MCP (Model Context Protocol) is the open standard that lets AI assistants call external tools. RakuAI exposes its spatial runtime over MCP — 17 native tools covering scene queries, anchors, and captures, plus a universal passthrough surface that reaches the full ~9,500-endpoint API. Once connected, your assistant can reason about a real space: measure distances, list objects, query what changed, and drive the world model through natural language.
The headline contract is 17 native tools — a versioned, stable API surface integrators can pin to. A tool picker may show many more (147 is expected, not a bug): the registry also carries 7 universal passthrough tools and 123 subsystem-catalog wrappers. The 17 native tools are the ones to build on.
scene_query — spatial distance, occupancy, free-space extentsscene_describe — object list, pose deltas, area summariescapture_list — enumerate captures attached to your accountcapture_status — check reconstruction progresscapture_open — load a capture into the session contextcapture_create — start a new capture sessionxr_create_anchor — place a named spatial anchorxr_list_anchors — enumerate anchors in the scenexr_remove_anchor — remove an anchor by IDxr_get_session — inspect the active XR sessionload_world_model — attach an adapter to the runtimeingest_frame — feed a world-model frameset_render_target — configure the output surfacestart_simulation — begin the simulation loop (sandbox / dev only)get_scene_state — full scene-graph snapshotget_metrics — runtime performance snapshotapi_call / api_search reach the full
~9,500-endpoint raku-api surface; engine_call / engine_search reach the C++ engine API.
These passthrough tools are available on every tier and let your assistant reach anything in the platform
that isn’t yet wrapped as a native tool. They are the “escape hatch” — use the 17 native tools
first for stability.
All four clients connect over MCP. The two transports are stdio (local — your editor spawns the server as a child process) and Streamable HTTP (remote — point at the hosted endpoint with a bearer token). The steps below use stdio for local clients and HTTP for hosted ones.
Both clients use the same mcpServers JSON block. Claude Code reads ~/.claude.json; Claude Desktop reads claude_desktop_config.json.
raku-runtime: git clone https://github.com/RakuXR/raku-runtime.gitpip install 'mcp>=1.2.0' fastapi pydantic jsonschema requests httpx~/.claude.json (Claude Code) or claude_desktop_config.json (Claude Desktop — macOS: ~/Library/Application Support/Claude/, Windows: %APPDATA%\Claude\):Restart the client. The Raku tools appear in the tool picker. Verify with: "Use raku get_metrics to show me what’s running."
ChatGPT Plus and Team support MCP server connectors. You’ll need a bearer token from your RakuAI account and the hosted MCP endpoint.
https://mcp.rakuai.com, transport Streamable HTTP.
Note: ChatGPT’s MCP UI is evolving. If the UI has changed since this was written,
the underlying protocol is stable — point any Streamable HTTP MCP client at
https://mcp.rakuai.com with your bearer token.
Google AI Studio supports MCP tool servers via its extensions / function-calling surface. Gemini Advanced in Google Workspace also supports MCP.
https://mcp.rakuai.com, transport Streamable HTTP.
Note: Gemini’s MCP client is under active development. The hosted endpoint
(https://mcp.rakuai.com) is a standard Streamable HTTP MCP server and will work
with any conformant Gemini MCP client.
VS Code 1.99+ added MCP server support in Copilot Chat (Agent mode). Add a workspace or global MCP config file:
raku-runtime and install dependencies (same as Claude above)..vscode/mcp.json in your project:Open Copilot Chat in Agent mode. The Raku tools are available for selection. Ask: "Use the raku get_scene_state tool and tell me how many nodes are in the scene."
| Symptom | Cause / fix |
|---|---|
| No Raku tools appear | Check cwd and PYTHONPATH point at the repo root. Run python -m src.mcp.stdio_server by hand — it should log tools registered (stdio): 147. |
| Client shows ~147 tools, not 17 | Expected, not a bug. The 17 native tools are the stable contract; the registry also carries 7 universal passthrough + 123 subsystem-catalog wrappers. |
Tool calls return {"status": "denied"} |
Server is in production mode (read-only). Set RAKU_MCP_MODE=sandbox in the env block to enable mutation tools for local dev. |
ModuleNotFoundError: src |
cwd / PYTHONPATH not set to the repo root. Both must point at the directory containing the src/ package. |
| Garbled or no responses (stdio) | Something is writing to stdout and corrupting the JSON-RPC stream. The server keeps stdout clean (all logs go to stderr). Check for any debug print() calls in local code. |
These prompts work against any Raku capture once the MCP connection is live. Start with the read-only tools — they carry zero mutation risk and return structured spatial data your assistant can reason about directly.
scene_query. Returns a list of objects with distances and confidence scores. Good first test after connecting.scene_query with two anchor targets. Returns distance in metres as structured data, not a prose estimate.scene_describe. Returns object inventory grouped by type — furniture, fixtures, equipment.capture_list + capture_status. No mutation — pure inventory query.scene_describe with a time filter. Returns a delta record: moved, added, and removed objects since the reference timestamp.xr_create_anchor (mutation tool). The runtime validates the pose against physics before applying. The anchor persists in the scene.These are illustrative. The 17 native tools + passthrough surface cover the full scene management lifecycle. For the complete tool reference and JSON schema, see mcp.html.
Nothing silently rewrites your scene. The RakuAI runtime is the authority over physics, collision volumes, transforms, and canonical scene state. An AI assistant’s mutation tool calls are proposals; the runtime validates every one before applying it.
The pages developers read most before writing their first MCP call.
RakuAI is an NVIDIA Inception member (accepted May 2026). The NVIDIA-accelerated 3D Gaussian splatting stack in Raku Capture is the same technology behind the scene queries you’re connecting to here. Read more →
NVIDIA Inception is a free program for AI startups; RakuAI’s membership does not imply that NVIDIA endorses RakuAI’s products. Learn more at nvidia.com/startups.
RakuAI is built on AWS and an AWS Activate participant. Production reconstruction runs on Azure today; AWS GPU capacity (G5 / G6e) is on our roadmap, honestly gated until quota lands.
“AWS” and “AWS Activate” are trademarks of Amazon.com, Inc. or its affiliates. RakuAI’s participation does not imply that AWS endorses RakuAI’s products.