fix: refactor mcp servers into separate packages

[reidbarber]

Splits the mcp servers into separate packages. Include a private internal package for shared code.

Before:

npx @react-spectrum/mcp s2
npx @react-spectrum/mcp react-aria

After:

npx @react-spectrum/mcp@
npx @react-aria/mcp

Also updates the npx commands to use @latest

✅ Pull Request Checklist:

• Included link to corresponding React Spectrum GitHub Issue.
• Added/updated unit tests and storybook for this change (for new code or code which already has tests).
• Filled out test instructions.
• Updated documentation (if it already exists for this component).
• Looked at the Accessibility Practices for this feature - Aria Practices

📝 Test Instructions:

Generate markdown docs:

yarn workspace @react-spectrum/s2-docs generate:md

Build the MCP servers:

yarn build:mcp

Start a docs server:

yarn start:s2-docs

Update your MCP config:

{
  "mcpServers": {
    "React Spectrum (S2)": {
      "command": "node",
      "args": [
        "{your-path}/react-spectrum/packages/dev/mcp/s2/dist/s2/src/index.js"
      ],
      "env": {
        "DOCS_CDN_BASE": "http://localhost:1234"
      }
    },
    "React Aria": {
      "command": "node",
      "args": [
        "{your-path}/react-spectrum/packages/dev/mcp/react-aria/dist/react-aria/src/index.js"
      ],
      "env": {
        "DOCS_CDN_BASE": "http://localhost:1234"
      }
    }
  }
}

🧢 Your Project:

[rspbot]

Build successful! 🎉

• View the storybook
• View the S2 storybook
• View the documentation
• View the S2 docs

[snowystinger]

I'm sure I just missed some conversation but, why split it in two? I thought having 2 different api end points was good enough?

[snowystinger]

why not have these be shared? is the code just inlined when bundled right now such that you don't need a shared package?
the project structure is a bit odd as a result

[reidbarber]

Where would the dependencies go without a shared package? I guess one option is to have the shared code in one of the two packages, but it seemed better to have an internal shared one.

[snowystinger]

right, but the structure is weird as it is right now

• this package is private
• this package is inside of a 'src' directory
• modules imported from this package are referenced via a relative path instead of from the package workspace name

this is why i asked if the code was being inlined instead of actually shared

[reidbarber]

I've improved the structure to avoid confusion. I think this is what we want:

• mcp-shared is a private package
• @react-spectrum/mcp and @react-aria/mcp import from there using relative paths

I'm not sure about outputing src/ in the dist folder. Would that be a tsconfig.json setting?

[snowystinger]

is a private package
import from there using relative paths

why?

[devongovett]

I don't think these packages are bundled right now, just compiled with tsc.

[rspbot]

Build successful! 🎉

• View the storybook
• View the S2 storybook
• View the documentation
• View the S2 docs

[snowystinger]

structure is still weird to me, but i'd prefer we move this along and we can figure out the private vs public shared package later

[rspbot]

Build successful! 🎉

• View the storybook
• View the S2 storybook
• View the documentation
• View the S2 docs

[LFDanLu]

looks good to me, tested the functionality in cursor and it seems to work well. Noticed a warning when building the mcp package, but might be benign?

[LFDanLu]

maybe benign but I got this when running yarn workspace @react-spectrum/mcp build

(node:82090) [MODULE_TYPELESS_PACKAGE_JSON] Warning: Module type of file:///Users/danilu/dev/react-spectrum/packages/dev/s2-docs/src/iconAliases.js is not specified and it doesn't parse as CommonJS.
Reparsing as ES module because module syntax was detected. This incurs a performance overhead.
To eliminate this warning, add "type": "module" to /Users/danilu/dev/react-spectrum/packages/dev/s2-docs/package.json.

weird since this does have "type": module...