ViroReact MCP Server, By ReactVision

The ViroReact MCP server gives your coding agent structured, source-level knowledge of ViroReact (@reactvision/react-viro), the most widely used open-source library for building AR and VR experiences with React Native. Think of it as a living guide to ViroReact, always current, that plugs straight into the tools you already use.

Connect it to Claude, ChatGPT, Codex, Cursor or any other MCP client, and your agent can look up every component's props and events, find working example scenes, generate and validate scenes, check what runs on which platform, and diagnose errors against known issues. No hunting through docs, no guesswork.

This repository holds the server's knowledge layer: the indexer and every read-only tool, which you can read, run locally and contribute to. You don't need it to use the server; connect to the hosted one below.

Connect

The server is hosted at:

https://mcp.reactvision.xyz/viro

There is no API key. Add the URL as a remote (HTTP) MCP server, then click Authenticate: you'll be sent to ReactVision to sign in and pick the team the usage is billed to. A free ReactVision Studio account is enough.

Client	How
Claude (web, Desktop, Cowork)	Settings → Connectors → Add custom connector → paste the URL
Claude Code	claude mcp add --transport http reactviro https://mcp.reactvision.xyz/viro
ChatGPT	Add a custom app/connector with the URL and OAuth authentication
Codex CLI	codex mcp add reactviro --url https://mcp.reactvision.xyz/viro
Cursor, VS Code, others	Add a remote/HTTP MCP server with the URL; the client opens the browser to sign in

Config-file clients take the same URL:

{
  "mcpServers": {
    "reactviro": {
      "type": "http",
      "url": "https://mcp.reactvision.xyz/viro"
    }
  }
}

Full setup guide: https://viro-community.readme.io/docs/viro-mcp-server

Features

Every tool is prefixed reactviro_. The tools below are all in this repository; they are read-only and answer from a knowledge base built from the ViroReact source.

Components and API

• list_components, list_categories, get_component: the component catalog, with forgiving name lookup ("Box" finds ViroBox)
• get_component_props, get_component_events, list_props: props and event signatures extracted from the TypeScript source, including JSDoc and @since
• get_platform_matrix, check_platform_support: what works on iOS, Android, Meta Quest, visionOS and the web, and whether a given scene will
• list_lighting_models, list_physics_body_types, list_animation_easings, get_shader_uniforms, list_event_handlers, changelog_since: AR domain reference

Search and source

• search, list_files, get_file, get_docs: hybrid full-text and semantic search over components, docs and examples
• get_overview, get_tree, stats, find_symbol, find_native_bridge: find your way around the codebase
• list_examples, get_example, examples_using: real AR scenes from the ViroReact showcase app

Scenes

• generate_scene, validate_scene, list_assets_needed: scaffold TSX and lint it against the extracted prop schemas
• diagnose_error: match an error or stack trace against curated known issues

Only on the hosted server

The hosted server adds tools that run on ReactVision's infrastructure and aren't part of this repository: rendering a scene to screenshots, previewing a scene inside a recorded AR session, generating images and 3D models into your Studio library, converting Studio scenes and 8th Wall projects, and checking your team's usage. Your client lists them once connected.

Authentication and usage

The hosted server uses OAuth 2.1 ("Sign in with ReactVision"). A request without a token gets a 401 pointing at /.well-known/oauth-protected-resource, the client runs OAuth with PKCE, and you pick the team to bill on ReactVision's consent screen. Tokens are never stored by the server. Every tool call is metered against that team's plan; ask your agent to call reactviro_get_usage to see what's left.

Running it locally

Requires Node 22.

npm install
npm run index            # build knowledge/reactviro.db from a local ViroWorkspace
npm run dev              # http://127.0.0.1:3000/viro

The indexer reads a ViroWorkspace checkout containing viro and, if present, its docs, showcase, react-viro-onnx and react-viro-face-tracking siblings; anything missing is skipped. By default it looks two directories above the working directory, so clone this repository into ViroWorkspace/, or set PROJECT_DIR to the folder that contains ViroWorkspace. Component props and events are extracted with the TypeScript compiler API at index time; nothing is parsed at query time.

The local server has no authentication and no metering, and binds to 127.0.0.1. Point any MCP client at http://127.0.0.1:3000/viro. Every variable is documented in .env.example.

npm test                 # vitest
npm run typecheck
npm run build && npm start

Layout

• config.ts: what gets indexed, and the tool prefix. Change indexing behaviour here, not in the indexer.
• indexer/: walks the source, extracts the API surface, writes SQLite + FTS5 (plus embeddings when AI_GATEWAY_URL and AI_GATEWAY_KEY are set).
• src/tools/: one module per tool group; custom.ts wires them up.
• data/: curated knowledge edited by hand (platform matrix, known issues, AR domain reference). No re-index needed after editing.

Contributing

Issues and pull requests are welcome. A new tool goes in src/tools/<group>.ts, takes its name from `${config.toolPrefix}_…`, uses a .strict() Zod schema, and is registered in custom.ts with read-only annotations. Fixes to data/*.json are especially useful: a wrong cell in the platform matrix, or a known issue that diagnose_error should recognise.

Security

Please report vulnerabilities privately, as described in SECURITY.md, rather than in a public issue.

Community

Discord is the best place to find the team and other developers building with ViroReact:

Please follow our Code of Conduct.

Enterprise Support and Partners

For teams adopting XR at scale, the ReactVision team works directly with you on architecture, migrations from 8th Wall or Unity, performance audits, and shipping production experiences. https://reactvision.xyz/contact

For independent agencies and consultants vetted by the ReactVision team: https://reactvision.xyz/partners

Find Out More

• Website: https://reactvision.xyz
• ViroReact: https://github.com/ReactVision/viro
• ViroReact docs: https://viro-community.readme.io/docs/overview
• ReactVision Studio: https://studio.reactvision.xyz
• Blog: https://updates.reactvision.xyz

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Licensed under the Elastic License 2.0: you may read, modify and run this code, but not offer it to others as a hosted or managed service. © ReactVision, Inc.

ViroReact itself is MIT licensed and free forever: https://github.com/ReactVision/viro