prefabs, set_prefab_ref

bridge_project (14): create_script, delete_script, describe_project, edit_script, ensure_input_action, get_package_details, get_project_config, get_project_info, list_project_files, read_file, set_project_config, set_project_thumbnail, trigger_hotload, write_file

bridge_scaffold_gameplay (41): add_achievement_trigger, add_interaction_prompt, add_interaction_station, add_leaderboard_stat, add_steam_stat_currency, create_achievement_set, create_carry_system, create_currency_account, create_currency_pickup, create_day_night_clock, create_economy_wallet, create_elo_rating_system, create_event_bus, create_event_director, create_gacha_drop_table, create_game_manager, create_health_system, create_hold_to_confirm, create_idle_economy, create_idle_income, create_interactable, create_inventory, create_leaderboard_panel, create_loot_table_resource, create_meta_progression, create_needs_system, create_npc_controller, create_objective_system, create_offline_progress, create_pickup, create_placement_mode, create_player_controller, create_round_phase_machine, create_round_state_machine, create_save_slots, create_save_system, create_signed_save, create_speedrun_leaderboard, create_stat_modifier_system, create_team_assigner, create_trigger_zone, create_weighted_loot_table, scaffold_map_vote_flow

bridge_scaffold_polish (9): add_flicker_light, create_camera_shake, create_combo_meter, create_cutscene_director, create_dialogue_system, create_floating_combat_text, create_proxy_nametag, create_round_timer_hud, create_worldpanel_ui

bridge_scene (3): create_scene, describe_scene, load_scene

bridge_screenshot (7): take_screenshot, capture_view, screenshot_from, screenshot_orbit, save_camera_bookmark, capture_visual_baseline, compare_visual_baseline, all returning inline PNG images

bridge_ui (4): add_panel_buildhash, add_screen_panel, add_world_panel, create_razor_ui

bridge_validation (9): find_broken_references, inspect_networked_object, networking_lint, razor_lint, sandbox_lint, save_inspect, scene_validate, services_query, validate_project

bridge_vehicle (4): create_physics_grab_tool, create_seat_system, create_vehicle_controller, tune_vehicle

bridge_visuals (15): add_beam, add_daynight_sun, add_envmap_probe, add_light, add_post_process, add_render_target_camera, add_trail, apply_atmosphere, apply_post_fx_look, bake_reflections, create_camera_effects, create_particle_effect, set_fog, set_skybox, spawn_vpcf

bridge_workflow (3): checkpoint_scene, list_checkpoints, restore_checkpoint

bridge_world (16): add_cave_waypoint, add_forest_poi, add_forest_trail, add_terrain_clearing, add_terrain_hill, add_terrain_trail, add_water_body, build_terrain_mesh, clear_cave_path, clear_forest_pois, clear_terrain_features, paint_forest_density, place_along_path, raycast_terrain, sculpt_terrain, set_forest_seed

Plus 7 lifeline tools (editor-down diagnostics that answer even after a crash) and 6 names served by the engine's own built-ins, and the native server's freebies: scene_tree, get/set_game_object, the asset_* family, read_console, compile_status.

🩹 Troubleshooting

#1 issue: port 7269 not answering, the editor isn't running, or the MCP server is off (Editor → Preferences → MCP Server; on by default). #2: a stale port registration, if the log says [MCP] Couldn't start MCP server, a dying editor instance still holds the port; wait, then restart once. Missing bridge_* tools = the addon isn't in your Libraries/ or didn't compile, exactly what the lifeline's read_log / get_compile_errors are for. Full guide: sboxskins.gg/claudebridge/troubleshooting.

💡 Tips

Use the plugin. The brain + agent + screenshot skill is most of the value, one command.
checkpoint_scene before big batches: roll back if you hate it. Keep .scene files in Git.
Ask for systems by name: "build me an inventory / a save system / an economy" routes to a proven recipe.
Test multiplayer early: "boot a test client and check my sync" is one sentence now.

📜 License

Source-available (no redistribution): the s&box Claude Bridge Source-Available License 1.0. Use it freely to build your games, free or commercial, and modify it locally. No redistributing, mirroring, repackaging, re-hosting, or offering it as a service. The games you build with it are yours, unrestricted. Name and branding are trademarks (see NOTICE). Pre-relicense versions remain AGPL-3.0-or-later.

🔗 Links

Docs: sboxskins.gg/claudebridge
· GitHub: github.com/LouSputthole/Sbox-Claude
· Issues: github.com/LouSputthole/Sbox-Claude/issues
· npm (lifeline): npmjs.com/package/sbox-mcp-server

· Feedback: [email protected]

One addon, one command, zero ceremony. 273 native tools · 28 toolsets + a brain trained on real shipped games, for Claude, Codex, or any AI. Describe your game, the AI builds it. 🧀

💬 A note on the (early) reviews

I've seen the thumbs-down reviews from early in the Claude Bridge release, and I want to address them directly.

I'm quite certain it shipped in a rough, broken state for the first week or two, my apologies for that. Every review since has been positive, so I'm glad it's resolved. Either way, I want the feedback.

I built this tool for people who have game ideas but don't necessarily know how to code. The goal isn't to replace creativity. It's to give more people a way to build their dream game by letting an AI act like a coding assistant inside the editor.

That said, if the tool didn't work for you, that matters. A bad install, a broken tool call, a confusing setup step, or missing docs is on me to fix.

The bridge has matured a lot since those early days, the native era removed the fragile parts of the old setup entirely (Node processes, file polling, temp-dir mismatches), and the last three releases added the cinematic wave, real multiplayer testing with a second live client, and a Codex distribution. A lot of those fixes came straight from user reports. Thank you to everyone who took the time to tell me what broke instead of silently launching the tomato cannon. 🍅

If you had a bad experience, please reach out: [email protected]. I'll move quickly on real issues and keep improving it.

Thanks to everyone giving it a shot, testing it, breaking it, and helping make it better.

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